An inexpensive, small, low-power consumption, wide-band, high resolution
spectrum analyzer is provided as a listening device for throw-away
applications such as surveillance that involve deployment of large
numbers of battery-powered spectrum analyzer modules to detect a signal
source such as two-way radio traffic. Power requirements are minimized by
the utilization of only one chirp generator to elongate battery life
while providing a high resolution result. In order to minimize power
drain the spectrum analyzer includes a single compound-chirp Fourier
Transform generator. The compound chirp generator is used in one
embodiment with a surface acoustic wave, SAW, dispersive delay line in
conjunction with a surface electromagnetic wave, SEW dispensive delay
line. The compound chirp generator permits performing two spectrum
analysis functions, one resulting in coarse resolution frequency bins,
and the other resulting in refining the coarse resolution bins into fine
resolution frequency bins for the high resolution required for signal
recognition.