Efficient low-sidelobe pulse compression

A pulse compression system for compressing the echo signal returns from the pulse waveforms of electromagnetic energy propagated by a transmitter comprising:

• means for receiving an echo signal;
• a sliding window discrete Fourier Transform (DFT) circuit comprising:
• analog delay means with N signal taps, with a predetermined delay between each pair of adjacent signal taps;
• phasor means including a series of resistor-type networks for resistively phase weighting the signals on said N taps to yield N.sup.2 phase weighted signals;
• and
• N adder circuits, each adder circuit adding a particular set of N signals from said N.sup.2 phase weighted signals so that only one frequency may peak at each adder circuit output;
• means for applying the echo signal from said receiving means to the delay means of said sliding window DFT circuit without clock sampling;
• means for differentially delaying the outputs from said N adder circuits;
• and
• means for adding the differentially delayed outputs from said differentially delaying means to yield a short pulse which will have a peak amplitude when an echo signal is properly indexed in said delay line means of said sliding window DFT.