Enhanced coupled, even mode terminated baluns and mixers constructed therefrom

A novel mixer circuit technology, based on what the author calls the planar balun, that is appropriate for microstrip or suspended-substrate mixer construction is introduced. The multilayer planar balun is an even-mode-terminated structure which provides coupling in which odd-mode impedance and velocity can be controlled without greatly affecting even-mode characteristics. The planar balun and mixer circuitry are described, and comparisons are made with other baluns. Wideband mixer performance and balun voltage distribution are shown. A planar balun mixer fabricated in a 0.25-in/sup 2/ surface mount package is demonstrated.<>