Design of Compact Rotman Lens Using Truncated Ports With Energy Distribution Slots

Qiuyan Liang,Jianping Zhao,Guanxi Zhang,Baohua Sun,Gaonan Zhou

doi:10.1109/access.2019.2925000

Qiuyan Liang, Jianping Zhao + Show 3 more

Open Access

https://doi.org/10.1109/access.2019.2925000

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Abstract

A compact Rotman lens is presented in this paper. The compact Rotman lens consists of a lens body and truncated ports with the energy distribution slots. By truncating the long triangular transitions of the traditional Rotman lens, the lengths of lens ports are reduced effectively. However, the impedance discontinuity problem is caused by truncating the triangular transition. To solve this problem, the energy distribution slots are designed between the feed lines and the truncated lens body apertures. The energy distribution slot is evolved from the 1-2 power divider, which creates a transition process for the wave energy propagating from the feed lines and realizes good impedance match between the lens body and the feed lines. To validate the proposed design, a 4×7 Rotman lens has been designed and prototyped at 10 GHz. The Rotman lens exhibits a scanning range of ±33°, 27% bandwidth for VSWR <; 2, and the isolation between beam ports better than 17.2 dB within the operation bandwidth. Basing on the advantages of compact size, low cost, easy processing, and wide bandwidth, the proposed compact Rotman lens may have wide applications in the multi-beam antenna systems.

Highlights

Passive beam-formers have received considerable attention with the expansion of wireless communications in the last several decades [1]–[3]
Due to its many advantages such as true time delay (TTD) characteristics, multi-beam capabilities, and wide bandwidth, it has been widely used in multibeam antenna systems, such as commercial radars and base stations antenna systems
In [10], a multilayer substrate integrated waveguide (SIW) technology is used to fold the array ports of the Rotman lens and the broadband star-shaped coupling slots are used as transition, which constitute a compact multi-beam antenna system

Summary

INTRODUCTION

Passive beam-formers have received considerable attention with the expansion of wireless communications in the last several decades [1]–[3]. In [10], a multilayer substrate integrated waveguide (SIW) technology is used to fold the array ports of the Rotman lens and the broadband star-shaped coupling slots are used as transition, which constitute a compact multi-beam antenna system. Q. Liang et al.: Design of Compact Rotman Lens Using Truncated Ports With Energy Distribution Slots. Are not suitable for the massive civilian applications Another approach to reduce the physical size of the Rotman lens is to use the dielectric substrates with high permittivity. Most of such substrates are expensive and not suitable for the massive productions.

STRUCTURE OF COMPACT ROTMAN LENS

STEP 1

STEP 2

CONCLUSION