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Publication numberUS3611146 A
Publication typeGrant
Publication dateOct 5, 1971
Filing dateMay 20, 1969
Priority dateMay 20, 1969
Publication numberUS 3611146 A, US 3611146A, US-A-3611146, US3611146 A, US3611146A
InventorsHerbert Warren Cooper, Charles Moskowitz
Original AssigneeWestinghouse Electric Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Integrated microwave radiator and generator
US 3611146 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

W 1 I 11 11111 tates a e inventors llilerhert Warren Cooper llilyattsville, MdL; Charles Mioslkowitz, Eandallstown, N.Y. Appl. No. 826,170 Filed May 20, 11969 Patented Oct. 5, 11971 Assignee Westinghouse Electric Corporation Pittsburgh, Pa.

INTEGRATED MICROWAVE RADIATOR AND GENERATOR 20 Claims, 41 Drawing Figs.

US. Cl 325/105, 325/125, 331/96, 331/107 lint. Cl 1111031) 7/08 Field 01 Search 325/ 105,

Attorneys-F. H. H

[56] References Cited UNITED STATES PATENTS 3,249,891 5/1966 Rutz 331/107 3,475,759 10/1969 Winegard 343/701 X 3,509,465 4/1970 Andre et a1. 325/373 3,521,169 7/1970 Turner etai 325/105 Primary ExaminerBenedict V. Safourek enson and E. P. Klipfel ABSTRACT: A hybrid integrated microwave radiator includes a negative resistance semiconductor element mounted on a dipole radiator. The hybrid integrated circuit provides an impedance-transforming network whereby cnergization of the semiconductor element through connections to the radiator produces oscillations in the circuit of the semiconductor element for driving the radiator.

PATENTEU um 5|97| 3,6 1' 1. 146

. NEUTRAL PLANE FIG. 3

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RADIATOR x 01005 BY ATTORNEY INTEGRATED MICROWAVE RADIATOR AND GENERATOR BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to dipole radiators and, more particularly, to a hybrid integrated dipole radiator having a negative resistance semiconductor element mounted thereon and providing an impedance-transformation network for establishing oscillations for driving the radiator.

2. Description of the Prior Art Heretofore in the prior art, much study has been made of microwave power generation by diode elements of the IM- PA'I'T (abbreviation for impatt ionization transit time, or avalanche transit time) types such as Read diodes, as well as those of the bulk effect, or GUNN type. Particular interest in the use of such devices for microwave applications results from the miniaturization capability thereby afforded.

Miniaturized radiating devices are adaptable for numerous microwave applications, such as use as elements of a large array for a radar system, in beacon service, and as active chaff. Array-type systems may be of two types, one in which all elements radiate independently to generate a multiplicity of spectral lines and in which the power is radiated into a solid angle characteristic of a dipole radiator, and another in which the elements are coupled and phase locked to produce coherent output radiation of the individual elements and form a directive beam. Prior art structures typically have required physical displacement or separation of the microwave oscillating source and the radiating element to enable the required closely spaced relationships of the radiating elements as required in a radar array. The oscillating'source and the radiating element to enable the required closely spaced relationships of the radiating elements a required in a radar array. The oscillating source and the radiating element therefore required interconnection by a transmission line, inherently introducing transmission line losses, undue phase sensitivity, and additionally resulting in an undesirably large and complex system.

Where microwave systems are required for use as active chaff or in beacon applications, it is necessary that the oscillating and radiating structure be compact, of reasonable power output, and of minimum cost. Particularly, in beacon type applications, such as for homing systems, the expense of the oscillating and radiating devices must be such as to economically justify disposing of the radiation system once the lost object or person is located. Prior art devices fail to satisfy these combined requirements of size, low cost, and sufficiently high power output.

SUMMARY OF THE INVENTION These and other defects and inadequacies of prior art systems and structures are overcome by the integrated microwave radiator of the invention.

