A very-wide bandwidth digital VCO implemented in GaAs HBTs using frequency multiplication and division

A digital high-speed voltage-controlled oscillator (VCO) has been developed which uses frequency-multiplication and division to attain a wide frequency range of 0.5-13.66 GHz. The circuit is implemented in differential current-mode logic using GaAs-AlGaAs heterojunction bipolar transistors (HBTs). This paper discusses top-level system design as well as the design of several key components.