A Compact Circularly Polarized Octagonal Microstrip Patch Antenna for Wi-Fi 6E Communications

Abstract - Wi-Fi 6E extends the Wi-Fi 6 standard into the newly opened 6 GHz band (5.925–7.125 GHz), offering wider channels and reduced congestion compared to 2.4 GHz and 5 GHz bands. Compact antennas operating in this band are needed for access points, client devices, and IoT terminals. This paper presents a compact circularly polarized (CP) microstrip patch antenna operating at 6.2075 GHz, designed for Wi-Fi 6E communication systems. The antenna uses an octagonal radiating patch on a Rogers RT/duroid 6002 substrate (εr = 2.94, h = 1.6 mm). Right-hand circular polarization (RHCP) is achieved by cutting an inclined rectangular slot at the patch centre and placing parasitic octagonal slots near the patch boundary. A rectangular slot in the ground plane acts as a defected ground structure (DGS) to tune impedance and keep the axial ratio low. The antenna was developed through four design stages in Ansys HFSS. The final design achieves S11 = −33.75 dB, VSWR = 1.04, gain = 3.67 dB, and axial ratio = 2.16 dB. The 3.67 dB gain gives a broad beam suitable for indoor Wi-Fi 6E coverage, where wide angular coverage matters more than a narrow high-gain beam. The design is single-fed, compact, and built on standard PCB material. Key Words: Wi-Fi 6E; 6 GHz band; circular polarization; defected ground structure (DGS); microstrip patch antenna; octagonal patch; RHCP; indoor communication.