Wideband And Wide Beamwidth Design Based On Printed Dipole Antenna And Tapered Slot Antenna

With the development of wireless communication systems,antennas with good performance such as wide impedance bandwidth,wide beamwidth,relatively high front-to-back ratio and stable radiation pattern are becoming more and more popular.Especially in the applications of phased array,a wide frequency band means that it can be applied to more application scenarios and a wide beamwidth means that a wide range of beam scans can be achieved.Therefore,the study of antenna element of broadband and wide beamwidth has a very important engineering significance.In the applications of phased array,printed dipole antennas and tapered slot antennas are popular because of their low cost,small size,high efficiency,light weight,ease of installation and manufacture.It is difficult for conventional printed dipole antennas and tapered slot antennas to achieve a sufficiently wide half power beamwidth(HPBW)in a wide frequency band.In my thesis,the characteristics of wideband and wide beamwidth are studied deeply based on printed dipole antenna and tapered slot antenna.The main work and research results of the thesis are:1.Design of a wideband and wide beamwidth printed dipole antennas.A double dipoles antenna with a bilateral symmetric directors is designed.The shape of the conventional printed dipole antenna is modified by two pairs of v-shape patches to improve its broadband characteristics.The introduction of bilateral directors expand the beamwidth of the high frequency band,which also makes the antenna have more stable radiation characteristics and further improves the impedance characteristics.The antenna measures42×27×0.6 mm~3,has an impedance bandwidth of more than 77.6%(7.5-17.0 GHz),achieves the beamwidth greater than 135°and 70°on the E-plane and H-plane.2.Design of a wideband and wide beamwidth tapered slot antenna.By investigating the effects of different loadings on the half-power beamwidth of exponentially tapered slot antennas,a wideband and wide beamwidth tapered slot antenna is designed.The proposed antenna is based on the microstrip-fed exponentially tapered slot antenna,and the front-to-back ratio of the antenna is improved by loading multiple sets of slots and back patches.The size of the antenna is 20×19×0.6 mm~3.The simulation and measurement show that the working frequency of the voltage standing wave ratio better than 2 is 74.5%(8-17.5GHz);the beamwidth better than 105°is obtained on the E-plane,and the beamwidth better than 55°is obtained on the H-plane;and a medium-to-high degree of front-to-back ratio is obtained in the entire frequency band,and the FBR range is within12-21 dB.The tapered slot antenna can simultaneously achieve the triple characteristic of a wideband,a wide beamwidth,and a relatively high front-to-back ratio.