Abstract

This paper describes the design of a resistive monolithic Q-band HEMT mixer for optimum conversion loss and IMD performance. Transistor two-sided harmonic measurements across Vds and Vgs revealed the presence of IMD sweet spots that were used to optimize the conversion loss and IMD behavior of the mixer.Minimum conversion loss of 10 dB was measured in the 40.8-49 GHz RF frequency band,showing a reasonable agreement with simulation results.Mixer single-tone IMD was measured and simulated.The minimum output level at 3FIF was less than –102 dBm for an RF input level of –10 dBm and for a bias point near the predicted sweet spot.