Terminal Multiple Antenna Systems

With the rapid development of mobile communication, MIMO technology and smart antenna technology have become the two key technologies in wireless communications. The MIMO technology can not only improve the spectrum utilization and data throughput without increasing the transmission power, but can also enhance the reliability of data transmission. The smart antenna can filter out the interference signal of non-radiation zone effectively. In this paper, the hand-held terminal MIMO antennas and the smart antennas for small base stations are studied. The main contributions are as follows:1. The elements of MIMO antennas of the dimensions of 10mm × 0mm × 5mm are designed which cover GSM1900 (1880-1920MHz), LTE2300 (2300-2400MHz) and LTE2500 (2540-2620MHz). Based on these designs, the MIMO antenna of four elements and eight elements are designed. The measured results show that the mutual couplings between the elements are all below-10dB in the operating frequency bands without introducing any physical decoupling circuits. The envelope correlation coefficients between the elements are all below 0.5; the ratios of mean effective gain are all below 3dB; and the elements have high radiation efficiencies, all meeting the design requirements.2. The optimization theory of power transmission efficiency between two antenna arrays is used for the design of smart antennas for small base stations. Two smart antennas are designed, respectively with four elements and six elements. The antenna elements are monopole antennas. The smart antennas realize beam switching by using feeding networks. The simulation and measured results indicate that these two smart antennas have achieved the desired performances. The gain of six-element smart antenna is higher than four-element smart antenna by 2dB. This design proves the feasibility of the optimization theory of power transmission efficiency between two antenna arrays.