Compact 0.5–18 GHz double‐ridged guide horn antenna

Abstract

Broadband double‐ridged guide horn (DRGH) antennas are extensively used in antenna measurement and electromagnetic compatibility and interference testing, especially the 1– 18 GHz DRGH antenna which is widely accepted as a standard for this band. Certain deficiencies in the radiation patterns have been identified and corrected by several authors, but the use was still limited to the 1–18 GHz frequency band. The incorporation of absorber materials and lenses has resulted in horn antennas with wider bandwidths; however, this complicates the manufacturing process and restricts these designs to lower power applications. Simulated and measured results for a new 0.5–18 GHz (36:1) DRGH antenna are presented here. The wider bandwidth is made possible by a new cavity design and optimising the design of the other antenna sections to allow wideband operation without using a lens or absorber. The new design has double the bandwidth ratio and is very compact, with an aperture size of 26.4 cm 15.2 cm; the aperture sides are less than 12% larger than the sides of the aperture of the conventional 1–18 GHz DRGH antenna (24.2 cm 13.6 cm).