# Hybrid-decoupling-based shared-aperture phased array antenna for Ku/Ka-band with low profile, wide-angle scanning and high isolation

## TL;DR

This paper introduces a compact, dual-band antenna with improved performance for Ku and Ka bands, enabling wide scanning angles and high isolation.

## Contribution

A novel hybrid-decoupling approach combining array decoupling surfaces and defected ground structures for dual-band phased array antennas.

## Key findings

- Ka-band elements achieve wide-angle scanning of ±45° with effective surface current coupling suppression.
- Ku-band elements demonstrate over 31 dB port isolation and scanning up to ±55° in both E- and H-planes.
- The antenna has an ultra-thin profile of 2.35 mm and inter-band isolation of 35 dB (Ku) and 18 dB (Ka).

## Abstract

This paper presents a low-profile Ku/Ka dual-band shared-aperture phased array antenna (SAPAA) that addresses conventional limitations in profile height, port isolation, and scanning angles through a hybrid-decoupling approach combining array decoupling surfaces (ADS) with defected ground structure (DGS), complemented by structural reuse techniques. The Ka-band elements utilize co-designed array decoupling surface layers integrated with DGS to effectively suppress surface current coupling, achieving wide-angle scanning capability of \documentclass[12pt]{minimal}
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\begin{document}$$\pm 45^\circ$$\end{document} across the 32–36 GHz frequency band. For the dual-polarized Ku-band elements, feed matching is optimized through cross-shaped slots employing DGS structural reuse, demonstrating orthogonal port isolation exceeding 31 dB within the 14–18 GHz operational band while extending the scanning range to \documentclass[12pt]{minimal}
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\begin{document}$$\pm 55^\circ$$\end{document} in both E- and H-planes. The antenna features an ultra-thin profile of merely 2.35 mm (0.28\documentclass[12pt]{minimal}
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\begin{document}$$\lambda _h$$\end{document}), with measured inter-band isolation reaching 35 dB in the Ku-band and 18 dB in the Ka-band. Experimental verification confirms the design’s high performance and practical utility, offering a compact solution for multi-band integrated communication systems.