Polar loop radio frequency (RF) transmitter having increased dynamic range amplitude control
First Claim
1. A method for controlling an amplitude modulated signal supplied to a power control loop, comprising:
- receiving, in a first variable gain element, a power level signal and an inverse representation of a power control signal;
receiving, in a second variable gain element, an error signal and the power control signal; and
receiving, in a third variable gain element, an amplitude modulated (AM) signal and the power control signal, the third variable gain element having a gain characteristic configured to reduce the gain applied to the AM signal when the power control signal falls below a minimum predetermined value, and to provide the AM signal as a reference signal with a constant (average) level for the power control loop.
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Accused Products
Abstract
A closed loop power control system for a radio frequency (RF) transmitter comprises a first variable gain element located in a power control loop and configured to receive a power level signal and an inverse representation of a power control signal, a second variable gain element located in the power control loop and configured to receive an error signal and the power control signal, and a third variable gain element configured to receive an amplitude modulated (AM) signal and the power control signal, the third variable gain element having a gain characteristic configured to operate to reduce the gain applied to the AM signal when the power control signal falls below a minimum predetermined value, and to provide the AM signal as a reference signal.
38 Citations
20 Claims
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1. A method for controlling an amplitude modulated signal supplied to a power control loop, comprising:
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receiving, in a first variable gain element, a power level signal and an inverse representation of a power control signal;
receiving, in a second variable gain element, an error signal and the power control signal; and
receiving, in a third variable gain element, an amplitude modulated (AM) signal and the power control signal, the third variable gain element having a gain characteristic configured to reduce the gain applied to the AM signal when the power control signal falls below a minimum predetermined value, and to provide the AM signal as a reference signal with a constant (average) level for the power control loop. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A closed loop power control system for a radio frequency (RF) transmitter, comprising:
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a first variable gain element located in a power control loop and configured to receive a power level signal and an inverse representation of a power control signal;
a second variable gain element located in the power control loop and configured to receive an error signal and the power control signal; and
a third variable gain element configured to receive an amplitude modulated (AM) signal and the power control signal, the third variable gain element having a gain characteristic configured to reduce the gain applied to the AM signal when the power control signal falls below a minimum predetermined value, and to provide the AM signal as a reference signal with a constant (average) level for the power control loop. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A portable transceiver having a closed loop power control system for a radio frequency (RF) transmitter, comprising:
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transmit and receive circuitry;
a first variable gain element located in a power control loop and configured to receive a power level signal and an inverse representation of a power control signal;
a second variable gain element located in the power control loop and configured to receive an error signal and the power control signal; and
a third variable gain element configured to receive an amplitude modulated (AM) signal and the power control signal, the third variable gain element having a gain characteristic configured to reduce the gain applied to the AM signal when the power control signal falls below a minimum predetermined value, and to provide the AM signal as a reference signal with a constant (average) level for the power control loop. - View Dependent Claims (17, 18, 19, 20)
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Specification