A triple band local oscillator coupling system based on a phase grating for five-meter Dome-A terahertz explorer telescope.For heterodyne receivers, broadband and integrated local oscillator (LO) coupling schemes are crucial.  In this paper, we present a novel terahertz broadband receiver system based on a one-pixel phase grating.  We designed a phase grating that can simultaneously couple the LO signals at 690, 850, and 1300 GHz to a superconducting hot-electron bolometer mixer at the incident angles of 25.7°, 20.6°, and 13.3°, respectively.  At these three frequencies, the measured diffraction efficiencies of the phase grating are as high as 70%, 73%, and 65%, and the total power coupling efficiencies of the LO coupling system are 22%, 23%, and 23%, in good agreement with the simulated results. 
phase grating
We designed a phase grating that can simultaneously couple the LO signals at 690, 850, and 1300 GHz to a superconducting hot-electron bolometer mixer at the incident angles of 25.7°, 20.6°, and 13.3°, respectively. 
superconducting hot-electron bolometer mixer
A triple band local oscillator coupling system based on a phase grating for five-meter Dome-A terahertz explorer telescope.For heterodyne receivers, broadband and integrated local oscillator (LO) coupling schemes are crucial.  This efficient and highly integrated multiband receiver system has potential applications in the proposed Five-meter Dome-A Terahertz Explorer telescope.
Five-meter Dome-A Terahertz Explorer telescope