A 5-PORT HYBRID RING MIXER DESIGN

The design, construction and measured experimental characteristics of a Ka-band balanced mixer based on microstrip technology, are presented . The mixer,vas realised using a configuration of a rat-race hybrid wi th five ports and two GaAs beam lead Schottky diodes. This type of bal anced mixer is advantageous because it avoids via holes, airbridges an d crossing transmission lines that deteriorate the performance of the circuit, and make its construction more difficult. The circuit was con structed in uniplanar microstrip configuration, so the circuits patter n was defined on one side of the substrate only, using thin film techn iques. Performance characteristics of the mixer are presented as a fun ction of RF and LO power, RF frequency and voltage bias of the Schottk y diodes.