A wideband gilbert cell mixer with an integrated marchand balun using 0.5-μm GaAs enhancement-mode pHEMT technology

In this study, a fully integrated active Gilbert cell mixer with two Marchand baluns was proposed. The proposed circuit was designed at 12 GHz with bandwidth from 7.5 to 19 GHz and fabricated in a 0.5-μm pHEMT process. In addition, the "current bleeding" technique was also provided in the Gilbert cell mixer to boost the conversion gain. The greatest conversion gain of 4.5 dB can be achieved in the designed circuit under LO input power of -2 dBm. Both RF-IF and LO-IF isolations were better than 30 dB. The third order intercept point input power, IIP₃, achieved as high as 2 dBm. The mixer works from 7.5 to 19 GHz.