Device considerations and modeling for the design of an InP-based MODFET millimeter-wave resistive mixer with superior conversion efficiency

We report on the device considerations for resistive FET mixer applications and discuss the design and fabrication of an optimized InP-based 0.1 /spl mu/m gate length planar-doped pseudomorphic In/sub 0.42/Al/sub 0.58/As-In/sub 0.65/Ga/sub 0.35/As modulation-doped FET (MODFET) well-suited for resistive mixer applications. In addition, we present a general large-signal model suitable for describing the FET in its passive mode of operation to assist in the design and simulation of such mixers. Finally, we discuss the theoretical design of a novel W-band, image-reject resistive mixer based on a large-signal model of our optimized device. The predicted performance of the mixer under +8 dBm of LO drive indicates a minimum conversion loss of 9 dB at 94 GHz, a significant improvement of over 3 dB in comparison to similar GaAs-based mixers, suggesting the potential of InP-based resistive mixer technology to achieve superior conversion loss performance.<
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