A high aperture efficiency, single reflector antenna with 60 degrees scanning

The author describes a novel type of microwave single-reflector antenna, with surface geometry based on an ellipse rather than a parabola, which gives a much greater field of view. This scanning reflector, like the torus antenna, combines reasonable scanning in one plane with good focusing in the other. It is superior in scanning ability to the torus and all other single reflectors because it has much greater aperture efficiency and is thus smaller while giving the same performance. The surface has been optimized for minimum aperture phase errors and numerically simulated. The scanning profile is a fourth-order curve that approximates tilted parabolas over different limited ranges. Extending the profile into a two-dimensional focusing surface is accomplished using an iterative perturbation method to minimize its variation from the appropriate tiled paraboloid. Excellent results are attained for a single reflector with a +or-30 degrees field of view, with almost no peak gain loss and only 1.5-dB sidelobe elevation for a 30 lambda wide aperture.<>