CA2328813C - High-frequency oscillation circuit - Google Patents
High-frequency oscillation circuit Download PDFInfo
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- CA2328813C CA2328813C CA002328813A CA2328813A CA2328813C CA 2328813 C CA2328813 C CA 2328813C CA 002328813 A CA002328813 A CA 002328813A CA 2328813 A CA2328813 A CA 2328813A CA 2328813 C CA2328813 C CA 2328813C
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- 230000010355 oscillation Effects 0.000 title claims abstract description 176
- 239000013078 crystal Substances 0.000 claims abstract description 103
- 239000003990 capacitor Substances 0.000 claims description 15
- 230000008859 change Effects 0.000 claims description 9
- 238000005259 measurement Methods 0.000 claims description 9
- 238000001179 sorption measurement Methods 0.000 claims description 6
- 239000000126 substance Substances 0.000 claims description 6
- 230000002349 favourable effect Effects 0.000 claims description 5
- 239000000428 dust Substances 0.000 claims description 3
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 10
- 230000004044 response Effects 0.000 description 8
- 239000010408 film Substances 0.000 description 7
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical class CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 4
- 238000006116 polymerization reaction Methods 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 230000010485 coping Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000003466 anti-cipated effect Effects 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000036039 immunity Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000002459 sustained effect Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
- H03B5/00—Generation of oscillations using amplifier with regenerative feedback from output to input
- H03B5/30—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element being electromechanical resonator
- H03B5/32—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element being electromechanical resonator being a piezoelectric resonator
- H03B5/36—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element being electromechanical resonator being a piezoelectric resonator active element in amplifier being semiconductor device
Abstract
A high-frequency oscillation circuit incorporates a crystal oscillator having a natural oscillation frequency in a high-frequency area within a closed circuit including one or more logic elements. Therefore, this circuit copes with an oscillation frequency of 1 MHz to 2 GHz or more in basic oscillation frequency of a crystal oscillator and it oscillates with stability at the basic oscillation frequency of the crystal oscillator.
Description
SPECIFICATION
HIGH-FREQUENCY OSCILLATION CIRCUIT
F'TRT,D OF THE INVENTION
The present invention relates to a high-frequency oscillation circuit, and more particularly, to a high-frequency oscillation circuit useful for enhancing sensitivity of various measuring instruments used as weight sensor, chemical sensor, biosensor, viscosity sensor, film thickness meter, gas sensor, floating dust sensor, immunity sensor or the like.
While recently various measuring instruments using crystal as weight sensor, chemical sensor, biosensor, viscosity sensor, film thickness meter or the like have been numerously developed, it has been needed urgently to develop a high precision and highly sensitive measuring instruments to cope with such a demand for diversity of materials to be detected and precise quantitative determination of materials to be detected.
As is generally known, however, a wafer used for a crystal oscillator has such a nature as to cause distortion (piezo-electric effect) when a voltage is applied to thin film electrodes attached to both side faces faces thereof and return to its initial state when the voltage is removed. Because of this nature, a crystal oscillator oscillates at a natural frequency determined by its thickness. Thereby, in a crystal wafer, when its thickness varies by adsorbing a substance, a basic frequency (i.e., the natural oscillation frequency or basic oscillation frequency) of the crystal oscillator is varied.
The change 4f of this natural oscillation frequency is proportionate to a change in thickness. If the change in thickness dimension is replaced by a change Om in mass, the following equation called Sauerbrey's equation can be introduced.
4f = - {2fo2/( pq " Nq)l~z} x (Om/A) wherein fois a basic oscillation frequency, p q and uq are density and elastic modulus of the crystal, respectively, and A is the area of a portion performing piezo-electric response.
From this equation, it is understood that, since the sensitivity 4f is proportionate to the square of the basic oscillation frequency fo, it is desirable to use a crystal oscillator whose fo is great. However, if fo becomes too great, the thickness is reduced, and the oscillator tends to be easily broken. Therefore, it is general to use a crystal oscillator whose fo is between 5 and 10 MHz under the normal atmosphere, and even in a solution, merely a crystal oscillator whose greatest oscillation frequency fo is 30 MHz is used, and a measurement exceeding the maximum detection limit of a general-purpose crystal oscillator has not yet been attained.
While there is also an example of measurement using the seventh order overtone mode (63 MHz) of a crystal oscillator whose fo is 9MHz, its detection limit is reported as 0.1 ng, which showed no remarkable improvement in sensitivity, compared with the conventional method of 1 ng ("The Latest Method of Separation, Purification and Detection", p. 441, by NTS Publishing Co., issued May 26, 1997).
On the other hand, in contrast with such a situation as above, there is also proposed a high-frequency oscillation circuit using a crystal oscillator not as a weight sensor but for controlling the frequency of an oscillation circuit.
However, in many cases these circuits were analog circuits which are complicated and hard-to-adjust as numerous parts such as transistor, coupling transformer, inductance, etc., are used, and were expensive and not suitable to be used as a measuring instrument for various sensors.
HIGH-FREQUENCY OSCILLATION CIRCUIT
F'TRT,D OF THE INVENTION
The present invention relates to a high-frequency oscillation circuit, and more particularly, to a high-frequency oscillation circuit useful for enhancing sensitivity of various measuring instruments used as weight sensor, chemical sensor, biosensor, viscosity sensor, film thickness meter, gas sensor, floating dust sensor, immunity sensor or the like.
While recently various measuring instruments using crystal as weight sensor, chemical sensor, biosensor, viscosity sensor, film thickness meter or the like have been numerously developed, it has been needed urgently to develop a high precision and highly sensitive measuring instruments to cope with such a demand for diversity of materials to be detected and precise quantitative determination of materials to be detected.
As is generally known, however, a wafer used for a crystal oscillator has such a nature as to cause distortion (piezo-electric effect) when a voltage is applied to thin film electrodes attached to both side faces faces thereof and return to its initial state when the voltage is removed. Because of this nature, a crystal oscillator oscillates at a natural frequency determined by its thickness. Thereby, in a crystal wafer, when its thickness varies by adsorbing a substance, a basic frequency (i.e., the natural oscillation frequency or basic oscillation frequency) of the crystal oscillator is varied.
The change 4f of this natural oscillation frequency is proportionate to a change in thickness. If the change in thickness dimension is replaced by a change Om in mass, the following equation called Sauerbrey's equation can be introduced.
4f = - {2fo2/( pq " Nq)l~z} x (Om/A) wherein fois a basic oscillation frequency, p q and uq are density and elastic modulus of the crystal, respectively, and A is the area of a portion performing piezo-electric response.
From this equation, it is understood that, since the sensitivity 4f is proportionate to the square of the basic oscillation frequency fo, it is desirable to use a crystal oscillator whose fo is great. However, if fo becomes too great, the thickness is reduced, and the oscillator tends to be easily broken. Therefore, it is general to use a crystal oscillator whose fo is between 5 and 10 MHz under the normal atmosphere, and even in a solution, merely a crystal oscillator whose greatest oscillation frequency fo is 30 MHz is used, and a measurement exceeding the maximum detection limit of a general-purpose crystal oscillator has not yet been attained.
