A Wideband Magnetoelectric Dipole Antenna With Wide Beamwidth for Millimeter-Wave Applications
Zhiming Xiao, Yongmei Pan, Xiyao Liu, Kwok Wa Leung
Abstract
A wideband magnetoelectric (ME) dipole antenna with wide half-power beamwidth (HPBW) in both the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> -planes is investigated for millimeter-wave (mm-wave) applications. This antenna mainly consists of a core ME dipole structure at the center and two parasitic Π-shaped patches at the two sides, and it is fed by a Γ-shaped probe. Compared with the traditional ME dipole antenna fed by an L-shaped probe, the proposed ME dipole shows a comparable impedance bandwidth of over 50%, but it exhibits a more simplified configuration and a smaller footprint due to the loading effect of the Γ-shaped feeding probe. Moreover, thanks to the supplementary effect of the end-fire radiation characteristics of the parasitic Π-shaped patches, the proposed antenna features much expanded beamwidths in both the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> -planes. The measured results indicate that this antenna with a footprint of 0.442λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.268λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> can obtain a −10 dB impedance bandwidth of 61.7% (21.4–40.5 GHz), a 3 dB gain bandwidth of 47.5% (23.9–38.8 GHz), and a 120°-HPBW pattern bandwidth (within the band, the HPBWs of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> -planes are both over 120°) of 32.3% (26–36 GHz), showing merits of small size, wideband, and widebeam, which are very desirable for the mm-wave wireless communication systems and radar systems.