MIMO Application For 5^th Generation Mobile Device Application

From 4th generation telecommunication to 5th generation telecommunication,new technologies bubbles up to meet the need of better and quick communication.One of these essential technology is Massive MIMO.Comparing with the traditional MIMO technology,Massive MIMO realizes quicker speed of transmission by enhancing the scale of MIMO array and implementing more and more antenna elements into MIMO array.However,research of Massive MIMO array for mobile device application encounters some problem for some kind.Comparing with the antenna array built for the base station application,volume of mobile device is smaller.To implement more and more antenna elements in mobile device,outlook of mobile device can be very bulky and thus not be welcomed by customers.More and more researches has been done by trying to make antenna array more compact than before.In this way,more and more antenna elements can be set in the limited space.However,with little space between antenna elements,isolation between different antenna elements become very low because of interference caused by radiation.Mainstreams of solving this problem mainly can be concluded by the following two methods.First,decreasing the distance between two adjacent antennas.Methods like using diversity technology or implementing some specific isolating structure can improve isolation between antenna elements and keep structure more tight.The second way of solving the problem mentioned above is designing antenna elements which are capable of working in higher frequency.Structure proposed in this paper are designed by following these two schemes and are introduced by combining its own novelty.This paper first introduces the design of a compactly arranged antenna pair.This pair contains two different type antennas including a slot antenna and a loop antenna.Even two antennas are compactly arranged,isolation between them remains more than 14 dB in their operating band.This antenna pair realizes a dual-band radiation and has been utilized to build an 8-port antenna array for MIMO application in smartphone.The measured efficiencies of the proposed MIMO array reaches more than 60%Then,a compactly arranged 4-port antenna array with high isolation is presented in this letter.A novel decoupling loop is adopted in this antenna array,this proposed decoupling structure helps with improving the isolation between two adjacent antenna elements and capable of enhancing the bandwidth of the original antenna array.In the end of this paper,a broadband dual-polarized mm-wave antenna array is proposed.Different from previous designations,this array utilizes circular shape slot to realize a wide band dual-polarized radiation.In addition,a novel grating structure is adopted for circular slot.With the proposed structure,a better radiation performance is realized.Operating frequency of this antenna array is measured from 26 to 38GHz,which is calculated for more than 30%of bandwidth.Peak realized gain of this antenna array reaches more than 13dBi for V-pol and H-pol and scanning angle of this array reaches±40°.By designing and discussing these antenna structures mentioned above,this paper gives a relativelycomprehensive solution for antenna array application of mobile devices.The first two structures works in frequncy under 6GHz and this kind of design aims to solve the problem of enhancing the scale of antenna array in short-term.The last design of millimeter-wave antenna faces the future demand of quicker and quicker speed of telecommunication.