Design of Low Power Class-C Voltage Controlled Oscillator Using 0.13 µm SiGe BiCMOS for K-band Applications

Recently, the implementation of a complete RF transceiver system at the mm-wave band is of main interest as the recent technological trend is to build a complete system on chip (SOC). One of the main keys of the transceiver systems is the voltage-controlled oscillator (VCO) which is considered the main building block of the phase locked loop (PLL) frequency synthesizer. Realizing VCO with wider tuning range (TR) and low phase noise at the mm-wave frequency range is considered a challenging task. In this work, a cross coupled differential pair Class-C voltage controlled oscillator is employed to improve the phase noise across wider tuning range. The proposed design is based on the 0.13 μm SiGe BiCMOS process technology. A new varactor circuit is proposed to extend the tuning range. In order to extend the tuning range of the VCO more and more, a bank of fixed capacitors is added to the LC tank with a controlled MOS switches. Multiple tuning ranges are achieved using the proposed LC tank. The EM effects of the paths and interconnections through the layout are taken into considerations before fabrication. The proposed LC VCO achieved maximum post-layout phase noise of -97 (dBc/Hz) at 1 MHz offset from the carries. In addition, it achieves a wide tuning range between 18.2 GHz to 26 GHz. Moreover, the proposed VCO consumes only 12 mW from 1.2 voltage supply.