While there is also an example of measurement using the seventh order overtone mode (63 MHz) of a crystal oscillator whose fo is 9MHz, its detection limit is reported as 0.1 ng, which showed no remarkable improvement in sensitivity, compared with the conventional method of 1 ng ("The Latest Method of Separation, Purification and Detection", p. 441, by NTS Publishing Co., issued May 26, 1997).
On the other hand, in contrast with such a situation as above, there is also proposed a high-frequency oscillation circuit using a crystal oscillator not as a weight sensor but for controlling the frequency of an oscillation circuit.
However, in many cases these circuits were analog circuits which are complicated and hard-to-adjust as numerous parts such as transistor, coupling transformer, inductance, etc., are used, and were expensive and not suitable to be used as a measuring instrument for various sensors.
A low-frequency oscillation circuit using a logic element in part is known (JP-A-3-165236) ("JP-A" means unexamined published Japanese patent application), "The Electronic Circuit Parts Utilization Handbook", p.67, by CQ Publishing Co., issued on November 1, 1985). This oscillation circuit, however, usees only an oscillator having a natural frequency in a low-frequency area, so that it cannot cope with a demand for higher sensitivity, making it hard to realize a high-frequency oscillation circuit showing high-frequency stability. Furthermore, there was a need to design and constitute an oscillation circuit to suit a crystal oscillator to be oscillated and its frequency (Japanese patent application No. 2000-31513).
SUMMARY OF THE INVENTION
The present invention overturns common knowledge of a conventional oscillation circuit.
The present invention aims to provide a high-frequency oscillation circuit which can keep a stable high-frequency oscillation to easily cope with the natural oscillation frequency of a crystal oscillator as a sensor even if it becomes high, and yet which can be easily manufactured at a low cost.
In accordance with one aspect of the present invention there is provided a high-frequency oscillation circuit comprising: a closed loop circuit including a first logic element inverter (IC1) having an input and an output within said closed loop circuit; a second logic element inverter (IC2) having an input and an output external to said closed loop circuit, wherein said output of said first logic element inverter (IC1) is connected to said input of said second logic element (IC2); a resistor (~) being disposed within said closed loop circuit and connected parallel to said first logic element inverter (IC1); a crystal device (X), selected from a group of crystal devices having various basic oscillation frequencies, for high frequency oscillation being disposed within said closed loop circuit and connected serially to a capacitor (C), wherein said crystal device (X) and said serially connected capacitor (C) are connected in parallel to said first logic element inverter (IC1), wherein the oscillation circuit has an 4a oscillation frequency in a range between 50 MHz and 1.8 GHz and wherein the oscillating frequency is a function of the crystal device (X).
In accordance with another aspect of the present invention there is provided a high-frequency oscillation circuit comprising: a closed loop circuit including a first logic element inverter (IC1) having an input and an output within said closed loop circuit; a second logic element inverter (IC2) having an input and an output external to said closed loop circuit, wherein said output of said first logic element inverter (IC1) is connected to said input of said second logic element (IC2); a first resistor (R2) being disposed within said closed loop circuit and connected parallel to said=first logic element inverter (IC1); a crystal device (X2), selected from a group of crystal devices having various basic oscillation frequencies, for high frequency oscillation being disposed within said closed loop circuit and connected serially to a second resistor (R1), wherein said crystal device (X2) and said serially connected second resistor (R2) are connected in parallel to said 4b first logic element inverter (IC1), wherein a node between said crystal device (X2) and said second resistor (R1) is connected to ground via a serial connection of a capacitor (C1) and an inductance (Ll) for selecting a favourable overtone oscillation, and wherein the oscillation circuit has an oscillation frequency in a range between 50 MHz and 1.8 GHz and wherein the oscillating frequency is a function of the crystal device (X2 ) .
Other and further objects, features, and advantages of the invention will appear more fully from the following description, taken in connection with the accompanying 4c drawings.
Fig. 1(a) is a diagram showing an embodiment of a high-frequency oscillation circuit using a logic element "NAND" and a crystal oscillator having a basic oscillation frequency of 50 MHz.
Fig. 1(b) is a graph showing an oscillation waveform of the circuit in Fig. 1(a).
Fig. 2(a) is a diagram showing an embodiment of a high-frequency oscillation circuit using a logic element "NAND" and a crystal oscillator having a basic oscillation frequency of 100 MHz.
Fig. 2(b) is a graph showing an oscillation waveform of the circuit in Fig. 2(a).
Fig. 3(a) is a diagram showing an embodiment of a high-frequency oscillation circuit using a logic element "inverter" and a crystal oscillator having a basic oscillation frequency of 155 MHz.
Fig. 3(b) is a graph showing an oscillation waveform of the circuit in Fig. 3(a).
Fig. 4(a) is a diagram showing an embodiment of a high-frequency oscillation circuit using a logic element "inverter" and an overtone crystal oscillator of 100 MHz.
Fig. 4(b) is a graph showing an oscillation waveform of the circuit in Fig. 4(a).
Fig. 5 is a graph showing the stability of an oscillation frequency per hour of the circuit shown in Fig.
2(a) in case of using a normal crystal oscillator.
Fig. 6 is a graph showing the stability of an oscillation frequency per hour of the circuit shown in Fig.
2(a) in case of using a crystal oscillator on which a styrene film was deposited for one minute by the plasma polymerization method.
Fig. 7 is a diagram showing another embodiment of the high-frequency oscillation circuit of the present invention.
Fig. 8(a) is a graph showing an oscillation waveform measured by oscilloscope in case a crystal oscillator having a basic oscillation frequency of 20 MHz is used in the circuit shown in Fig. 7.
Fig. 8(b) is a graph showing an oscillation waveform measured by oscilloscope in case a crystal oscillator having a basic oscillation frequency of 33 MHz is used in the circuit shown in Fig. 7.
Fig. 8(c) is a graph showing an oscillation waveform measured by oscilloscope in case a crystal oscillator with a basic oscillation frequency of 50 MHz is used in the circuit shown in Fig. 7.
Fig. 8(d) is a graph showing an oscillation waveform measured by oscilloscope in case a crystal oscillator having a basic oscillation frequency of 155 MHz is used in the circuit shown in Fig. 7.
Fig. 9(a) is a graph showing changes in the oscillation frequency with the lapse of time when one of the oscillation circuits of Fig. 7 is used and saturated acetone steam of the same concentration is adsorbed on crystal oscillators coated with a plasma polymerized styrene film of the same weight .
Fig. 9(b) is an enlarged graph of the measurement result by using the crystal oscillator having the basic oscillation frequency of 9 MHz in Fig. 9(a).
pETATT.ED DESCRIPTION OF THE INVENTION
Studying hard to solve the foregoing problems, the inventor used a readily available logic element, made a closed circuit by connecting its input and output with a capacitor, a resistor and a crystal oscillator having a natural oscillation frequency in a high-frequency area, and discovered that an oscillation circuit capable of keeping a more stable high-frequency oscillation can be unexpectedly obtained by the operation time or response speed of the logic element, the time constant of the capacitor and the resistor or the like, resulting in completion of the present invention.
