Abstract: There is provided an image rejection mixer for downconversion of an incoming signal to a lower intermediate frequency signal, using the absolute difference of frequencies between the incoming signal and the local oscillator signal. The image rejection mixer is set up to accept and downconvert incoming signals at two discrete frequencies f.sub.h and f.sub.l, where the local oscillator frequency is positioned mid-way between those frequencies f.sub.h and f.sub.l. There are two signal paths in the image rejection mixer, either one or the other of which is chosen by positioning a controllable single pole, double throw switch into one of its two switch positions. The output of the switch is led to a mixing element, from which an intermediate frequency signal is derived.

Abstract: A system that provides information to authorized users regarding the location of speed traps via a wireless communication network connected to a computer wide area network. The system includes the use of a detector for speed detecting equipment, such as a radar detector, which detects the presence of speed detecting equipment and transmits the detection information into an electronic device in the motor vehicle. The electronic device communicates is coupled to a physical location device, such as a GPS receiver, which provides the specific location and direction of the motor vehicle when detection occurs. The electronic device is also coupled to a wireless modem that connects to a wireless communication network and to the wide area network. Connected to the wide area network is a central server that receives uploaded information from a plurality of other motor vehicle operators to create a large information database.

Abstract: An electromagnetic signal detector with a means for detecting a first electromagnetic signal within a plurality of bands of frequencies, generating an alarm signal in response, and reinitiating an alarm signal for a second subsequent signal in one of said band of frequencies different from said first electromagnetic signal detection, is provided. The alarm signal response can be muted. The audible alarm signal reinitiates at any point in an alarm signal generation, even during muting, if a second subsequent electromagnetic signal of a different frequency band is detected.

Abstract: The present invention provides a broad band, multi-band radar detector which may be configured so as to have two or three down conversion stages. There are three mixers in the circuit, the second of which has a frequency synthesized local oscillator which is governed by a phase lock loop feedback circuit under the control of a microprocessor, so that the output frequency of the second local oscillator may be varied by an amount equal to .+-.f.sub.adj. The first local oscillator is also under the control of the microprocessor, so that a specific intermediate frequency signal from the first mixer may be derived. By varying the frequency of the second frequency synthesized local oscillator, the tuning range of the radar detector may be increased in each frequency band of interest by an amount equal to .+-.f.sub.adj for all frequency values in each respective frequency band of interest.

Abstract: A spectrum analyzer measures a time difference between two or more signals with different carrier frequencies or a time delay between two or more signals with the same carrier frequency. The spectrum analyzer includes at least two measurement channels, each of the measurement channels has a frequency mixer, a local oscillator and an IF (intermediate frequency) filter for mixing an input signal to be measured with a local signal of the local oscillator to produce an IF signal which passes through the IF filter, and a demodulator provided in one of the measurement channels to demodulate the IF signal produced from the input signal to generate a trigger signal to start an operation of the other measurement channel.

Abstract: Method and apparatus for the detection of a target receiver unit such as an enemy radar or radio receiver is disclosed. The surveillance system of this invention includes a transmitter unit coupled to an antenna to establish an electromagnetic surveillance field that includes signal components at two predetermined surveillance frequencies. When a target receiver is located within the surveillance field, the target receiver produces a second electromagnetic field having signal components at the intermodulation products of the surveillance field signal components due to a nonlinear mixing process that occurs within the target receiver. Signal components at predetermined intermodulation frequencies are detected by a receiver circuit within the surveillance system that has a passband excluding signal components at the two predetermined surveillance frequencies.

Abstract: A method and system is provided for real-time detection of important multiple pulsed or CW signals of varying amplitude and frequency, from a group of simultaneously intercepted wideband intermediate frequency (IF) channels. The method is implemented in a channelized receiver system with a parameter encoder which filters the IF signals in a time-shared mode by dividing the IF channel bandwidth into progressively decreasing sub-band levels, multiplexing the IF signals from each sub-band and analyzing the time multiplexed IF signals to obtain the IF signal parameters. The system is flexible with programmable parameters and has the ability to eliminate most of the spurious signals with high probability of interception of the real signals. Conventional pulse descriptor words, band limited pre-detection samples and time-frequency pulse images are output for subsequent analysis or tactical application.

Abstract: Apparatus for detecting the presence of a speed detection system includes a microcontroller, a laser detector circuit coupled to the microcontroller, a radar detector circuit coupled to the microcontroller and a display coupled to the microcontroller, wherein the microcontroller receives signals from the laser detector and radar detector circuits and in response to the signals fed thereto, the microcontroller provides an output signal indicating which of the laser and radar detector circuits fed a signal thereto.

