Dc power control for power amplifiers

A communications device, comprising:

• a signal generator configured to provide a signal-of-interest to be amplified via a power amplifier and transmitted over an RF antenna;
• a transmission path extending between the signal generator and the power amplifier and comprising a delay element, wherein the delay element delays the signal-of-interest to provide a delayed signal-of-interest on the transmission path;
• a control path extending between the signal generator and the power amplifier and comprising a signal analyzer and a tunable DC power supply, wherein the signal analyzer is configured to analyze the signal-of-interest by evaluating an envelope thereof and induce a change in a DC power level provided by the tunable DC power supply based thereon;
• and
• wherein the power amplifier receives the DC power from the tunable DC power supply and amplifies the delayed-signal-of-interest as a function of the DC power, thereby facilitating transmission of the signal-of-interest over the RF antenna.

A transmitter, comprising:

• a transmission path extending between a signal generator and an RF antenna port configured to couple to an RF antenna, wherein the signal generator provides a signal-of-interest on the transmission path;
• a delay element disposed on the transmission path and adapted to delay the signal-of-interest, thereby providing a delayed signal-of-interest;
• a power amplifier disposed on the transmission path and adapted to provide an RF signal to the RF antenna port based on the delayed signal-of-interest;
• a control path to provide a time-varying DC supply signal to the power amplifier based on the signal-of-interest, wherein the DC supply signal at a given time is a function of an amplitude or envelope of the delayed signal-of-interest expected to be encountered by the power amplifier at the given time.

A method of signal transmission, comprising:

• generating a delayed signal-of-interest from a signal-of-interest, wherein the delayed signal-of-interest is delayed with respect to the signal-of-interest but otherwise corresponds thereto;
• determining whether an envelope associated with the signal-of-interest has a predetermined relationship with an envelope threshold, and providing a time-varying DC power supply that has a DC power level based on whether the predetermined relationship if fulfilled or not;
• and
• amplifying the delayed-signal-of-interest by using the time-varying DC power supply to facilitate transmission of the signal-of-interest.

A method of signal transmission, comprising:

• providing a signal-of-interest over a plurality of time windows;
• determining a plurality of magnitude values for the signal-of-interest for the plurality of time windows, respectively;
• generating a DC power supply based on the plurality of magnitude values, wherein a DC power level for a second time window is set based on a magnitude value determined in a first time window, the second time window being a predetermined number of time windows after the first time window;
• generating a delayed signal-of-interest from the signal-of-interest, wherein the delayed signal-of-interest is delayed by the predetermined number of time windows with respect to the signal-of-interest but otherwise at least substantially corresponds thereto;
• and
• amplifying the delayed-signal-of-interest by using the generated DC power supply.

A transmitter, comprising:

• a transmission path extending between a signal generator and an RF antenna port configured to couple to an RF antenna, wherein the signal generator is configured to provide a signal-of-interest on the transmission path;
• a delay element disposed on the transmission path and configured to delay the signal-of-interest, thereby providing a delayed signal-of-interest;
• a power amplifier disposed on the transmission path and adapted to provide an RF signal to the RF antenna port based on the delayed signal-of-interest;
• and
• a control path configured to provide a time-varying DC supply signal to the power amplifier based on a fast track version of the signal-of-interest, wherein the delayed signal-of-interest lags behind the fast track version of the signal-of-interest at any given time, and wherein a voltage level of the time-varying DC supply signal is set based on the fast track signal at a first time window and corresponds to an amplitude or envelope of the delayed signal-of-interest expected to be encountered by the power amplifier at a second time window which is after the first time window.