New approach to the design of corrugated horn antennas

Abstract

In this paper, we present two new corrugated horn antenna designs in circular waveguide. The first one is a converter horn antenna from monomode circular waveguide TE11 to corrugated waveguide HE11 mode in a very efficient way. The conversion efficiency varies between 98 % and 99%. The HE11 mode has highly desired radiation pattern characteristics for applications like satellite communications, radar, remote- sensing, etc, nevertheless, when the requirements are more stringent this mode is not good enough and we must look for other solution. This one corresponds to the fundamental gaussian beam, which has outstanding features, such as being a free space mode, having high matching efficiency with a reflector, no sidelobes, perfect symmetry, etc. The second horn antenna presented generates very efficient fundamental gaussian beams at the output (99%-99.9%). It is important to say that the input must look like a gaussian beam, an HE11 for instance, which presents a 98.4% of gaussian beam or similar. We also show a new design in which we are working now, consisting in the junction of the two aforementioned designs. They form an unique horn antenna that results in the TE11 mode, from the fundamental gaussian beam mode. These components have been analysed using the Mode Matching and the Generalised Scattering Matrix techniques and the Moment Method as well as the equations in [1] to get the far field radiation pattern. Our results have been checked against those obtained by other authors.