Abstract: An open-space battery housing portion 9a is integrally formed in a portion of a connecting mechanism 11 of a device main body 1 to house a secondary battery 6 between a main circuit substrate 3 and a connecting plate 22 when the connecting plate 22 is coupled with the connecting mechanism 11, in which the connecting plate 22 also serves as a cover member for the battery housing portion 9a, whereby the secondary battery 6 can be removed from the battery housing portion 9a when the connecting plate 22 is uncoupled from the connecting mechanism 11.

Abstract: A frequency scheme for a police radar detector enables the K band and the K.sub.a band to be scanned during a single sweep of a local oscillator which drives a mixer at its fundamental operating mode to produce intermediate frequency signals around 5 Ghz. The frequency scheme simultaneously activates two or four frequency conversion paths in the police radar detector. Accordingly, a radar warning alarm can be given upon detection of radar signals in any one of the frequency conversion paths. The ambiguity as to which one of the two or four frequency conversion paths is receiving a detected radar signal is resolved by applying first and second modulation signals to first and second local oscillators, respectively, so that the radar band of the detected radar signal can also be included within the radar warning alarm. The first and second modulation signals are in quadrature to one another and quadrature correlation is used to determine which frequency conversion path is receiving a radar signal.

Abstract: An input stage for a police radar detector includes a single mixer together with at least one preamplifier to detect radar signals in the X, K and K.sub.a bands. A preamplifier may be used on the X band alone, the K band alone, the K.sub.a band alone, the X and K bands or the X, K and K.sub.a bands. The use of these preamplifiers provides better noise figure; however, multiple responses cannot be scanned at the same time in bands utilizing a preamplifier with sufficient selectivity to reduce noise in its respective image bands to tolerable levels so that some or all of the receiver responses are swept independently with the preamplifier or preamplifiers being enabled one at a time as appropriate for each band being scanned. Since more sweep time is required when multiple responses are no longer swept simultaneously, a currently preferred form of the input stage couples the K.sub.a band signals to a single mixer through a preamplifier which permits multiple responses to be swept in the K.sub.

Abstract: An input stage of a police radar detector is configured so that a near end of a mixer is coupled to an antenna for receiving high frequency signals and a far end of the mixer is coupled to the antenna for receiving low frequency signals. A local oscillator and an intermediate frequency amplifier are also coupled to the far end of the mixer. The low frequency signals, X band police radar signals, are coupled to the far end of the mixer through a band rejection filter, which serves as a diplexer, a preamplifier and a first bandpass filter. The local oscillator is coupled to the far end of the mixer through a second bandpass filter and the far end of the mixer is coupled to the intermediate frequency amplifier through a low pass filter. The high frequency signals, K band and K.sub.a band signals, are coupled to the near end of the mixer from the antenna through a high pass filter.

Abstract: A radar detector suppresses nuisance alerts due to detection of a third harmonic of a common LO signal of other radar detectors by detecting a second harmonic of the offending LO signal. If a detected radar signal in the K.sub.a band is of a frequency within a suspect range corresponding to possible third harmonic spurious LO signals, a determination is made as to whether a potential alert blocking signal around the second harmonic of a nominal 11.55 Ghz signal is also present. In the illustrated embodiment, the second harmonic alert blocking signal which is checked has a frequency which is 2/3 the frequency of the detected K.sub.a signal .+-. a guard band of, for example .+-.40 Mhz, and is within a range of frequencies from about 22.813 Ghz to about 23.8 Ghz. If no blocking signal has been detected within about 10 seconds before or within three sweeps after detection of the K.sub.a band signal in the suspect range, the detected K.sub.a band signal is reported.

Abstract: Disclosed is a radar detector for frequency sweeping a wide band range by using a VCO circuit to detect a radar signal, wherein the frequency precision of the received band can be improved by using comparatively simple and inexpensive circuits.

Abstract: The disclosed device enables the user to verify the speed of their vehicle responsive to sensing that a speed measuring device has been used to measure their speed. The device includes a speed measuring device detector designed to sense operation of a speed measuring device. When the detector senses such operation, it activates a speed measuring device mounted on the vehicle which instantaneously measures the vehicle speed and then stores the measured speed for later display and for printing a permanent record, if desired.

