A Linear E/W-Band Resistive IQ Mixer MMIC in a GaN-on-SiC HEMT Technology

This paper demonstrates an IQ mixer monolithic microwave integrated circuit (MMIC) targeting the E-Band satellite communication bands from 71 to 76 and 81 to 86 GHz. The MMIC is based on a resistive mixer topology and utilizes a 100-nm gate-length GaN-on-SiC high-electron-mobility transistor technology. The IQ mixer achieves an average conversion loss of 11 dB (10-11.8 dB) over an RF bandwidth of at least 70.5-95 GHz. For an LO and RF input power of 16 and 15 dBm, respectively, the conversion loss compression is only 0.3 dB. For lower LO power (PLO) levels, an almost constant difference between input-referred 1-dB compression point (IP1 dB) and PLO of 4.8 dB can be observed. The fact that IP1 dB is larger than PLO is an essential indicator of an efficient use of PLO and describes an important characteristic of the presented IQ mixer MMIC.