Design And Printed Circuit Board Level Implementation Of A Narrow Band LC VCO

Abstract

A Voltage Controlled Oscillator (VCO) using a 0.6 μm CMOS technology has been designed and fabricated. The design's tuning range is from 390 MHz to 410 MHz, with the center frequency being 400 MHz. The oscillator is powered by a 2.5 volt power supply. The controlling voltage varies from 0.87 to 1.6 volts. Simulation of the LC VCO was carried out in the Advanced Design System (ADS) program. For the printed circuit board level implementation, the layout was first performed using the ADS program, and then its image was transferred on to a printed circuit board. The device footprints were incorporated in the circuit board layout. The dimension of the copper board was 1.5 x 0.6 inches. The frequency of oscillations on the printed circuit board was found to be 381.14 MHz while the simulations in ADS, showed a frequency of 391 MHz, which represents a deviation of 2.55 %. By changing the capacitor of the tank circuit on the board, the frequency of oscillation varies from 300.47 MHz to 464.8 MHz as seen on the spectrum analyzer. The oscillator output current was 5 mA and its output power was 7 mW.