Micromachined waveguide antennas for 1.6THz

A new type of horn antenna for operation at 1.6THz, that can be fabricated monolithically with 1/4-height micromachined waveguide, is described. Height limitations imposed by the micromachining process are overcome by removing a tapered slot in the upper surface of a scalar horn, allowing the E-plane fields to extend outside the confines of the metallic structure before radiation, with a consequent reduction in E-plane beamwidth. 1.6THz radiation pattern measurements for different designs show that, while there is scope for further optimisation, 3dB beamwidths of 24 deg and 17.5 deg in the E- and H-planes, respectively, can be achieved.