A 128-channel pulse-swallow frequency synthesizer includes a 3-mW VCO, a 2.2 mW 16/17 dual-modulus prescaler, a 9-b program counter, and a 7-b swallow counter, The circuit is fully integrated with the exception of the loop-filter capacitor, The ECL prescaler incorporates current sharing and circuit stacking techniques to reduce power consumption, Fabricated in a 1-mu m, 20-GHz BiCMOS process, the circuit operates from a 3-V supply and occupies an active area of 0.28 mm(2).