WLAN Substrate Integrated Waveguide Filter with Novel Negative Coupling Structure

Abstract

A fourth-degree Substrate Integrated Waveguide (SIW) crossed coupled band pass filter for WLAN band is designed by using a new negative coupling structure. It consists of two U shape microstrip lines on top and bottom planes with via holes at the center of them. This paper investigates the phase characteristics of negative and positive coupling structures and their effects. The design, fabrication and testing processes of the proposed filter are presented. The measured results seem to be consistent with the results obtained from simulator packages.