Substrate Integrated Waveguide Filtenna With Two Controllable Radiation Nulls

Chuanyun Wang,Zhiwen Han,Haiwen Liu,Xin Wang,Zhijiao Chen

doi:10.1109/access.2020.3005948

Abstract

In this paper, a novel substrate integrated waveguide (SIW) filtenna with two controllable radiation nulls is proposed, which has the advantage of good radiation characteristics. Radiation nulls are generated by electric and magnetic mixed coupling structure and fundamental mode, respectively. And a quasi-elliptic characteristic can be obtained at the boresight gain direction. By changing the length of perturbation slot and the strength of electric coupling and magnetic coupling, the position of radiation nulls can be controlled independetly. Compared to conventional filtenna, the proposed SIW filtenna has no extra filtering circuit to increase the dimension and complexity. Two resonant modes in the passband can be excited through loading electric and magnetic mixed coupling structure in one SIW cavity. The measured results are in good agreement with simulated results. The good frequency selectivity and out-of–band rejection are achieved. The proposed antenna exhibits a maximum realized gain of 5.8 dBi at the operating bandwidth. The measured impedance bandwidth is from 9.44 GHz to 9.68 GHz and the cross-polarization levels are lower than -20 dB in both planes.

Highlights

With the development of substrate integrated waveguide (SIW) technology owning some advantages such as low profile, easy integration and so on, SIW has been studied by lots of experts in microwave and millimeter wave communication systems [1], [2]
Filtenna is a good method to significantly reduce the size of the RF front-end of communication systems
The relative dielectric constant and loss tangent are 2.2 and 0.0015, respectively. It consists of a SIW cavity and electric and magnetic mixed coupling structure, a transverse slot as radiation element is located in the center of resonant cavity

Summary

Introduction

With the development of substrate integrated waveguide (SIW) technology owning some advantages such as low profile, easy integration and so on, SIW has been studied by lots of experts in microwave and millimeter wave communication systems [1], [2]. SIW is widely used to design antennas, filters, and other RF components [4]–[6]. Filtenna is a good method to significantly reduce the size of the RF front-end of communication systems. A lot of filtennas using SIW technology have been investigated and proposed [7]–[15]. [7] proposed a filter antenna using a common cavity cascaded to radiation element. A single-layered SIW filtenna with parasitic patch was proposed in [8].

Methods

Results

Conclusion