BROAD-BAND SINGLE-BALANCED AND DOUBLE-BALANCED RESISTIVE HEMT MONOLITHIC MIXERS

A double-balanced (DB) 3-18 GHz and a single-balanced (SE) 2-16 GHz resistive HEMT monolithic mixer have been successfully developed, The DB mixer consists of a AlGaAs/InGaAs HEMT quad, an active LO balun, and two passive baluns for RF and IF, At 16 dBm LO power, this mixer achieves the conversion losses of 7.5-9 dB for 4-13 GHz RF and 7.5-11 dB for 3-18 GHz RF, The SE mixer consists of a pair of AlGaAs/InGaAs HEMT's, an active LO balun, a passive IF balun and a passive RF power divider, At 16 dBm LO power, this mixer achieves the conversion losses of 8-10 dB for 4-15 GHz RF and 8-11 dB for 2-16 GHz RF, The simulated conversion losses of both mixers are very much in agreement with the measured results, Also, the DB mixer achieves a third-order input intercept (IP3) of +19.5 to +27.5 dBm for a 7-18 GHz RF and 1 GHz IF at a LO drive of 16 dBm while the SE mixer achieves an input IP3 of +20 to +28.5 dBm for 2 to 16 GHz RF and 1 GHz IF at a 16 dBm LO power, The bandwidth of the RF and LO frequencies are approximately 6:1 for the DB mixer and 8:1 for the SB mixer, The DB mixer of this work is believed to be the first reported DB resistive HEMT MMIC mixer covering such a broad bandwidth.