A mixer computer-aided design tool based in the time domain

A time-domain-based technique for computer-aided mixer analysis and design is presented. The design tool uses SPICE to arrive at the steady-state solution of the network equations in the mixer circuit. These nonsinusoidal waveforms are studied to understand the interaction of diode, circuit, and drive conditions. Graphically derived criteria are developed to optimize mixer performance. Circuit characteristics such as conversion loss, input and output impedances at small-signal frequencies are rapidly calculated by using a fast Hartley transform (FHT) to generate the Fourier transform of the required waveforms. This technique can be used to analyze mixers that can be described in terms of transmission lines, lumped components or any other element blocks available with SPICE.<>