Feipeng Wang

TL;DR: In this paper, a hybrid wideband EER power amplifier for the WLAN 802.11g system is proposed, which shows an overall efficiency of 36% and power-added efficiency of 28% for a WLAN IEEE 802.15.4 signal at 19dBm (80 mW) output power at 2.4 GHz.

Abstract: An efficiency-enhanced power-amplifier system design is presented based on wide-bandwidth envelope tracking (WBET) with application to orthogonal frequency-division multiplexing wireless local area network systems. Envelope elimination and restoration (EER) and WBET are compared in terms of the time mismatch sensitivity between the base-band amplitude path and the RF path, and it is demonstrated that WBET is much less sensitive than EER to these effects. An adaptive time-alignment algorithm for the WBET system is developed and demonstrated. The analysis and algorithm are verified by experimental results. The measurement shows that the peak drain efficiency of the complete system was 30% at a 2.4-GHz orthogonal frequency-division multiplexing output power of 20 dBm.

TL;DR: A monolithic SiGe BiCMOS envelope-tracking power amplifier is demonstrated for 802.11g OFDM applications at 2.4 GHz with off-chip digital predistortion employed to improve EVM performance.

TL;DR: A high-efficiency wide-bandwidth envelope amplifier and a GaAs MESFET class AB RFPA are designed and implemented for the WLAN 802.11g system to improve the linearity and overall system drain efficiency.

TL;DR: Promising results indicate the feasibility of realizing true single-chip wireless transceivers with on-chip RF SiGe PAs for spectrally-efficient non-constant-envelope modulation schemes.