Design Of Narrow Beam Planar Array Antenna For Elevator Environment Coverage

The past 20 years, the mobile communication technology has achieved great development, the dream of anytime, anywhere communicated with anyone is getting closer and closer to us, mobile communication has become an indispensable part of people’s lives. With the improvement of people’s living standards, People put forward higher requirements on mobile communication. With the commercial of 4G, operators are stepping up 4G network coverage from urban to rural areas, extensive coverage expand fast, but the coverage under complicated environments are unsatisfactory. Such as shopping malls, internal elevator, parking, tunnels and other closed environments covered almost blind, so that depth coverage become the ‘last kilometer’ of built anytime anywhere mobile communications network. This article focuses on the network coverage solution under elevator Environment. First, the paper analyzes the research status of the coverage under elevator environment, comparing the various the coverage schemes under elevator environment considering to the coverage, cost, loss, and the difficulty of installing and maintaining, finally confirmed that it is the most feasible design for designing a narrow beam plane arrays in an elevator shaft cover.According to the required criterion of narrow environment and the basic theory of the antenna design, we discuss two dual-band planar array antennas for narrow beam finite size dense group array implementation, it can show from the comparative analysis that mutual coupling between elements makes an big influence on the radiation parameters and circuit parameters, It can greatly reduce the mutual coupling between the elements by staggered array element horizontal direction of maximum radiation to improve the overall antenna performance. To meet the needs of intensive arraying and low cost, the article designed a high-frequency dipole with low-cost and broadband and a miniaturization high-gain low-frequency dipole at the expense of bandwidth by improving the traditional printed dipole; and designed a equal amplitude-phase feed network in order to meet the needs of high-gain antenna requirements;It can achieve the best balance between the radiation parameters and the circuit parameters by the overall simulation and optimization of ‘field’ and ‘circuit’. Finally, by prototyping, and the test results showed that low mutual coupling schemes can meet the design requirements.In addition, at the perspective of Smith chart, the article prove that the input impedance trace curve on the Smith Chart at the source side is a ideal circle which rotates around the ‘characteristic impedance’ when the source mismatched with the transmission line. The law which provide a theoretical basis and design ideas on complex impedance matching of using the Smith Chart. In this paper, a equal reflection correction vector method was proposed based on conjugate impedance matching theory, which can make a correction of impedance matching discontinuity effects quickly, thereby increasing the efficiency of the simulation.