An Ultra Wide-Band VCO Using MOS Varactor in 0.35µm SiGe BiCMOS Technology

The fully integrated voltage-controlled oscillator is one of the most important and challenging building blocks in the implementation of a single-chip in today's communication system. In this paper design and realization of an ultra linear wide-band, low phase noise and low current consumption to achieve 4.16~6.1GHz tuning range, LC VCO for WLAN application is presented. Configuration of this circuit is simulated by AMOS 0.35 mum SiGe BiCMOS process that includes high-speed SiGe heterojunction bipolar transistor (HBTs).MOS varactor is used to realize a wide tuning range. The phase noise level is -103.478 dBc/Hz at 1 MHz offset at an oscillation frequency of 5.9 GHz. the Kvco changes from 174 MHz/V to 205 MHz/V. It topology giving a linear wide tuning range greater 1900 MHz, from 4.160 GHz up to 6.035 GHz with a supply voltage of 3.0 V with DC current consumption is 2.26 mA.

1. Introduction

Unlicensed National Information Infrastructure (UNII) band (for 5–6 GHz) has been authorized in many countries for WLAN high-speed applications. Some of these are 802.11a and recently developed 802.11n, operating at 5 GHz band with a greater data rate approaching 108 Mbit/s satisfactory output power, tuning range increase their important in today's wireless application.