Wide-bandwidth electron bolometric mixers: a 2DEG prototype and potential for low-noise THz receivers

A new type of electron bolometric (hot electron) mixer is presented. The authors have demonstrated a three-order-of-magnitude improvement in the bandwidth compared with previously known types of electron bolometric mixers, by using the two-dimensional electron gas (2DEG) medium at the hetero-interface between AlGaAs and GaAs. Both in-house, MOCVD-grown material and MBE material were tested with similar results. The conversion loss (L/sub c/) at 94 GHz is presently 18 dB for a mixer operating at 20 K, and calculations indicate that L/sub c/ can be decreased to about 10 dB in future devices. Calculated and measured curves of L/sub c/ versus P/sub Lo/ and I/sub DC/, respectively, agree well. It is argued that there the several different known configurations of electron bolometric mixers will all show wide bandwidth, and that these devices are likely to become important as low-noise terahertz receivers in the future.<
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