Analysis and design LC cross coupled VCO regarding different phase noise approaches

Abstract

This paper presents two fully integrated cross coupled low phase noise K and Ku bands LC Voltage Controlled Oscillators (VCO) using symmetric spiral inductors that have been designed and simulated using commercial 0.18μm CMOS technology. The simulated phase noises are around -136.2 dBc/Hz and -129.3 dBc/Hz (PMOS and NMOS respectively) at the offset frequency of 1MHz from the 16.1 GHz and 18.8 GHz center frequencies. The Power consumptions of both VCO circuits are about 10 mW. These designs are one of the best phase noises (by means of increasing tank quality factor) reported till now. Also, two phase noise approaches (Time and frequency domain) have been discussed.