Analysis of a self-oscillating mixer based on a slow wave-structure

Abstract

This work presents a self-oscillating mixer (SOM) based on a slow-wave structure for phase-noise reduction. Emphasis is placed on the analysis/optimization methods, which include aspects such as conversion gain, nonlinear distortion, and operation boundaries. In a first stage, the parameters of the slowwave structure are optimized to obtain a low phase-noise spectral density. As an example, a structure based on a unit cell containing a Schiffman section is considered. Then, the SOM behavior is addressed through an analytical model that should enable an understanding of its main operation characteristics. A practical FET-based circuit at 2.3 GHz is simulated with some novel harmonic-balance techniques and experimentally characterized.