Study On Compact Dual Polarized Antenna Array With High Isolation

In recent years,wireless communication technology has developed rapidly,and it is about to enter the era of 5G.But the communication frequency band has become increasingly crowded,and as a result new technologies are in urgent need to improve the utilization of the frequency band with the advantages of small size,large capacity and high speed.With the feature of employing multiple antennas to transmit or receive signals individually,multiple-input-multiple-output?MIMO?technology not only provides higher user rates at a lower cost but also raises the data capacity by increasing the number of channels.Therefore,it will be a vital part of the upcoming 5G communications technology.A dual polarized antenna is the combination of two antennas with orthogonal polarizations and works in the duplex modes,i.e.,transmit and receive at the same time.Under the circumstances of high port isolation without interference and working independently for the antennas,the capacity of the communication system would be doubled to realize frequency division multiplexing.However,mutual coupling is a key issue in MIMO antenna design because of its deterioration for the performance of the overall system,not only impacting the efficiency but also the the correlation of antennas.With further advancement of MIMO technology,the demand for the suppression of mutual coupling between the components is becoming a tough milestone.This thesis focuses on the requirements of the future 5G communication system and mainly completed the following work:?1?A dual-polarized slot-coupled planar patch antenna is designed with the working band of 3.3-3.6GHz and a good port isolation within the working band.?2?A hybrid three-dimensional metamaterial decoupling structure was designed.The design consists of the grounded capacitively loaded loops?GCLLs?and the?-shaped elements.The?-shaped elements are placed orthogonally over the grounded capacitively loaded loops.By incorporating the meta-structures into the high-density array configuration,the isolation levels between adjacent radiating elements in both the E-and H-plane orientations are improved by as much as 7.15 dB.Whereas the decouping structure has no effect on the isolation between the cross-polarized ports.?3?Aimed at the difficulty in installation and lack of stability for the hybrid three-dimensional metamaterial decoupling structure mentioned above,the?-shaped elements were improved.The improved structure is based on the planar strips which are also placed orthogonally over the grounded capacitively loaded loops.By loading improved decoupling elements in the middle of a two-element dual-polarized array,with an element spacing of 0.6?_0,it can not only achieve a good decoupling effect but also have the advantages like easy installation and engineering applications.