Power control for a transmitter
First Claim
1. A transmitter comprising:
- a modulator providing a phase-modulated constant-envelope radio-frequency signal;
a dividing unit dividing a signal provided by said modulator into a first signal and a second signal which are identical to each other;
a first processing branch for processing a respective first signal provided by said dividing unit, said first processing branch comprising a first phase shifter and a first power amplifier connected to each other in series;
a second processing branch for processing a respective second signal provided by said dividing unit, said second processing branch comprising a second phase shifter and a second power amplifier connected to each other in series;
a combining unit combining signals provided by said first and said second processing branch;
a first control arrangement for controlling the power of a signal output by said combining unit at least for higher power levels by controlling the amplifications applied by said first power amplifier and by said second power amplifier to a respectively received signal; and
a second control arrangement for controlling the power of a signal output by said combining unit at least for lower power levels by controlling the phase shifts applied by said first phase shifter and by said second phase shifter to a respectively received signal.
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Accused Products
Abstract
The invention relates to a transmitter which comprises a modulator providing a phase-modulated constant-envelope radio-frequency signal, and to a method of controlling the power level of a signal output by such a transmitter. In order to enable a power control over a large power range, it is proposed that a provided phase-modulated constant-envelope radio-frequency signal is divided into two identical signals for the power control. A first control arrangement then controls the output power for higher power levels by controlling amplifications applied to the two signals. A second control arrangement controls the output power for lower power levels by controlling phase shifts applied to the two signals. The processed signals are then combined and provided as a power controlled output signal.
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Citations
23 Claims
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1. A transmitter comprising:
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a modulator providing a phase-modulated constant-envelope radio-frequency signal;
a dividing unit dividing a signal provided by said modulator into a first signal and a second signal which are identical to each other;
a first processing branch for processing a respective first signal provided by said dividing unit, said first processing branch comprising a first phase shifter and a first power amplifier connected to each other in series;
a second processing branch for processing a respective second signal provided by said dividing unit, said second processing branch comprising a second phase shifter and a second power amplifier connected to each other in series;
a combining unit combining signals provided by said first and said second processing branch;
a first control arrangement for controlling the power of a signal output by said combining unit at least for higher power levels by controlling the amplifications applied by said first power amplifier and by said second power amplifier to a respectively received signal; and
a second control arrangement for controlling the power of a signal output by said combining unit at least for lower power levels by controlling the phase shifts applied by said first phase shifter and by said second phase shifter to a respectively received signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of controlling the power level of a signal output by a transmitter, said method comprising:
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dividing a provided phase-modulated constant-envelope radio-frequency signal into a first signal and a second signal which are identical to each other;
controlling the power level of an output signal of said transmitter at least in case of higher required power levels by controlling amplifications applied separately to said first signal and to said second signal; and
controlling the power level of an output signal of said transmitter at least in case of lower required power levels by controlling phase shifts applied separately to said first signal and to said second signal; and
combining said processed first signal and said processed second signal and providing said combined signal as a power controlled output signal. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification