Analysis of Oscillation Amplitude and Phase Error in Multiphase LC Oscillators

Abstract

Abstract This work proposes a novel method to find the phase error and oscillation amplitude in multiphase LC oscillators. A mathematical approach is used to find the relationship between every stage's output phase and its coupling factor. To much more general analysis, every stage assumed to have a different coupling factor. The mismatches in LC tanks are considered as the main source of phase errors and accordingly the phase deviation of each stage is calculated in a distinct equation. Then the amplitude of oscillation for each stage is individually derived using phase error results. Not only considering different coupling factors increases the generality of this work but also the results are in better conformance with simulations compared to previous works. The theoretical results are evaluated and confirmed through extensive simulations using ADS software.