Design, simulation and analysis of a hybrid envelope tracking supply modulator for high frequency transmitters

One of the most essential blocks in modern communication systems is radio frequency power amplifiers (RFPA). It is typically the final stage of a wireless transmitter. The amplified RF signal can be utilized for a variety of applications in wireless communications. PAs are included in both mobile user equipment (UE) and base transceiver station (BTS) to amplify an RF signal to a nominal power level. In recent years, with surge in wireless communications there is a high demand for optimizing RFPAs operation which causes long lasting batteries and lowering the cooling cost in stations. This research focuses on design, simulation and analysis of a hybrid envelope tracking supply modulator (SM) with high speed response which improves RFPAs operation. The proposed SM tracks wideband code division multiple access (WCDMA) signal. It is designed with 180nm CMOS technology. The aim is to reinforce the slew rate and consequently improving the modulator behavior. Slew rate has been increased up to 182.69 V/μs .Circuit simulations using 180nm transistors and 3.3v supply voltage are done in ADS simulation environment

Keywords:

RF PA , Supply modulator , Envelope tracking , Slew rate , WCDMA.