Research On Wideband SIW Cavity-backed Slot Antenna

With the development of modern communication,the communication frequency is gradually developing toward the millimeter wave,and the trend of broadbandization is becoming more and more obvious.The research of millimeter-band wideband SIW back cavity slot antenna has gradually become a research hotspot.This paper carried out W-band wideband SIW back cavity gap design and application research.The main contents include:Firstly,the high-order resonance mode supported by the SIW resonator is studied.A narrow-slot W-band slot antenna is designed with a bandwidth covering nearly 75%of the W-band.The hybrid mode of TM₁₃₀ and TM₃₁₀,the TM₃₂₀ mode,and the TM₃₃₀ mode are excited in the resonant cavity simultaneously,and a multi-resonances characteristic is achieved to form the wideband performance.The antenna sample was developed.The impedance bandwidth of-10dB was 79.93¹05.24GHz?28.6%?.The pattern was stable and the cross polarization was low in the whole frequency band.The test results verify the correctness of the design.Secondly,in order to further increase the gain,a wide-slot W-band SIW back cavity slot antenna is designed.Exciting the resonance of the three high-order modes of TM₃₂₀20 mode,TM₃₃₀mode and TM₃₄₀,the impedance bandwidth of-10dB is 73.5⁹9.8GHz?30.35%?,and the in-band gain exceeds 13dBi.The gain is increased by nearly 3 dB compared to the narrow slot antenna.It is possible to further realize high gain broadband antenna design.Thirdly,a high-gain broadband Cassegrain antenna is designed by using a wide-slot SIW back cavity slot antenna as a feed.The high-order mode SIW back cavity slot antenna has a wide bandwidth and a small beam width variation in the frequency band,and is suitable as a feed for a Cassegrain antenna.The designed Cassegrain antenna has a wide bandwidth and good in-band pattern performance with a gain of 34dBi.Fourthly,a 2×2 antenna array is constructed with a wide-slot SIW back cavity slot antenna as the antenna unit.The developed 4-element array antenna has a simulation gain of 19dBi.Tests show that the antenna array is basically consistent with the simulation results.The W-band SIW back cavity slot antenna designed in this paper has a wide bandwidth,stable pattern and low cross-polarization.It can be used as a primary feed for Cassegrain antennas or directly into a low-profile high-gain broadband back cavity.The slot antenna array has a good application prospect.