A very small frequency generator system for spread spectrum EHF applications

The author reports on a novel synthesizer architecture utilizing a hybrid direct digital/direct analog approach, which was optimized for small size, fast tuning, low spurious, and low phase noise for a hopping EHF (extra-high-frequency) terminal. Performance data for the completed frequency generator system are presented and show 500-ns frequency switching speeds over a 600-MHz tuning bandwidth centered at 11.1 GHz, with 2.2-Hz resolution. Single-sided phase noise L(f) is less than -80 dBc/Hz at a 1-kHz offset from the 11-GHz output and the worst-case spurious is -40 dBc. The complete unit was packaged in 72 in/sup 3/, weighs 3.0 lb, and requires 16.5 W of DC power during continuous operation.<>