ISBN 9783843927161

978-3-8439-2716-1, Reihe Elektrotechnik

Ahmed Elmaghraby
Transmitter Leakage Cancellation in Cellular Handset Receivers

140 Seiten, Dissertation Universität Erlangen-Nürnberg (2015), Softcover, A5

Zusammenfassung / Abstract

The rapidly growing mobile communication market requires handsets to be versatile to support the different standards and different bands. To achieve such flexibility, frequency division duplexing front-ends rely on employing multiple expensive duplex filters to suppress TX leakage into RX. Hence, an integrated solution to suppress TX leakage and relax the requirements of the duplex filters is needed to reduce their cost. Moreover, with the introduction of LTE carrier aggregation (CA), multiple oscillating frequencies and clocks simultaneously coexist, resulting in cross talk between the frequency sources. This cross talk, in addition to the leaked modulated TX signal, generate undesirable modulated spurious signals within the RX band. The modulated spurs cause specification violations even with the highest performance duplex filters. Thus, the importance of TX leakage suppression has extended beyond relaxing the duplexer requirements, to meeting sensitivity in case of LTE CA. In this dissertation, two integrated TX leakage cancellation techniques are proposed, investigated, and verified.