Research And Design Of Miniaturized Broadband Dual Polarized Antenna

In the past few decades,the technical standards of mobile communication systems have been continuously developed.Correspondingly,the hardware in communication systems has also been continuously updated.It is foreseeable that due to the explosive growth of the amount of information,antennas used as transceivers in communication systems are facing increasingly severe challenges.To meet this challenge,utilizing a broadband dual-polarized antenna is a very effective method.Due to the continuous evolution of communication standards,the frequency bands used in civil communications are also increasing.Compared with narrowband antennas,wideband antennas can cover multiple working frequency bands at the same time,thereby avoiding the need to use multiple antennas,which can reduce the complexity of the system and improve the reliability of the system.Antenna’s polarization diversity technology is also widely used.Because there is no correlation between a pair of orthogonally polarized electromagnetic waves,by transmitting or receiving two kinds of orthogonally polarized electric field waves,the multipath effect can be effectively overcome and limited frequency band resources can be saved.Due to its various advantages,the broadband dual-polarized antenna is in line with the development trend of communication systems.This paper studies the wideband and miniaturization of dual-polarized antennas.Combined with scientific research projects,three different dual-polarized antennas are proposed.The first antenna works at 3.9-5.6GHz and is a side-fed cross-dipole antenna.Different from the traditional dipole antenna,it uses the edge feeding method,and the two dipoles are printed on different dielectric substrates.This antenna has the advantage of being easy to manufacture.It uses strong coupling between dipole patches to expand the bandwidth.At the same time,this antenna uses shorting structure to improve port isolation.Studies have shown that the mechanism of improved port isolation is because it can improve the symmetry of the parasitic patch.The second antenna works at 3.0-3.8GHz and is a high-isolation,low-profile cross-dipole antenna.Since the reflected wave of the artificial magnetic conductor has the same phase as the incident wave,the metal reflecting plate can be replaced by the artificial magnetic conductor.Therefore,the profile of the antenna can be greatly reduced,thereby miniaturizing the antenna.However,our research shows that the use of artificial magnetic conductors will lead to an additional coupling between ports.In this design,the use of short pin with thesame radius as the coaxial can effectively guide the direction of the current on the surface of the artificial magnetic conductor to the main polarization direction,thereby obtaining excellent port isolation.The third antenna works between 1.4-1.8GHz and is a miniaturized wideband dual-polarized patch antenna.Although the use of artificial magnetic conductors can effectively reduce the profile,it is worth mentioning that artificial magnetic conductor structures will occupy too much horizontal space.To solve this problem,we propose a patch antenna with a grid slot.Since two modes are excited at the same time,the bandwidth of the antenna is expanded without increasing the height of the patch antenna.Therefore,this wideband dual-polarized antenna has a compact horizontal size while maintaining a low profile.