Transmitter
First Claim
1. A transmitter comprisinga 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, andmeans 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.
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Accused Products
Abstract
A transmitter comprises a device (20) for frequency up-conversion of a communication signal having at least two consecutive frequency conversion stages, a power amplifier (27) for amplifying the output signal therefrom for obtaining a transmission signal and means (29) for extracting the transmission signal. It also has 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 two devices use the same local oscillators (25, 26). The transmitter also has means for signal parameter adaptation of the communication signal on basis of the feedback signal for obtaining a desired character of the transmission signal. The frequency down-conversion device comprises a local oscillator combiner (30) producing a combined frequency signal used for frequency down-conversion of the transmission signal reducing the number of conversion stages in the path of the extracted transmission signal with respect to the corresponding number of the frequency up-conversion device.
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Citations
41 Claims
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1. 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.
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22. A method for signal processing in a transmitter comprising the following steps:
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a) frequency up-conversion of a communication signal to a higher frequency by consecutively mixing the communication signal with a signal from at least two consecutive local oscillators for a stepwise frequency up-conversion of the communication signal, b) amplifying the output signal resulting from the frequency up-conversion for obtaining a transmission signal, c) extracting the transmission signal, d) 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 by using the same local oscillators as for the frequency up-conversion for frequency down-conversion of the transmission signal, and e) adapting signal parameters of the communication signal on basis of said feedback signal for obtaining a desired character of said transmission signal, characterized in that in step d) frequency signals of at least two of said local oscillators are mixed for combining them into a combined local oscillator frequency signal, which is then used in said frequency down-conversion stage for frequency down-conversion of the transmission signal, thus reducing the number of frequency conversion stages in the transmission signal path of the frequency down-conversion with respect to the number of frequency conversion stages in the communication signal path of the frequency up-conversion. - View Dependent Claims (23, 24, 25, 26, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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- 27. A method according to, characterized in that a frequency signal emitted by at least one of said local oscillators is delayed on the path to said frequency down-conversion stage so as to substantially match the delay of this frequency signal from said local oscillator to this stage through the local oscillator signal combining step with the delay of this signal to this stage through the frequency up-conversion step a) and the power amplifying step b).
Specification