A K-band Monolithic Multifunctional Mixer with High Reliability under Fast Neutron Radiation

A highly integrated monolithic multifunctional mixer implemented by a 130nm GaAs mHEMT process is presented in this paper. With modified on-chip Marchand baluns, double balanced diode-ring mixer with direct intermediate frequency (IF) extraction is realized. Serving as a selector for transmitting or receiving modes, the IF single pole double throw (SPDT) switch with isolation better than 55dB is demonstrated. A coupler located at the local oscillator (LO) port was also integrated on the chip for power monitoring. Measured results exhibit 6.5-10dB up-conversion loss and 8.7-12dB down-conversion loss of the mixer over the radio frequency (RF) range of 18.5-26GHz. The RF-to-IF, LO-to-IF and LO-to-RF isolations are better than 20dB, 35dB and 45dB, respectively. What's more, effects of fast neutron radiation with fluences up to 1e14/cm2 on the chip's reliability was further studied. With no performance degradation, the fabricated multifunctional mixer is applicable to various wireless and communication systems in hostile environment.