A Simple Optimization Method for Generating High-Purity Amplitude and Phase Modulation

Published

June 27, 2022

Author(s)

Archita Hati, Craig Nelson

Abstract

We present a simple method for the adjustment of an in-phase (I) and quadrature-phase (Q) Armstrong type modulator for use as a calibrator in precision noise metrology. The availability of relatively pure levels of both amplitude modulation (AM) and phase modulation (PM) can greatly simplify the optimal alignment and calibration of metrology equipment such as AM and PM noise measurement systems. The phase and amplitude imbalance of the components that constitute an IQ modulator results in an undesired combination of AM and PM. These impairments must be corrected to generate the pure signals required for metrology. Our proposed method corrects for these non-ideal impairments and offers nearly ideal operation of the modulator without needing any additional hardware. We present calibration procedure and error analysis of such a modulator when used as a calibrator for a PM and AM noise measurement system.

Citation

IEEE Transactions on Instrumentation and Measurement

Volume

71

Pub Type

Journals

Download Paper

https://doi.org/10.1109/TIM.2022.3186367

Local Download

Keywords

Amplitude modulation, Armstrong modulator, Phase modulation, Phase noise, IQ modulator, Single sideband (SSB) modulation, Uncertainty

Citation

Hati, A. and Nelson, C. (2022), A Simple Optimization Method for Generating High-Purity Amplitude and Phase Modulation, IEEE Transactions on Instrumentation and Measurement, [online], https://doi.org/10.1109/TIM.2022.3186367, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=934262 (Accessed October 17, 2025)