High Gain and Low Grating Lobe Electrically Large Array Antenna by Using Fabry-Perot Cavity

Yunyang Zhang,Ting Pan,Zuping Qian,Wenquan Cao

doi:10.1109/access.2019.2933404

Abstract

In this paper, a high gain and low grating lobe electrically large array antenna is proposed by using Fabry-Perot cavity (FPC). The feeding array antenna is composed by elements with electrically large property (ELP) based on TM30 mode. The FPC between a ground plane and a single-layer partially reflecting surface (PRS) made by substrate with arrays of square metal patches printed on both the top and bottom surfaces is used here to narrow the beamwidth of element patterns, thus the large grating lobes of array caused by large element spacing can be avoided. By analyzing the parameters of PRS unit cell, suitable cell spacing is determined. Finally, a 2 × 2 array was fabricated and measured to validate its effectiveness. Measurements demonstrate that the gain of the array can reach up 20.9dBi at the center working frequency. When the element spacing is 1.47λ0, the maximum grating lobe level at 21GHz is only -15.5dB.

Highlights

Microstrip antenna plays an important role in communication system
Planar antennas with electrically large property (ELP) that break through size limitation of traditional patch antenna can solve the problem to some extent [1]–[3]
In order to solve the above contradiction and realize low grating lobe array by using ELP element, in Fig. 1(b), a single-layer partially reflecting surface (PRS) is added as a superstrate above the ELP antenna to adjust the element patterns

Summary

INTRODUCTION

Microstrip antenna plays an important role in communication system. With the actual requirements of broadband and high-speed data transmissions, the development of microstrip components in millimeter wave (MMW) and terahertz (THz) wave bands have become an inevitable trend. Y. Zhang et al.: High Gain and Low Grating Lobe Electrically Large Array Antenna by Using FPC decreases complexity of design and optimization as well as simplify manufacturing and reduce cost. Zhang et al.: High Gain and Low Grating Lobe Electrically Large Array Antenna by Using FPC decreases complexity of design and optimization as well as simplify manufacturing and reduce cost This method of solving large element spacing in arrays is proposed and applied in [9]. As is well-known, Fabry-Perot cavities (FPC) is often used to enhance antenna gain and expand bandwidth [10]–[18] compared with traditional antennas [19], [20] This structure has excellent advantage to suppress the grating lobes of array caused by large element spacing.

ANTENNA DESIGN AND WORKING PRINCIPLE

PARAMETER ANALYSIS

CONCLUSION