Microwave circuit for step-down frequency mixer - with pump frequency tuned input output pi filter, and fine tuning facility for intermediate frequency stage

摘要

The application is to microwave signal transmission, and the construction of a parametric congruent step down mixer with real mirror frequency terminal conductance. The input comprises a parallel LC circuit (Lh, Ch) which is tuned to the pumping frequency (p). It is linked to the output by a reactance diode (S) (o), RD) and an inductance (L). The output comprises a Pi filter with capacitors (Cx, C2) in the parallel limbs and an inductance (Lz) in the series connection. The intermediate frequency z, is determined by the fine tuning of the input circuit and the Pi filter. The components are chosen to match the load conductance (Gz) with the resonant output conductance of the mixer. The input-parallel circuit (Lh, Ch) may be constructed out of two parallel open feeders each approximately one quarter of the length of the pump frequency wave length.