Research On Broadband And Wide Beamwidth Dipole Antenna

In the radar system,the phased array antenna is needed to scan the beam at a wide angle in order to expand the target search range.The beam width of the antenna element often determines the beam scanning range of the phased array antenna,so the wide beamwidth antenna element can realize the wide-angle scanning of the phased array antenna.In the field of modern communication,different communication systems are compatible with each other.In suburban and other open areas,in order to improve the coverage of the signal,the antenna needs to meet the requirements of broadband and wide beamwidth.In this paper,the following work is done on the basis of dipole antenna for the wide beamwidth application in radar and communication system.Firstly,the wideband wide beamwidth electromagnetic dipole antenna element is designed and fabricated and the performance of the antenna array is simulated.In this paper,the method of folding the antenna arm and adding vertical parasitic structures is adopted to effectively widen the beamwidth of the antenna.Aiming at the beamwidth stability problem of the antenna,this paper starts with the surface current distribution of the antenna,and realizes the beamwidth stability of the antenna by cutting the antenna arm.The measured half-power beamwidth of the antenna is 174?±4.6°.Aiming at the coupling problem of antenna array,the decoupling design is carrned out.Secondly,the wideband wide beamwidth dual-polarized electromagnetic dipole antenna element is designed and fabricated and the performance of the antenna array is simulated.By analyzing the surface current of the dual-polarized electromagnetic dipole antenna,it is found that the radiation of the dual-polarized electromagnetic dipole antenna is mainly concentrated in the magnetic dipole.Therefore,the method of folding antenna arms can not effectively broaden the beamwidth of the antenna.In this paper,a pair of parasitic metal structures are respectively placed in each of the two polarization directions of the antenna arm,and the current intensity on the parasitic metal structure is increased by folding the antenna arm to increase the radiation intensity,so as to broaden the horizontal beamwidth of the dual-polarized electromagnetic dipole antenna.By adjusting the height of the parasitic metal structure of the facade and adding branches,the beamwidth at each frequency is adjusted.The measured half-power beamwidth of the antenna is 94.5°±8.5°.The array performance of the element is simulated and analyzed.Finally,the wideband wide beamwidth dual-polarized planar dipole antenna element and antenna array are designed.It is difficult to guarantee the precision of L-type feeding line accurately in the assembly process.The dual-polarized electromagnetic dipole antenna printed on the dielectric substrate is very simple to manufacture and the precision of the feeding structure can be well guaranteed.In this paper,the horizontal half-power beamwidth of the antenna is expanded by adding four symmetrical metal plate structures at the bottom of the antenna to conduct secondary radiation.The vertical parasitic structure is made into a stepped shape so that the parasitic structure can broaden the horizontal beamwidth at different working frequencies.The simulated half-power beamwidth of the antenna is 87.88°±5.78°.At the same time,the performance of the array composed of antenna elements is simulated...