Research On Small-size And Multi-band Mobile Phone Antenna

With the development of mobile communication,the research on miniaturization and multi band of mobile antenna has never stopped.The first reason is the requirement of miniaturization for mobile phone appearance,and the second reason is that the development of mobile communication makes mobile phone antenna need to support more and more frequency band.Last year,5th generation mobile networks(5G)has entered the commercial stage in China,the research of this paper focus on the design of miniaturization and multi-band for 5G MIMO mobile phone antenna.In order to achieve the two purposes,based on the basic antenna theory and antenna small-size technology,and analysed the advantages and disadvantages of 5G MIMO mobile phone antenna,the idea of antenna design in this paper is constituted.Finally,the performance index of mobile phone antenna is designed.The main content of this paper includes two aspects:The first is to design a sub-6 GHz dual-band 8×8 MIMO antenna according to the sub-6 GHz band employed for 5G communication in China(3.3GHz-3.6GHz and 4.8GHz-5GHz).The antenna design refers to the structure design of the side-edge frame,and uses the double-sided transmission line feed structure to make the resonance antenna outside the side-edge frame.The size of the antenna elements is 19 mm × 6 mm.The simulation results show that all antenna elements with return loss below-6 d B cover two sub-6 GHz bands(3.3 GHz-3.6 GHz and 4.8 GHz-5 GHz).In the working frequency band,there is a good isolation between the two antennas,among which S12,S23 and S34 are less than-10 d B.In the operating frequency band,the total efficiency of the antenna is higher than 55%,and ECC is less than 0.1.The second is to design an 8 × 8 MIMO antenna which supports 4G LTE band and sub-6 GHz band at the same time.The MIMO antenna is designed on the premise of reserving enough space for low-frequency antenna through the choice of isolation degree and space between placement.The advantage of the MIMO antenna is that it supports not only sub-6 GHz frequency band but also 4G frequency band,and has the Abstract advantage of low profile.The overall size of the antenna is 19.5mm × 11.8mm × 3.8mm.The simulation results show that all the antennas with return loss below-6 d B cover sub-6 GHz bands(3.3 GHz-3.6 GHz and 4.8 GHz-5 GHz),and cover 4G LTE2300 and LTE2500.In the operating frequency band,there is a good isolation between the two antennas which S12,S23 and S34 are less than-10 d B.In the operating frequency band,the total efficiency of the antenna is higher than 50%,and ECC is less than 0.15.Finally,the MIMO antenna is measured.