RMS frequency error performance and spurious signals in two-point modulators due to path imbalances

Authors

GÖKHUN SELÇUK
KAAN ÜÇEL

DOI

10.3906/elk-1804-141

Abstract

In this study the authors introduce an analysis of rms frequency error performance and spurious signals generated by two-point modulators. The analysis is not limited to a constant delay and magnitude imbalance between modulation paths but allows frequency-dependent group delay and amplitude variations as well. Moreover, a discrete time phase frequency detector model is incorporated in Laplace domain analysis that takes into account the sampling nature of a phase-locked loop (PLL). Using the spectrum of pulse width modulated charge pump pulses, the spurious signals at the output of the PLL are evaluated. The proposed formulae are tested on a practical setup and quite accurate results are obtained.

Keywords

Frequency error, phase-locked loop, pulse width modulation, two-point modulator

First Page

432

Last Page

442

Recommended Citation

SELÇUK, GÖKHUN and ÜÇEL, KAAN (2020) "RMS frequency error performance and spurious signals in two-point modulators due to path imbalances," Turkish Journal of Electrical Engineering and Computer Sciences: Vol. 28: No. 1, Article 32. https://doi.org/10.3906/elk-1804-141
Available at: https://journals.tubitak.gov.tr/elektrik/vol28/iss1/32