This paper considers an approach for the behavioral modeling of the conversion mechanism in a nonlinear device suitable for the analysis of RF/microwave mixers. The core of the model consists of the conversion matrix of the nonlinear cell under investigation, which represents its linearization around the large-signal state. This approach allows for a straightforward implementation in CAD using the conversion matrix that is constructed from either simulation or measurements, this latter of which is considered in this paper. Model order is significantly reduced due to the absence of the local oscillator signal in the analysis frequency plan; the intermodulation products are calculated in relative amplitude and phase, and allocated in the spectrum on the basis of the conversion matrix coefficients. We illustrate the technique by implementing this model in commercial CAD software, which allows an in-depth insight into the conversion mechanism and illustrates the application to the design of a sub-harmonic mixer.
Citation: International Journal of Rf and Microwave Computer-Aided Engineering
Pub Type: Journals
Behavioral modeling, conversionmatrix, sub-harmonic mixers, nonlinera circuit design.