Title :
A pHEMT power amplfier with an on-off modulator
Author :
Hao-Shun Yang ; Li-Wei Lin ; Chen, Yi-Jan Emery
Author_Institution :
Grad. Inst. of Electron. Eng., Nat. Taiwan Univ., Taipei, Taiwan
Abstract :
This paper presents a transformer-based switching-type RF power amplifier with an on-off modulator using a 0.15-¼m pHEMT process. In order to overcome the inherent limitation of ground potential at the source node of transistor models in this pHEMT process, an on-off modulator was designed for the proposed pulse-modulated polar transmitter system. Measurement using a single-tone signal at 2.2 GHz and a 3.8-V supply, this pHEMT power amplifier with the proposed on-off modulator under full turn-on condition achieves 50.1% efficiency at 26.7-dBm output power level. Moreover, it achieves 45.3% efficiency at 23.7-dBm output power level under the half turn-on condition. Furthermore, the isolation of this system at the peak output power level under full turn-off condition is 23.3 dB which is much better than using gate bias control to switch the cell of power transistors.
Keywords :
high electron mobility transistors; optical modulation; power amplifiers; power transistors; frequency 2.2 GHz; ground potential; on-off modulator; pHEMT power amplfier; source node; transformer-based switching-type; transistor models; voltage 3.8 V; Logic gates; Modulation; PHEMTs; Power amplifiers; Radio frequency; Switches; RF power amplifiers; microwave amplifiers; pHEMT; radio transmitters; transformer;
Conference_Titel :
Power Amplifiers for Wireless and Radio Applications (PAWR), 2013 IEEE Topical Conference on
Conference_Location :
Santa Clara, CA
Print_ISBN :
978-1-4673-2915-6
Electronic_ISBN :
978-1-4673-2931-6
DOI :
10.1109/PAWR.2013.6490183