A Compact Dual-Band Microstrip Patch Antenna for Sub-6 GHz and mmWave 5G Applications Using Parasitic Loading

This paper presents a compact 5G square shaped microstrip antenna incorporating parasitic patches with dimensions of 50 × 50 × 1.6 mm3. The proposed design introduces a simplified structure capable of covering selected sub-6 GHz frequencies along with the first mm-wave band in a single antenna. The antenna is fabricated on a Rogers RT Duroid 5800B substrate with a relative permittivity of 2.2 and a low loss tangent of 0.0009. To achieve dual-band operation, the radiating patch is integrated with strategically placed parasitic elements and employs a half-ground plane configuration, targeting the N79 band (4.4-5.0 GHz) and the N258 band (24.25-27.5 GHz) allocated for 5G communications. The incorporation of parasitic patches enables resonances at 4.7 GHz and 26 GHz, with Voltage Standing Wave Ratio (VSWR) values maintained below 2, ensuring excellent impedance matching. The measured reflection coefficients reach –32.7 dB at 4.7 GHz and –43.1 dB at 26 GHz, confirming high return loss performance. Furthermore, the antenna demonstrates a peak gain of 5.29 dB at 4.7 GHz and 7.17 dB at 26 GHz, making it suitable for both short-range C-band and long-range K-band applications. Simulation and experimental results show strong agreement in terms of VSWR, reflection coefficients, gain, and radiation pattern, validating the reliability of the proposed design. Owing to its compact structure, efficient radiation characteristics, and multiband capability, the antenna is highly suitable for integrating the above structure into future 5G wireless communication systems.