Bandwidth extended designs of double-ridged guide horn antennas

Abstract

The explosive growth in bandwidth requirements on antennas and antenna systems, driven by various industries, also drives the need for the ever‐increasing bandwidth of antennas used for testing. The broadband Double-Ridged Guide Horn (DRGH) antenna finds widespread use in antenna measurement and ElectroMagnetic Compatibility/Interference (EMC/I) testing. An example of a DRGH used extensively for testing is the 1-18 GHz DRGH antenna. A study using ElectroMagnetic (EM) simulation was performed to determine the factors that limit the bandwidth of these antennas. All the parts and sub-assemblies of the DRGH were investigated to determine the impact of each part and or sub-assembly on the electrical performance of the antenna. This was done in simulation using reduced complexity models and parametric studies. The design changes that resulted from this study were implemented in several prototype antennas used for verification. It was found that it is possible to design DRGH antennas with bandwidth ratios of 100:1 and possibly beyond. It is expected that at higher frequencies, the limit will be the manufacturing tolerances and technology, and at lower frequencies, the maximum permissible size of the antenna.