High‐Isolation Low Cross‐Polarization Phased‐Array Antenna for MPAR Application

Abstract

The design and analysis of 12 × 12‐element planar array of a dual‐polarized aperture‐coupled microstrip patch antenna operating in the frequency band of 2.7 GHz to 3.0 GHz for multifunction applications are presented. High‐isolation between horizontal and vertical polarization ports and low cross‐polarization are achieved through an aperture‐coupled feed. The reflection coefficient and the isolation of horizontal and vertical ports at different scan angles are examined. The array antenna is fabricated and its radiation patterns are measured in the far‐field and near‐field chambers. The embedded element pattern of designed element is measured in the near‐field chamber and is used for calculating the array scanning radiation pattern.

Meta-Surface Wall Suppression of Mutual Coupling Between Microstrip Patch Antenna Arrays for THZ-Band Applications

“…This is because on a finite ground-plane the surface waves are reflected and diffracted at the edges of the substrate, which results in a significant amount of energy loss [4,5]. To date numerous techniques have been explored to improve the radiation performance of patch antennas implemented on substrates [6][7][8]. This includes incorporating photonic bandgap (PBG) or electromagnetic bandgap (EBG) structures around the radiating elements [9][10][11][12].…”

Far‐field cancellation of cross‐polarisation based on mirroring subarrays of densely arranged PDM apertures

“…So far, to our knowledge, similar theoretical analysis and practical implementations have not been reported. Compared to previous approaches based on mirroring elements [11][12][13][14][15][16][17][18][19], this approach is array based. To obtain an optimal XPD, the only requirement is the identity of the mirrored subarrays, regardless of the scale and their original XPD.…”

“…However, due to the near-field coupling between the densely arranged elements, the effectiveness of this method was severely reduced. Conventional study showed that mirroring the neighbouring radiating elements could improve the XPDs [11][12][13][14][15][16][17][18][19]. However, while the near-field coupling was not considered, mirroring neighbouring elements will result in significantly enlarged feeding networks.…”

“…In this work, we propose a robust, subarray-based three-step approach that can significantly enhance the XPD specification of such array antennas. Different from conventional methods that rely on designing highly isolated orthogonal mode transducers (OMTs) and mirroring neighbouring radiating elements [9][10][11][12][13][14][15][16][17][18][19], this approach is based on mirroring identically divided subarrays. Theoretical, simulation and experimental results showed that by dividing an in-phase feed planar array into identical subarrays and properly arranging them into a π-phase feed array, the XPD of the original array could be remarkably enhanced using far-field cancellation.…”

Dual‐polarised hybrid feed microstrip patch antenna for multifunction application

“…Also, since the network of weather surveillance (WSR-88D) radars has been upgraded to dualpolarised radars, it is required that MPAR be capable of transmitting and receiving horizontally and vertically polarised waves simultaneously. In terms of bandwidth, MPAR is required to operate from 2.7 to 2.9 GHz, which is the frequency band assigned for aeronautical radio navigation [3,4].…”