Explicit design of remote-tuned combiner for GSM and WCDMA signals: Research Articles

The problems associated with combining multiple GSM carriers and WCDMA signals onto a single antenna are developed leading to a unique solution. This solution is based upon the concept of cascading directional filters to meet the electrical requirements, which may readily be tuned electrically leading to remote-tuned products capable of injecting one or more WCDMA channels into the same communication band as several GSM carriers. A particular solution is presented, which exhibits both optimum amplitude and group delay characteristics for the WCDMA signal. Closed-form expressions are given for the network functions including the amplitude and group delay characteristics. By developing techniques similar to those used in Rhodes (Theory of Electrical Filters. Wiley: New York, 1976), explicit formulas for element values in the general 2nth degree network are given and proved. A practical operating unit for the US cellular band has been designed and constructed. Measured per- formance is given and shows excellent agreement with theory. Copyright © 2007 John Wiley & Sons, Ltd. Dedicated to Professor Sean Scanlan on the occasion of his 70th birthday.