Title :
A Transistor-Based Analog Predistorter With Unequal Delays for Memory Compensation
Author :
Lee, Yong-Sub ; Lee, Mun-Woo ; Kam, Sang-Ho ; Jeong, Yoon-Ha
Author_Institution :
Dept. of Electron. & Electr. Eng., Pohang Univ. of Sci. & Technol., Pohang, South Korea
Abstract :
A transistor-based analog predistorter (APD) with memory effect compensation is represented. The nonlinearity of a gain amplifier generated by a low supply voltage is used as an error generator. The predistorted signal by the unequal-delayed nonlinear paths improves the linearity by compensating for memory effects of the power amplifier (PA). For verification, the proposed APD with three-branch nonlinear paths is implemented with a 30-W class-AB PA and tested using two-tone and various wideband code division multiple access (WCDMA) signals at 2.14 GHz. From the measured results, the proposed APD significantly improves the linearity of the PA with memory effects.
Keywords :
UHF power amplifiers; analogue circuits; code division multiple access; delays; distortion; WCDMA; error generator; frequency 2.14 GHz; gain amplifier; memory effect compensation; power 30 W; power amplifier; transistor-based analog predistorter; unequal-delayed nonlinear paths; wideband code division multiple access; Analog predistorter (APD); delay; linearity; memory effects; power amplifier (PA);
Journal_Title :
Microwave and Wireless Components Letters, IEEE
DOI :
10.1109/LMWC.2009.2032024