An F-band fundamental mixer using 75-nm InP HEMTs for precise spectrum analysis

A broad band, single fundamental mixer is developed by using 75-nm InP HEMT technology for use in precise spectrum analysis at frequencies above 110 GHz. The mixer has a diplexer at the drain terminal separating LO/RF signals from an IF signal and functions in both resistive and drain-LO-injection modes. In the drain-LO-injection mode, a conversion loss of 3 dB is measured on-chip. The mixer exhibits an IF bandwidth of more than 20 GHz on a wafer at an RF frequency of 116 GHz with an LO signal of 110 GHz and LO power of only 3 dBm. On the other hand, a conversion loss of 6.5 dB and an IF bandwidth of more than 30 GHz are measured on-chip in the resistive mode. The mixer chip is mounted in a module package, and we report on design and characterization of the mixer and module package. Our mixer module shows promise for millimeter-wave high precision measurements or wireless communication systems because of its low conversion loss, wide bandwidth, and low LO power performance.