W-band Broadband Mixer

In communication system, broadband mixer playing a important role in the super-heterodyne receiver is a crucial component of the system. The broad RF bandwidth can be utilized to extend the frequency range of existing receivers. The study of the broadband mixer is meaningful in the communication system.Broad-band integrated circuit mixers using the fin-line-suspended microstrip hybrid configuration are designed. The signal of LO passes through the waveguide-to- suspended microstrip and suspended band-pass filer to two diodes. The signal of RF passed through the waveguide-to-fin-line to two diodes too. The IF power is exported through the low-pass filter .The isolation between LO port and RF port is well received because fin-line and suspended micro-stripe have made up a 180 degree knot.Two broadband mixers have been fabricated and tested with the LO at 94GHz. The conversion losses are both less than 10dB with the RF swept from 75 to 110GHz .For the mixer of number 1, the conversion losses are less than 9dB with the RF swept from 75 to 105GHz and the isolation of LO-IF is more than 25dB. For the mixer of number 2, the conversion losses are less than 9dB with the RF swept from 77 to 105GHz and the isolation of LO-IF is more than 30dB.The P1dB of RF port are both more than 5dBm.