Generation and correlation of digitally controlled coherent frequency-hopped waveforms using surface acoustic wave devices

A digitally controlled coherent frequency synthesizer is reported which uses two surface acoustic wave chirp filters to generate frequency-hopped waveforms. Attractive features are wide bandwidth and instantaneous switching between frequencies, which are selected by an external word generator. Experimental results show waveforms which hop every 2.5 µs within a 12.5-MHz band. Phase coherence between pulses is demonstrated by correlating the waveform in a surface acoustic wave plate convolver.