Abstract: Operating a police radar detector to suppress nuisance radar alerts due to received signals that are not police radar signals includes receiving electromagnetic signals; mixing received electromagnetic signals with a local oscillator signal that is swept at a constant sweep rate; and accumulating a virtual image of the signal environment represented by received electromagnetic signals. Analysis of the virtual image is performed for signals suspected of being nuisance signals that could result in nuisance radar alert so that any nuisance signals within the virtual image can be identified and ignored by the alarm portion of the police radar detector.

Abstract: Operating a police radar detector to suppress nuisance radar alerts due to received signals that are not police radar signals includes receiving electromagnetic signals; mixing received electromagnetic signals with a local oscillator signal that is swept at a constant sweep rate; and accumulating a virtual image of the signal environment represented by received electromagnetic signals. Analysis of the virtual image is performed for signals suspected of being nuisance signals that could result in nuisance radar alert so that any nuisance signals within the virtual image can be identified and ignored by the alarm portion of the police radar detector.

Abstract: Operating a police radar detector to suppress nuisance radar alerts due to received signals that are not police radar signals includes receiving electromagnetic signals; mixing received electromagnetic signals with a local oscillator signal that is swept at a constant sweep rate; and accumulating a virtual image of the signal environment represented by received electromagnetic signals. Analysis of the virtual image is performed for signals suspected of being nuisance signals that could result in nuisance radar alert so that any nuisance signals within the virtual image can be identified and ignored by the alarm portion of the police radar detector.

Abstract: Detecting continuous wave police radar includes receiving an input signal from a first antenna, the input signal comprising a continuous wave emission within at least one radar band; sweeping a composite local oscillator signal through a range of frequencies from a first frequency to a second frequency in a predetermined time period so that the composite local oscillator signal has a first chirp rate with a first chirp rate magnitude of between 0.15 MHz/?s and 3.5 MHz/?s or even higher; and mixing the input signal from the first antenna with the sweeping composite local oscillator signal to produce an output signal having an intermediate frequency. A next step can include determining that the input signal from the first antenna includes a police radar signal based on the output signal.

Abstract: Detecting continuous wave police radar includes receiving an input signal from a first antenna, the input signal comprising a continuous wave emission within at least one radar band; sweeping a composite local oscillator signal through a range of frequencies from a first frequency to a second frequency in a predetermined time period so that the composite local oscillator signal has a first chirp rate with a first chirp rate magnitude of between 0.15 MHz/?s and 3.5 MHz/?s or even higher; and mixing the input signal from the first antenna with the sweeping composite local oscillator signal to produce an output signal having an intermediate frequency. A next step can include determining that the input signal from the first antenna includes a police radar signal based on the output signal.

Abstract: Operating a police radar detector to suppress nuisance radar alerts due to received signals that are not police radar signals includes receiving electromagnetic signals; mixing received electromagnetic signals with a local oscillator signal that is swept at a constant sweep rate; and accumulating a virtual image of the signal environment represented by received electromagnetic signals. Analysis of the virtual image is performed for signals suspected of being nuisance signals that could result in nuisance radar alert so that any nuisance signals within the virtual image can be identified and ignored by the alarm portion of the police radar detector.

Abstract: Detecting continuous wave police radar includes receiving an input signal from a first antenna, the input signal comprising a continuous wave emission within at least one radar band; sweeping a composite local oscillator signal through a range of frequencies from a first frequency to a second frequency in a predetermined time period so that the composite local oscillator signal has a first chirp rate with a first chirp rate magnitude of between 0.15 MHz/?s and 3.5 MHz/?s or even higher; and mixing the input signal from the first antenna with the sweeping composite local oscillator signal to produce an output signal having an intermediate frequency. A next step can include determining that the input signal from the first antenna includes a police radar signal based on the output signal.

Abstract: Detecting continuous wave police radar includes receiving an input signal from a first antenna, the input signal comprising a continuous wave emission within at least one radar band; sweeping a composite local oscillator signal through a range of frequencies from a first frequency to a second frequency in a predetermined time period so that the composite local oscillator signal has a first chirp rate with a first chirp rate magnitude of between 0.15 MHz/?s and 3.5 MHz/?s or even higher; and mixing the input signal from the first antenna with the sweeping composite local oscillator signal to produce an output signal having an intermediate frequency. A next step can include determining that the input signal from the first antenna includes a police radar signal based on the output signal.

Abstract: A bandpass filter passes a range of frequencies with low loss while suppressing frequencies above and below the passed range of frequencies. One or more spurlines is included into the existing structure of the bandpass filter so that a selected odd multiple of the passed frequency range is suppressed.

Abstract: A microwave filter is provided that includes a transmission line having a signal input port and a signal output port, a stub connected to the transmission line between the input port and the output port, and a spurline embedded in the stub. The microwave filter is configured to substantially attenuate a frequency while substantially passing at least one predetermined odd harmonic of the frequency.

