CA2044044C - Radar apparatus with jamming indicator and receiver device with jamming indicator - Google Patents
Radar apparatus with jamming indicator and receiver device with jamming indicatorInfo
- Publication number
- CA2044044C CA2044044C CA002044044A CA2044044A CA2044044C CA 2044044 C CA2044044 C CA 2044044C CA 002044044 A CA002044044 A CA 002044044A CA 2044044 A CA2044044 A CA 2044044A CA 2044044 C CA2044044 C CA 2044044C
- Authority
- CA
- Canada
- Prior art keywords
- broadband
- pass filter
- low
- output
- coupled
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
- H04K3/00—Jamming of communication; Counter-measures
- H04K3/20—Countermeasures against jamming
- H04K3/22—Countermeasures against jamming including jamming detection and monitoring
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/36—Means for anti-jamming, e.g. ECCM, i.e. electronic counter-counter measures
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
- H04K3/00—Jamming of communication; Counter-measures
- H04K3/80—Jamming or countermeasure characterized by its function
- H04K3/82—Jamming or countermeasure characterized by its function related to preventing surveillance, interception or detection
- H04K3/825—Jamming or countermeasure characterized by its function related to preventing surveillance, interception or detection by jamming
Abstract
The invention relates to a radar apparatus having a wideband preselector filter (15), a wideband preamplifier (16), a narrowband IF filter (19) and a jamming indicator (11). In order to obtain a warning against a jammer being active within the large bandwidth of the preselector filter (15) but outside the narrowband IF filter (19), the jammer indicator (11) has the same bandwidth as the wideband preselector filter and is connected after the preamplifier (16), but before the narrowband IF filter (19). A warning is necessary as a jammer of this type may greatly reduce the sensitivity of the radar apparatus by saturating the preamplifier (16).
Description
2~4q~4 Radar apparatus with ~amming indicator and receiver device with iamming indicator The invention relates to a radar apparatus, provided with an antenna, a transmitting and receiving unit coupled to the antenna, whereby the receiving unit is provided with a broadband preamplifier stage, to which signals, received with the aid of the antenna are applied, and with a bandwidth-limiting element coupled to it, the radar apparatus being furthermore provided with a jamming indicator, coupled to an output of the receiving unit, which indicator is suitable for detecting at least a part of the interference signals, detected with the aid of the antenna and the receiving unit and which for this purpose generates an interference signal-representing indication signal.
The invention also relates to a receiver device provided with a similar jamming indicator.
Radar equipment, provided with jamming indicators, capable of dete Ining the direction and the strength of signals from jamming sources, are known from the technical literature, for instance "Introduction to Radar Systems" by M.I. Skolnik and are described in the chapter "Electronic Counter-Counter Measures". Said jamming indicators aim at detecting interference signals, containing frequency components, which are substantially equal to the frequency of the transmitting unit. These frequency components can penetrate the entire receiving unit. In this respect, a substantial class of interference signals is overlooked, in particular signals, whose frequencies lie within the bandwidth of the preamplifier stage of the receiving unit, but differ possibly intentionally from the frequency of the transmitting unit. These signals cannot penetrate the receiving unit and cannot be detected with state-of-the-art jamming indicators. Providing they are of sufficient strength, these signals can saturate the preamplifier stage of the receiving unit, thus rendering the radar apparatus lnsensitlve to lncomlng target echoes. It ls even possible that an obiect emltting lnterference slgnals of the above-mentloned type, can approach the radar wlthout being detected. The invention has for its ob~ect to provide a solution to this problem.
According to one aspect, the invention provides a radar apparatus, comprising: an antenna; a transmitting unit and a receiving unit each coupled to said antenna wherein said receiving unit includes a broadband preampllfier stage, to which signals, received with the aid of said antenna are applied, said broadband preamplifier stage providing a broadband output, said receiving unlt further includlng a bandwidth-limiting element receiving said broadband output;
and a jamming indicator, operatlng ln a bandwidth substantlally equal to the preamplifier stage bandwidth, coupled to said broadband preamplifier stage of said recelvlng unit whereln sald iammlng lndicator receives at an input, said broadband output of sald broadband preampllfler stage and whereln sald ~ammlng lndlcator generates an lnterference slgnal-representlng slgnal sultable for controlllng an lndlcatlon means for dlsplaying at least a part of any lnterference slgnals, sald ~ammlng lndlcator belng provlded wlth means for suppresslng radar echo slgnals so that the lndlcatlon slgnal substantlally excluslvely represents lnterference slgnals.
