Quad-Ridge Horn Antenna With Elliptically Shaped Sidewalls

We present a quad-ridge horn antenna as a feed for a reflector antenna for use in radio astronomy applications. The antenna uses elliptically shaped sidewalls to limit the variation of beamwidth over a wide frequency range and to obtain greater radiation pattern rotational symmetry. The antenna is dual-polarized and matched over more than a 4:1 bandwidth. A design procedure is presented and a prototype designed according to this procedure is shown. Measured and simulated results of the prototype agree with each other well. The antenna is analyzed with a prime focus reflector to determine the range of efficiencies that can be expected.