DESIGN OF CAVITY-BACKED FULL-MODE SUBSTRATE INTEGRATED WAVEGUIDE ANTENNA FOR X-BAND (10 GHZ) APPLICATIONS

Abstract

This paper presents the design and analysis of a cavity-backed full-mode (FM) Substrate Integrated Waveguide (SIW) antenna operating in the X-band at 10 GHz. The proposed work is an extension of an earlier millimeter-wave design initially targeted at 30 GHz, which faced fabrication and measurement constraints. By scaling the design to 10 GHz, reliable fabrication and experimental feasibility are achieved while preserving the advantages of cavity-backed SIW structures, such as high front-to-back ratio, improved aperture efficiency, and enhanced gain. Furthermore, a four-element FM SIW cavity-backed antenna array arranged around a square patch is investigated to demonstrate beam steering through selective ON/OFF excitation and phase control. Simulation results confirm wide impedance bandwidth (~300 MHz), high port isolation (>30 dB), flexible beam steering, and stable radiation characteristics, making the proposed design suitable for X-band communication, sensing, and radar applications.