A linear, ultra wideband, low-power, 2.1-5 GHz, VCO

Abstract

A linear, Ultra Wideband, low-power VCO, suitable for UWB-FM applications is proposed, forming the main part of a UWB-FM transmitter. The VCO is designed in TSMC 90 nm digital CMOS process and includes a Source-Coupled Multivibrator, used as current-controlled oscillator (CCO) which generates output frequencies between 2.1 and 5GHz and a voltage-to-current (V-to-I) converter which translates the VCO input voltage modulation signal to current. Two single-ended inverter buffers are employed to drive either a differential or a single-ended UWB antenna. The presented VCO is designed for 1V power supply and exhibits a linear tuning range of 2.1-5 GHz, a differential output power of -7.83dBm +/- 0.78dB and low power consumption of 8.26mW, including the output buffers, at the maximum oscillation frequency. It is optimized for a very high ratio of tuning range (81.69%) over power consumption equal to 9.95 dB. The desired frequency band of 3.1-5 GHz for UWB-FM applications is covered for the entire industrial temperature range (-40 to 125 degrees C). Copyright (C) 2010 John Wiley & Sons, Ltd.