Accordlng to another aspect, the lnventlon provldes a recelver devlce partlcularly suitable for application in a radar apparatus wherein sald device is coupled to an antenna 204404~
and whereln said recelver devlce lncludes a recelvlng unit provlded wlth a broadband preampllfler stage and whereln sald broadband preampllfler stage recelves an lnput and provldes a broadband output slgnal, sald recelver devlce comprlslng: a bandwldth llmltlng element coupled to recelve sald output slgnal from sald broadband preampllfler stage; a ~ammlng lndlcator, operatlng ln a bandwldth substantlally equal to the preampllfler stage bandwldth, for detectlng lnterference slgnals and generatlng an lnterference slgnal-representlng lndlcatlon slgnal sultable for controlllng an lndlcatlon means for dlsplaylng, whereln sald ~ammlng lndlcator has an lnput for recelvlng sald output slgnal from sald broadband preampllfler stage and whereln sald lnput ls connected between sald broadband preampllfler stage and sald bandwldth-llmltlng element, sald ~ammlng lndlcator belng provided with means for suppresslng radar echo slgnals so that the lndlcatlon slgnal substantlally excluslvely represents lnterference slgnals.
The lnventlon wlll now be descrlbed ln more detall wlth reference to the followlng flgures of whlch:
Flg. 1 represents a radar apparatus wlth a ~ammlng lndlcator accordlng to the lnventlon;
Flg. 2 represents an embodlment of the recelvlng unlt of flg. l; and Flg. 3 represents an embodlment of the iammlng lndlcator of flg. 1.
Flg. 1 represents a radar apparatus 1. The radar apparatus 1 ls provlded wlth an antenna 2 which ls connected with a transmlttlng unit 4 by way of a duplexer 3. The radar - 2a -A
-- 204404~
apparatus 1 may relate to both a tracklng radar and a search radar. The transmittlng unlt 4 ls sultable for the transmlsslon of radar pulses havlng a frequency fO. The echo slgnals reflected by targets are recelved wlth the ald of antenna 2 and are applled to the recelvlng unlt 5 vla duplexer 3. The radar echo slgnals are ampllfled ln the recelvlng unlt 5 and are converted to an lntermedlate frequency fm. Vla output 6, the recelvlng unlt 5 controls a vldeo generator 7 for presentlng the recelved target echo slgnals on a vldeo display 8. Both range and azlmuthal dlrectlon of the target can be presented for dlsplay on the basls of establlshed technlques.
The lnventlon ls however by no means conflned to such a type of radar and ls also applled to other types of radar such as 3-D radar systems. In the present case, the azlmuthal dlrectlon of the target - 2b -Q 4 '1 is derived from the momentaneous position of the antenna, which is fed to the video generator 7 via line 9.
According to the invention, the receiving unit 5 is also provided with a second output 10 through which interference signals, received by means of the receiving unit 5, are fed to a ~amming indicator ll.
The receiving unit 5 will now be described in more detail. As will be explained below, the jamming indicator 11 is provided with means for detecting interference signals. By interference signals is meant signals emitted, (usually as a result of deliberate ~amming), which may severely degrade the performance of a radar apparatus.
The interference signals detected by the ~amming indicator 11 are applied to a video generator 12, which adapts the interference signals for presentation on a video display 13. The video display 13 is also suitable for displaying both the strength and direction of the interference signal. As stated above, the direction ensues from the momentaneous direction of the antenna 2, which is supplied to the video generator 12 via line 9.
Fig. 2 represents a possible embodiment of the receiving unit 5, which is based on the superheterodyne principle. The input 14 is provided with a preselector filter 15 which only admits signals which lie within the operating frequency band of the receiver. The operating frequency band is usually limited only by international agreements concerning the use of radio and radar frequencies.
In most cases the receiving unit 5 is provided with a preamplifier 16 which may increase the input sensitivity of the receiving unit 5.
