Field effect transistor as heterodyne terahertz detector

A theory of nonlinear response of the channel of a field effect transistor subjected to two terahertz beams (measured signal and local oscillator) with the close frequencies has been developed. It is shown that electric current flowing in the transistor channel drastically increases heterodyne efficiency. Also, it is demonstrated that such a heterodyne detector is capable of operating effectively with very high intermediate frequencies up to 10÷100 GHz.