Title :
Analysis of envelope signal injection for improvement of RF amplifier intermodulation distortion
Author :
Leung, Vincent W. ; Deng, Junxiong ; Gudem, Prasad S. ; Larson, Lawrence E.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of California, La Jolla, CA, USA
Abstract :
Adaptive bias techniques based on envelope signal power detection have been proposed for linearity enhancement and dc current reduction in RF amplifiers. Experimental results show an improvement in amplifier linearity, although asymmetric intermodulation distortion (IMD) was observed. This work rigorously studies the effects of the envelope signal injection on amplifier distortion using the Volterra series formulations. The results intuitively explain the spectral regrowth asymmetry, and point to a design technique in which third-order IMD can be optimally cancelled. The theory was verified through comparison to measurement and simulation results.
Keywords :
Volterra series; intermodulation distortion; radiofrequency amplifiers; signal detection; BiCMOS integrated circuits; RF amplifier; Volterra series; adaptive bias techniques; amplifier distortion; amplifier linearity; asymmetric intermodulation distortion; dc current reduction; envelope signal injection; envelope signal power detection; linearity enhancement; spectral regrowth asymmetry; wideband code division multiple access; Circuits; Envelope detectors; Intermodulation distortion; Linearity; Multiaccess communication; Power amplifiers; RF signals; Radiofrequency amplifiers; Signal analysis; Wireless communication; Adaptive bias; BiCMOS integrated circuits; RF amplifier; SiGe; Volterra Series; envelope injection; intermodulation distortion; spectral regrowth; wideband code division multiple access (WCDMA);
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2005.848176