In a mixer stage 17, the filtered and amplified input signal is mixed with an oscillator signal fx (18). The difference frequency fm ~ Ifo ~ fxl thus obtained is applied to an intermediate frequency filter l9, producing the intermediate frequency signal fm at the output 6.
2044~4 On the basis of established techniques, input 20 of the jamming indicator can be connected to output 6 of the receiving unit 5. In fig. 1 and 2 this existing connection is marked by a dotted line 21.
The signal bandwidth of output 6 is so small that only received signals of frequencies, which are substantially equal to the transmit freqency f0 of the radar apparatus 1, can be detected. This is directly related to the operation of the intermediate frequency filter 19.
According to the invention, the input 20 of the Jamming indicator 11 is connected to output 10 of the superheterodyne receiving unit 5, as presented in fig. 1 and 2. This causes the dotted connection 21 to be dropped. The signal bandwidth of output 10 is far larger than the signal bandwidth of output 6. All signals which can pass the broadband preamplifier stage, comprising the preselector filter 15 and preamplifier 16, referred to in fig. 2, are here available for processing in the jamming indicator 11. Due to the fact that the jamming indicator 11, according to the invention, is provided with signals operating in a larger bandwidth than the signals of output 6, a far wider range of interference signals can be detected and presented for display than is the case with state-of-the-art radars.
Fig. 3 illustrates an embodiment of the jamming indicator 11. The signals originating from output 10 are rectified by rectifier circuit 22 and pass through a low-pass filter 23. The rectifier circuit 22 shall preferably have a bandwidth, which at least includes the bandwidth of the preamplifier stage. In this way all received interfering signals can be detected. The rectified and filtered signals are subsequently compared in threshold circuit 24 with an adjustable threshold voltage. To this end, the threshold circuit 24 is provided with an adjustable threshold voltage generator 25 and a comparator 26, to which the above-mentioned voltages are supplied. If the threshold voltage is exceeded, the rectified and filtered voltage will as a so-called indication signal 2~0~4 be applied to the video generator 12 via switching means 27. The video generator 12 controls the video display 13, which is generally suitable for displaying the strength and the direction of the ~amming source. Low-pass filter 23 and threshold circuit 24 prevent rectified, pulse-shaped radar echo signals from reaching the indication means, in the present case the video generator 12 and video display 13.
The receiving unit 5 and jamming indicator 11 can, according to the invention, also be designed as a single receiving unit 28, as indicated by a dotted line in fig. 1, dotted line 21 having been dropped.
The invention also relates to a receiver device provided with a similar jamming indicator.
Radar equipment, provided with jamming indicators, capable of dete Ining the direction and the strength of signals from jamming sources, are known from the technical literature, for instance "Introduction to Radar Systems" by M.I. Skolnik and are described in the chapter "Electronic Counter-Counter Measures". Said jamming indicators aim at detecting interference signals, containing frequency components, which are substantially equal to the frequency of the transmitting unit. These frequency components can penetrate the entire receiving unit. In this respect, a substantial class of interference signals is overlooked, in particular signals, whose frequencies lie within the bandwidth of the preamplifier stage of the receiving unit, but differ possibly intentionally from the frequency of the transmitting unit. These signals cannot penetrate the receiving unit and cannot be detected with state-of-the-art jamming indicators. Providing they are of sufficient strength, these signals can saturate the preamplifier stage of the receiving unit, thus rendering the radar apparatus lnsensitlve to lncomlng target echoes. It ls even possible that an obiect emltting lnterference slgnals of the above-mentloned type, can approach the radar wlthout being detected. The invention has for its ob~ect to provide a solution to this problem.
According to one aspect, the invention provides a radar apparatus, comprising: an antenna; a transmitting unit and a receiving unit each coupled to said antenna wherein said receiving unit includes a broadband preampllfier stage, to which signals, received with the aid of said antenna are applied, said broadband preamplifier stage providing a broadband output, said receiving unlt further includlng a bandwidth-limiting element receiving said broadband output;
and a jamming indicator, operatlng ln a bandwidth substantlally equal to the preamplifier stage bandwidth, coupled to said broadband preamplifier stage of said recelvlng unit whereln sald iammlng lndicator receives at an input, said broadband output of sald broadband preampllfler stage and whereln sald ~ammlng lndlcator generates an lnterference slgnal-representlng slgnal sultable for controlllng an lndlcatlon means for dlsplaying at least a part of any lnterference slgnals, sald ~ammlng lndlcator belng provlded wlth means for suppresslng radar echo slgnals so that the lndlcatlon slgnal substantlally excluslvely represents lnterference slgnals.
