Summary
International Symposium on Antennas and Propagation
2008
Session Number:3C23
Session:
Number:3C23-3
Compact Repeater Antenna System with Extremely High Isolation in the 800MHz band
Masayuki Nakano, Takashi Inoue,
pp.-
Publication Date:2008/10/27
Online ISSN:2188-5079
Summary:
The radio repeater is an attractive solution for cost-effective expansion of coverage in cellular systems. The direct relay radio repeater (not the frequency conversion type) is particularly cost-effective due to its simple structure. However, when this type of repeater is used to extend coverage in open areas, radio echoes tend to occur between the two antennas at the repeater station. Since repeater stations require high RF gain, especially in rural areas, the antenna directed toward the base station and the antenna directed toward the mobile stations must be installed separately so as not to cause radio echoes and this separate installation increases the installation costs. To address this problem, antennas with high isolation using a choke at the antenna reflector but at the expense of greater physical size have been proposed [1]; however, they do not yet provide an effective solution. This is because the repeater antenna systems need to be compact in order to withstand high winds. This issue is extremely critical especially for 800 MHz band systems compared to 2 GHz band systems. This paper proposes a small repeater antenna system for the 800 MHz band with extremely high isolation characteristics.