A new coplanar waveguide/slotline double-balanced mixer

A novel design concept for a broadband planar mixer, using single-sided substrate processing, is presented. Through the use of a diode crossover quad and coplanar waveguide/slotline baluns, the need for via holes and back metallization has been eliminated. The design offers a potential reduction in production costs compared to other mixer types. The planar construction is highly reliable and lends itself to modular MIC (microwave integrated circuit) applications. A sample mixer operating at 6-18 GHz with a fixed IF (intermediate frequency) of 1 GHz demonstrates a 5.0- to 8.5-dB conversion loss.<>