SUMMARY OF THE INVENTION
The present invention overturns common knowledge of a conventional oscillation circuit.
The present invention aims to provide a high-frequency oscillation circuit which can keep a stable high-frequency oscillation to easily cope with the natural oscillation frequency of a crystal oscillator as a sensor even if it becomes high, and yet which can be easily manufactured at a low cost.
In accordance with one aspect of the present invention there is provided a high-frequency oscillation circuit comprising: a closed loop circuit including a first logic element inverter (IC1) having an input and an output within said closed loop circuit; a second logic element inverter (IC2) having an input and an output external to said closed loop circuit, wherein said output of said first logic element inverter (IC1) is connected to said input of said second logic element (IC2); a resistor (~) being disposed within said closed loop circuit and connected parallel to said first logic element inverter (IC1); a crystal device (X), selected from a group of crystal devices having various basic oscillation frequencies, for high frequency oscillation being disposed within said closed loop circuit and connected serially to a capacitor (C), wherein said crystal device (X) and said serially connected capacitor (C) are connected in parallel to said first logic element inverter (IC1), wherein the oscillation circuit has an 4a oscillation frequency in a range between 50 MHz and 1.8 GHz and wherein the oscillating frequency is a function of the crystal device (X).
In accordance with another aspect of the present invention there is provided a high-frequency oscillation circuit comprising: a closed loop circuit including a first logic element inverter (IC1) having an input and an output within said closed loop circuit; a second logic element inverter (IC2) having an input and an output external to said closed loop circuit, wherein said output of said first logic element inverter (IC1) is connected to said input of said second logic element (IC2); a first resistor (R2) being disposed within said closed loop circuit and connected parallel to said=first logic element inverter (IC1); a crystal device (X2), selected from a group of crystal devices having various basic oscillation frequencies, for high frequency oscillation being disposed within said closed loop circuit and connected serially to a second resistor (R1), wherein said crystal device (X2) and said serially connected second resistor (R2) are connected in parallel to said 4b first logic element inverter (IC1), wherein a node between said crystal device (X2) and said second resistor (R1) is connected to ground via a serial connection of a capacitor (C1) and an inductance (Ll) for selecting a favourable overtone oscillation, and wherein the oscillation circuit has an oscillation frequency in a range between 50 MHz and 1.8 GHz and wherein the oscillating frequency is a function of the crystal device (X2 ) .
Other and further objects, features, and advantages of the invention will appear more fully from the following description, taken in connection with the accompanying 4c drawings.
Fig. 1(a) is a diagram showing an embodiment of a high-frequency oscillation circuit using a logic element "NAND" and a crystal oscillator having a basic oscillation frequency of 50 MHz.
Fig. 1(b) is a graph showing an oscillation waveform of the circuit in Fig. 1(a).
Fig. 2(a) is a diagram showing an embodiment of a high-frequency oscillation circuit using a logic element "NAND" and a crystal oscillator having a basic oscillation frequency of 100 MHz.
Fig. 2(b) is a graph showing an oscillation waveform of the circuit in Fig. 2(a).
Fig. 3(a) is a diagram showing an embodiment of a high-frequency oscillation circuit using a logic element "inverter" and a crystal oscillator having a basic oscillation frequency of 155 MHz.
Fig. 3(b) is a graph showing an oscillation waveform of the circuit in Fig. 3(a).
Fig. 4(a) is a diagram showing an embodiment of a high-frequency oscillation circuit using a logic element "inverter" and an overtone crystal oscillator of 100 MHz.
Fig. 4(b) is a graph showing an oscillation waveform of the circuit in Fig. 4(a).
Fig. 5 is a graph showing the stability of an oscillation frequency per hour of the circuit shown in Fig.
2(a) in case of using a normal crystal oscillator.
Fig. 6 is a graph showing the stability of an oscillation frequency per hour of the circuit shown in Fig.
2(a) in case of using a crystal oscillator on which a styrene film was deposited for one minute by the plasma polymerization method.
Fig. 7 is a diagram showing another embodiment of the high-frequency oscillation circuit of the present invention.
Fig. 8(a) is a graph showing an oscillation waveform measured by oscilloscope in case a crystal oscillator having a basic oscillation frequency of 20 MHz is used in the circuit shown in Fig. 7.
Fig. 8(b) is a graph showing an oscillation waveform measured by oscilloscope in case a crystal oscillator having a basic oscillation frequency of 33 MHz is used in the circuit shown in Fig. 7.
Fig. 8(c) is a graph showing an oscillation waveform measured by oscilloscope in case a crystal oscillator with a basic oscillation frequency of 50 MHz is used in the circuit shown in Fig. 7.
Fig. 8(d) is a graph showing an oscillation waveform measured by oscilloscope in case a crystal oscillator having a basic oscillation frequency of 155 MHz is used in the circuit shown in Fig. 7.
Fig. 9(a) is a graph showing changes in the oscillation frequency with the lapse of time when one of the oscillation circuits of Fig. 7 is used and saturated acetone steam of the same concentration is adsorbed on crystal oscillators coated with a plasma polymerized styrene film of the same weight .
Fig. 9(b) is an enlarged graph of the measurement result by using the crystal oscillator having the basic oscillation frequency of 9 MHz in Fig. 9(a).
pETATT.ED DESCRIPTION OF THE INVENTION
Studying hard to solve the foregoing problems, the inventor used a readily available logic element, made a closed circuit by connecting its input and output with a capacitor, a resistor and a crystal oscillator having a natural oscillation frequency in a high-frequency area, and discovered that an oscillation circuit capable of keeping a more stable high-frequency oscillation can be unexpectedly obtained by the operation time or response speed of the logic element, the time constant of the capacitor and the resistor or the like, resulting in completion of the present invention.
The present invention provides a high-frequency oscillation circuit characterized by incorporating a crystal oscillator having a natural oscillation frequency (i.e., basic oscillation frequency) in a high-frequency area into a closed circuit including a logic element.
In the present invention, a closed circuit is formed by using a logic element. It is possible to use a readily available logic element such as NAND circuit, NOR circuit, inverter or the like which is heretofore publicly known, but it is preferable to use a high-speed TTL (Transistor-Transistor Logic) element or CMOS (Complementary Metal Oxide Semiconductor) element so as to cope with a high-frequency oscillation. Also, in a high-frequency oscillation circuit into which a crystal oscillator having a basic oscillation frequency in a high-frequency area is incorporated, it is possible to use a logic element CMOS, which is fast in the response speed, so as to cope with the high frequency.
As a crystal oscillator having a natural oscillation frequency in a high-frequency area, a crystal oscillator having a natural oscillation frequency corresponding to the oscillation frequency of the circuit generally between and 1800 MHz, preferably between 50 and 1800 MHz, more preferably between 100 and 1800 MHz, and the most 25 preferably between 150 and 1800 MHz can be given. As another crystal oscillator for high frequency, a crystal oscillator having a basic oscillation frequency corresponding to an oscillation frequency generally between 1 MHz and 2GHz, preferably of 150 MHz or more can be given as an example.
