초록 ▼

A police radar warning receiver is disclosed including a DSP circuit having a correlator and a peak detector to provide after each sweep of a swept local oscillator a dynamic threshold for that sweep as affected by all prior sweeps and against which information from that sweep is evaluated to determ

A police radar warning receiver is disclosed including a DSP circuit having a correlator and a peak detector to provide after each sweep of a swept local oscillator a dynamic threshold for that sweep as affected by all prior sweeps and against which information from that sweep is evaluated to determine whether to generate an alarm enable indicative of receipt of a police radar signal.

대표청구항 ▼

A police radar warning receiver comprising: IF signal means for producing an IF sweep pattern as an oscillator signal is swept in frequency between a first frequency and a second frequency in response to mixing of received RF signals in at least one band of police radar signal frequencies with said

A police radar warning receiver comprising: IF signal means for producing an IF sweep pattern as an oscillator signal is swept in frequency between a first frequency and a second frequency in response to mixing of received RF signals in at least one band of police radar signal frequencies with said swept oscillator signal; FM discriminator means responsive to said IF signal means for producing an FM sweep pattern corresponding to FM demodulation of said IF sweep pattern as said IF sweep pattern is produced; sampler means for repeatedly sampling at sample intervals said FM sweep pattern as it is produced whereby to produce a series of digital sample words each associated with a respective sample interval; correlator means for correlating each digital sample word as it is produced with a plurality of proceeding said digital sample words and a complex correlator function whereby to provide a series of complex digital correlator words each associated with a respective sample interval; averager means for accumulating for each of at least a plurality of said sample intervals, an average of the complex digital correlator word produced each sweep and associated with a said sample interval over a plurality of sweeps of the oscillator signal whereby to produce a series of averager words each associated with a respective one of said plurality of sample intervals; substitution means for replacing in said series of averager words an averager word associated with a selected sample interval with a substitute averager word corresponding to the correlator word from that sample interval; threshold means for providing after a given sweep of the oscillator signal a dynamic threshold word corresponding to the magnitude of said series of averager words; and peak detector means for providing an alarm enable after said given sweep if an averager word has a magnitude greater than said dynamic threshold word whereby to indicate receipt of a police radar signal.