Millimeter-wave three-port transistor drain mixer

The analysis and optimizing design for three-port device drain mixer in Ka- band were given. The nonlinear equivalent circuit and its parameters were s imulated and obtained from the small signal S parameter and the DC measurem ents of three-port device. And then, the drain mixer circuit was designed w ith optimum conversion gain of the drain mixer which was derived from the h armonic balance method and the conversion matrices method. The test result shows that the mixer has conversion gain 4dB at RF 27.4GHz and LO 33.4GHz/1 0dBm.