摘要 |
A center-line filter for a radar receiver (50) is a cascade of an analog filter (54A) and a digital filter (58A). The purpose of the filter cascade is to filter out all but a single line of a pulsed spectrum. The signal is passed through the analog filter, and then over-sampled by an analog-to-digital convertor (56A). A sharp cutoff FIR filter is used as the digital filter (58A) to eliminate the remaining undesired lines. since the analog filter already has the correct matched filter characteristic in the passband, the digital filter passband is deliberately wider and unsymmetrical. After digital filtering, the filter output is decimated by a decimation processor (60A) to provide a desired output data rate. <IMAGE> |