Dual-Band Miniaturized DGS Patch Antenna for High-Efficiency Sub-6 GHz 5G Systems

Sub- 6 GHz 5G user equipment demands compact, low-cost antennas that maintain high radiation efficiency and stable coverage. Conventional microstrip designs often struggle to simultaneously achieve miniaturization, dual-band operation, and robust performance on lossy substrates such as FR-4. Existing dual-band patch antennas based on slot loading, EBG structures, or metasurfaces typically incur increased complexity, larger electrical footprints, or limited bandwidth. To address these limitations, this work proposes a dual-band miniaturized defected-ground-structure (DGS) integrated patch antenna with an inset-fed rectangular radiator optimized for sub-$\mathbf{6 ~ G H z} \mathbf{~ 5G}$bands. The antenna geometry is tuned to generate two wellseparated resonances around 3.50 GHz and 4.90 GHz while preserving a small electrical size suitable for integration in user terminals. A combined dataset of full-wave EM simulations and experimental measurements is used, including reflection coefficient responses, realized gain, radiation efficiency, and E/Hplane patterns across both bands, with S-parameter and far-field data obtained using a vector network analyzer and anechoic chamber. The measured results confirm dual-band operation with fractional bandwidths above ten percent, realized gains of approximately 4.5 dBi and 5.3 dBi in the lower and upper bands, and radiation efficiencies close to ninety percent. Radiation patterns remain quasi-broadside with half-power beamwidths in the$70-80^{\circ}$range and cross-polarization suppression above$\mathbf{2 1 ~ d B}$, indicating good polarization purity. Our results indicate that this proposed zeroth-normalized SCDGS-based miniature antenna represents a very good trade-off in size, bandwidth selfefficiency, and gain making it a suitable contender for future sixth-generation compact sub- 6 GHz 5G user equipment.