In accordance with the invention, the microwave radiator comprises a hybrid integrated circuit including a dipole radiator on which is mounted a two terminal semiconductor ele ment having negative resistance characteristics. The element may comprise an IMPA'IT type device or a GUNN type device capable of oscillation as a diode oscillator. The impedance-transforming network required for oscillations is provided by suitable forming of, and electrical connections to, the radiator and particularly includes lumped and distributed impedance elements and values. The hybrid-integrated structure therefore provides an impedance-transforming network for conjugate matching of the susceptance and negative conductance of the semiconductor element and the driving point impedance of the radiator to provide for generation of signal oscillations.

The semiconductor element is physically mounted on a portion of the radiator near the driving point thereof and preferably, as in one embodiment, disposed in the neutral plane of the radiator. The hybrid integrated structure may be formed by the deposition and selective etching techniques on a suitable substrate which furthermore may be positioned in displaced relationship from a reflecting plane to afford control of the radiation pattern. In addition to providing certain of the conjugate impedance-matching elements, the radiating element may also provide thennal dissipation, or a heat sink, for the semiconductor element.

The hybrid integrated microwave radiator of the invention is physically compact in size, employs a minimum of components, and of relatively low cost. The radiator also is efficient in operation, particularly due to elimination of coupling transmission line losses between the semiconductor oscillating element and the radiating element.

The device of the invention is therefore ideally suited for numerous microwave applications. These and other features and advantages of the apparatus of the invention will become apparent and more fully understood from the following description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a first embodiment of an integrated microwave radiator in accordance with the invention;

FIG. 2 is a cross-sectional view of a portion of the apparatus of FIG. 1 taken along the line 2-2;

FIG. 3 is a planar view of a second embodiment of an in tegrated microwave radiator in accordance with the invention; and

FIG. 4 is a schematic of an equivalent circuit of the integrated microwave radiator of the invention in accordance with either of the foregoing embodiments thereof.

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1 is shown a first embodiment of an integrated microwave radiator in accordance with the invention. The device 10 includes a substrate 12 on which are formed dipoleradiating elements 14 and 16, respectively having integral bias leads 18 and 20 oriented perpendicularly thereto and positioned at the central or driving points of the radiating elements 14 and 16. The substrate 12 may be of any suitable insulating material such as alumina or beryllia and the radiating elements and associated bias leads may be of any suitable conducting material such as chrome-gold. Preferably, the radiator ele ments and bias leads are formed by depositing a layer of chrome-gold on the substrate 12 which is thereafter operated upon by conventional photoresist techniques to produce the pattern shown in FIG. I. The radiating elements 14 and 16 comprise a flat dipole of approximately one-half wavelength in physical length at the operating frequency.

The device 11), as noted, comprises a hybridintegrated oscillator-radiator providing a single compact structure both he source of oscillations and the radiator or antenna, specifically the dipole elements 14 and 16 in FIG. l. The active ele' ment of the oscillating circuit comprises a two terminal negative resistance semiconductor device 22 mounted on one of the dipole radiators and particularly on the radiator 14 preferably by ultrasonic bonding for mechanical and electrical connection thereto. Preferably, the element 22 comprises either an IMPATT (abbreviation for i'mpatt ionization transit time, or avalanche transit time) device such as a Read diode, or a bulk effect semiconductor device, such as a GUNN diode. Hereinafter, the element 22 is referred to as a diode inclusive of any of the described types of devices. A lead wire or ribbon 24, typically gold, connects the exposed terminal of the diode 22 to the other element 16 of the radiator, or antenna, to which it is bonded as shown at 26.

An impedance-transforming network is required to satisfy conditions of oscillation of the diode 22 particularly due to the loading by the impedance of the antenna with which it is associated. The network includes tabs 30 and 32 formed preferably integrally with the radiating elements 14 and 16 and corresponding parts of a capacitive structure 34, the construction of which is described in detail hereinafter. The

capacitive tab structure provides part of a matching network and the inductance of the wire lead 24 provides the other part thereof for satisfying the conditions for oscillation.

