Effects of noisy and modulated interferers on the free-running oscillator spectrum

A new methodology for the prediction of oscillator phase dynamics under the effect of an interference signal is presented. It is based on a semianalytical formulation in the presence of a noisy or modulated interferer, using a realistic oscillator model extracted from harmonic-balance simulations. T...

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Bibliographic Details
Authors: Sancho Lucio, Sergio Miguel|||0000-0003-3343-1053, Pontón Lobete, María Isabel|||0000-0001-8537-1502, Suárez Rodríguez, Almudena|||0000-0002-5266-5544
Format: article
Publication Date:2018
Country:España
Institution:Universidad de Cantabria (UC)
Repository:UCrea Repositorio Abierto de la Universidad de Cantabria
Language:English
OAI Identifier:oai:repositorio.unican.es:10902/15605
Online Access:http://hdl.handle.net/10902/15605
Access Level:Open access
Keyword:Amplitude modulation
Frequency-domain analysis
Injection pulling
Interferer
Microwave oscillator
Phase modulation
Phase noise
Description
Summary:A new methodology for the prediction of oscillator phase dynamics under the effect of an interference signal is presented. It is based on a semianalytical formulation in the presence of a noisy or modulated interferer, using a realistic oscillator model extracted from harmonic-balance simulations. The theoretical analysis of the phase process enables the derivation of key mathematical properties, used for an efficient calculation of the interfered-oscillator spectrum. The resulting quasi-periodic spectrum is predicted, as well as the impact of the interferer phase noise and modulation over each spectral component, in particular over the one at the fundamental frequency. It is demonstrated that under some conditions, the phase noise at this component is pulled to that of the interference signal. Resonance effects at multiples of the beat frequency are also predicted. In addition, the effects of interferer phase and amplitude modulation on the oscillator phase dynamics have been studied and compared. For that analysis, efficient simulation techniques have been developed. The analyses have been validated with experimental measurements in an FET-based oscillator at 2.5 GHz, obtaining excellent agreement.