Ultrawideband Compact Magnetoelectric Dipole Antenna/Array With Dual-Polarization

Abstract

Design of ultra-wideband (UWB) dual-polarized antenna with compact size is presented in this communication, which is composed of a triple-layer magnetoelectric (ME) dipole, a pair of cross-placed Γ-shaped feeding structure and a box-shaped reflector. Three layers of the ME dipole cover low (around 1.5 GHz), middle (3.5 GHz) and high (4.5 GHz) bands respectively, leading to an ultra-wide operating band from 1 to 5 GHz. The total size of the design is 75mm (0.75λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) × 75mm (0.75λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) × 55mm (0.55λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ). An array that consists of 8 such antenna elements is designed, fabricated, and measured. Results show that the voltage standing wave ratio (VSWR) is less than two over the whole operating band for all ports. As for the radiation characteristics, boresight gain ranging from 5.3 to 8.8 dBi is achieved for each antenna element, when it comes to the array, a peak gain of 17.23 dBi occurs at 4 GHz when all the antenna elements are excited with identical amplitude and phase. Beam scanning is also realized in the whole operating band through phase disposing, the scanning range is up to ±45° from 1 to 2 GHz and ±30° from 2 to 5 GHz.