With reference to FIG. 2 in which is shown a cross section of the device 12 of FIG. 1 taken along the line 2-2, there is shown a convenient construction for providing the capacitive structure 34 of the matching network. The tabs 30 and 32 are shown formed on the substrate and coated with a dielectric such as silicon dioxide 36 which extends between the tabs and 32 to the substrate 15 and presents a planar upper surface, in a preferred embodiment. A conducting element such as a layer of chrome-gold 38 is deposited over the dielectric to form interconnected capacitive coupling with the tabs 30 and 32. By appropriately selecting the tab area and the dielectric thickness, the desired capacitive reactance for the matching network may be achieved.

Referring again to FIG. 1, a capacitive element 40 including tabs 41 and 42 integrally fonned with bias lines 18 and 20, respectively, and of construction similar to the capacitive element 34 may be provided for isolation purposes in a manner and for a reason described more fully hereafter. The bias lines 18 and 20 further include terminals 44 and 46 for connection to a bias supply or energization source and preferably are formed on corresponding integral tabs and 47. The tabs 45 and 47 may additionally be employed as part of a capacitive element 48 of a similar construction to the element 40.

The purpose of the capacitive elements 40 and 48 is to isolate the bias as supply connected to the terminals 44 and 46 from the high-frequency oscillations generated at the antenna and particularly conducted in the elements 14 and 16. Thus, the element 40 is positioned at one-quarter wavelength from the driving point of the antenna, generally defined by the common center of the elements 14 and 16 and the capacitive element 48 is positioned one-quarter wavelength from the element 40. At the driving point of the antenna, therefore, and looking in the direction of the bias supply, the capacitive element 40 presents an open circuit at the described driving position and, from the capacitive element 40, the capacitive element 48 similarly appears as an open circuit.

Preferably, the device 12 is mounted by studs 50 to a reflecting plane 52 of conductive material which serves to increase the forward gain of the radiator by controlling the configuration of the radiation field pattern. The reflecting plane 52 and the plane of the device 12 are parallel and spaced by a distance which achieves the maximum gain or desired field configuration. I

The reflecting plane 52 also conveniently provides a mount for a bias or energization source 54 which may be of similar lateral dimensions to the plane 52 and the substrate 12. The terminals of the source 54 are connected through leads 55 and 56 to the terminals 44 and 46 of the bias lines 18 and 20 associated with the antenna. The energizing voltage with regard to the microwave frequencies generated by the device 10 of the invention, may be considered as DC or pulsed DC and may include frequencies into the video range. If the source 54 includes a metal housing, the housing conveniently may function as a reflecting plane, and the separate plane 52 thereby may be omitted. i

The device of the invention thus provides in a relatively simplified, hybrid integrated structure both the source of oscillations and the reactive elements necessary for conjugate matching of a negative conductance of the diode oscillator or generator and the radiating elements or antenna.

In FIG. 3 is a planar view of a second embodiment of an integratedmicrowave radiator in accordance with the invention. In this embodiment, a folded dipole antenna or radiator is emplayed and a semiconductor diode is mounted thereon. A neutral plane on the folded dipole is defined as shown in FIG. 3, and preferably the diode is positioned symmetrically with respect to that neutral plane. The device of FIG. 3 may be formed by suitable deposition and photoresist processes on an insulating substrate in the manner described with respect to the device 10 of FIG. 1 and may be mounted in the manner shown in FIG. 1.

The folded dipole radiator 58 of FIG. 3 includes an endless loop, outer conductive section 60 and an interior, or enclosed elongated element 62. The spacing between the elements 60 and 62 is selected to provide a desired value of impedance transformation as hereinafter described.

