Research And Design Of High-Performance Directional Planar Slot Antenna

As the fifth-generation mobile communication technology rapidly develops,broadband and integrated communication scenarios have put forward more stringent requirements for the performance and size of antennas.Due to its small size and low profile advantages,the planar slot antenna is very suitable for the development trend of communication systems and has become a research hotspot.Therefore,designing high-performance and high-integration planar slot antennas is the focus and difficulty of this thesis.This thesis presents a theoretical study of planar slot antennas based on multimode resonance theory,slow wave theory,and substrate integrated waveguide（SIW）theory.Three planar slot antennas were designed respectively,targeting the problems of limited bandwidth,low integration,and single frequency band.The specific contents are as follow:1.A wideband slot loop antenna is designed and experimentally verified based on the multimode theory.This antenna utilizes loading with short-circuit via holes,circular patch,and circular resonant ring to excite three resonant modes of the cavity TM₀₁ mode,patch TM₀₂ mode,and ring TM₀₂ mode,and achieves bandwidth enhancement through the coupling between the three modes.The measured results show that the fabricated antenna prototype covers a frequency band of4.68 GHz to 6.6 GHz in the C-band,with a relative bandwidth of 34%,achieving wide bandwidth characteristics.2.A miniaturized slow-wave substrate integrated waveguide（SW-SIW）cavity-backed slot antenna working is designed and experimentally verified based on the slow wave theory and SIW theory.The antenna adopts a dual-layer structure,with metal blind holes loaded inside the lower layer dielectric substrate to concentrate the electric field in the upper layer dielectric substrate.Meanwhile,the upper surface of the lower layer dielectric substrate is loaded with periodically arranged rectangular metal patches to concentrate the magnetic field in the lower layer dielectric substrate.This slow-wave structure realizes the separation of electric and magnetic fields in the upper and lower layers,thereby reducing the propagation velocity of electromagnetic waves in the SIW cavity.The measured results show that the fabricated antenna prototype has a center frequency of 10.43 GHz and a gain of 5.7 d B at the resonance poin in the X-band.The antenna cavity has an area of 6.4 mm×6.4 mm and achieves a 50%reduction in cavity size compared to the traditional SIW cavity-backed slot antenna at the same resonant frequency,achieving miniaturization characteristics.3.A tri-frequency SIW cavity-backed slot antenna is designed and experimentally verified based on the multimode theory and SIW theory.Firstly,a dual-frequency SIW cavity-backed slot antenna is designed by loading a non-resonant slot.The antenna generates two resonance points in the X-band,at 9.22 GHz and 10.22 GHz,respectively.Then,on the basis of this structure,a new low-frequency resonance is excited in the C-band using magnetic coupling by loading a short-circuit via hole near the center of the cavity to form an induction window,and thus a tri-frequency backed slot antenna is designed.The measured results show that the fabricated tri-frequency antenna prototype has resonance points at 6.72 GHz,9.03 GHz,and 10.3 GHz in the C-band and X-band,achieving multi-band characteristics.