Polar loop radio frequency (RF) transmitter having increased dynamic range amplitude control

A closed loop power control system for a radio frequency (RF) transmitter, comprising:

• 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 coupled between a modulator and a comparator within the closed loop power control system, the 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.

A portable transceiver having a closed loop power control system for a radio frequency (RF) transmitter, comprising:

• 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 coupled between a modulator and a comparator within the closed loop power control system, the 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.