# Wideband tilted beam end-fire antenna using double semi-circular rings

## TL;DR

A new compact antenna design is introduced for high-frequency wireless communication, offering wide bandwidth and high gain suitable for 5G and mmWave applications.

## Contribution

The novel design of a wideband tilted-beam end-fire antenna using double semi-circular rings for microwave and mmWave applications is presented.

## Key findings

- The antenna is impedance matched from 11.5 to 62.5 GHz with return loss better than 12 dB.
- It achieves a peak gain of 11.6 dBi at 40 GHz with a compact electrical size of 1.28 × 1 × 0.08 λ₀³.
- The design provides end-fire radiation with a tilted beam angle of 65° ± 10° in the 24–40 GHz range.

## Abstract

This article presents a novel wideband (WB) tilted-beam end-fire planar antenna for microwave and millimeter-wave (mmWave) applications. The antenna comprises of a microstrip fed double semi-circular rings over a curvilinear slotted ground plane. It is impedance matched over a broad frequency range from 11.5 to 62.5 GHz, covering the 5G New Radio (NR) mmWave bands n257, n258, n260, n261, and partly covering the unlicensed 60 GHz band. Across this entire band, the antenna exhibits a return loss better than 12 dB and a gain exceeding 6.5 dBi, with a peak gain of 11.6 dBi at 40 GHz. The overall electrical size of the antenna is 1.28 \documentclass[12pt]{minimal}
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\begin{document}$$\textrm{65}^{\circ }$$\end{document} ± \documentclass[12pt]{minimal}
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\begin{document}$$\textrm{10}^{\circ }$$\end{document}. A prototype of the antenna is fabricated and experimentally characterized. The measured results show good agreement with full-wave simulations, validating the proposed design. Owing to its compact planar geometry, wide bandwidth, and high gain, the antenna is a strong candidate for future high-data-rate wireless communication systems.