Quad-Element MIMO Antennas with Isolation Enhancement for LTE Femtocell Base Stations

• Main Authors: Huang-Cheng Zhou, 周煌程
• Other Authors: 陳晏笙
• Format: Others
• Online Access: http://ndltd.ncl.edu.tw/handle/7mpkx9

碩士 === 國立臺北科技大學 === 電子工程系研究所 === 104 === This thesis proposes two multiple-input–multiple-output (MIMO) antennas for femtocell long-term-evolution (LTE) base stations; one antenna aims at LTE lower frequency bands (698-960 MHz), and the other focuses on meeting the full LTE specification (698–960 MHz and 1710–2690 MHz). One antenna is not only operating in 698−960 MHz for femtocell LTE base stations, but it also employs four-unit antenna elements. A pentagonal conductor wall is established on the ground plane; accordingly, not only does isolation improve, but the electromagnetic interference between the antenna and other electronic components is reduced. We design a top-loading meandered monopole with dual sleeves attached to each side of the radiating body, optimizing the characteristics of impedance bandwidth and radiation efficiency concurrently. The other one is operating in full LTE specification for femtocell LTE base stations, using four elements to increase the channel capacity. The antenna configuration is optimized for good impedance matching and high radiation efficiency. In particular, we propose a simple structure, neutralization lines, with extremely low costs to enhance the isolation. This structure uses solid wires, which connect the position having strongest coupled current of two adjacent elements; accordingly, the suspended solid wires achieve isolation enhancement of 40 dB. All performance show that the proposed two MIMO antennas are very suitable to apply the femtocell base stations.