Accordlng to another aspect, the lnventlon provldes a recelver devlce partlcularly suitable for application in a radar apparatus wherein sald device is coupled to an antenna 204404~
and whereln said recelver devlce lncludes a recelvlng unit provlded wlth a broadband preampllfler stage and whereln sald broadband preampllfler stage recelves an lnput and provldes a broadband output slgnal, sald recelver devlce comprlslng: a bandwldth llmltlng element coupled to recelve sald output slgnal from sald broadband preampllfler stage; a ~ammlng lndlcator, operatlng ln a bandwldth substantlally equal to the preampllfler stage bandwldth, for detectlng lnterference slgnals and generatlng an lnterference slgnal-representlng lndlcatlon slgnal sultable for controlllng an lndlcatlon means for dlsplaylng, whereln sald ~ammlng lndlcator has an lnput for recelvlng sald output slgnal from sald broadband preampllfler stage and whereln sald lnput ls connected between sald broadband preampllfler stage and sald bandwldth-llmltlng element, sald ~ammlng lndlcator belng provided with means for suppresslng radar echo slgnals so that the lndlcatlon slgnal substantlally excluslvely represents lnterference slgnals.
The lnventlon wlll now be descrlbed ln more detall wlth reference to the followlng flgures of whlch:
Flg. 1 represents a radar apparatus wlth a ~ammlng lndlcator accordlng to the lnventlon;
Flg. 2 represents an embodlment of the recelvlng unlt of flg. l; and Flg. 3 represents an embodlment of the iammlng lndlcator of flg. 1.
Flg. 1 represents a radar apparatus 1. The radar apparatus 1 ls provlded wlth an antenna 2 which ls connected with a transmlttlng unit 4 by way of a duplexer 3. The radar - 2a -A
-- 204404~
apparatus 1 may relate to both a tracklng radar and a search radar. The transmittlng unlt 4 ls sultable for the transmlsslon of radar pulses havlng a frequency fO. The echo slgnals reflected by targets are recelved wlth the ald of antenna 2 and are applled to the recelvlng unlt 5 vla duplexer 3. The radar echo slgnals are ampllfled ln the recelvlng unlt 5 and are converted to an lntermedlate frequency fm. Vla output 6, the recelvlng unlt 5 controls a vldeo generator 7 for presentlng the recelved target echo slgnals on a vldeo display 8. Both range and azlmuthal dlrectlon of the target can be presented for dlsplay on the basls of establlshed technlques.
The lnventlon ls however by no means conflned to such a type of radar and ls also applled to other types of radar such as 3-D radar systems. In the present case, the azlmuthal dlrectlon of the target - 2b -Q 4 '1 is derived from the momentaneous position of the antenna, which is fed to the video generator 7 via line 9.
According to the invention, the receiving unit 5 is also provided with a second output 10 through which interference signals, received by means of the receiving unit 5, are fed to a ~amming indicator ll.
The receiving unit 5 will now be described in more detail. As will be explained below, the jamming indicator 11 is provided with means for detecting interference signals. By interference signals is meant signals emitted, (usually as a result of deliberate ~amming), which may severely degrade the performance of a radar apparatus.
The interference signals detected by the ~amming indicator 11 are applied to a video generator 12, which adapts the interference signals for presentation on a video display 13. The video display 13 is also suitable for displaying both the strength and direction of the interference signal. As stated above, the direction ensues from the momentaneous direction of the antenna 2, which is supplied to the video generator 12 via line 9.
Fig. 2 represents a possible embodiment of the receiving unit 5, which is based on the superheterodyne principle. The input 14 is provided with a preselector filter 15 which only admits signals which lie within the operating frequency band of the receiver. The operating frequency band is usually limited only by international agreements concerning the use of radio and radar frequencies.
