Experimental realisation of micromachined terahertz waveguide-fed antipodal tapered slot antenna

A terahertz (THz) waveguide-fed antipodal tapered slot antenna (ATSA) based on silicon micromachined technology is proposed. The ATSA is composed of an antipodal tapered slots structure and a WR2.2 feeding waveguide, monolithically fabricated by deep reactive-ion etching, and sputtering gold and gold-gold thermo-compression bonding. The input return loss is tested and shows a level below -15 dB within 480 to 500 GHz. The gaussicity of radiation patterns at the working band is calculated to be 90%. Through further experiment, at 492 GHz, the ATSA exhibits asymmetric beamwidths of 25.5° and 25° in the E- and H- planes, respectively, and sidelobes below -8 dB, along with a 14.6 dB gain, which agree well with the simulated results. The proposed THz waveguide-fed ATSA is suitable for use as a feeder of THz imaging and detection systems.