Dual mode power amplifier
View Patent ↗A dual mode power amplifier can include a linear gain section and a non-linear gain section configured together as a polar amplifier. The dual mode power amplifier may be used to transmit GFSK, 4-DPSK, and 8-DPSK modulated data. In one mode, both non-linear and linear gain sections may be used to transmit 4-DPSK and 8-DPSK modulated data. Alternatively, in another mode, the linear gain section may be bypassed while the non-linear gain section may be used to transmit GFSK modulated data. By selecting the operating mode, the dual mode power amplifier may be advantageously configured to use relatively less power while supporting GFSK, 4-DPSK, and 8-DPSK modulation schemes.
1. A dual mode power amplifier comprising:
a non-linear gain section receiving frequency modulating inputs and a first gain signal;
a linear gain section receiving amplitude modulating inputs, the first gain signal, and a mode select signal, the linear gain section being configured to selectively output a constant based on the mode select signal; and
a mixer configured to mix outputs of the non-linear gain section and the linear gain section, and generate a mixed signal as an output of the dual mode power amplifier.
2. The dual mode power amplifier of claim 1 , wherein the non-linear gain section includes a switching amplifier that receives the frequency modulating inputs and the first gain signal.
3. The dual mode power amplifier of claim 2 , wherein the switching amplifier includes a plurality of transistor structures, each transistor structure including breakdown-resistant transistors.
4. The dual mode power amplifier of claim 2 , wherein the linear gain section includes:
a mode controller for receiving the mode select signal and the first gain signal;
a linear amplifier for receiving the amplitude modulating inputs and a second gain signal output by the mode controller; and
a multiplexer for receiving an output of the linear amplifier and the constant, and generating an output of the linear gain section, the multiplexer being controlled by the mode controller.
5. The dual mode power amplifier of claim 4 , wherein the mode controller is configured to saturate at least one device of the linear amplifier using the second gain signal.
6. A method of selectively providing one of Gaussian frequency-shift keying (GFSK) modulation and differential phase-shift keying (DPSK) modulation, the method comprising:
coupling frequency modulating inputs to a non-linear gain section;
coupling amplitude modulating inputs to a linear gain section;
coupling a first gain signal to the non-linear and linear gain sections;
configuring the linear gain section in one of a normal mode and a bypass mode; and
mixing outputs of the non-linear and linear gain sections to generate an amplifier output signal.
7. The method of claim 6 , wherein when the linear gain section is configured in the bypass mode, an output of the linear gain section is a unity value and the amplifier output signal is GFSK modulated.
8. The method of claim 6 , wherein when the linear gain section is configured in the bypass mode, an output of the linear gain section is a constant value and the amplifier output signal is GFSK modulated.
9. The method of claim 6 , wherein when the linear gain section is configured in the normal mode, the amplifier output signal is DPSK modulated.