Side lobe level reduction of pyramidal double ridged horn antenna

Abstract

Ridged horn antennas are widely used for broadband applications. Horn antennas, ridged or non-ridged, suffer from side lobes. In this paper, a double ridged horn antenna will be presented, with a unique ridge shape. A configuration has been found for high gain and low side lobe level at the H-plane, and at the E-plane in contrary to what is found in most of the ridged horn antennas. A VSWR of 1.4:1 was simulated at a frequency range of 2.7–3.5 GHz with a perfect waveguide port for the designed antenna, and a VSWR of around 1.8:1 was measured at a frequency of 3 GHz using a coaxial to waveguide adapter for the fabricated antenna. Both of the simulated and measured results show that the unique ridge shape has high influence on the side lobes — for specific frequencies. The presented antenna is similar to corrugated horn antenna in terms of antenna parameters and performance — both show low side lobe levels. Inside the horn, exist two polygons with the same thickness of the used waveguide ridges, which are the proposed novel ridges.