In most cases the receiving unit 5 is provided with a preamplifier 16 which may increase the input sensitivity of the receiving unit 5.
In a mixer stage 17, the filtered and amplified input signal is mixed with an oscillator signal fx (18). The difference frequency fm ~ Ifo ~ fxl thus obtained is applied to an intermediate frequency filter l9, producing the intermediate frequency signal fm at the output 6.
2044~4 On the basis of established techniques, input 20 of the jamming indicator can be connected to output 6 of the receiving unit 5. In fig. 1 and 2 this existing connection is marked by a dotted line 21.
The signal bandwidth of output 6 is so small that only received signals of frequencies, which are substantially equal to the transmit freqency f0 of the radar apparatus 1, can be detected. This is directly related to the operation of the intermediate frequency filter 19.
According to the invention, the input 20 of the Jamming indicator 11 is connected to output 10 of the superheterodyne receiving unit 5, as presented in fig. 1 and 2. This causes the dotted connection 21 to be dropped. The signal bandwidth of output 10 is far larger than the signal bandwidth of output 6. All signals which can pass the broadband preamplifier stage, comprising the preselector filter 15 and preamplifier 16, referred to in fig. 2, are here available for processing in the jamming indicator 11. Due to the fact that the jamming indicator 11, according to the invention, is provided with signals operating in a larger bandwidth than the signals of output 6, a far wider range of interference signals can be detected and presented for display than is the case with state-of-the-art radars.
Fig. 3 illustrates an embodiment of the jamming indicator 11. The signals originating from output 10 are rectified by rectifier circuit 22 and pass through a low-pass filter 23. The rectifier circuit 22 shall preferably have a bandwidth, which at least includes the bandwidth of the preamplifier stage. In this way all received interfering signals can be detected. The rectified and filtered signals are subsequently compared in threshold circuit 24 with an adjustable threshold voltage. To this end, the threshold circuit 24 is provided with an adjustable threshold voltage generator 25 and a comparator 26, to which the above-mentioned voltages are supplied. If the threshold voltage is exceeded, the rectified and filtered voltage will as a so-called indication signal 2~0~4 be applied to the video generator 12 via switching means 27. The video generator 12 controls the video display 13, which is generally suitable for displaying the strength and the direction of the ~amming source. Low-pass filter 23 and threshold circuit 24 prevent rectified, pulse-shaped radar echo signals from reaching the indication means, in the present case the video generator 12 and video display 13.
The receiving unit 5 and jamming indicator 11 can, according to the invention, also be designed as a single receiving unit 28, as indicated by a dotted line in fig. 1, dotted line 21 having been dropped.
Claims (6)
1. A radar apparatus, comprising an antenna; a transmitting unit and a receiving unit each coupled to said antenna wherein said receiving unit includes a broadband preamplifier stage, to which signals, received with the aid of said antenna are applied, said broadband preamplifier stage providing a broadband output, said receiving unit further including a bandwidth-limiting element receiving said broadband output; and a jamming indicator, operating in a bandwidth substantially equal to the preamplifier stage bandwidth, coupled to said broadband preamplifier stage of said receiving unit wherein said jamming indicator receives at an input, said broadband output of said broadband preamplifier stage and wherein said jamming indicator generates an interference signal-representing signal suitable for controlling an indication means for displaying at least a part of any interference signals, said jamming indicator being provided with means for suppressing radar echo signals so that the indication signal substantially exclusively represents interference signals.
2. Radar apparatus as claimed in claim 1, wherein said means for suppressing comprises a rectifier circuit coupled to the receiving unit, a low-pass filter coupled to the output of the rectifier circuit and, coupled to the output of the low-pass filter, an adjustable threshold circuit which generates the indication signal.
3. Radar apparatus as claimed in claim 2, wherein said threshold circuit is provided with a threshold voltage generator, which generates an adjustable threshold voltage, and with a comparator to which the threshold voltage and the output signal of the low-pass filter are applied and a switching means controlled by the comparator to which the same output signal of the low-pass filter is applied, the switching means being in a pass condition when the output signal of the low-pass filter exceeds or equals the threshold voltage and in a block condition when the output signal of the low-pass filter is smaller than the threshold voltage.