Abstract: A noiseless radar detector with a dielectric resonator to suppress stray electromagnetic radiation generated by a local oscillator within the radar detector is disclosed. The dielectric resonator acts as an RF microwave absorber/attenuator if the resonant frequency of the dielectric resonator corresponds to the frequency of the interference from the local oscillator.

Abstract: A radar/laser speed detection countermeasure device for use on a motorcycle is disclosed which detects and annunciates radar and/or laser based speed detection devices in use in the immediate physical area for the purposes of speed limit law enforcement. The device consists of a main detector body mounted in an interior cavity of a motorcycle, which is electrically connected to a remote mounted sensing head unit and a remote mounted indication and control panel. Hidden components and interconnecting wiring reduce the chance of theft and preserve the appearance of customized motorcycles.

Abstract: A radar detector apparatus, or a laser detector apparatus, or a combination radar/laser detector apparatus, has a solar power panel and a rechargeable battery. Additionally, circuitry is provided to minimize current drain by shutting off power to the radar or laser detector when operation of the vehicle has stopped for a predetermined period of time. A circuit arrangement is also provided in the form of detector circuitry and control circuitry, for automatically actuating the radar or laser detector when the vehicle is in motion, to ensure operation thereof without the necessity of intervention by a vehicle operator.

Abstract: A speed detection signal sensor system for use with a vehicle. The system includes a signal sensing device positioned in a housing assembly. The housing assembly includes a reflective portion such as a mirror. The sensing device is positioned between the reflective portion and the housing. A sensor is positioned relative to the housing assembly and the reflective portion for sensing a speed detection signal which is directed towards the vehicle either from a forward position or a rearward position relative to the vehicle. A signal sensing indicator may be positioned relative to the housing assembly and generally in the reflective portion. Alternatively, the signal sensing indicator may be positioned externally of the housing assembly for attachment in a convenient location. The signal sensing indicator provides indicia that a speed detecting signal has been sensed by the detecting device.

Abstract: A radar detector includes a graphical display for displaying a spectral representation of detected signals.

Abstract: Apparatus for detecting the presence of a speed detection system includes a microcontroller, a laser detector circuit coupled to the microcontroller, a radar detector circuit coupled to the microcontroller and a display coupled to the microcontroller, wherein the microcontroller receives signals from the laser detector and radar detector circuits and in response to the signals fed thereto, the microcontroller provides an output signal indicating which of the laser and radar detector circuits fed a signal thereto.

Abstract: In a channelized receiver there is dual pulse present detection in which an RF signal is converted to a digital word and there are dual digital thresholds, each digital threshold having a programmable standard for determining when a pulse is present after said pulse has exceeded the particular threshold value and for determining which pulse will be reported based on which pulse arrived first. The invention also involves arbitration between adjacent channels in a channelized receiver to determine which signals are real and which signals represent spill-over energy from signals in adjacent channels and also including arbitration between spatial sectors to determine which signals are real and which signal represents spill-over energy from adjacent sectors.

Abstract: A helmet and radar detector integration system comprising a radar laser detector. A structure is for mounting the radar laser detector onto a motorcycle. An impact resistant helmet is worn by a person operating the motorcycle. A component in the helmet is for supporting a light cluster array. The light cluster array when illuminated, can be reflected in the helmet into the eyes of the person. A facility is for electrically coupling the radar laser detector to the light cluster array supporting component. When the radar laser detector illuminates the light cluster array, the person can safely look out through the helmet without anything obstructing vision. The person seeing the reflected light cluster array can still look out through the helmet.

Abstract: The disclosed device enables the user to verify the speed of their vehicle responsive to sensing that a radar device has been used to measure their speed. The device includes a radar detector designed to sense a radar beam. When the detector senses the beam, it activates a speed measuring device mounted on the vehicle which instantaneously measures the vehicle speed and then stores the measured speed for later display and for printing a permanent record, if desired.

Abstract: A wideband microwave detector includes: a first local oscillator outputting a first local oscillation output containing a basic wave component, a secondary high harmonic component and a tertiary high harmonic component and being swept within a predetermined frequency range; a first mixer performing frequency mixing of the first local oscillation output and an antenna input input through an antenna and outputting a first mixing output; a second local oscillator outputting a second local oscillation output; a second mixer performing frequency mixing of the first mixing output and the second local oscillation output for generating a second mixing output, a single frequency discriminator for detecting a specific frequency in a discrimination input, and mode selector switch alternately switching a single super heterodyne reception mode, in which the first mixing output of the first mixer is introduced into the frequency discriminator as the discrimination input and a double super heterodyne reception mode, in whic