The outer element 60 further includes an integral tab 64 on which is mounted, as by ultrasonic or gold eutectic bonding, a semiconductor diode 66. The mounting provides physical connection of the diode 66 to the tab 64 and electrical, capacitive coupling of one terminal thereof to the tab 64 and thus to the outer, or exterior section 60. Similarly to FIG. 1, a second terminal 67 of the diode 66 is connected through a gold lead 68 to a terminal 69 on the inner element 62. The inductance of the lead 68 provides a part of the inductance of the matching network as required for oscillations. The relatively fixed length of the lead 68, however, results in that inductance value being of relatively fixed amount. For this purpose, a U-shaped notch 70 is fonned in one portion of the inner element 62, the configuration of the notch 70 and the relative displacement thereof from the neutral plane of the device defining the value of inductance introduced thereby into the impedance transforming network.

Capacitive elements 72 and 74 couple the inner and outer sections or elements 60 and 62 of the dipole radiator and are positioned substantially in the neutral plane thereof to present a high-frequency short circuit between these elements. The elements 72 and 74 are constructed in accordance with state of the art MOS surface capacitor techniques and may be metal-oxide semiconductor capacitors in a flipchip mounting.

A positive DC or video line 76 is formed on the substrate along the neutral plane of the device and is connected by lead 77 to the second terminal 67 of the diode 66. Ground lead connections 78 and 79 are formed in parallel-spaced relation thereto, and symmetrically with respect to the neutral plane. The leads or strips 78 and 79 preferably include tab pairs 80, 81 and 82, 83, respectively, forming part of capacitive elements 84 and 86 of the type hereinabove described with respect to FIG. 1 for isolating the bias supply for the device from the microwave oscillations generated therein. The tabs 82 and 83 further include terminals 88 and 89 to which leads 90 and 91 may be connected for common connection to one terminal of the energizing or bias supply. The DC or video line, or strip, 76 includes terminal 92 to which lead 93 is joined for connection of the video strip 76 to the other terminal of the energizing DC or video source.

In FIG. 4 is shown an equivalent circuit for the integrated microwave radiator of the particular construction of FIG. 3. but which circuit also serves to explain the operation of the structure of FIG. 1. The impedance values presented by elements associated with the radiator and the diode, respectively, are illustrated in FIG. 4 as disposed on correspondingly labeled sides of an imaginary separating plane xx. The negative resistance diode 66 is represented in FIG. 4 by resistor 66' having a corresponding value of negative conductance -G and a capacitor connected in shunt to the resistor 66, representative of the inherent capacitance of the diode, and identified by a value capacitive susceptance, B The inductance of the wire lead 68 is represented by inductor 68' having an inductive reactance X The driving point impedance of the radiator is represented by an inductor having inductive susceptance B along with the radiation conductance G and shunted by the susceptance B, which corresponds to the inductance between the elements 60 and 62. The U-shaped notch 70 presents an inductance represented in FIG. 44 at 70' and having a series inductive reactance value X The inductive susceptance inherently provided by the radiator or provided therein as by the U- shaped notch 70 defines a driving point impedance of the radiator to provide a desired input admittance which essentially matches the negative conductance and susceptance of the semiconductor diode. The impedance-transforming network thus afforded satisfies the conditions for oscillation of the diode oscillating circuit and particularly conjugate matches the negative conductance of the diode generator with the driving point admittance of the radiator. v

As noted, the equivalent circuit schematically shown in FIG. 4 corresponding to the structure of FIG. 3 serves in a similar fashion to explain the conjugate impedance matching afforded by the device of FIG. 1. The particular structures or modifications of structures employed in the two disclosed embodiments of the invention for affording, through integrated or hybrid integrated circuit techniques, the necessary impedance element to effect the conjugate matching may, of course, be modified in accordance with any suitable techniques for satisfying the matching requirements.