4. A receiver device particularly suitable for application in a radar apparatus wherein said device is coupled to an antenna and wherein said receiver device includes a receiving unit provided with a broadband preamplifier stage and wherein said broadband preamplifier stage receives an input and provides a broadband output signal, said receiver device comprising: a bandwidth limiting element coupled to receive said output signal from said broadband preamplifier stage; a jamming indicator, operating in a bandwidth substantially equal to the preamplifier stage bandwidth, for detecting interference signals and generating an interference signal-representing indication signal suitable for controlling an indication means for displaying, wherein said jamming indicator has an input for receiving said output signal from said broadband preamplifier stage and wherein said input is connected between said broadband preamplifier stage and said bandwidth-limiting element, said jamming indicator being provided with means for suppressing radar echo signals so that the indication signal substantially exclusively represents interference signals.
5. A receiver device as claimed in claim 4, wherein said means for suppressing comprises a rectifier circuit coupled to the receiving unit, a low-pass filter coupled to the output of the rectifier circuit and, coupled to the output of the low-pass filter, an adjustable threshold circuit which generates the indication signal.
6. A receiver device as claimed in claim 5, wherein the threshold circuit is provided with a threshold voltage generator which generates an adjustable threshold voltage, a comparator to which the threshold voltage and the output signal of the low-pass filter are applied and a switching means controlled by the comparator, to which the same output signal of the low-pass filter is applied, the switching means being in a pass condition when the output signal of the low-pass filter exceeds or equals the threshold voltage and in a block condition when the output signal of the low-pass filter is smaller than the threshold voltage.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL9001414A NL9001414A (en) | 1990-06-21 | 1990-06-21 | RADAR DEVICE WITH FAULT INDICATOR AND RECEIVER WITH FAULT INDICATOR. |
| NL9001414 | 1990-06-21 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2044044A1 CA2044044A1 (en) | 1991-12-22 |
| CA2044044C true CA2044044C (en) | 1998-04-28 |
Family
ID=19857288
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002044044A Expired - Fee Related CA2044044C (en) | 1990-06-21 | 1991-06-06 | Radar apparatus with jamming indicator and receiver device with jamming indicator |
Country Status (10)
| Country | Link |
|---|---|
| US (1) | US5173701A (en) |
| EP (1) | EP0462641B1 (en) |
| JP (1) | JPH04232487A (en) |
| AU (1) | AU638135B2 (en) |
| CA (1) | CA2044044C (en) |
| DE (1) | DE69118247T2 (en) |
| ES (1) | ES2085954T3 (en) |
| GR (1) | GR3019878T3 (en) |
| NL (1) | NL9001414A (en) |
| TR (1) | TR26048A (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5457460A (en) * | 1992-11-17 | 1995-10-10 | Honeywell Inc. | Embedded threat data recorder |
| US5715045A (en) * | 1996-05-15 | 1998-02-03 | Laser Technology, Inc. | Countermeasure detecting circuit, and associated method, for a laser speed detecting apparatus |
| DE19631590C2 (en) * | 1996-08-05 | 1999-09-23 | Bosch Gmbh Robert | Method for the treatment of interference signals in a motor vehicle radar system and motor vehicle radar system therefor |
| US5950110A (en) * | 1997-08-06 | 1999-09-07 | Interactive Techanologies, Inc. | Jamming detection in a wireless security system |
| US9275690B2 (en) | 2012-05-30 | 2016-03-01 | Tahoe Rf Semiconductor, Inc. | Power management in an electronic system through reducing energy usage of a battery and/or controlling an output power of an amplifier thereof |
