Design Of The New Miniaturized Broadband Bow-tie Antenna

In recent years,with the rapid development of wireless communication technology,the demand for miniaturized,wide-band,high-gain,and low-cost antennas has exploded.Therefore,research on the ultra-wideband antennas with excellent practical performance has become a hot spot.It is found that the bow-tie antenna has a flat structure with a thin profile,and has wide bandwidth,simple structure,easy processing,and low manufacturing cost,which is very suitable for the current needs of large-scale production.In this thesis,a wideband linearly polarized bow-tie antenna and a broadband circularly polarized crossed dipole antenna are studied.The antenna performance is optimized by improving the antenna structure,and the proposed antennas are studied through theoretical analysis and software simulation analysis.The main contents of this thesis are as follows:First,a broadband linearly polarized bow-tie antenna with coupled metal plates is proposed.The antenna has a simple structure consisting of four metal plates placed independently for increasing bandwidth and gain,and a folded reflector for a stable radiation pattern and a flatter gain curve.The metal plates surrounding and coupling the radiation element cause the antenna to generate a new resonant frequency,improving the impedance characteristics of the antenna in the operating frequency band.The reflector is in the form of a fold,which not only effectively suppresses the side lobes,but also improves the gain at high frequencies.The antenna is simulated by HFSS to obtain the optimized structural parameters,and the influence of the introduced structure on the performances of the antenna is analyzed.The simulation results show that the size of the antenna is 42 mm×29 mm×23.6mm.When S₁₁?-10 d B,the frequency band of the antenna are within 2.35?4.52 GHz,and the relative bandwidth is 63.2%.Moreover,the gain is 4.4?6.45 d Bi,and the cross polarization characteristic is good.Secondly,a new broadband circularly polarized crossed bow-tie dipole antenna is proposed.The antenna uses four circular parasitic patches and a cylindrical composite cavity simultaneous.Both the radius and position of the four circular parasitic patches are slightly different.This structure realizes the widening of the impedance bandwidth and the axial ratio bandwidth,while ensuring the gain of antenna.The antenna is simulated by HFSS to obtain the optimal structural parameters,and the influence of the introduced structure on the performances of the antenna is analyzed.The simulation results show that the-10 d B impedance bandwidth of antenna is 77.76%,working in the band from 2.13 GHz to 4.84GHz,and the gain in the operating band is 7.91?11.55 d Bi.For the band from 2.38 GHz to4.58 GHz,the axial ratio of antenna is smaller than 3 d B,i.e.,the 3 d B axial ratio bandwidth is 63.22%,and a good left-handed circularly polarized radiation is achieved.In addition,the antenna has a simple structure and a small size of?×(40 mm)²×28.1 mm.The two kinds of designed antennas provide a reference for the antenna design of wireless communication.