Patent ID: 6690743
Filing Date: 2004-02-10
Classification: H03C,H03F,H04B,H04L

Abstract:
A linearization arrangement of a power amplifier, which arrangement comprises an I/Q modulator in which the baseband signals I and Q containing data are combined and modulated to a final frequency, one or more power amplifiers to be linearized and generating delay, by which power amplifiers the final frequency signal is amplified and which signal is conveyed to an antenna to be transmitted after the amplification, and a sampling arrangement by which the amplified, final frequency signal is sampled before the antenna, and an I/Q demodulator to which said signal sample is applied and in which the signal sample is demodulated to baseband and I and Q sample signals are separated from it, and a feedback in which the I and Q sample signals demodulated and separated from the signal sample are summed to the actual I and Q signals, and a local oscillator from which a local oscillator signal is conveyed to the I/Q modulator and the I/Q demodulator, whereby an arrangement is provided between the local oscillator and the I/Q demodulator, by which arrangement the local oscillator signal applied to the I/Q demodulator is delayed in order to compensate the delay generated in the power amplifiers, wherein:the arrangement for delaying the local oscillator signal applied to the I/Q demodulator is an amplifier which is optimized to produce a desired delay to a desired frequency range; the delay generated in the amplifier delaying the local oscillator signal applied to the I/Q demodulator is generated by arranging the amplifier to be band-passing at the frequency of the local oscillator signal; and the matching of the input of the amplifier delaying the local oscillator signal applied to the I/Q demodulator is high-passing and the matching of the output is low-passing.