Analog-Filter Digital-Correlator Hybrid Spectrometer

A system is described for measuring the power spectrum and cross spectral density of wide-band (≥ 50 MHz) noise-like signals which occur, for example, in radio astronomy. The system utilizes a comb-filter bank followed by digital correlator processing of each filter output. The cost equation, design factors, and a sample system are described. For measurement of the spectrum at a large number of frequencies, the system cost of the hybrid system is shown to be much lower than the cost of spectrometers which utilize either a filter-bank or digital correlator alone.