半模SAFSIW谐振腔耦合带通滤波器设计与实现  

Design and Implementation of Half-Mode SAFSIW Resonator Coupled Bandpass Filter

作　　者：刘维红 黄倩 宋维勇 LIU Wei-hong;HUANG Qian;SONG Wei-yong(School of Electronic Engineering,Xi'an University of Posts and Telecommunications,Xi'an 710121,China)

机构地区：[1]西安邮电大学电子工程学院,西安710121

出　　处：《微波学报》2021年第5期91-95,共5页Journal of Microwaves

基　　金：陕西省重点研发计划(2020GY-040)。

摘　　要：空气隙填充基片集成波导(Slab Air-Filled Substrate Integrated Waveguide, SAFSIW)作为一种新型的导波结构,被广泛应用于毫米波传输线以及无源电路的设计,由于SAFSIW中空气隙的存在,其相较于传统的SIW具有更高Q值。本文基于半模双腔耦合SAFSIW设计并实现了一款中心频率为19 GHz的带通滤波器。为了改善滤波器的带外抑制,通过给谐振器并联枝节线结构,在滤波器的上边28 GHz处,引入一个传输零点,大大改善了滤波器的带外抑制特性。利用双面覆铜的LCP基板进行了滤波器的加工,并对其进行测试。测试结果表明,该滤波器中心频率为19 GHz,相对带宽达18%,插入损耗优于-4.2 dB,回波损耗小于-16 dB。由于上边带传输零点的引入,该滤波器在28.5 GHz时,上边带抑制达到-36 dB以下。实物测试相比于仿真结果有一定的恶化,主要原因是由于SMA转接头带来的损耗以及HMSAFSIW谐振腔的加工误差所导致。As a new type of guided wave structure, SAFSIW(Slab Air-Filled Substrate Integrated Waveguide) is widely used in the design of millimeter wave transmission lines and passive circuits. Compared with the traditional SIW structure, SAFSIW has higher Q value due to the existence of air gap. In this paper, a compact band-pass filter is designed based on the half mode double cavity coupling SAFSIW. By connecting the stub line structure in parallel in the resonator, a transmission zero is introduced in the upper band of the filter, which greatly improves the out of band suppression characteristics of the filter. The filter is implemented by LCP process and tested. The measured results show that the center frequency of the filter is 19 GHz, the fraction bandwidth is 18%, the insertion loss is better than-4.2 dB, and the return loss is below-16 dB. Due to the introduction of transmission zeros in the upper sideband of the filter, the upper sideband suppression is below-36 dB at 28.5 GHz. The measured result of the fabricated filter has a certain deterioration compared with the simulation result, mainly due to the loss caused by the SMA connector and the machining error of the HMSAFSIW resonant cavity.

关 键 词：半模SAFSIW 带通滤波器 枝节加载 带外抑制 

分 类 号：TN713.5[电子电信—电路与系统]