A 3-33 GHz PHEMT MMIC distributed drain mixer

A compact wide-band GaAs PHEMT MMIC distributed drain mixer covering the RF frequency from 3 to 33 GHz is reported in this paper. The measured results show that the conversion loss of the distributed drain mixer is better than 4 dB over the frequency range at LO power 13 dBm without IF amplification. Using the matching circuit in the output of the FETs, the LO-to-IF and LO-to-RF isolations are better than 19 dB from 3 to 33 GHz. This mixer utilized a simple distributed topology with single-gate HEMTs and achieved a very broad band performance comparable to the cascode or dual-gate distributed mixers. The overall chip size of this MMIC is only 1.7 x 1 mm(2).