Power amplification with envelope tracking to provide envelope-based biasing and supply voltages

Abstract

Disclosed herein are amplification systems that are dynamically biased based on a signal indicative of an envelope of an input radio-frequency (RF) signal being amplified. The amplification systems include a power converter with an envelope tracker and an RC circuit. The envelope tracker and the RC circuit are configured to generate an envelope-based biasing signal to bias a power amplifier and an envelope-based supply voltage to power the power amplifier.

What is claimed is: 
     
         1 . A power amplification system comprising:
 a power amplifier configured to amplify an input radio-frequency (RF) signal to generate an output RF signal when powered by an envelope-based supply voltage and biased by an envelope-based biasing signal, the envelope-based biasing signal and the envelope-based supply voltage each indicative of an envelope of the input RF signal; and   a power converter having a supply port to receive a supply voltage, a bias port to receive a biasing signal, an envelope port to receive an envelope signal, a bias output port to provide the envelope-based biasing signal to the power amplifier, a supply output port to provide the envelope-based supply voltage to the power amplifier, an envelope tracker, and a resistor-capacitor (RC) circuit, the envelope tracker configured to receive the envelope signal and to generate an envelope tracker signal that is combined with the supply voltage to provide the envelope-based supply voltage, the RC circuit configured to combine the biasing signal with the envelope tracker signal to generate the envelope-based biasing signal.   
     
     
         2 . The power amplification system of  claim 1  wherein the power amplifier includes a plurality of cascode amplifiers coupled in parallel. 
     
     
         3 . The power amplification system of  claim 2  further comprising one or more switches configured to pass or block the envelope-based biasing signal to a respective one or more of the plurality of cascode amplifiers. 
     
     
         4 . The power amplification system of  claim 1  wherein the RC circuit is configured to combine the biasing signal with the envelope-based supply voltage to generate the envelope-based biasing signal. 
     
     
         5 . The power amplification system of  claim 1  wherein the RC circuit includes one or more resistors or one or more capacitors. 
     
     
         6 . The power amplification system of  claim 1  wherein the power converter further includes an LC combiner that combines the envelope tracker signal and the supply voltage to provide the envelope-based supply voltage. 
     
     
         7 . The power amplification system of  claim 6  wherein the LC combiner includes a capacitor coupled to the envelope tracker and an inductor coupled to the supply port. 
     
     
         8 . The power amplification system of  claim 1  wherein the envelope tracker is implemented as a buffer amplifier. 
     
     
         9 . The power amplification system of  claim 1  wherein the envelope tracker is implemented as a digital-to-analog converter. 
     
     
         10 . The power amplification system of  claim 1  wherein the envelope tracker signal is indicative of the envelope of the input RF signal. 
     
     
         11 . The power amplification system of  claim 1  wherein the envelope-based biasing signal is configured to enhance a linearity of the power amplifier. 
     
     
         12 . The power amplification system of  claim 1  further comprising a bias time alignment circuit configured to adjust a timing of the biasing signal. 
     
     
         13 . The power amplification system of  claim 12  further comprising an envelope alignment circuit configured to adjust a timing of the envelope signal. 
     
     
         14 . The power amplification system of  claim 13  further comprising a bias shaping circuit configured to manipulate a shape of the biasing signal to enhance linearity or efficiency of the power amplifier. 
     
     
         15 . A radio-frequency (RF) module comprising:
 a packaging substrate configured to receive a plurality of components; and   a power amplification system implemented on the packaging substrate, the power amplification system including a power amplifier configured to amplify an input radio-frequency (RF) signal to generate an output RF signal when powered by an envelope-based supply voltage and biased by an envelope-based biasing signal, the envelope-based biasing signal and the envelope-based supply voltage each indicative of an envelope of the input RF signal; and the power amplification system also including a power converter having a supply port to receive a supply voltage, a bias port to receive a biasing signal, an envelope port to receive an envelope signal, a bias output port to provide the envelope-based biasing signal to the power amplifier, a supply output port to provide the envelope-based supply voltage to the power amplifier, an envelope tracker, and a resistor-capacitor (RC) circuit, the envelope tracker configured to receive the envelope signal and to generate an envelope tracker signal that is combined with the supply voltage to provide the envelope-based supply voltage, the RC circuit configured to combine the biasing signal with the envelope tracker signal to generate the envelope-based biasing signal.   
     
     
         16 . The RF module of  claim 15  wherein the power amplifier includes a plurality of cascode amplifiers coupled in parallel. 
     
     
         17 . The RF module of  claim 16  wherein the power amplification system further comprises one or more switches configured to pass or block the envelope-based biasing signal to a respective one or more of the plurality of cascode amplifiers. 
     
     
         18 . A wireless device comprising:
 a transceiver configured to generate a radio-frequency (RF) signal;   a front-end module (FEM) in communication with the transceiver, the FEM including a packaging substrate configured to receive a plurality of components, the FEM further including a power amplification system implemented on the packaging substrate, the power amplification system including a power amplifier configured to amplify an input radio-frequency (RF) signal to generate an output RF signal when powered by an envelope-based supply voltage and biased by an envelope-based biasing signal, the envelope-based biasing signal and the envelope-based supply voltage each indicative of an envelope of the input RF signal; and the power amplification system also including a power converter having a supply port to receive a supply voltage, a bias port to receive a biasing signal, an envelope port to receive an envelope signal, a bias output port to provide the envelope-based biasing signal to the power amplifier, a supply output port to provide the envelope-based supply voltage to the power amplifier, an envelope tracker, and a resistor-capacitor (RC) circuit, the envelope tracker configured to receive the envelope signal and to generate an envelope tracker signal that is combined with the supply voltage to provide the envelope-based supply voltage, the RC circuit configured to combine the biasing signal with the envelope tracker signal to generate the envelope-based biasing signal; and   an antenna in communication with the FEM, the antenna configured to transmit the output RF signal received from the power amplification system.   
     
     
         19 . The wireless device of  claim 18  wherein the power amplifier includes a plurality of cascode amplifiers coupled in parallel. 
     
     
         20 . The wireless device of  claim 19  wherein the power amplification system further comprises one or more switches configured to pass or block the envelope-based biasing signal to a respective one or more of the plurality of cascode amplifiers.