High-Performance Circularly Polarized MIMO Antenna for 5G mmWave n261 Band Using Asymmetric Stubs

This research presents the design and analysis of a circularly polarized MIMO antenna employing an inset-fed rectangular patch integrated with asymmetric stubs and slots. The antenna is specifically optimized for 5G millimeter-wave (mmWave) applications targeting the n261 band (27.50–28.35 GHz), with a center frequency of 28 GHz.The structure is fabricated on a Rogers RT/duroid 5880 substrate, characterized by a compact footprint of 19.64 × 30.25 × 0.79 mm³. The proposed design achieves operating bandwidth of 27.44 - 28.79 (1.36) GHz.based on the 2:1 VSWR and operating bandwidth of 1.28 GHz (27.46–28.74 GHz) based on the –10 dB return loss criterion