2011 International Microwave Symposium

Plenary Speaker: Professor J. David Rhodes CBE, FRS, FR Eng., in his presentation "Migration of WCDMA and 4G LTE into Existing Cellular Bands" will explore the following: 
To optimize the introduction of either WCDMA or LTE into existing cellular bands it is desirable to produce combiners for the new and existing base stations to utilize the same antenna structure. If it is assumed that the output of the base stations consist of diplexers separating their own transmit and receive bands then the critical additional requirements for the combiner are:
1.    To minimize the transmission loss over the transmit bands
2.    To have sufficient isolation between the transmitters to minimize the IM products generated in the receive bands by the transmitters
3.    To minimize the loss in the receive bands or capture the noise figure and intercept points with sufficient gain for the given base station
4.   In the case of WCDMA to have an acceptable level of group delay distortion of the transmit signal

1. For a given Q of resonators it is necessary to only have 15dB of attenuation for each transmit band over the other transmit bands to minimize loss. To provide the full isolation requires higher degree filters with higher Q’s to achieve the same loss.
2. An isolation level of 30dB between the base stations can be readily achieved with a balanced filter and is sufficient to prevent unacceptable levels of IM products
3. Over the receive bands either a balanced filter solution can be used in the same way as the transmit bands or a receive LNA can be incorporated to feed both base stations
4. If the guard band between the base station frequencies is small then group delay equalization will be required in the transmit filter for WCDMA signals
All of these issues will be addressed and design techniques will be presented which optimize the solution for both the WCDMA and LTE problems.
The performance of several different combiners will be given which successfully achieve all of the objectives.

Biography of the speaker:
He has received the OBE and CBE from the Queen and also several Technology and Export Awards. From Leeds University he received the BSc. Ph.D., D.Sc. and Honorary D.Eng Degrees and further Honorary Degrees from Bradford and  Napier Universities. 
He is a fellow of the IEEE, IET, RAE, The Royal Society and a Foreign Associate of the Academy of Engineering (USA).
He has been awarded numerous prizes including the Microwave Prize, the Browder J. Thompson Award, The Guillimin – Cauer Award and the Microwave Career Award all from the IEEE together with the CASS Golden Jubilee Medal and the Third Millenium Medal; The JJ Thompson Medal and the Faraday Medal from the IET; The Mountbatten Medal from the National Electronics Council; The Mullard Award from the Royal Society and the premier distinction from the Royal Academy of Engineering of The Prince Philip Gold Medal. He 
has also received the European Microwave Career Award and many business awards.
He founded Filtronic plc more than 30 years ago and grew it into an international microwave company with 10 operations on 4 continents with peak sales of $0.5 B and a market capitalization of $2.5 B. He retired 4 years ago and has grown a new business within the private 
company Isotek Electronics Ltd., where he has been the majority shareholder, in the area of microwave sub-systems and which has recently been acquired by Filtronic plc. The remaining Isotek business, which develops and manufactures hyperbaric welding systems for sea depths down to 4000m, continues to grow under his ownership. He is also an Emeritus Professor at Leeds University.