Gap independent coupling into parallel plate terahertz waveguides using cylindrical horn antennas

Abstract

We demonstrate how replacing the silicon lenses, traditionally used to couple radiation into parallel plate waveguides, with integrated cylinder-based horn couplers not only greatly improves ease of use and fabrication but also features gap independent coupling. The couplers, created from chords of a cylinder, give reflection free transmission through the waveguide that is on the order of the quasi-optical approach. The gap independent coupling is demonstrated through a precise measurement of the metal conductivity of the THz skin depth layer.