A 30-65 GHz wideband double-balanced gilbert-cell mixer using GaAs pHEMT technology

This article presents a wideband, double-balanced microwave/millimeter-wave Gilbert-cell mixer, using 0.15 μm GaAs pHEMT technology. Two baluns and a matching network are used in RF- and LO-ports to convert single-ended signals to differential signals, for wideband use. This mixer demonstrates an average conversion gain is 2.22 ± 1.5 dB at P _LO = 2 dBm, from 30 to 65 GHz. The LO-to-RF and LO-to-IF isolations are all better than 28 dB, between 30 and 65 GHz. The measured P1dB and IIP3 are 5 dBm at 40 GHz and 10 dBm at 60 GHz, respectively. The mixer occupies a chip area, including probing pads, of 1.68 mm ² and consumes 21 mA, with a supply voltage of 5V.