Reactive reflectors

A reflector that satisfies Abbé´s sine condition requires the angle of reflection to differ from the angle of incidence. This can be achieved with an artificial reactive surface with variable reactance. To show this, a wedge made of an array of shorted square waveguides is investigated both theoretically and experimentally. It is shown that an analysis, based on the modal-matching technique, can accurately predict the scattered beam positions and magnitudes due to an incident wave of either parallel or perpendicular polarisation. The angle of reflection can easily be controlled by choosing a proper wedge angle. The results suggest a great promise for the design of a coma-corrected reflector or lens antenna for both polarisations.