An improved power-added efficiency 19-dBm hybrid envelope elimination and restoration power amplifier for 802.11g WLAN applications

Feipeng Wang, Donald F. Kimball, Jeremy D. Popp, Annie Hueiching Yang, Donald Y. Lie, Peter M. Asbeck, Lawrence E. Larson

Research output: Contribution to journalArticle

255 Scopus citations


A comparison of envelope elimination and restoration (EER) and envelope tracking (ET) is discussed and a "hybrid" wideband EER power amplifier (PA) for the WLAN 802.11g system is proposed. A 60% efficiency (the output envelope signal power/input dc power) DC-20-MHz wideband envelope amplifier is designed for wideband EER and wideband ET (WBET) applications. A design method is developed to optimize the efficiency of the envelope amplifier for a given peak-to-average ratio and average slew rate of the envelope signal. An experimental "hybrid" Class-E EER system shows an overall efficiency (modulated RE output power/envelope amplifier dc input power) of 36% and power-added efficiency (the modulated RE output power/envelope amplifier dc input power plus RE input power) of 28% for a WLAN 802.11g signal at 19-dBm (80 mW) output power at 2.4 GHz. Digital predistortion, time alignment, and memory effect mitigation are implemented. The measured 3% error vector magnitude exceeds the 802.11g specification for 5% for a 54-Mb/s modulation signal.

Original languageEnglish
Pages (from-to)4086-4098
Number of pages13
JournalIEEE Transactions on Microwave Theory and Techniques
Issue number12
StatePublished - Dec 1 2006



  • Class E
  • Dc-dc converter
  • Delta-modulation (DM)
  • Digital predistortion
  • Envelope elimination and restoration (EER)
  • Envelope tracking (ET)
  • Hysteresis control
  • Memory effect
  • Modulator
  • Orthogonal frequency-division multiplexing (OFDM)
  • Polar transmitter

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