COMPUTATIONAL ELECTROMAGNETIC ANALYSIS OF WAVEGUIDE-FED ANTENNAS FOR IMPROVED RADIATION AND PROPAGATION CHARACTERISTICS

Accurate control of guided-wave propagation and aperture radiation is essential for achieving efficient and directional performance in waveguide-fed antennas operating at microwave and millimeter-wave frequencies. This study presents the design and full-wave electromagnetic analysis of a rectangular waveguide-fed antenna operating at 11.10 GHz. The methodology combined analytical characterization of the dominant TE₁₀ mode with computational electromagnetic simulation using CST Studio Suite 2024 and a frequency-domain solver over 8-14 GHz. For an air-filled rectangular waveguide with a broad-wall dimension of 22.86 mm, the calculated TE₁₀ cutoff frequency was 6.56 GHz. The simulation evaluated field distributions, S-parameters, VSWR, impedance bandwidth, radiation efficiency, directivity, realized gain, far-field characteristics, and electromagnetic power flow. At the operating frequency, 0.985 W of input power was accepted, while 0.922 W was radiated through the aperture, demonstrating effective electromagnetic energy transfer. The results confirmed satisfactory directional radiation and TE₁₀-mode operation, indicating the suitability of the configuration for mmWave communication. Future optimization should address bandwidth enhancement, fabrication validation, beam steering, and antenna-array integration.