In the high-frequency oscillation circuit relative to the present invention, it is possible to incorporate a crystal oscillator having a basic oscillation frequency in a high-frequency area into a closed circuit including a high-frequency cMOS as a logic element. This oscillation circuit has quite a novel circuit content and circuit constitution of a type that could not be anticipated or expected by the conventional electronic circuit. Such a high-frequency oscillation circuit as this is suited for oscillation of an oscillator, particularly a crystal oscillator for chemical measurement.
The closed circuit in the present invention can be formed by connecting a capacitor, a resistor and a crystal oscillator having a natural oscillation frequency in a high-frequency area to the input and output of such a logic element, and properly adjusting an operation time or response speed of the logic element, the natural oscillation frequency of the crystal oscillator, and the time constant or the like of the capacitor and resistor.
As a concrete circuit constitution of the closed circuit, such an embodiment as one using, for example, two NANDs or one inverter can be given. However, in view of a sustained oscillation property of a stable high oscillation frequency, an embodiment to select a high-s speed TTL or CMOS to suit the natural oscillation frequency in a high-frequency area of the crystal oscillator incorporated into the closed circuit, or an embodiment to select a logic element CMOS having a response speed capable of coping with the basic oscillation frequency in the high-frequency area is preferable.
As another preferable embodiment of the present invention, the following embodiments can be mentioned.
(1) A high-frequency oscillation circuit having high-frequency stability, which comprises a crystal oscillator for high frequency disposed within a closed circuit that is formed with a logic element, and (2) A high-frequency oscillation circuit, which comprises a crystal oscillator having a basic oscillation frequency in a high frequency area, in a closed circuit that is formed so as to connect the input and output of a logic element.
PRFFRRRFD EMBODIMENTS OF THE INVENTION
In the following, the present invention is described in more detail, but the invention is not limited thereto.
Embodiments 1 The high-frequency oscillation circuits, in case a logic element NAND is used, are shown in Figs. 1 and 2, respectively. Fig. 1(a) shows an example of an oscillation circuit when a crystal oscillator X1 for a basic frequency of 50 MHz is used; Fig. 1(b) shows an oscillation waveform of the same circuit as measured by using an oscilloscope. Fig. 2(a) shows an example of an oscillation circuit when an overtone (oscillation frequency of a sub-oscillation) crystal oscillator X2 in the 3rd or 5th order of 100 MHz is used; Fig. 2(b) shows an oscillation waveform of the same circuit as measured by using an oscilloscope.
In Fig. 1(a) and Fig. 2(a), IC1 - IC3 are NANDs as logic elements, X1 is a crystal oscillator having a basic oscillation frequency of 50 MHz, X2 is a crystal oscillator having a basic oscillation frequency of 100 MHz, C1 - C3 are capacitors, and R1 - R2 are resistors.
Each closed circuit is constituted by connecting the output of the logic element IC1 to the input of IC2, and connecting the output of IC2 to the input of IC1. IC3 is a buffer for taking out the output of the oscillation circuit to the outside. In each of closed circuits a crystal oscillator X1 or X2 is disposed. The impedance of each of the crystal oscillators X1 and X2 becomes the lowest at their natural oscillation frequencies (i.e., basic oscillation frequencies).
Consequently, in each oscillation circuit, each capacitor C and each resistor R are set at such a value as the circuit impedance has the lowest value where the impedance of the crystal oscillators X1 or X2 is the lowest, in view of the operating speed of the logic element IC.
The values of the above circuit components (parts) and the names of the logic elements are shown in Fig. 1(a) and Fig. 2(a), respectively. In Fig. 1(a), the type of the logic elements ICl, IC2 and IC3 are 74LS00; C1 is lOpF; C2 is 7pF; C3 is 100pF; R1 is 470; and R2 is 330. In Fig.
2(a), the type of the logic elements IC1, IC2 and IC3 are 74HC00; C2 is lpF; C3 is 100pF; R1 and R2 are 300.
However, such values of the circuit parts and names of the logic elements are not absolute,.and since the impedance of the circuit is low enough in their vicinities, the circuit will oscillate at the natural oscillation frequencies of the crystal oscillators X1 or X2.
As are clear from Fig. 1(b) and Fig. 2(b), in each of the oscillation circuits shown in Figs. 1 and 2, the waveform at the above circuit constants takes a substantially pure sine wave and can be measured accurately enough by an ordinary frequency counter.
Next, oscillation circuits, in case an inverter is used as a logic element, are shown in Figs. 3 and 4, respectively. Fig. 3 shows an example of using a crystal oscillator X1 having a basic oscillation frequency of 155 MHz. Fig. 4 shows an example of using an overtone crystal oscillator X2 in the 3rd or 5th of 100 MHz.
Each symbol is the same as in Embodiments 1. The logic element IC is an inverter and L1 is an inductance.
Also, IC2 is a buffer to take out the output of the oscillation circuit outside. In each oscillation circuit, a closed circuit is constituted by connecting the input and output of the inverter ICl. The crystal oscillator X1 or X2 is disposed in this closed circuit. The impedance of each of the crystal oscillators X1 and X2 becomes the lowest at their natural oscillation frequencies. Consequently, each oscillation circuit oscillates at the natural oscillation frequency of the crystal oscillator X1 or X2.
Fig. 3(a) shows an example of a circuit which excites the optimum oscillation at the basic oscillation frequency of the crystal oscillator X1. The basic oscillation frequency of the crystal oscillator Xl in this example is 155 MHz. The values of the capacitor C1 and the resistor R1 which are concrete circuit parts as well as the name of the logic element IC are shown in the drawing.
Fig. 4(a) shows an example of a circuit which oscillates the most favorably at each overtone. C1 and L1 are for selecting a desired order. The drawings show the value of the circuit parts and the name of the logic element in case the circuit is oscillated at the natural oscillation frequency of 100 MHz by using the 5th order (or 3rd order of 33 MHz) of the crystal oscillator X2 having the basic oscillation frequency of 20 MHz.
In Fig. 3(a), the type of the logic elements IC1 and IC2 are 74HCU04AP; C1 is 50pF; R1 is 500k~; and L1 is 0.5pH. In Fig. 4(a), the type of the logic elements IC1 and IC2 are 74HCU04; C1 is 150pF; Rl is 100; and L1 is 0.5pH.
These value of the circuit parts and name of logic element are not definite, but it is the same as in case of Embodiments 1 in that, if a value is in the vicinity, the impedance of the circuit is low enough, so the circuit will oscillate at the natural oscillation frequency of the crystal oscillator X1 or X2.
As are clear from Fig. 3(b) and Fig. 4(b), in each of the oscillation circuits, the waveforms at the above circuit constant show a substantially pure sine wave, and the frequency can be measured accurately enough by an ordinary frequency counter.
Fig. 5 shows the degree of stability of the oscillation frequency in an hour in case of the circuit having the oscillation frequency of 100 MHz using an ordinary crystal oscillator, in the Embodiment shown in Fig. 2(a). Fig. 6 shows the degree of stability of the oscillation frequency in an hour in case of the circuit using a crystal oscillator on which a styrene film is deposited for one minute by a plasma-polymerization method, in which the circuit having an oscillation frequency of 100 MHz is the same one of the embodiment as shown in Fig.
