Patent ID: 7161990
Filing Date: 2007-01-09
Classification: H03F,H04L

Abstract:
1. A predistortion amplifier comprising: a 2-variable polynomial calculating unit for performing predistortion of signals by calculating a polynomial using real and imaginary parts of a baseband complex input signal as its two variables and having a complex coefficient; an orthogonal modulator for performing orthogonal modulation of the real and imaginary parts of an output signal of the polynomial calculating unit using two carriers orthogonal to each other; a power amplifier for amplifying the output of the orthogonal modulator; a distributor for distributing the output of the power amplifier: an orthogonal demodulator for performing orthogonal demodulation over an output signal of the distributor and generating a baseband complex demodulation signal; and a coefficient updating section for sequentially updating a complex coefficient vector of the polynomial calculating unit on the basis of said baseband complex input signal and said baseband complex demodulation signal, wherein said 2-variable polynomial calculating unit comprises: and imaginary parts of said baseband complex input signal, and