120 GHz GaAs Single-Balanced Mixer

This paper presents a resistive down-conversion single-balanced mixer in WIN semiconductor's 0.1 mu m GaAs process. This mixer operates within the low terahertz region up to a frequency of 120 GHz. The measured upper-side band conversion loss is lower than 12.2 dB up to 115 GHz and lower than 14.4 dB up to 120 GHz at a fixed LO frequency of 110 GHz. The LO-RF isolation of the mixer is further enhanced using a selective drain biasing technique, which is demonstrated for the first time in the low terahertz region. The article also includes the first demonstration of phase and magnitude imbalances between the two output IF signals at these low terahertz frequencies, which are measured to be less than 7.6 degrees and 0.41 dB, respectively, within an IF frequency range of 1-8 GHz.