2(a).
It will be understood from Fig. 5 that, by maintaining constant the temperature of each of oscillation circuits mentioned in Embodiments 1, the variation in oscillation frequency of the circuit per hour is of a value within the range of 10 Hz. Further, as shown in Fig. 6, the variation in oscillation frequency per hour of the circuit using the crystal oscillator on which a styrene film is deposited for one minute by plasma polymerization method is also within the range of 10 Hz.
It is also confirmed that each of the circuits in Embodiments 2 shows the same oscillation property of a highly stable high-frequency as in Embodiments 1.
A high-frequency oscillation circuit using an inverter as a logic element is shown in Fig. 7. Fig. 7 shows an oscillation circuit using a crystal oscillator whose basic oscillation frequency is between 20 MHz and 155 MHz.
In Fig. 7, IC1 and IC2 are inverters as logic elements; X is a crystal oscillator; C is a capacitor; and R is a resistor. The concrete values of the capacitor C
and the resistor R and the name of the logic element IC
are shown in the drawing. Further, IC2 is a buffer to take out the output of the oscillation circuit outside.
In this oscillation circuit, a closed circuit is constituted by connecting the input and the output of the inverter IC1. The crystal oscillator X is placed in this closed circuit. The impedance of the crystal oscillator X
becomes the lowest at its basic oscillation frequency.
Accordingly, the circuit will oscillate at the natural oscillation frequency of the crystal oscillator X. For instance, the oscillation frequency can be 1 to 19 MHz, 20 MHz, 33 MHz, 50 MHz, and 155 MHz in the circuit of Fig. 7.
In Fig. 7, the type of the inverter IC1 and IC2 is 74HCU04AP; R is 500 k~; and C is 1000 pF.
The above values of the circuit elements and the names of the logic elements are not restrictive, but, since the impedance of the circuit is low enough in the vicinities, the oscillation circuit oscillates at the basic oscillation frequency of the crystal oscillator X. It is desirable to select a logic element CMOS capable of coping with this range of frequency.
Fig 8(a), (b), (c) and (d) show output waveforms measured by an oscilloscope in case crystal oscillators X
having basic oscillation frequencies of 20 MHz, 33 MHz, 50 MHz, and 155 MHz are respectively used in the circuit of Fig. 7. As is clear from each Figure, the output waveform by the above circuit constant has a shape between a rectangular and a sine wave and shows approximately a sine wave at 155 MHz. The oscillation frequency of the oscillation circuit showing these output waveforms can be sufficiently measured by an ordinary frequency counter.
Thus, by selectively using one of crystal oscillators X having various basic oscillation frequencies from 1 MHz to 2 GHz, they can be oscillated on the same circuit at the basic oscillation frequency of each crystal oscillator.
Conventionally, it has been a common knowledge to design and constitute an oscillation circuit the most favorable for each crystal oscillator. The present invention overturns the common knowledge regarding conventional oscillation circuits.
Figs. 9(a) and 9(b) show changes in the oscillation frequency with the lapse of time when one of the oscillation circuits of Fig. 7 is used and saturated acetone steam of the same concentration (as measured by extracting 2 ml of head space of the acetone solution and injecting it into a gas adsorption measurement vessel of 1000 ml) is adsorbed on crystal oscillators (of 9 MHz, 50 MHz, 155 MHz) coated with a plasma polymerized styrene film of the same weight (subjected to electric discharge output of 100 W, monomer pressure of 100 Pa, and 1 minute of polymerization time).
In Figs. 9(a) and 9(b), gas adsorption responses are shown, when measured, respectively, by using: (~) a crystal oscillator having a basic oscillation frequency of 9 MHz; (~) a crystal oscillator having a basic oscillation frequency of 50 MHz; and (1) a crystal oscillator having a basic oscillation frequency of 155 MHz.
As the basic oscillation frequencies of the crystal increase, the amount of change in frequency responding to the acetone steam of the same concentration remarkably increases.
In Figs. 9(a) and 9(b), the average values of gas adsorption at respective frequencies show frequency responses of 30 Hz in case of 9 MHz (~), 1200 Hz in case of 50 MHz (~), and 2500 Hz in case of 155 MHz respectively. Evidently, the higher the basic oscillation frequency of a crystal oscillator used for gas adsorption is, the greater amount of response by gas adsorption is shown.
In the high frequency oscillation circuit shown in Fig.
7, it is not necessary to change the circuit constant in correspondence to the basic oscillation frequency of the crystal oscillator to be used. With such an oscillation circuit, it is possible to cope with as it is, even if a crystal oscillator as a sensor is changed according to purposes of measurement so as to change a basic frequency, which was heretofore difficult. If such a high-frequency oscillation circuit is used, a precision high-sensitive measuring instrument which is the most favorable for measurement of a super-high sensitive gas sensor or the amount of floating dust can be readily fabricated.
The high-frequency oscillation circuit using the logic elements according to the present invention, though using inexpensive parts and being a simple circuit, continues highly stable oscillation by a crystal oscillator having a high natural oscillation frequency.
As a result, the high-frequency oscillation circuit of the present invention enables to measure precisely a delicate change in natural oscillation frequency of a crystal oscillator as a sensor, and a use of such a high-frequency oscillation circuit enables to readily fabricate a super-high-sensitive, precision measurement instrument favorable for measurement such as a super-high sensitive weight sensor, a viscosity sensor, and the like.
Having described our invention as related to the present embodiments, it is our intention that the invention not be limited by any of the details of the description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.
In the present invention, a closed circuit is formed by using a logic element. It is possible to use a readily available logic element such as NAND circuit, NOR circuit, inverter or the like which is heretofore publicly known, but it is preferable to use a high-speed TTL (Transistor-Transistor Logic) element or CMOS (Complementary Metal Oxide Semiconductor) element so as to cope with a high-frequency oscillation. Also, in a high-frequency oscillation circuit into which a crystal oscillator having a basic oscillation frequency in a high-frequency area is incorporated, it is possible to use a logic element CMOS, which is fast in the response speed, so as to cope with the high frequency.
As a crystal oscillator having a natural oscillation frequency in a high-frequency area, a crystal oscillator having a natural oscillation frequency corresponding to the oscillation frequency of the circuit generally between and 1800 MHz, preferably between 50 and 1800 MHz, more preferably between 100 and 1800 MHz, and the most 25 preferably between 150 and 1800 MHz can be given. As another crystal oscillator for high frequency, a crystal oscillator having a basic oscillation frequency corresponding to an oscillation frequency generally between 1 MHz and 2GHz, preferably of 150 MHz or more can be given as an example.
In the high-frequency oscillation circuit relative to the present invention, it is possible to incorporate a crystal oscillator having a basic oscillation frequency in a high-frequency area into a closed circuit including a high-frequency cMOS as a logic element. This oscillation circuit has quite a novel circuit content and circuit constitution of a type that could not be anticipated or expected by the conventional electronic circuit. Such a high-frequency oscillation circuit as this is suited for oscillation of an oscillator, particularly a crystal oscillator for chemical measurement.
