An SIW Filtering Antenna Array with Quasi-Elliptic Gain Response Based on Intercavity Bypass Coupling

摘要

In this article, a filtering antenna array based on substrate integrated waveguidern(SIW) is proposed with quasi-elliptic gain responses for the first time. Two radiationrnnulls in the gain responses at two sides of the frequency band edges are designed by applyingrna novel intercavity bypass coupling scheme. First, by carefully analyzing the bypass couplingrnbetween the in-band and out-of-band modes in a single oversized TE_(103) mode cavityrnresonator, quasi-elliptic filtering responses are achieved for a two-output filter. Afterward,rnthose cavity resonators coupled with the two outputs are replaced by cavity-backed slotrnantennas to achieve the proposed filtering cavity-backed slot antenna array. Only one cavityrnis required in our design to achieve the two transmission zeros and the function of powerrndivider. As a result, the complexity of the proposed filtering antenna array is reduced. Arnprototype operating at Ka band is designed, fabricated and measured with a center frequencyrnof 28.5 GHz and fractional bandwidth of 1.25%. Similar characteristics can bernobserved between the gain response of the proposed filtering antenna and the transmissionrnresponses of the two-output filter. The proposed SIW filtering antenna array has greatrnpotential to be integrated into millimeter-wave transceiver modules.