Low-Profile Proximity-Coupled Cavity-Less Magneto-Electric Dipole Antenna

Magneto-electric dipole (ME-dipole) antennas offer several advantages, including wide impedance bandwidth, stable high gain, unidirectional radiation, and low back-lobe radiation patterns, making them suitable for modern wireless communication systems. However, the thickness of conventional ME-dipole antennas is typically about a quarter wavelength (0.25 (Formula presented.) ) at the center operating frequency, which may not be desirable for portable device applications. This work introduces a new feeding method that reduces the antenna profile and ground plane size while maintaining the same advantages. A suspended horizontal line is proposed to excite the cavity-less ME-dipole antenna through proximity coupling. The measured results demonstrate a wide impedance bandwidth of 45.3% (ranging from 2.05 GHz to 3.25 GHz) and an average in-band gain of 9 dBi with stable (Formula presented.) dBi in-band variation with a ground reflector of size about 0.89 (Formula presented.). More importantly, the cavity-less design reduces the overall thickness of the antenna to 0.17 (Formula presented.) at the center operating frequency.