TY - GEN
T1 - Optimum design of doherty RFPA for mobile WiMAX base stations
AU - Hussaini, Abubakar Sadiq
AU - Sadeghpour, Tahereh
AU - Abd-Alhameed, Raed
AU - Child, Mark B.
AU - Ali, Nazar T.
AU - Rodriguez, Jonathan
PY - 2012
Y1 - 2012
N2 - RF power amplifiers in mobile WiMAX transceivers operate in an inherently nonlinear manner. It is possible to amplify the signal in the linear region, and avoid distortion, using output power back-off; however, this approach may suffer significant reduction in efficiency and power output. This paper investigates the use of Doherty techniques instead of back-off, to simultaneously achieve good efficiency and acceptable linearity. A 3.5 GHz Doherty RFPA has been designed and optimized using a large signal model simulation of the active device, and performance analysis under different drive levels. However, the Doherty EVM is generally poor for mobile WiMAX. Linearity may be improved by further digital pre-distortion, and a simple pre-distortion method using forward and reverse AM-AM and AM-PM modeling. Measurements on the realized amplifier show that this approach satisfies the EVM requirements for WiMAX base stations. It exhibits a PAE over 60%, and increases the maximum linear output power to 43 dBm, whilst improving the EVM.
AB - RF power amplifiers in mobile WiMAX transceivers operate in an inherently nonlinear manner. It is possible to amplify the signal in the linear region, and avoid distortion, using output power back-off; however, this approach may suffer significant reduction in efficiency and power output. This paper investigates the use of Doherty techniques instead of back-off, to simultaneously achieve good efficiency and acceptable linearity. A 3.5 GHz Doherty RFPA has been designed and optimized using a large signal model simulation of the active device, and performance analysis under different drive levels. However, the Doherty EVM is generally poor for mobile WiMAX. Linearity may be improved by further digital pre-distortion, and a simple pre-distortion method using forward and reverse AM-AM and AM-PM modeling. Measurements on the realized amplifier show that this approach satisfies the EVM requirements for WiMAX base stations. It exhibits a PAE over 60%, and increases the maximum linear output power to 43 dBm, whilst improving the EVM.
KW - digital pre-distortion
KW - Doherty
KW - linearity
KW - OFDM
KW - RFPA
UR - https://www.scopus.com/pages/publications/84873825995
U2 - 10.1007/978-3-642-35155-6_59
DO - 10.1007/978-3-642-35155-6_59
M3 - Conference contribution
AN - SCOPUS:84873825995
SN - 9783642351549
T3 - Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering
SP - 700
EP - 705
BT - Mobile Multimedia Communications - 6th International ICST Conference, MOBIMEDIA 2010, Revised Selected Papers
T2 - 6th International ICST Conference on Mobile Multimedia Communications, MOBIMEDIA 2010
Y2 - 6 September 2010 through 8 September 2010
ER -