Patent ID: 7634238
Filing Date: 2009-12-15
Classification: H03F

Abstract:
1. A multi-band lookup table type predistorter for adding predistortion components for canceling distortion components produced by a power amplifier to an input transmitting signal and outputting the result comprising: N output side variable band signal extractors for extracting output signals in N frequency bands from output signals from the power amplifier, wherein N is an integer of 2 or greater; N input side variable band signal extractors for extracting transmitting signals in said N frequency bands from the input transmitting signal; N difference detectors for detecting differences between transmitting signals in N frequency bands and N output signals from said N output side variable band signal extractors; N lookup tables for reading distortion compensation data of corresponding N frequency bands by using differences of said N frequency bands as reference signals; N adders for adding the distortion compensation data read out from said N lookup tables to the transmitting signals in the corresponding N frequency bands; a combiner for combining the added outputs from said N adders and outputting the combined result as a transmitting signal with the predistortion; and a frequency band controller for controlling frequency bands of said N output side variable band signal extractors and said N output side variable band signal extractors commonly, wherein said frequency band controller comprises,