Micromachined waveguide antennas for 1.6 THz

J.W. Bowen, S. Hadjiloucas, B.M. Towlson, L.S. Karatzas,
S.T.G. Wootton, N.J. Cronin, S.R. Davies, C.E. McIntosh,
J.M. Chamberlain, R.E. Miles and R.D. Pollard

A new type of horn antenna for operation at 1.6 THz, that can befabricated 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. 1.6 THz radiation pattern measurements for different designs show that, while there is scope for further optimisation, 3 dB beamwidths of 24° and 17.5° in the E- and H-planes, respectively, can be achieved.