Research On Omnidirectional Miniature Antenna And Its Array Technology Based On Wiretapping Bullet

With the continuous development of military technology,the means of acquiring battlefield intelligence is getting richer and richer.As a special gun cartridge,the appearance of the wiretapping bullet is similar to that of ordinary gun cartridges,with miniature wireless signal transmitting circuit embedded inside,when it is used,it will be fired to the enemy camp,which can transmit back the enemy’s conversation as well as valuable sound signals and use it to master the battlefield dynamics.And limited by the size of the gun cartridge,the miniaturization of the wireless RF circuit and the design of the antenna become a difficult point.The antenna plays a crucial role in the transmission of wireless signals,and the performance of the antenna will directly affect the transmission quality and distance of the signal.Therefore,this paper conducts a simulation study on different types of antennas for the background of wiretapping bullets.First of all,the antenna placement problem was studied,and the advantages and disadvantages of the internal antenna and external antenna were analyzed respectively,among which for the internal type of antenna,the monopole antenna,normal mode helix antenna,and gradient helix antenna were simulated and studied respectively,and some miniaturization techniques were used to make the size of the antenna as small as possible,and finally all three antennas achieved the size requirements for placement inside the wiretapping bullet,and all of them have omnidirectional radiation characteristics.Secondly,the external antenna of the sound bombs was studied,in order not to affect the aerodynamic shape of the bullet,the conformal antenna was selected as the external antenna,and the commonly used conformal antenna was compared and analyzed,and after the comparison study,the slotted cylinder antenna was selected as the conformal antenna of the wiretapping bullet.On this basis,the miniaturization of the planar slot antenna is firstly simulated and then the miniaturization method of the planar slot antenna is introduced into the miniaturization of the slotted cylinder antenna to realize the miniaturization of the slotted cylinder antenna.At the same time,the omnidirectional radiation of the antenna is achieved by opening multiple slots on the bullet to form a circular array.Finally,the design of the conformal antenna is completed by using dielectric filling to cover the slots and protect the overall shape of the shell.Finally,the miniaturized RF signal transmitting circuit was analyzed and designed,and a signal receiving system was built,based on which the designed conformal antenna was matched and connected to the RF circuit,and then the effective transmission distance of the signal was tested to prove the effectiveness of the designed antenna.