| The ultra-wideband antenna not only solves the problem of small frequency capacity,but also solves the technical difficulties such as slow data transmission rate and vulnerability to interference,and has been a research hotspot in the antenna.Wide-slit antennas have the advantage of wide bandwidth compared to narrow-slit antennas,making it easier to achieve ultra-wideband.The microstrip slot antenna has the advantages of low profile,wide bandwidth and easy conformality.However,in order to solve this problem,the integrated substrate gap waveguide(ISGW)is selected as the problem of leakage of electromagnetic waves in the high-band microstrip antenna.The transmission line,combined with the ultra-wideband slot antenna,has been developed and applied in the 5G millimeter wave band.The main work of this paper is as follows:(1)A wide-slot slot antenna based on ISGW is proposed.The structure is to etch a square wide slit structure on the floor above the ISGW,and feed it through a stepped microstrip line.The microstrip line is Xg/4 impedance transformer impedance-matches the microstrip line characteristic impedance to the load impedance.The gap and the stepped microstrip line also achieve the matching effect,and the lowermost mushroom-like structure is removed two to reduce the coupling.The optimal size of the antenna is determined by software simulation.The relative bandwidth of this antenna is 41.90%,and the gain reaches lOdBi.The simulation results show that the ISGW-based square wide slot slot antenna designed in this chapter is an ultra-wideband,high-gain antenna.(2)An improved window-shaped gap is proposed.The relative bandwidth is increased,the gain is increased by 0.5dBi to 10.5dBi,and the return loss of the high-frequency part is significantly reduced.Then a binary array based on the power divider of this window type slot antenna is proposed.The power splitter is improved by the ordinary one-two-divided power splitter,mainly adding three layers of impedance conversion.Broadening the bandwidth,the antenna gain is 3dB higher than the single antenna.(3)A dual-polarized wide-slit antenna based on ISGW is proposed.The antenna structure is selected from the principles of orthogonal polarization technology and parasitic element decoupling technology.The unidirectional antenna structure is designed based on the antenna structure of Chapter 3,and the two single antenna ports are orthogonally placed to form orthogonal polarization.The main parameter variables are the gap size and the arrangement and number of mushroom-like structures.The main performance indicators are port isolation,gain,return loss,and cross polarization.The relative impedance bandwidth is 38.8%,the average gain is lOdBi,the isolation is 20dB by the high isolation of the orthogonal placement itself and the 8 mushroom structure as the parasitic unit,and the electric field analysis proves that there is a lower port.coupling.Compared with other dual-polarized antennas,it can be proved that the antenna has good isolation,high gain,good diversity characteristics,and meets ultra-wideband performance. |
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