Circularly Polarized High Gain Antenna Design Using Slot‐Notch Mechanism for Millimeter Wave 5G Applications

Abstract

This study presents the development of a compact, broadband microstrip patch antenna operating at 32.6 GHz, tailored for fifth‐generation (5G) millimeter‐wave (mm‐wave) communication systems. Designed on low‐loss Rogers RO4003 ( ε r = 3.38, 0.8 mm), the structure ensures minimal dielectric loss and stable broadband performance. The radiating patch includes a central rectangular slot for bandwidth enhancement, upper‐corner open‐ended notches for current control and surface‐mode suppression, and lower‐edge rectangular stubs to improve impedance matching and polarization performance. The proposed design exhibits a resonant frequency centered at 32.6 GHz and delivers a measured impedance bandwidth of 1.5 GHz (31.7–33.2 GHz). At resonance, the antenna exhibits −24.8 dB reflection, indicating excellent matching. In terms of characteristics, the antenna achieves a peak gain of 7.2 dB at 32.6 GHz, making it suitable for directional transmission in compact communication modules. The proposed antenna supports circular polarization, reducing polarization mismatch and multipath fading. It achieves a 0.5 GHz 3‐dB axial‐ratio bandwidth (32.4–32.9 GHz), ensuring stable circular‐polarization performance over a significant portion of the operating band. A prototype of the antenna was fabricated and tested, with the experimental results showing excellent agreement with simulated data, thereby confirming the design's viability for real‐world mm‐wave 5G applications.