Antenna Isolation Considerations in WCDMA Repeater Deployment

Wideband code division multiple access (WCDMA) or widely known as 3G in Malaysia, promises more data-enriched services at higher data rates. However, 3G cell radius is much smaller compared to GSM and thus more base stations are required to cover a comparable GSM area. Another solution to solve the coverage problem is through repeater deployment. Channel-selective repeater is one of the promising solutions offered in the market. However, one must first consider antenna isolation in order to avoid self-oscillation before installing the repeater. This paper attempts to give some introduction to repeater system with emphasis on the antenna isolation issue. Factors that affect antenna isolation are elaborated and a case study is reviewed to illustrate the antenna isolation measurement. Lastly, the result shows that the antenna isolation highly depends on the antennas separation and antenna loss