In summary, the integrated microwave radiator of the invention is compact in size, simple in construction, and low in cost, in addition to affording high efficiency in operation by elimination of transmission line losses, phase stability problems due to excessive line lengths, and the like which are inherent to structures of the prior art. The device is therefore useful in numerous microwave applications including not only pennanent systems such as large radar arrays, but also in systems requiring disposal of, or nonrecovery of, radiating elements of the type of the subject invention.

, We claim as our invention:

1. An integrated microwave radiator comprising:

radiating means of planar configuration mounted on a single planar surface for radiating microwave oscillations,

semiconductor means for generating microwave oscillations, physically mounted on the surface of said radiating means and electrically connected thereto for driving said radiating means with microwave oscillations, and

an impedance transforming network including in part the electrical impedance values of said radiating mans and requisite additional impedance means mounted on and electrically connected thereto for conjugate matching of the susceptance and negative conductance of the semiconductor generating means to enable the generation of oscillations by said generating means.

2. An integrated microwave radiator as recited in claim 1 wherein there are further provided:

bias leads of planar configuration mounted on said single planar surface, extending orthogonally from said radiating means and connected thereto for supplying electrical energization to said semiconductor generating means for generating microwave oscillations.

3. An integrated microwave radiator as recited in claim 2 wherein said bias leads include reactance means associated therewith and positioned with respect to the driving point of said radiating means for isolating the microwave oscillations from said bias leads.

4. An integrated microwave radiator as recited in claim 1 wherein:

said semiconductor generating means comprises a two terminal negative resistance semiconductor element.

5. An integrated microwave radiator as recited in claim 4 wherein said element comprises an lMPA'IT diode.

6. An integrated microwave radiator has recited in claim 41 wherein said element comprises a bulk effect semiconductor diode.

7. An integrated microwave radiator as recited in claim 2 further comprising:

a planar substrate of dielectric material, one planar surface thereof defining said single planar surface,

said radiating means comprises a planar radiating element of conducting material formed on said substrate in a first orientation, and

said orthogonally mounted bias leads comprise planar conducting elements electrically connected to said radiating element and formed on said substrate in a second orientation perpendicular to said first orientation.

8. An integrated microwave radiator as recited in claim 7 wherein there is further provided means defining a reflecting plane for reflecting microwave radiations of said radiating element, and positioned parallel to and displaced from the plane of said radiating element and said bias leads for increasing the forward gain of said radiating means.

9. An integrated microwave radiator as recited in claim 8 wherein there is further provided an energization source for connection to said bias leads and mounted underlying said reflecting plane.

111. An integrated microwave radiator as recited in claim 9 wherein said energization source includes a metal casing, and said means defining said reflecting plane comprises said metal casing.

11. An integrated microwave radiator as recited in claim 7 wherein said requisite additional impedance means, includes the inherent capacitance of said generating means mounted on said radiating means.

12. An integrated microwave radiator as recited in claim 11 wherein said requisite additional impedance means further includes an inductance means comprising a slot formed in said planar radiating means.

13. An integrated microwave radiator as recited in claim 7 wherein:

said planar conducting element of said radiating means comprises a dipole antenna having first and second sections aligned in said first orientation on said substrate,

said bias leads comprise first and second conducting strips formed in parallel, adjacent relationship on said substrate in said second orientation and integrally connected to corresponding ones of said dipole sections at the adjacent ends thereof,

said generating means comprises a negative resistance semiconductor diode mounted on one of said dipole sections adjacent the driving point thereof, and

said diode is electrically connected at a first terminal thereof to said one dipole section by the mounting thereon, and is electrically connected at a second terminal thereof by a connecting conductor wire to the driving point of the other of said dipole elements.

