A Ka-Band Class-C BiCMOS VCO with Temperature Compensation

This paper presents a Ka-band class-C Voltage-Controlled Oscillator (VCO) with a temperature compensation circuit. The VCO core circuit is implemented by class-C topology with 6-bit capacitor array to achieve a wide frequency tuning range, 4GHz. The temperature compensation circuit consists of temperature detection circuit, logic circuit and bias voltage generate circuit. The Ka-band VCO is designed using TowerJazz 0.18 μm SiGe BiCMOS technology with a supply voltage of 3.3 V, and the effectiveness of the temperature compensation circuit is verified by the simulations when temperature varies from -40°C to 125°C. The VCO has the operating frequency ranges from 23.5 to 29.6GHz, and the phase noise at 1MHz offset frequency is - 107dBc/Hz while consumes 10mA from a 3.3V supply voltage. Without compensation, the frequency varies 360MHz over temperature, while the variation reduced to 31MHz with compensation.