Dual-Beam and Tri-Band SIW Leaky-Wave Antenna With Wide Beam Scanning Range Including Broadside Direction

Yunjie Geng,Yujian Li,Zheng Li,Zhan Zhang,Meie Chen,Junhong Wang

doi:10.1109/access.2019.2957763

Yunjie Geng, Yujian Li + Show 4 more

Open Access

https://doi.org/10.1109/access.2019.2957763

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Abstract

In this letter, a novel dual-beam and tri-band leaky-wave antenna (LWA) based on substrate integrated waveguide (SIW) structure is proposed, which has the capability of wide beam scanning range including broadside direction. The antenna consists of two kinds of periodic structures which can excite two -1st spatial harmonic waves and result in two radiation beams simultaneously. Through theoretical dispersion diagram analysis of the unit cells of two periodic structures and by applying the techniques of impedance-matching and reflection-cancelling, the open-stopbands at broadside are suppressed. Then the main beam of the proposed LWA can scan from backward to forward through broadside when frequency changes. Moreover, a tri-band application can be achieved in the dual-beam antenna by optimization of the second periodic structure. The measured results validate that the proposed SIW LWA has three operating frequency bands. In band 1 from 8.6 to 9.2 GHz, there is one beam scanning from 42° to 71° in the forward, in band 2 from 10 to 12 GHz, there is one beam scanning from -40° to 4° in the backward, and in band 3 from 12.5 to 15 GHz, there is a dual-beam scanning from -55° to 54° including broadside direction, which show good agreements with the simulated results.

Highlights

Leaky-wave antennas (LWAs) have attracted significant attentions in microwave and millimeter-wave regions due to their simple feeding network, frequency beam scanning capability and high directivity [1]
LWAs are classified as uniform structures [5], [6] and periodic structures [7], [8] based on the guiding wave systems
The periodic LWA is formed by introducing periodic unit cells along slow-wave guiding structure

Summary

Introduction

Leaky-wave antennas (LWAs) have attracted significant attentions in microwave and millimeter-wave regions due to their simple feeding network, frequency beam scanning capability and high directivity [1]. These features make leaky-wave antenna a good candidate for modern wireless communication systems, e.g. automotive radar sensor [2], analog real-time spectrum analyzer [3], and the fifth generation (5G) mobile communication [4]. The slow-wave structure itself is a non-radiation structure, but the introduced periodic unit cells can excite infinite spatial harmonics, some of which are locating in the fast-wave region, such as the -1st spatial harmonic (n = -1) mode, and can leak away from the structure. In the open-stopband region, a large reflection coefficient is encountered and the radiation power drops substantially

Methods

Findings

Conclusion