Computational analysis of the effect of absorber shape and size on antenna performance in an anechoic chamber

Anechoic chambers play a critical role in EMC testing, aerospace, and space applications, providing a reflection-free environment essential for accurate antenna characterization and electromagnetic measurements. The paper investigates the effect of different shapes and sizes of absorbers in an anechoic chamber on antenna performance. The chamber is modeled with absorbers made of carbon-loaded foam, with three distinct shapes: pyramid, oblique pyramid, and block-shape, and different absorber lengths, which are considered as parameters for the study. A biconical antenna, commonly used for broadband EMC testing, is placed in the chamber, and its reflection coefficient, and directivity are analyzed. The results emphasize that absorber geometry significantly influences the performance of both the chamber and the antenna. Additionally, theoretically calculated absorber heights do not always yield optimal results, highlighting the need for systematic optimization.<p></p>