The closed circuit in the present invention can be formed by connecting a capacitor, a resistor and a crystal oscillator having a natural oscillation frequency in a high-frequency area to the input and output of such a logic element, and properly adjusting an operation time or response speed of the logic element, the natural oscillation frequency of the crystal oscillator, and the time constant or the like of the capacitor and resistor.
As a concrete circuit constitution of the closed circuit, such an embodiment as one using, for example, two NANDs or one inverter can be given. However, in view of a sustained oscillation property of a stable high oscillation frequency, an embodiment to select a high-s speed TTL or CMOS to suit the natural oscillation frequency in a high-frequency area of the crystal oscillator incorporated into the closed circuit, or an embodiment to select a logic element CMOS having a response speed capable of coping with the basic oscillation frequency in the high-frequency area is preferable.
As another preferable embodiment of the present invention, the following embodiments can be mentioned.
(1) A high-frequency oscillation circuit having high-frequency stability, which comprises a crystal oscillator for high frequency disposed within a closed circuit that is formed with a logic element, and (2) A high-frequency oscillation circuit, which comprises a crystal oscillator having a basic oscillation frequency in a high frequency area, in a closed circuit that is formed so as to connect the input and output of a logic element.
PRFFRRRFD EMBODIMENTS OF THE INVENTION
In the following, the present invention is described in more detail, but the invention is not limited thereto.
Embodiments 1 The high-frequency oscillation circuits, in case a logic element NAND is used, are shown in Figs. 1 and 2, respectively. Fig. 1(a) shows an example of an oscillation circuit when a crystal oscillator X1 for a basic frequency of 50 MHz is used; Fig. 1(b) shows an oscillation waveform of the same circuit as measured by using an oscilloscope. Fig. 2(a) shows an example of an oscillation circuit when an overtone (oscillation frequency of a sub-oscillation) crystal oscillator X2 in the 3rd or 5th order of 100 MHz is used; Fig. 2(b) shows an oscillation waveform of the same circuit as measured by using an oscilloscope.
In Fig. 1(a) and Fig. 2(a), IC1 - IC3 are NANDs as logic elements, X1 is a crystal oscillator having a basic oscillation frequency of 50 MHz, X2 is a crystal oscillator having a basic oscillation frequency of 100 MHz, C1 - C3 are capacitors, and R1 - R2 are resistors.
Each closed circuit is constituted by connecting the output of the logic element IC1 to the input of IC2, and connecting the output of IC2 to the input of IC1. IC3 is a buffer for taking out the output of the oscillation circuit to the outside. In each of closed circuits a crystal oscillator X1 or X2 is disposed. The impedance of each of the crystal oscillators X1 and X2 becomes the lowest at their natural oscillation frequencies (i.e., basic oscillation frequencies).
Consequently, in each oscillation circuit, each capacitor C and each resistor R are set at such a value as the circuit impedance has the lowest value where the impedance of the crystal oscillators X1 or X2 is the lowest, in view of the operating speed of the logic element IC.
The values of the above circuit components (parts) and the names of the logic elements are shown in Fig. 1(a) and Fig. 2(a), respectively. In Fig. 1(a), the type of the logic elements ICl, IC2 and IC3 are 74LS00; C1 is lOpF; C2 is 7pF; C3 is 100pF; R1 is 470; and R2 is 330. In Fig.
2(a), the type of the logic elements IC1, IC2 and IC3 are 74HC00; C2 is lpF; C3 is 100pF; R1 and R2 are 300.
However, such values of the circuit parts and names of the logic elements are not absolute,.and since the impedance of the circuit is low enough in their vicinities, the circuit will oscillate at the natural oscillation frequencies of the crystal oscillators X1 or X2.
As are clear from Fig. 1(b) and Fig. 2(b), in each of the oscillation circuits shown in Figs. 1 and 2, the waveform at the above circuit constants takes a substantially pure sine wave and can be measured accurately enough by an ordinary frequency counter.
Next, oscillation circuits, in case an inverter is used as a logic element, are shown in Figs. 3 and 4, respectively. Fig. 3 shows an example of using a crystal oscillator X1 having a basic oscillation frequency of 155 MHz. Fig. 4 shows an example of using an overtone crystal oscillator X2 in the 3rd or 5th of 100 MHz.
Each symbol is the same as in Embodiments 1. The logic element IC is an inverter and L1 is an inductance.
Also, IC2 is a buffer to take out the output of the oscillation circuit outside. In each oscillation circuit, a closed circuit is constituted by connecting the input and output of the inverter ICl. The crystal oscillator X1 or X2 is disposed in this closed circuit. The impedance of each of the crystal oscillators X1 and X2 becomes the lowest at their natural oscillation frequencies. Consequently, each oscillation circuit oscillates at the natural oscillation frequency of the crystal oscillator X1 or X2.
Fig. 3(a) shows an example of a circuit which excites the optimum oscillation at the basic oscillation frequency of the crystal oscillator X1. The basic oscillation frequency of the crystal oscillator Xl in this example is 155 MHz. The values of the capacitor C1 and the resistor R1 which are concrete circuit parts as well as the name of the logic element IC are shown in the drawing.
Fig. 4(a) shows an example of a circuit which oscillates the most favorably at each overtone. C1 and L1 are for selecting a desired order. The drawings show the value of the circuit parts and the name of the logic element in case the circuit is oscillated at the natural oscillation frequency of 100 MHz by using the 5th order (or 3rd order of 33 MHz) of the crystal oscillator X2 having the basic oscillation frequency of 20 MHz.
In Fig. 3(a), the type of the logic elements IC1 and IC2 are 74HCU04AP; C1 is 50pF; R1 is 500k~; and L1 is 0.5pH. In Fig. 4(a), the type of the logic elements IC1 and IC2 are 74HCU04; C1 is 150pF; Rl is 100; and L1 is 0.5pH.
These value of the circuit parts and name of logic element are not definite, but it is the same as in case of Embodiments 1 in that, if a value is in the vicinity, the impedance of the circuit is low enough, so the circuit will oscillate at the natural oscillation frequency of the crystal oscillator X1 or X2.
As are clear from Fig. 3(b) and Fig. 4(b), in each of the oscillation circuits, the waveforms at the above circuit constant show a substantially pure sine wave, and the frequency can be measured accurately enough by an ordinary frequency counter.
Fig. 5 shows the degree of stability of the oscillation frequency in an hour in case of the circuit having the oscillation frequency of 100 MHz using an ordinary crystal oscillator, in the Embodiment shown in Fig. 2(a). Fig. 6 shows the degree of stability of the oscillation frequency in an hour in case of the circuit using a crystal oscillator on which a styrene film is deposited for one minute by a plasma-polymerization method, in which the circuit having an oscillation frequency of 100 MHz is the same one of the embodiment as shown in Fig.
2(a).
It will be understood from Fig. 5 that, by maintaining constant the temperature of each of oscillation circuits mentioned in Embodiments 1, the variation in oscillation frequency of the circuit per hour is of a value within the range of 10 Hz. Further, as shown in Fig. 6, the variation in oscillation frequency per hour of the circuit using the crystal oscillator on which a styrene film is deposited for one minute by plasma polymerization method is also within the range of 10 Hz.