| US9509351B2 (en) | 2012-07-27 | 2016-11-29 | Tahoe Rf Semiconductor, Inc. | Simultaneous accommodation of a low power signal and an interfering signal in a radio frequency (RF) receiver |
| US9666942B2 (en) | 2013-03-15 | 2017-05-30 | Gigpeak, Inc. | Adaptive transmit array for beam-steering |
| US9531070B2 (en) | 2013-03-15 | 2016-12-27 | Christopher T. Schiller | Extending beamforming capability of a coupled voltage controlled oscillator (VCO) array during local oscillator (LO) signal generation through accommodating differential coupling between VCOs thereof |
| US9716315B2 (en) | 2013-03-15 | 2017-07-25 | Gigpeak, Inc. | Automatic high-resolution adaptive beam-steering |
| US9722310B2 (en) | 2013-03-15 | 2017-08-01 | Gigpeak, Inc. | Extending beamforming capability of a coupled voltage controlled oscillator (VCO) array during local oscillator (LO) signal generation through frequency multiplication |
| US9780449B2 (en) | 2013-03-15 | 2017-10-03 | Integrated Device Technology, Inc. | Phase shift based improved reference input frequency signal injection into a coupled voltage controlled oscillator (VCO) array during local oscillator (LO) signal generation to reduce a phase-steering requirement during beamforming |
| US9837714B2 (en) | 2013-03-15 | 2017-12-05 | Integrated Device Technology, Inc. | Extending beamforming capability of a coupled voltage controlled oscillator (VCO) array during local oscillator (LO) signal generation through a circular configuration thereof |
| US9184498B2 (en) | 2013-03-15 | 2015-11-10 | Gigoptix, Inc. | Extending beamforming capability of a coupled voltage controlled oscillator (VCO) array during local oscillator (LO) signal generation through fine control of a tunable frequency of a tank circuit of a VCO thereof |
| CN109861703B (en) * | 2017-11-30 | 2020-09-18 | 华为技术有限公司 | Wireless device and wireless local area network signal receiving method |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2910691A (en) * | 1954-11-05 | 1959-10-27 | Gen Precision Lab Inc | Radar anti-jamming device |
| US3838423A (en) * | 1958-10-15 | 1974-09-24 | Sperry Rand Corp | Anti-jamming circuit for angle tracking radars |
| US3427617A (en) * | 1959-04-21 | 1969-02-11 | Hazeltine Research Inc | Signal transmitting and receiving system |
| US3680106A (en) * | 1963-05-07 | 1972-07-25 | Us Navy | Method for displaying the range detection capability of a search radar in a noisy environment |
| US3870997A (en) * | 1965-02-03 | 1975-03-11 | Us Navy | Automatic gain integrator control |
| US3495244A (en) * | 1968-10-07 | 1970-02-10 | Hazeltine Research Inc | Interference discriminating apparatus |
| US4063239A (en) * | 1976-09-07 | 1977-12-13 | Johnson Robert H | Range or doppler gate deception rejection system |
-
1990
- 1990-06-21 NL NL9001414A patent/NL9001414A/en not_active Application Discontinuation
-
1991
- 1991-06-04 ES ES91201326T patent/ES2085954T3/en not_active Expired - Lifetime
- 1991-06-04 EP EP91201326A patent/EP0462641B1/en not_active Expired - Lifetime
- 1991-06-04 DE DE69118247T patent/DE69118247T2/en not_active Expired - Fee Related
- 1991-06-06 CA CA002044044A patent/CA2044044C/en not_active Expired - Fee Related
- 1991-06-11 US US07/713,279 patent/US5173701A/en not_active Expired - Fee Related
- 1991-06-17 AU AU78412/91A patent/AU638135B2/en not_active Ceased
- 1991-06-18 TR TR91/0693A patent/TR26048A/en unknown
- 1991-06-18 JP JP3171978A patent/JPH04232487A/en active Pending
-
1996
- 1996-05-10 GR GR960401257T patent/GR3019878T3/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| TR26048A (en) | 1993-11-01 |
| AU7841291A (en) | 1992-01-02 |
| DE69118247T2 (en) | 1996-10-24 |
| ES2085954T3 (en) | 1996-06-16 |
| JPH04232487A (en) | 1992-08-20 |
| EP0462641B1 (en) | 1996-03-27 |
| AU638135B2 (en) | 1993-06-17 |
| EP0462641A1 (en) | 1991-12-27 |
| CA2044044A1 (en) | 1991-12-22 |
| NL9001414A (en) | 1992-01-16 |
| GR3019878T3 (en) | 1996-08-31 |
| US5173701A (en) | 1992-12-22 |
| DE69118247D1 (en) | 1996-05-02 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |