Research On Substrate Integrated Waveguide Filtering Antenna

In recent years,substrate integrated waveguide(SIW)has been proposed as a new kind of waveguide structure that can be integrated into dielectric substrates and applied to microwave and millimeter wave bands.It has been widely used due to the advantages of low radiation,low insertion loss and high power capability.Thanks to the planar structure,SIW can realize the integration of active and passive devices,so as to realize the miniaturization of microwave and millimeter-wave multifunctional devices.Integration of SIW filter and antenna become a research hot spot in recent years.Different from the cascaded filter and antenna,the proposed antennas in this paper are highly integrated of filter and antenna without any increase of the antenna dimension,which realize both frequency selectivity and radiation characteristics.Due to the advantages of planar structure,the SIW based filtering antennas are competitive solutions to integrate with other devices in microwave and millimeter wave band system.Aiming at the research of SIW filtering antenna,the following work is carried out as follows.First,a SIW H-plane filtering horn antenna with embedded metallized via hole arrays is proposed in this paper.The SIW H-plane filtering horn originates from a simple SIW H-plane horn with very narrow bandwidth and no frequency selectivity performance.To significantly increase bandwidth,two metal strips are printed on both sides of the substrate near the radiating aperture of the horn antenna.Critically,four rows of inductive metallized via holes are embedded into the flare region of the horn antenna,forming three coupled resonant cavities to achieve filtering function without any increase of the antenna dimension.The proposed SIW H-plane filtering horn antenna achieves good frequency selectivity,which satisfies the increasing demand of the miniaturization and integration of multi-functional devices.An optimized prototype is manufactured and measured to verify the design feasibility.The measured results show that the antenna has high frequency selectivity form 16.3 to 17.27 GHz with the average gain of 5.1d B,and the simulation efficiency is greater than 75%,showing the validity of the integrated design of filter and horn antenna.Second,a wideband single-layer SIW filtering antenna with compact structure is investigated.The proposed antenna is designed based on a SIW resonant cavity operating at its TE₁₁₀ mode.A straight radiating slot is integrated on the top surface of the cavity.The resonator can be splitted into two half-mode resonators,generating a radiation null at the right edge of the passband.At the same time,two U-shaped slots are etched on the bottom surface of the cavity.One of the U-shaped slots is used to generate a radiation null at the left edge of the passband while the other U-shaped slot introduces the modified half-TE₁₁₀ mode in the right half cavity,broadening the bandwidth of the antenna.Finally,the third-order filtering antenna is obtained with 11.84%impedance bandwidth in only one SIW resonant cavity.An optimized prototype is fabricated and measured to verify design,the antenna operates in 11.12-12.52 GHz,the average gain in the band is 5d B,and the simulation efficiency is greater than 78%.The simulation and measurement results show that the proposed antenna owns features of simple structure,wide bandwidth and good frequency selectivity.