초록 ▼

A pulse expansion and compression system, especially useful for radar ranging, comprising a pulse coder for expanding an input pulse and a pulse compressor of the matched-filter type. The coder consists of a plurality of delay stages into which the input pulse is fed, a discrete Fourier transform (D

A pulse expansion and compression system, especially useful for radar ranging, comprising a pulse coder for expanding an input pulse and a pulse compressor of the matched-filter type. The coder consists of a plurality of delay stages into which the input pulse is fed, a discrete Fourier transform (DFT) circuit to which the output signals of the delay stages are fed, a time-dispersionmeans (TDM) comprising an arrangement of delay stages for differently delaying the output signals from the DFT, and a coherent summer for adding the real and imaginary parts of the signals from the TDM. The summer output is fed to a phase modulator and then to the transmitter. The echo signals are conjugated, time-inverted, and passed through the same DFT as the input pulse signal. The outputs of the DFT are then passed through a TDM of the same type as the first TDM, but this time in time-inverted order. The outputs of the second TDM are fed through a coherent summer and an envelope detector to provide a cross-correlated facsimile of the original input pulse.

대표청구항 ▼

Signal-processing means comprising: pulse coder means for providing a series of weighted pulses from a single input pulse, the time interval of the series being greater than that of said input pulse, said coder means including input-signal expansion means (ISEM) into which the input signal is fed, s

Signal-processing means comprising: pulse coder means for providing a series of weighted pulses from a single input pulse, the time interval of the series being greater than that of said input pulse, said coder means including input-signal expansion means (ISEM) into which the input signal is fed, said ISEM comprising at least one delay stage, weighting means comprising a discrete Fourier transform circuit to which the output of the ISEM is fed, and a first time-dispersion means to which the outputs of said weighting means are fed for spreading the series of weighted pulses over a still greater time interval; and pulse-compression means, of the matched filter type including weighting means which is the same as that employed in said coder means, for receiving and processing echo signals corresponding to the output signals of said time-dispersion means.