A generic approach to optimum design of microwave and millimeter wave subharmonic mixers

The design of suharmonic mixers is complicated and involves separation of signals and application of correct loading at idler frequencies. In this paper we present a novel generic approach, which enables the designer to establish the optimum loading conditions for the different signals to get low conversion loss and good matching simultaneously. The method is demonstrated by a design example of a 30GHz x2 subharmonic mixer. In this example it is shown that a non-optimal design can yield conversion loss of up to 13.5db, while an optimal design using our approach yields 3.6db conversion loss.