Wide-Band X-Band Microstrip Image Rejection Balanced Mixer (Correspondence)

A compact image rejection balanced mixer developed in microstrip medium is described. This integrated mixer gives over 20-dB image rejection and 10.6/spl plusmn/0.6-dB noise figure (including 2.5-dB IF contribution) over 8-to 12-GHz range ; it was designed on a 40-ohm impedance basis and is scalable to any 40-percent fractional bandwidth in the 1- to 12-GHz range.