Multiresonant Circular Microstrip Antenna with Defected Ground Structure for X, Ku and Ka Band Sensing and Satellite Applications

Abstract

This paper presents the design and analysis of a compact multiresonant circular microstrip antenna incorporating a defected ground structure (DGS) for high-frequency sensing and satellite communication applications. The antenna is fabricated on a Rogers RT/Duroid 5880 substrate to ensure low dielectric loss and stable performance at microwave frequencies. An H-shaped slot etched in the ground plane modifies the surface current distribution, enabling the generation of multiple resonant modes without increasing antenna size. Simulation results demonstrate distinct operating bands spanning portions of the X, Ku, and Ka frequency ranges, with reflection coefficients below 10 dB, indicating effective impedance matching. The radiation characteristics remain stable across these bands, and the antenna exhibits moderate gain suitable for compact high-frequency systems. The proposed structure combines simple geometry, small form factor, and multiband capability, making it a promising candidate for advanced sensing platforms, satellite links, and wideband microwave devices.