Design and characterization of a broadband focal plane array for THz imaging

A novel broadband monolithic THz antenna design that covers the 0.625 THz-1.125 THz band is developed as the imaging pixel of THz focal plane array. Each pixel consists of heterostructure backward diodes monolithically integrated with impedance tuned THz antennas. Since THz responsivity of the pixel is optimized by conjugate matching between the antenna and the diode, it is important to characterize antenna impedance. To this end, an indirect impedance characterization method for THz antennas using coplanar probe measurements is presented.