Skip to main content Accessibility help
  • Print publication year: 2011
  • Online publication date: November 2011

11 - Power amplifier applications



Power amplifiers (PAs) are usually the last active component in the RF chain in modern radar and telecommunication equipment. Their nonlinear behavior has a significant impact on the overall system performance and quite often is the most limiting factor in modern radio systems. The purpose of a power amplifier is mainly to boost the radio signal to sufficient power levels suitable for a wired or wireless transmission from the transmitter to the receiver. Typically, they work at relatively high power levels and hence are a major power consumer in the overall transmitter system. However, their conversion efficiency from DC supply power to RF output power is traditionally very poor. Further, it is strongly dependent on the RF signal drive level and highest when the amplifier is operated in its most nonlinear region and the output RF power compressed or even saturated. Efficiency and linearity are severely contradicting power amplifier requirements and the most important parameters to be traded off.

One of the biggest selling factors for mobile handsets is ‘talk time.” For other battery operated systems such as wireless sensor networks or even satellites the ‘time in operation’ is commercially a highly valued asset. For fixed wireless transmitter systems (e.g., base stations) the running cost and the electricity bill are commercially most relevant, they translate directly into carbon footprint and related CO2 emission. Most military platforms that are capable of carrying a modern radar system are limited in space, energy and cooling capability, hence the efficiency of the radar transmit power amplifier mostly determines the performance and size of the radar equipment that can be implemented on a given platform. The overall efficiency of a power amplifier subsystem is highly commercially relevant and detailed system requirements and tradeoffs need to be well understood when deciding on a power amplifier architecture.

Related content

Powered by UNSILO
Raab, F. H.Average efficiency of power amplifiersProceedings of the RF Technology Expo 1986Anaheim, CA 1986 474
Raab, F. H.Asbeck, P.Cripps, S.Kenington, P. B.Popovic, Z. B.Pothecary, N.Sevic, J. F.Sokal, N. O.22 2003
Reynaert, P.Steyaert, M.RF Power Amplifiers for Mobile CommunicationsSpringer 2006 25
Armstrong, J.Peak-to-average power reduction for OFDM by repeated clipping and frequency domain filteringIEE El. Lett 38 246 2002
Saul, A.Comparison between recursive clipping and active constellation extension for peak reduction in OFDM systemsProceedings of the International Symposium on Wireless Personal Multimedia CommunicationsYokusukaJapan 2003
Sathananthan, K.Tellambura, C.Coding to reduce both PAR and PICR of an OFDM signalCommun. Lett 6 2002
Paterson, K. G.Generalized Reed–Muller codes and power control in OFDM modulationIEEE Trans. Inf. Theory 6 104 2000
Davis, J. A.Jedwab, J.Peak-to-mean power control in OFDM, Golay complementary sequences, and Reed-Muller codesIEEE Trans. Inf. Theory 45 2397 1999
Byoung-Jo, C.Hanzo, L.Crest factors of complementary-sequence-based multicode MCCDMA signalsIEEE Trans. Wireless Commun 2 1114 2003
Doherty, W. H.A new high efficiency power amplifer for modulated wavesProc. IRE 24 1163 1936
Kahn, L. R.Single sideband transmission by envelope elimination and restorationProc. IRE 40 803 1952
Chireix, H.High power outphasing modulationProc. IRE 23 1370 1935
Raab, F. H.Asbeck, P.Cripps, S.Kenington, P. B.Popovic, Z. B.Pothecary, N.Sevic, J. F.Sokal, N. O.38 2003
Cripps, S. C.Advanced Techniques in RF Power Amplifier DesignArtech House 2002
Wiegner, D.Luz, G.Juschke, P.Machinal, R.Merk, T.Seyfried, U.Templ, W.Pascht, A.Quay, R.Van Raay, F.AlGaN/GaN-based power amplifiers for mobile radio applications: a review from the system supplier's perspectiveInt. J. Microw. Wireless Technol 2 95 2010
Gysel, U.H.A new N-way power divider/combiner suitable for high Power applicationsIEEE MTT-S Int. Symp. Dig 1975 116
Levy, R.Lind, L.Synthesis of symmetrical branch-guide directional couplersIEEE Trans. Microw. Theory Tech 16 80 1968
Gupta, R. K.Anderson, S. E.Getsinger, W. J.Impedance-transforming 3 dB 90° HybridsIEEE Trans. Microw. Theory Tech 35 1303 1987
Lange, J.Interdigitated stripline quadrature hybridIEEE Trans. Microw. Theory Tech 17 1150 1969
Sevick, J. 1987
Guanella, G.Novel matching systems for high frequenciesBrown–Boveri Rev 31 1944 327
Ruthroff, C. L.Some broad-band transformersProc. IRE 47 1959 1337
Cripps, S. C.RF Power Amplifiers for Wireless CommunicationsArtech HouseNorwood, MA 2006 290