Wideband Gain-Enhanced Filtering Vivaldi Antenna Based on Hybrid SIW-SSPP Structure and DCSM

Nowadays, the filtering Vivaldi antennas are more and more popular in long-distance communication applications due to anti-interference capability and high directivity, but the existing filtering Vivaldi antennas suffer from poor filtering performance and low gain. To address poor filtering performance, a feed scheme utilizing hybrid substrate integrated waveguide (SIW) and spoof surface plasmon polariton (SSPP) structure is proposed in this article to achieve good wideband filtering performance. To address low gain, first, utilizing loaded corrugated slots technique etches a set of inclined slots on radiator arms to suppress the low-frequency gain drop caused by edge diffraction current. Second, a high effective permittivity double-sided cross stripe metamaterial (DCSM) unit is developed and according to phase calibration theory nonuniformly loaded on the front end of the antenna to achieve wideband gain enhancement. For demonstration, the proposed antenna is fabricated and measured. The measured results show that the fabricated antenna operates at 8.14–12.29 GHz [fractional bandwidth (BW) 40.1%] with an average gain of 9 dBi and a high skirt selectivity of 23.88/21.25 dB/GHz, which verifies the superiority of the proposed antenna.