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: A detector for detecting continuous wave police radar that includes an antenna configured to receive an input signal, a diplexer in communication with the antenna to separate the input signal into a high-band signal and a low-band signal, a local oscillator configured to sweep through a range of frequencies to produce FLO, and a frequency multiplier to generate a first mixing signal that is an integer multiple of FLO. The detector also includes a high-band intermediate-frequency signal and a low-band intermediate-frequency signal with a switch configured to select one of them as an output intermediate-frequency signal. A second-stage mixes the output intermediate-frequency signal with FLO to generate an output signal, and a determination is made whether the input signal includes a police radar 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 device includes a radar signal detector that can determine a signal strength of a police radar signal and a direction of a source of the police radar signal. Additionally, the device includes a display in communication with the radar signal detector that provides a single display region having a visual appearance which varies based on both the direction and on the signal strength.

Abstract: An apparatus for a vehicle includes a radar detector configured to detect a police radar signal and a receiver configured to receive information about an image of an environment of the vehicle. A controller in communication with the radar detector and the receiver is configured to change at least one operating characteristic of the radar detector based on the received information.

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 device includes a radar signal detector configured to detect a police radar signal and determine a frequency of the police radar signal and a display in communication with the radar signal detector and configured to provide a first display portion associated with a first range of frequencies. In particular, the display is further configured to provide a visual indicator associated with the police radar signal, the visual indicator having a first position within the first display portion which varies based on the frequency of the police radar signal and the visual indicator having a first visual appearance when the frequency is within a predetermined subset of the first range of frequencies and a second visual appearance when the frequency is outside the predetermined subset of the first range of frequencies.

Abstract: A device includes a radar signal detector that can determine a signal strength of a police radar signal and a direction of a source of the police radar signal. Additionally, the device includes a display in communication with the radar signal detector that provides a single display region having a visual appearance which varies based on both the direction and on the signal strength.

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: A radar detector is operated to suppress nuisance radar alerts by identifying a first signal in radar band of interest, e.g., having a frequency that is a harmonic of a first nuisance local oscillator frequency leaked from a nearby radar detector and identifying a second signal having a frequency that is a harmonic of a second nuisance local oscillator frequency leaked from the radar detector where the first and second local oscillators are companion signals. A detector is also provided that suppresses nuisance radar alerts by detecting a first signal in a radar band, providing a first alert designating the detection of the first signal, determining that the first signal is a nuisance signal, providing a second alert designating that the first signal is a false alarm, and turning off the second alert after a predetermined period.

Abstract: A radar detector is operated to suppress nuisance radar alerts by identifying a first signal in radar band of interest, e.g., having a frequency that is a harmonic of a first nuisance local oscillator frequency leaked from a nearby radar detector and identifying a second signal having a frequency that is a harmonic of a second nuisance local oscillator frequency leaked from the radar detector where the first and second local oscillators are companion signals. A detector is also provided that suppresses nuisance radar alerts by detecting a first signal in a radar band, providing a first alert designating the detection of the first signal, determining that the first signal is a nuisance signal, providing a second alert designating that the first signal is a false alarm, and turning off the second alert after a predetermined period.

Abstract: In a police radar detector, a sweep signal defines at least one first sweep signal and at least one second sweep signal with the at least one second sweep signal being seamlessly inserted into the first sweep signal so that the first sweep signal is interrupted during the second sweep signal and restored after completion of the second sweep signal so that the first sweep signal can be continued. The frequencies swept by the at least one second sweep signal are thus overswept. By assigning the frequencies swept during the at least one first sweep to the radar bands of interest and the frequencies swept during the at least one second sweep to the frequencies used in the POP mode of operation by police radar, the short bursts of energy used in the POP mode can be detected.

Abstract: A novel frequency scheme for a police radar detector enables improved sweeping of the X, K, Ku and Ka radar bands. The novel frequency scheme requires two initial frequency conversions for detection of the X, K and Ka radar bands and a single initial frequency conversion for the Ku radar band with single initial frequency conversion being enabled by disabling the second mixer. During sweeping of the X, K and Ka bands, selectable, i.e., upper or lower, sideband suppression is employed to reduce undesired image sidebands and noise prior to the second frequency conversion. In addition, noise at the second IF frequency is reduced to prevent this noise from feeding through the second mixer into the second IF amplifier. During the Ku band sweep, the second mixer is bypassed and shunting of signals at the second IF frequency is disabled so that these signals enter the second IF amplifier.

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.