A Novel Circuit Architecture for High Performance of High-order Subharmonic Mixers

Abstract

A novel circuit architecture for high performance of high-order subharmonic (SH) mixers is proposed in this paper. According to the specified harmonic mixing order, one or more mixer diodes sub-arrays and corresponding power divider as well as phase shift network for RF and LO signals are arranged in the circuit. This proposed SH mixer circuit has improved conversion loss, wide dynamic range and high port isolation for high-order SH mixers. By phase cancellation of idle frequencies, the proposed SH mixer circuit can eliminate complicated design procedure of idle frequency circuits; by phase cancellation of leakage LO power to RF and IF port, and leakage RF power to LO port, the mixer circuit can get high port isolation in LO-IF/RF and RF-LO. The increased antiparallel diode pairs in each sub-array will also lead to well performance by lowering effective series resistance. The proposed SH mixer circuit can be easily realized with power divider and phase shift network for RF and LO signals.

Design of a ×4 subharmonic sub-millimeter wave diode mixer, based on an analytic expression for small-signal conversion admittance parameters

“…The purpose of this approach is to reuse the power at the idle frequencies by phase cancellation instead of filtering. This could theoretically be extended to any number of higher-order subharmonic mixers, somewhat similar to what is proposed by [3].…”