An envelope elimination and restoration power amplifier using a CMOS dynamic power supply circuit

Abstract

This paper presents a CDMA power amplifier using Kahn envelope elimination and restoration technique. A CMOS delta-modulated envelope amplifier with over 3MHz bandwidth is used as the dynamic power supply. Internal feedback was used on the envelope amplifier to reduce delay. A commercially available 1W GaAs/AlGaAs HFET power amplifier was tested in conjunction with the envelope amplifier. Using an IS-95 CDMA signal, a peak output power of 25 dBm was obtained at 836 MHz while achieving a maximum efficiency of 48% with ACPR of 47.9 dBc.