Image phased and idler frequency controlled mixer formed on an integrated circuit dielectric substrate

摘要

The tuned elements of a mixer organization are fabricated as slot-type microwave integrated circuit (MIC) elements formed by selected masking or etching of a continuous ground plane layer of conductor material on one side of an integrated circuit dielectric substrate, and of the discrete strips and other geometric forms affixed to the other side of the substrate. A pair of longitudinally aligned coplanar strip transmission line sections with an intermediate short longitudinally aligned slot transmission line section therebetween form hybrid junctions containing balanced diode modulation circuits where such coplanar lines and the slot line are joined. A strip line unit formed on the other side of the substrate is the input port for the RF input signal and is configured to provide a microstrip line-slot line transition at the midpoint of the slot line, feeding the RF input signal to both hybrid junctions with the same phase. The LO input signal is applied to the respective coplanar strip line sections with a constant phase difference therebetween of 90 DEG . This is conveniently provided by a quadrature hybrid. The IF outputs from the coplanar lines have a 90 DEG difference in phase and are received and summed by opposite and isolated ports of another quadrature hybrid to provide a common phase output IF signal.