Patent ID: 7065330

Claim:
A transmitter comprising a device for frequency up-conversion of a communication signal to a higher frequency comprising at least two consecutive frequency conversion stages each having a local oscillator and a frequency mixer for mixing the signal of the local oscillator with said communication signal for a stepwise frequency up-conversion of the communication signal, a power amplifier for amplifying the output signal from the frequency up-conversion device for obtaining a transmission signal, means for extracting the transmission signal, a device for frequency down-conversion of said extracted transmission signal to the same frequency as the communication signal before said up-conversion for creating a feedback signal, said frequency down-conversion device being adapted to use the same local oscillators as the frequency up-conversion device for frequency conversion of the transmission signal, and means for signal parameter adaptation of the communication signal on basis of said feedback signal for obtaining a desired character of said transmission signal, characterized in that said frequency down-conversion device comprises a local oscillator combiner having means for mixing frequency signals of at least two of said local oscillators for combining them into a combined local oscillator frequency signal, and that said local oscillator combiner is adapted to send this combined frequency signal to a frequency mixer of the frequency down-conversion device for frequency down-conversion of the transmission signal reducing the number of frequency conversion stages in the transmission signal path of the frequency down-conversion device with respect to the number of frequency conversion stages in the communication signal path of the frequency up-conversion device.