Novel voltage-controlled oscillator design by MOS-NDR devices and circuits

Abstract

This paper describes the design of a voltage-controlled oscillator (VCO) based on the negative differential resistance (NDR) devices. The NDR devices used in the work is fully composed by the metal-oxide-semiconductor field-effect-transistor (MOS) devices. This MOS-NDR device can exhibit the NDR characteristic in its current-voltage curve by suitably arranging MOS parameters. The VCO is constructed by three low-power MOS-NDR inverter. This novel VCO has a range of operation frequency from 151MHz to 268MHz. It consumes 24.5mW in its central frequency of 260MHz using a 2 V power supply. This VCO is fabricated by 0.35 /spl mu/m CMOS process and occupied an area of 120 /spl times/ 86 /spl mu/m/sup 2/.