A 26–38 GHz Monolithic Doubly Balanced Mixer

A novel configuration of doubly balanced mixer is presented for operating over the 26-38 GHz band. The monolithic microwave integrated circuit (MMIC) was implemented by GaAs 0.15 mum pHEMT technology with the compact size of 1times2.5 mm
²
. A 180deg hybrid circuit and two identical Marchand baluns were employed to achieve good port-to-port isolation. They also have wide band performance, make the mixer more compact, and simplify IF extraction. This mixer has a conversion loss of better than 6 dB, a dc-10 GHz IF bandwidth, and the LO-to-RF and LO-to-IF isolations are better than 20 dB and 29 dB, respectively.