A Millimeter-Wave Highly Linear VCO MMIC with Compact Tuning Voltage Converter

This paper presents a fully integrated highly linear and low phase noise voltage controlled oscillator (VCO) with a novel compact tuning voltage converter for millimeter-wave applications. The tuning voltage converter consists of only a few diodes and resistors and has nonlinear characteristics to correct varactor tuning curves. The authors fabricated the millimeter-wave VCO MMIC employing InGaP/GaAs HBT process. The MMIC chip size is 2.55 mm times 1.4 mm, in contrast the voltage converter has the size of 0.35 mm times 0.70 mm. The measured tuning sensitivity of 97 plusmn 12 MHz/V is achieved for voltages between 0 V and 5 V, and the temperature dependency is very small. Also the phase noise performance is -110.7 dBc/Hz at 1MHz offset from the carrier when the oscillation frequency is 38.2 GHz. This linearization technique can greatly reduce the configuration of the conventional software linearization system