Homodyne mixing at 150 GHz in a high electron mobility transistor

We explore the possibility of using an AlGaN/GaN high electron mobility transistor (HEMT) as a free-space coupled homodyne mixer. We used 150 GHz radiation from a Free Electron Laser, hence 5 times higher than the HEMT nominal band center at 30 GHz. The homodyne mixing provides a quasidc output signal, which makes the HEMT a detector of the radiation at 150 GHz.