It is also confirmed that each of the circuits in Embodiments 2 shows the same oscillation property of a highly stable high-frequency as in Embodiments 1.
A high-frequency oscillation circuit using an inverter as a logic element is shown in Fig. 7. Fig. 7 shows an oscillation circuit using a crystal oscillator whose basic oscillation frequency is between 20 MHz and 155 MHz.
In Fig. 7, IC1 and IC2 are inverters as logic elements; X is a crystal oscillator; C is a capacitor; and R is a resistor. The concrete values of the capacitor C
and the resistor R and the name of the logic element IC
are shown in the drawing. Further, IC2 is a buffer to take out the output of the oscillation circuit outside.
In this oscillation circuit, a closed circuit is constituted by connecting the input and the output of the inverter IC1. The crystal oscillator X is placed in this closed circuit. The impedance of the crystal oscillator X
becomes the lowest at its basic oscillation frequency.
Accordingly, the circuit will oscillate at the natural oscillation frequency of the crystal oscillator X. For instance, the oscillation frequency can be 1 to 19 MHz, 20 MHz, 33 MHz, 50 MHz, and 155 MHz in the circuit of Fig. 7.
In Fig. 7, the type of the inverter IC1 and IC2 is 74HCU04AP; R is 500 k~; and C is 1000 pF.
The above values of the circuit elements and the names of the logic elements are not restrictive, but, since the impedance of the circuit is low enough in the vicinities, the oscillation circuit oscillates at the basic oscillation frequency of the crystal oscillator X. It is desirable to select a logic element CMOS capable of coping with this range of frequency.
Fig 8(a), (b), (c) and (d) show output waveforms measured by an oscilloscope in case crystal oscillators X
having basic oscillation frequencies of 20 MHz, 33 MHz, 50 MHz, and 155 MHz are respectively used in the circuit of Fig. 7. As is clear from each Figure, the output waveform by the above circuit constant has a shape between a rectangular and a sine wave and shows approximately a sine wave at 155 MHz. The oscillation frequency of the oscillation circuit showing these output waveforms can be sufficiently measured by an ordinary frequency counter.
Thus, by selectively using one of crystal oscillators X having various basic oscillation frequencies from 1 MHz to 2 GHz, they can be oscillated on the same circuit at the basic oscillation frequency of each crystal oscillator.
Conventionally, it has been a common knowledge to design and constitute an oscillation circuit the most favorable for each crystal oscillator. The present invention overturns the common knowledge regarding conventional oscillation circuits.
Figs. 9(a) and 9(b) show changes in the oscillation frequency with the lapse of time when one of the oscillation circuits of Fig. 7 is used and saturated acetone steam of the same concentration (as measured by extracting 2 ml of head space of the acetone solution and injecting it into a gas adsorption measurement vessel of 1000 ml) is adsorbed on crystal oscillators (of 9 MHz, 50 MHz, 155 MHz) coated with a plasma polymerized styrene film of the same weight (subjected to electric discharge output of 100 W, monomer pressure of 100 Pa, and 1 minute of polymerization time).
In Figs. 9(a) and 9(b), gas adsorption responses are shown, when measured, respectively, by using: (~) a crystal oscillator having a basic oscillation frequency of 9 MHz; (~) a crystal oscillator having a basic oscillation frequency of 50 MHz; and (1) a crystal oscillator having a basic oscillation frequency of 155 MHz.
As the basic oscillation frequencies of the crystal increase, the amount of change in frequency responding to the acetone steam of the same concentration remarkably increases.
In Figs. 9(a) and 9(b), the average values of gas adsorption at respective frequencies show frequency responses of 30 Hz in case of 9 MHz (~), 1200 Hz in case of 50 MHz (~), and 2500 Hz in case of 155 MHz respectively. Evidently, the higher the basic oscillation frequency of a crystal oscillator used for gas adsorption is, the greater amount of response by gas adsorption is shown.
In the high frequency oscillation circuit shown in Fig.
7, it is not necessary to change the circuit constant in correspondence to the basic oscillation frequency of the crystal oscillator to be used. With such an oscillation circuit, it is possible to cope with as it is, even if a crystal oscillator as a sensor is changed according to purposes of measurement so as to change a basic frequency, which was heretofore difficult. If such a high-frequency oscillation circuit is used, a precision high-sensitive measuring instrument which is the most favorable for measurement of a super-high sensitive gas sensor or the amount of floating dust can be readily fabricated.
The high-frequency oscillation circuit using the logic elements according to the present invention, though using inexpensive parts and being a simple circuit, continues highly stable oscillation by a crystal oscillator having a high natural oscillation frequency.
As a result, the high-frequency oscillation circuit of the present invention enables to measure precisely a delicate change in natural oscillation frequency of a crystal oscillator as a sensor, and a use of such a high-frequency oscillation circuit enables to readily fabricate a super-high-sensitive, precision measurement instrument favorable for measurement such as a super-high sensitive weight sensor, a viscosity sensor, and the like.
Having described our invention as related to the present embodiments, it is our intention that the invention not be limited by any of the details of the description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.
Claims (9)
1. A high-frequency oscillation circuit comprising:
a closed loop circuit including a first logic element inverter (IC1) having an input and an output within said closed loop circuit;
a second logic element inverter (IC2) having an input and an output external to said closed loop circuit, wherein said output of said first logic element inverter (IC1) is connected to said input of said second logic element (IC2);
a resistor (R) being disposed within said closed loop circuit and connected parallel to said first logic element inverter (IC1);
a crystal device (X), selected from a group of crystal devices having various basic oscillation frequencies, for high frequency oscillation being disposed within said closed loop circuit and connected serially to a capacitor (C), wherein said crystal device (X) and said serially connected capacitor (C) are connected in parallel to said first logic element inverter (IC1), wherein the oscillation circuit has an oscillation frequency in a range between 50 MHz and 1.8 GHz and wherein the oscillating frequency is a function of the crystal device (X).
a closed loop circuit including a first logic element inverter (IC1) having an input and an output within said closed loop circuit;
a second logic element inverter (IC2) having an input and an output external to said closed loop circuit, wherein said output of said first logic element inverter (IC1) is connected to said input of said second logic element (IC2);
a resistor (R) being disposed within said closed loop circuit and connected parallel to said first logic element inverter (IC1);
a crystal device (X), selected from a group of crystal devices having various basic oscillation frequencies, for high frequency oscillation being disposed within said closed loop circuit and connected serially to a capacitor (C), wherein said crystal device (X) and said serially connected capacitor (C) are connected in parallel to said first logic element inverter (IC1), wherein the oscillation circuit has an oscillation frequency in a range between 50 MHz and 1.8 GHz and wherein the oscillating frequency is a function of the crystal device (X).
