A 5.7 GHz interpolative VCO using InGaP/GaAs HBT technology

A 5.7 GHz monolithic interpolative voltage-controlled oscillator using InGaP/GaAs HBT technology is demonstrated for the first time. Frequency tuning is achieved by changing the open loop gain instead of the tank capacitor. The experimental result showed that a 500 MHz tuning range at 5.7 GHz was realized, which can meet the requirement of 5.7 GHz ISM band.