Abstract: A mixer is provided having a mixing element, an input signal port for incoming signals at a frequency f.sub.IN, a local oscillator signal port for signals from a local oscillator having a fundamental frequency f.sub.LO, and an output port from which the resultant frequency may be taken. Means are provided to impose a DC component of bias voltage across the mixing element at one of three levels. The mixer is such that it has a pair of conduction threshold voltages which are substantially symmetrical above and below zero volts, beyond which the mixing element will be conductive at least when a signal from the local oscillator is imposed on it. The signal from the local oscillator has substantially sinusoidal voltage waveform, with a peak-to-peak voltage which is greater than the voltage difference between the pair of conduction threshold voltages.

Abstract: A compressive receiver of the type having a dispersive delay line is provided by an additional mixer which is responsive to the compressive receiver's local. oscillator and to an additional RF input. The output of the additional mixer is delayed and applied to the input of the dispersive delay line. The output of the dispersive delay line is divided, one of the divided outputs being delayed. The delayed output and the other dividend output are compared in a comparison circuit. The compressive receiver may be advantageously used as a direction finding or side lode cancelling compressive receiver.

Abstract: A power-saving type multi-band microwave detector is operable in a high sensitivity mode and a low sensitivity mode for achieving higher sensitivity for both non-modulated and modulated microwaves to make the detecting operation reliable without causing significant increase of power consumption. The power-saving type multi-band microwave detector includes a receiver circuit including a local oscillator for generating an oscillation output and means for sweeping the frequency of the oscillation output over a predetermined reception band, a power supply for periodically supplying a power for the receiver circuit to maintain the latter active while the power is supplied, and control circuit for controlling the receiver circuit and the power supply means for an intermittent microwave receiving operation.

Abstract: A microwave detector comprises a one side opened hollow member having a first portion and a second portion, a printed circuit board, on which a metal layer is formed on one side, the metal layer on the printed circuit board cooperating with the hollow member for forming a horn antenna at a position corresponding to the first portion and an oscillation cavity for housing a first local oscillator at a position corresponding to the second portion, the horn antenna including a throat portion communicated with the oscillation cavity, a first mixing circuit disposed in the throat portion, an intermediate frequency processing circuit formed on the other side of the printed circuit board and including a first intermediate frequency filter, a second mixing circuit and a second local oscillator, and means for establishing electrical connection between the first mixing circuit and the intermediate frequency processing circuit across the printed circuit board.

Abstract: An airborne radar warning receiver for track-while-scan radar including a first radar frequency receiver and logic circuitry for determining an increase in pulse rate frequency, second radar frequency receiver connected to a signal filter and an automatic gain control amplifier connected to the receiver and a logic circuitry connected to the amplifier and to the pulse rate frequency logic whereby the ratio is determined between the time from the start of scan until the radar beam illuminates the aircraft and the total scan time, thereby indicating the center of a search scan sector. A third radar frequency receiver connected to a signal filter and a logic circuitry connected to the receiver for indicating when signals are being radiated indicative of the launching of a radar controlled missile.

Abstract: A warning apparatus for monitoring a plurality of threat sectors includes a receiving antenna for each threat sector for receiving electromagnetic radiation, an alarm channel for each respective threat sector and an amplifier interconnected between an output of the antenna on an input of the alarm channel. The alarm channel includes a high pass filter, a rectifier, an integrator and a comparator connected in series, an input of the filter constituting the input of the alarm channel, an output of the comparator constituting an output of the alarm channel. A threat sector activator is connected to an output of the comparator and activated by an output signal from the comparator in response to an input signal applied to the comparator from the integrator which exceeds a reference level, the activated threat sector indicator of the respective alarm channel indicating the threatened sector.

Abstract: The input ports (18) of an imaging compressive receiver (20) receive from a tapped delay line (16) progressively delayed versions of a received signal s(t). Because of the delays, a signal component in the received signal appears at least at one of the input ports (18) of the compressive receiver (20) at a time when the compressive receiver (20) will detect it, even if the undelayed version occurs during a time at which the compressive receiver (20) would ordinarily be insensitive to it. Since the compressive receiver (20) is an imaging device, it provides relatively isolated channels between its input terminals (18) and its output terminals (38). The phase relationships between the delays in these channels remain constant despite changes in environmental factors, however, because the various channels are embodied in a common two-dimensional delay line.