2. A high-frequency oscillation circuit comprising:
a closed loop circuit including a first logic element inverter (IC1) having an input and an output within said closed loop circuit;
a second logic element inverter (IC2) having an input and an output external to said closed loop circuit, wherein said output of said first logic element inverter (IC1) is connected to said input of said second logic element (IC2);
a first resistor (R2) being disposed within said closed loop circuit and connected parallel to said first logic element inverter (IC1);
a crystal device (X2), selected from a group of crystal devices having various basic oscillation frequencies, for high frequency oscillation being disposed within said closed loop circuit and connected serially to a second resistor (R1), wherein said crystal device (X2) and said serially connected second resistor (R2) are connected in parallel to said first logic element inverter (IC1), wherein a node between said crystal device (X2) and said second resistor (R1) is connected to ground via a serial connection of a capacitor (C1) and an inductance (L1) for selecting a favourable overtone oscillation, and wherein the oscillation circuit has an oscillation frequency in a range between 50 MHz and 1.8 GHz and wherein the oscillating frequency is a function of the crystal device (X2).
a closed loop circuit including a first logic element inverter (IC1) having an input and an output within said closed loop circuit;
a second logic element inverter (IC2) having an input and an output external to said closed loop circuit, wherein said output of said first logic element inverter (IC1) is connected to said input of said second logic element (IC2);
a first resistor (R2) being disposed within said closed loop circuit and connected parallel to said first logic element inverter (IC1);
a crystal device (X2), selected from a group of crystal devices having various basic oscillation frequencies, for high frequency oscillation being disposed within said closed loop circuit and connected serially to a second resistor (R1), wherein said crystal device (X2) and said serially connected second resistor (R2) are connected in parallel to said first logic element inverter (IC1), wherein a node between said crystal device (X2) and said second resistor (R1) is connected to ground via a serial connection of a capacitor (C1) and an inductance (L1) for selecting a favourable overtone oscillation, and wherein the oscillation circuit has an oscillation frequency in a range between 50 MHz and 1.8 GHz and wherein the oscillating frequency is a function of the crystal device (X2).
3. The high-frequency oscillation circuit of claim 1 or claim 2, wherein said first logic element inverter (IC1) includes a high-speed TTL.
4. The high-frequency oscillation circuit of claim 1 or claim 2, wherein said first logic element inverter (IC1) includes a high-speed CMOS.
5. The high-frequency oscillation circuit of any one of claims 1 to 4, wherein said second logic element inverter (IC2) being disposed externally to and in serial connection with said closed loop circuit.
6. The high-frequency oscillation circuit of any one of claims 1 to 5, wherein said crystal oscillator (X) is a sensor element for chemical measurement of a predetermined parameter.
7. A measuring instrument for measuring a predetermined parameter by a sensor, wherein said measuring instrument comprises the high-frequency oscillation circuit of any one of claims 1 to 6 and wherein a change in said basic oscillation frequency of said crystal device (X) being indicative of said predetermined parameter.
8. The measuring instrument for measuring a predetermined parameter of claim 7, wherein said predetermined parameter includes at least one of a weight parameter and a film thickness parameter.
9. The measuring instrument for measuring a predetermined parameter of claim 7 or claim 8, wherein said sensor is at least one of a weight sensor, a chemical sensor, a film thickness meter, a gas sensor, a floating dust sensor, and an adsorption sensor.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000-031513 | 2000-02-09 | ||
| JP2000031513A JP2001221732A (en) | 2000-02-09 | 2000-02-09 | High frequency oscillation circuit showing high frequency stability |
| JP2000103709A JP2001289765A (en) | 2000-04-05 | 2000-04-05 | High-frequency oscillation circuit drive quartz oscillator for chemical measurement |
| JP2000-103709 | 2000-04-05 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2328813A1 CA2328813A1 (en) | 2001-08-09 |
| CA2328813C true CA2328813C (en) | 2005-09-20 |
Family
ID=26585087
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002328813A Expired - Fee Related CA2328813C (en) | 2000-02-09 | 2000-12-18 | High-frequency oscillation circuit |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US6798306B2 (en) |
| EP (1) | EP1146634B8 (en) |
| AU (1) | AU767454B2 (en) |
| CA (1) | CA2328813C (en) |
| DE (1) | DE60044021D1 (en) |
| NZ (1) | NZ508983A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004023109A (en) * | 2002-06-12 | 2004-01-22 | Seiko Epson Corp | Oscillation circuit and semiconductor integrated circuit |
| EP2779456B1 (en) * | 2013-03-15 | 2018-08-29 | Dialog Semiconductor B.V. | Method for reducing overdrive need in mos switching and logic circuit |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3879992A (en) | 1970-05-12 | 1975-04-29 | California Inst Of Techn | Multiple crystal oscillator measuring apparatus |
| US3689907A (en) * | 1970-08-03 | 1972-09-05 | Robbins Aviat Inc | Dewpoint monitor |
| US3676801A (en) * | 1970-10-28 | 1972-07-11 | Motorola Inc | Stabilized complementary micro-power square wave oscillator |
| US3760290A (en) | 1972-06-16 | 1973-09-18 | Quinder Electronics Inc | Crystal controlled variable frequency oscillator |
| US4321562A (en) * | 1979-01-11 | 1982-03-23 | Nippon Electric Co., Ltd. | Crystal oscillator circuit capable of changing the number of inverter stages coupled in series |
| CA1227357A (en) * | 1985-02-12 | 1987-09-29 | Minister Of National Defence | Method and apparatus for detecting presence and concentration of vapours in gaseous fluids |
| US4862114A (en) * | 1988-06-23 | 1989-08-29 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Crystal oscillators using negative voltage gain, single pole response amplifiers |
| JPH0752592B2 (en) | 1989-08-18 | 1995-06-05 | 株式会社東芝 | Semiconductor memory device |
| JPH03165236A (en) | 1989-11-24 | 1991-07-17 | Seiko Instr Inc | Oscillating circuit for piezoelectric element |
| JPH05273106A (en) | 1992-03-24 | 1993-10-22 | Toshiba Corp | Sulfur hexafluoride decomposed gas sensor |
| JPH07131249A (en) | 1993-10-29 | 1995-05-19 | Meidensha Corp | Crystal oscillation circuit |
| US5801596A (en) * | 1994-07-27 | 1998-09-01 | Citizen Watch Co., Ltd. | Temperature compensation type quartz oscillator |
-
2000
- 2000-12-18 CA CA002328813A patent/CA2328813C/en not_active Expired - Fee Related
- 2000-12-19 AU AU72381/00A patent/AU767454B2/en not_active Ceased
- 2000-12-19 NZ NZ508983A patent/NZ508983A/en unknown
- 2000-12-20 EP EP00127908A patent/EP1146634B8/en not_active Expired - Lifetime
- 2000-12-20 DE DE60044021T patent/DE60044021D1/en not_active Expired - Lifetime
- 2000-12-20 US US09/739,812 patent/US6798306B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| AU7238100A (en) | 2001-08-16 |
| US20020075089A1 (en) | 2002-06-20 |
| AU767454B2 (en) | 2003-11-13 |
| EP1146634B8 (en) | 2010-05-26 |
| EP1146634A2 (en) | 2001-10-17 |
| US6798306B2 (en) | 2004-09-28 |
| EP1146634B1 (en) | 2010-03-17 |
| DE60044021D1 (en) | 2010-04-29 |
| NZ508983A (en) | 2002-10-25 |
| CA2328813A1 (en) | 2001-08-09 |
| EP1146634A3 (en) | 2002-02-06 |
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