Abstract: Radio frequency signals having a plurality of frequency ranges are received and coupled to a plurality of transmission lines, each of the plurality of transmission lines being formed in a corresponding plurality of generally parallel planes. Circuitry is formed for each of the plurality of transmission lines to define substantially low impedances for all of the plurality of frequency ranges except for a frequency range or ranges to be carried by the corresponding transmission line. Signals are coupled to the plurality of transmission lines so that signals with the plurality of frequency ranges are received and distributed with substantially decreased reflection and substantially high impedance matching by the plurality of transmission lines.

Abstract: Radio frequency signals having a plurality of frequency ranges are received and coupled to a plurality of transmission lines, each of the plurality of transmission lines being formed in a corresponding plurality of generally parallel planes. Circuitry is formed for each of the plurality of transmission lines to define substantially low impedances for all of the plurality of frequency ranges except for a frequency range or ranges to be carried by the corresponding transmission line. Signals are coupled to the plurality of transmission lines so that signals with the plurality of frequency ranges are received and distributed with substantially decreased reflection and substantially high impedance matching by the plurality of transmission lines.

Abstract: A microwave filter is provided that includes a transmission line having a signal input port and a signal output port, a stub connected to the transmission line between the input port and the output port, and a spurline embedded in the stub. The microwave filter is configured to substantially attenuate a frequency while substantially passing at least one predetermined odd harmonic of the frequency.

Abstract: A bandpass filter passes a range of frequencies with low loss while suppressing frequencies above and below the passed range of frequencies. One or more spurlines is included into the existing structure of the bandpass filter so that a selected odd multiple of the passed frequency range is suppressed.

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.

Abstract: A microstripline microwave mixer circuit includes a waveguide microstrip filter formed by coupling a section of ridged waveguide to a microstripline circuit. The ridged waveguide based microstrip filter both serves as a high-pass filter for RF input signals and also provides a suitable termination for the RF input side of the mixer circuit resulting in a compact multifrequency mixer circuit with good performance. The section of ridged waveguide is coupled to the microstripline circuit such that the dielectric substrate of the microstripline circuit is within the waveguide section thereby increasing the effective dielectric constant of the waveguide interior and decreasing the dimensions of the waveguide. This configuration of the high-pass filter presents a smaller component than would be present in air-filled waveguide mixer circuits.

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 signals the operator of the motor vehicle of the presence and source direction of the radar signals. Preferably, the radar detector includes two antennas with shared circuitry in a single housing. One of the antennas is directed generally toward the front of the motor vehicle and the other antenna is directed generally to the rear of the motor 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. To determine the direction of origin of incident radar signals, the signals are detected in both antennas with the signal strengths in the two antennas being compared to determine the direction of origin of the signals.

Abstract: A radar detector for use in a motor vehicle employs amplitude detection to sense the presence of radar signals commonly used to monitor the speed of such motor vehicles. Amplitude signals are generated by down-converting received signals using a series of mixers, one of which is swept to insure signal detection, and compared to a threshold which is controlled such that noise is detected by the comparison on average a selected period of time. Detected amplitude signals must persist for a given period of time before they are considered to be potentially valid radar signals. After passing the first test of persistence, the signals are verified by means of frequency modulating the first of the series of mixers, detecting the frequency modulation and correlating the detected frequency modulation to determine whether the signal is valid and if so, to which radar frequency band the signal belongs. A first embodiment of the radar detector monitors the X band (10.475-10.575 Ghz), the Ku band (13.400-13.

Abstract: A low loss high-pass microwave filter for microstrip circuits comprises a single-ridge waveguide which is attached to a microstrip circuit in a manner to establish a cutoff frequency for the circuit. The single-ridge waveguide has a top wall and sidewalls with a ridge projecting centrally from the top wall into the waveguide. The waveguide is associated with the microstrip circuit such that the sidewalls of the waveguide extend through a dielectric substrate of the circuit parallel to and on opposite sides of a microstrip line of the circuit and are connected electrically and physically to the ground plane, which forms a bottom wall for the waveguide. The ridge of the waveguide has a width which is equal to or narrower than the microstrip line and is aligned with the microstrip line.

Abstract: A method and apparatus for coupling a double-ridge wavguide to a microstrip circuit. A lower ridge of a coupling section of waveguide is expanded by gradually increasing its width such that at the beginning of the coupling the lower ridge is equal to the width of the lower ridge of the double-ridge waveguide to be coupled and at the end of the coupling the width of the lower ridge is equal to the full width of the coupling. This flaring of the lower ridge creates an electrically conductive surface for receiving a ground plane for the microstrip circuit. Additionally, the upper ridge is altered gradually such that at the beginning of the coupling the ridge gap is equal to the gap in the double-ridge waveguide and at the end of the coupling the ridge gap is equal to the sum of the thicknesses of the dielectric substrate, the microstrip line, and the ground plane of the microstrip circuit.