Abstract: A structure of a reception frequency converting portion of a multi-band microwave detector, and including a microwave circuit comprises a horn antenna, two-port cavity integrally formed with the horn antenna and having one port communicated with a throat portion of the horn antenna, one-port cavity integrally formed with the two-port cavity and communicated with the other port of the two-port cavity, a mixer diode located at the throat portion of the horn antenna, a first local oscillator arranged within the two-port cavity, and a second local oscillator arranged within the one-port cavity.

Abstract: A frequency transmitter apparatus for testing a radar detector is provided that comprises a housing having three sections each with an outer surface. The three sections are configured so that the outer surface of each is directed away from the other two outer surfaces. A frequency transmitter is mounted on each section. The apparatus further comprising a device for receiving voltage from a voltage source to power the transmitter, a voltage indicator for monitoring voltage from the voltage source, and a switch for connecting the voltage indicator and the three transmitters to the receiving device. Each section shields the housing from the frequency from each of the three transmitters. The apparatus may, preferably, include a switch-selectable frequency feature.

Abstract: This is an arrangement to find two folding frequencies that fold into one frequency bin, which will save hardware. The input frequency in down converted into I and Q channels. Each channel requires one pair (two) of A/D converters. A total of three pairs of A/D converters are required. All three pairs of A/D converters have the SAME sampling frequency f.sub.s. There is a time delay of .tau. before the second pair of A/D converters, and 2.tau. before the third pair. At the outputs of the A/D converters FFT units followed by a signal processor are used to find the input frequencies by solving non-linear simultaneous equations.

Abstract: For receiving radar waves entering an antenna horn by the heterodyne method, the system is designed so that one of the local oscillation signals produced respectively by a local oscillator for the X- and K-band radar waves, a local oscillator for the Ka-band radar wave, and a local oscillator for leaked local oscillation waves can be selected to be used as the first local oscillation signal for beating down the radar waves at a first mixer. When a radar wave has been detected in the Ka-band receiving mode with the local oscillator for the Ka-band being selected, a signal processing circuit sets the heterodyne receiving system to the leaked local oscillation wave receiving mode, selecting the local oscillator for the leaked local oscillation waves as the first local oscillator. If a radar wave is detected in this mode, the signal processing circuit inhibits a warning apparatus from issuing the regular warning.

Abstract: A wideband radar detection apparatus includes a signal detection section, high rate signal processing section and a low rate signal processing section. The signal detection section sweeps through a range of preselected frequencies and generates an output signal having a pair of single cycle sinusoids for every detected signal. The output signal is provided to the high rate signal processing section and a Sliding Window Discrete Fourier Transform is performed thereon to generate a set of complex values that are related to the fundamental energy content at consecutive points in the sweep. The low rate signal processing section controls sweep parameters and also evaluates the complex values. If the magnitude of the complex values exceed a predefined threshold, then an alert is indicated.

Abstract: A police radar signal detector detects and monitors radar signals from up to nine (9) radar sources until a detected radar signal has not been redetected for a given number of detector operations, or spectrum sweeps, or until a detected signal has been displaced by a higher priority radar signal. In the police radar signal detector of the present invention, a user of the detector is advised not only of the presence of detected radar signals, the frequency band of detected radar signals and the relative field strength of the signals but also of the number of different radar signal sources which are transmitting signals toward the user's motor vehicle. The information provided to the user for the frequency band of detected radar signals and the relative field strength of the signals is for the highest priority radar signal detected if more than one signal has been detected and is being monitored by the detector of the present invention.

Abstract: A radar detection helmet is arranged to include radar circuitry, as well as a speaker member, mounted within the helmet, and further including a positionable light-emitting diode housing arranged for ease of positioning and observation of the light-emitting diode in use of the radar detection apparatus.

Abstract: An identification friend-or-foe system for vehicles wherein each vehicle is provided with a radiation transmitter and a receiver with a detector for detecting radiation transmitted by other vehicles. Each transmitter can transmit a first coded signal which can be detected by the receivers in other vehicles, the receivers providing an unblocking signal after the first coded signal is correctly identified. The unblocking signal clears a radiation transmission path in the vehicle, the path containing a reflector which reflects the received signal back to the source of the transmission. The reflector adds a further predetermined code to the signal reflected from the reflector with each vehicle having another detector for detecting a reflected signal and a device to identify the further predetermined code.

Abstract: A passive aircraft proximity detector for use in highway vehicles. This invention includes a unique internal antenna (1) feeding a superheterodyne receiver (2). A novel reference system (3) provides phase synchronous local oscillator injection. A signal analysis system (4) determines the presence of a valid signal and activates a tracking indicator (5). The analysis system also provides range data to an indicator which displays the approximate range of the aircraft (6). A mutable timed audio alarm is also incorporated (7).

