Enhancing Radio Frequency System Performance by Digital Signal Processing
2010 (English)Licentiate thesis, comprehensive summary (Other academic)
In this thesis measurement systems for the purpose ofcharacterization of radio frequency power amplifiers are studied.Methods to increase the speed, accuracy, bandwidth, as well as toreduce the sampling requirements and testing cost are presented. Amethod intended for signal shaping with respect to peak-to-averageratio reduction and its effects-improvements on the radio frequencyfront-end performance is investigated.
A time domain measurement system intended for fast and accuratemeasurements and characterization of radio frequency poweramplifiers is discussed. An automated, fast and accurate techniquefor power and frequency sweep measurements is presented.Multidimensional representation of measured figure of merits isevaluated for its importance on the production-testing phase ofpower amplifiers.
A technique to extend the digital bandwidth of a measurement systemis discussed. It is based on the Zhu-Frank generalized samplingtheorem which decreases the requirements on the sampling rate of themeasurement system. Its application for power amplifiers behavioralmodeling is discussed and evaluated experimentally.
A general method for designing multitone for the purpose ofout-of-band characterization of nonlinear radio frequency modulesusing harmonic sampling is presented. It has an application with thevalidation of power amplifiers behavioral models in theirout-of-band frequency spectral support when extracted fromundersampled data.
A method for unfolding the frequency spectrum of undersampledwideband signals is presented. It is of high relevance tostate-of-the-art radio frequency measurement systems which capturerepetitive waveform based on a sampling rate that violates theNyquist constraint. The method is presented in a compact form, iteliminates ambiguities caused by folded frequency spectra standingoutside the Nyquist band, and is relevant for calibration matters.
A convex optimization reduction-based method of peaks-to-averageratio of orthogonal frequency division multiplexing signals ispresented and experimentally validated for a wireless local areanetwork system. Improvements on the radio frequency power amplifierlevel are investigated with respect to power added efficiency,output power, in-band and out-of-band errors. The influence of thepower distribution in the excitation signal on power amplifierperformance was evaluated.
Place, publisher, year, edition, pages
SE-100 44 Stockholm, Sweden: Signal Processing, School of Eletrical Engineering, Royal Institute of Technology , 2010. , ix, 9 p.
Trita-EE, ISSN 1653-5146 ; 2010:030
IdentifiersURN: urn:nbn:se:kth:diva-24536OAI: oai:DiVA.org:kth-24536DiVA: diva2:351369
2010-08-20, 99:132, Kungsbäcksvägen 47 Gävle, SE-801 76, University of Gävle, 10:15 (English)
Eriksson, Thomas, Dr.
Händel, Peter, Prof.Björsell, Niclas, Dr.
QC 201010012010-10-012010-09-142010-10-01Bibliographically approved
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