A 4.5-5.8 GHz Differential LC VCO using 0.35 m SiGe BiCMOS Technology

Abstract

In this paper, design and realization of a 4.5-5.8 GHz, Gm LC voltage controlled oscillator (VCO) for IEEE 802.11a standard is presented. The circuit is implemented with 0.35´m SiGe BiCMOS process that includes high-speed SiGe Heterojunction Bipolar Transistors (HBTs). A linear, 1300 MHz tuning range is measured with accumulation-mode varactors. Fundamental frequency output power changes between -1.6 dBm and 0.9 dBm, depending on the tuning voltage. The circuit draws 17 mA from 3.3 V supply, including buffer circuits leading to a total power dissipation of 56 mW. Post-layout phase noise is simulated -110.7 dBc/Hz at 1MHz offset from 5.8 GHz carrier frequency and -113.4 dBc/Hz from 4.5 GHz carrier frequency. Phase noise measurements will be updated in the final manuscript. The circuit occupies an area of 0.6 mm2 on Si substrate including RF and DC pads.