A K-Band subharmonic down-converter in a GaAs metamorphic HEMT process

In this paper, we present the first implementation of a K-band subharmonic down-converter fabricated in a 0.18-mum GaAs Metamorphic High Electron Mobility Transistor (MHEMT) process. The low noise and high gain characteristics of the MHEMTs at K-band allow for the integration of a single-stage amplifier with a subharmonic mixer resulting in low-power broadband performance. The subharmonic mixer exhibits a conversion loss of 13 dB and IIP3 of +8 dBm from 23 to 30 GHz. With the addition of the amplifier, the down-converter exhibits a conversion loss of 3 dB, noise figure of 5 dB, and IIP3 of -5 dBm from 26 to 30 GHz. The single-stage amplifier exhibits InP-like performance with gain of 11 dB, NF of 1.5 dB, and dc power consumption of 15 mW.