A Ka-band GaInP/GaAs HBT double balanced downconvert mixer using lumped element balun

A Ka-band GaInP/GaAs HBT receiver has been designed and fabricated. This circuit is to be used in a multifunction T/R module for local multipoint distribution systems (LMDS) which include both analog and digital transmission. A conversion gain of greater than 15 dB was measured. These results are the best reported at Ka-band for a receiver using transistors from the digital HBT library.