141. An integrated microwave radiator as recited in claim 13 wherein said requisite additional impedance means of said impedance transforming network of said radiator comprises:

capacitance means including a capacitive element capacitively coupled to said first and second sections of said dipole antenna adjacent the driving points of each thereof, and

inductance means including the inductance of said connecting conductor wire. 15. An integrated microwave radiator as recited in claim 13 wherein:

said first and second bias conducting strips include a capacitive element integrally formed therewith and capacitively coupling said strips at a location thereon spaced onequarter wavelength at the microwave operating frequency of said radiator from the driving points of said dipole sections. 16. An integrated microwave radiator as recited in claim 15 wherein said bias conducting strips are respectively connected to opposite polarity terminals of an energizing source for energization of said diode.

17. An integrated microwave radiator as recited in claim 6 having a neutral plane in said second orientation, and wherein:

said radiating element comprises an elongated interior section and a closed loop exterior section spaced from and surrounding said interior element and coplanar therewith, and said interior and exterior sections are formed on said substrate in said first orientation and symmetrically positioned with respect to the neutral plane of said radiator,

said exterior element includes means for mounting said generating means thereon in symmetrically disposed rela tionship to said neutral plane,

said bias leads comprise a central conducting strip formed on said substrate and centrally aligned with said neutral plane and a pair of conducting strips formed on said substrate in parallel, spaced relationship with said central strip and symmetrically disposed about said neutral plane, and

said generating means comprises a negative resistance semiconductor diode electrically connected at a first terminal thereof to said exterior element by said mounting thereon and by said exterior element to said pair of conducting bias strips, and electrically connected at a second terminal thereof to said central bias strip by a first conductor wire and to said interior element by a second conductor wire.

18. An integrated microwave radiator as recited in claim 17 wherein said impedance-transforming network comprises:

capacitance means including the inherent capacitance of said diode mounted on said exterior element, and

inductance means including the inductance of said second conductor wire.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3249891 *Oct 29, 1964May 3, 1966IbmOscillator apparatus utilizing esaki diode
US3475759 *Oct 10, 1967Oct 28, 1969Winegard CoTelevision antenna with built-in cartridge preamplifier
US3509465 *Oct 22, 1965Apr 28, 1970Sylvania Electric ProdPrinted circuit spiral antenna having amplifier and bias feed circuits integrated therein
US3521169 *Jul 17, 1967Jul 21, 1970Turner Edwin MSubminiature integrated antenna
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3875513 *Jun 15, 1970Apr 1, 1975Westinghouse Electric CorpAntenna-coupled solid-state microwave generator systems capable of producing coherent output radiation
US4086535 *Jun 2, 1976Apr 25, 1978Meisei Electric Co. Ltd.Microwave oscillator
US4453269 *Sep 22, 1982Jun 5, 1984Chamberlain Manufacturing CorporationApparatus for improving the frequency stability of a transmitter oscillator circuit
US4843401 *Jan 26, 1988Jun 27, 1989Atlantic RichfieldMethod and apparatus for generating and radiating electromagnetic energy
US5850595 *Dec 1, 1994Dec 15, 1998Deutsche Thomson-Brandt GmbhArrangement for reducing interference in tuned circuits in integrated circuits
US6072991 *Sep 3, 1996Jun 6, 2000Raytheon CompanyCompact microwave terrestrial radio utilizing monolithic microwave integrated circuits
US7622999 *May 21, 2007Nov 24, 2009Canon Kabushiki KaishaElectromagnetic-wave oscillator
US7952441Oct 27, 2009May 31, 2011Canon Kabushiki KaishaElectromagnetic-wave oscillator
DE4341221A1 *Dec 3, 1993Jun 8, 1995Thomson Brandt GmbhAnordnung zur Verringerung von Störungen bei Schwingkreisen in integrierten Schaltungen
EP0015566A1 *Mar 7, 1980Sep 17, 1980Endress u. Hauser GmbH u.Co.Distance measuring instrument according to the pulse transit time method
Classifications
U.S. Classification257/664, 331/96, 331/107.00R, 455/91, 331/107.0SL, 455/129
International ClassificationH03B9/14
Cooperative ClassificationH03B2009/126, H03B9/147
European ClassificationH03B9/14F