Abstract: A multi-band microwave detector is designed for detecting microwaves of a plurality of target bands from a specific source and a reference band, which target band includes a specific target band.

Abstract: A police radar signal detector detects and monitors radar signals from up to nine (9) radar sources until a detected radar signal has not been redetected for a given number of detector operations, or spectrum sweeps, or until a detected signal has been displaced by a higher priority radar signal. In the police radar signal detector of the present invention, a user of the detector is advised not only of the presence of detected radar signals, the frequency band of detected radar signals and the relative field strength of the signals but also of the number of different radar signal sources which are transmitting signals toward the user's motor vehicle. The information provided to the user for the frequency band of detected radar signals and the relative field strength of the signals is for the highest priority radar signal detected if more than one signal has been detected and is being monitored by the detector of the present invention.

Abstract: Optical receiving system (20) and method are provided for receiving optical signals used to determine vehicle velocity. The receiver system (20) comprises an optical receiver unit (22) mounted on a vehicle (30) to detect an optical signal incident thereupon. The optical receiver unit (22) includes a radio frequency transmitter (44) for generating and transmitting a radio frequency signal when the optical receiver unit (22) detects an optical signal incident thereupon. The detector system further comprises an indicator unit (24) which includes a radio receiver (46) for receiving the radio frequency generated by the radio frequency transmitter (44) and for providing an indication of the reception thereof. In one embodiment, the indicator unit is a convention radar detection device. In one embodiment, a plurality of optical receiver units (22') are provided for positioning at differing locations upon a vehicle (30'). In another embodiment, a linear array (122) of optical receivers is provided.

Abstract: A low cost warning system for armored vehicles which uses multiple sensors ontaining detectors for IR and millimeter wave signals emanated by attacking missiles and/or projectiles to allow the launching of screening grenades. The sensors telemeter their coded signals to a receiver inside the vehicle which process the coded signals to direct the exercise of an active screening defense.

Abstract: A police radar signal detector detects and monitors radar signals from up to nine (9) radar sources until a detected radar signal has not been redetected for a given number of detector operations, or spectrum sweeps, or until a detected signal has been displaced by a higher priority radar signal. In the police radar signal detector of the present invention, a user of the detector is advised not only of the presence of detected radar signals, the frequency band of detected radar signals and the relative field strength of the signals but also of the number of different radar signal sources which are transmitting signals toward the user's motor vehicle. The information provided to the user for the frequency band of detected radar signals and the relative field strength of the signals is for the highest priority radar signal detected if more than one signal has been detected and is being monitored by the detector of the present invention.

Abstract: A method and apparatus for performing simple, rapid and accurate tests to determine the operational status of police band radar detecting equipment. A low-power, hand-held transmitter capable of transmitting signals within police radar bands for testing the receiver section and alerting circuitry of a radar detector.

Abstract: The data distribution network (DDN) improves processing throughputs (eight million bytes per second) whenever high data rates of unsorted data are input to a processing system by combining synethetic (hash) addresses with look-up tables. The DDN includes coarse steering logic, fine steering logic, and assignment logic for partially sorting and filtering data so that subsequent analysis procedures can find the data in a more orderly form. This increase the pulse density handling capability of a processing system without major size and weight impact.

Abstract: A police radar warning receiver includes an auto-mute feature by which a driver may be alerted to the presence of police radar but without the annoyance of an unnecessarily prolonged audible alarm. To this end, upon detection of the police radar signal, an audible alarm begins to beep at a selected intensity and at a beep rate corresponding to the strength of the signal. A predetermined time and/or a predetermined number of beeps after detection of the police radar signal, the intensity of the audible alarm is automatically reduced.

Abstract: A police radar detector detects both the presence of radar signals incident upon a motor vehicle using the detector and also determines the direction of origin of the source of detected radar signals and alerts the operator of the motor vehicle of the presence and source direction of the radar signals. The radar detector includes at least two antennas and preferably three or more antennas with detector circuitry shared among the antennas in a single detector housing. One of the antennas is directed generally toward the front of the motor vehicle and, for a three antenna embodiment, the second and third antennas are directed at angles of generally 120.degree. to the left and 120.degree. to the right of the front of the vehicle. As the police speed radar frequency bands are scanned or swept, each potential radar signal which is detected is processed to determine the direction of origin of the signals.