DIGITAL POWER AMPLIFIER

• US 20200136572A1
• Filed: 10/31/2018
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: WATKINS, Gavin Tomas
• Granted Patent: US 10,938,358 B2
• Time in Patent Office: Days
• CPC Class Codes: H03F 1/0205 in transistor amplifiers
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 2200/255 Amplifier input adaptation especially for transmission line coupling purposes, e.g. impedance adaptation
• CPC Class Codes: H03F 2200/301 the loading circuit of an amplifying stage comprising a coil
• CPC Class Codes: H03F 2200/336 A I/Q, i.e. phase quadrature, modulator or demodulator being used in an amplifying circuit
• CPC Class Codes: H03F 2200/423 Amplifier output adaptation especially for transmission line coupling purposes, e.g. impedance adaptation
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2203/21103 An impedance adaptation circuit being added at the input of a power amplifier stage
• CPC Class Codes: H03F 2203/21106 An input signal being distributed in parallel over the inputs of a plurality of power amplifiers
• CPC Class Codes: H03F 2203/21139 An impedance adaptation circuit being added at the output of a power amplifier stage
• CPC Class Codes: H03F 3/193 with field-effect devices H03F3/195 takes precedence
• CPC Class Codes: H03F 3/1935 with junction-FET devices
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03F 3/2178 using more than one switch or switching amplifier in parallel or in series H03F3/2173, H03F3/2175 take precedence
• CPC Class Codes: H03F 3/245 with semiconductor devices only
• CPC Class Codes: H03F 3/602 Combinations of several amplifiers
• CPC Class Codes: H04L 27/2614 Peak power aspects

Abstract

A digital power amplifier comprising two or more individually activatable amplifiers. The outputs of the amplifiers are connected causing an activated amplifier of the two or more amplifiers to load modulate another activated amplifier of the two or more amplifiers.

Claims

1. A digital power amplifier comprising two or more individually activatable amplifiers, wherein the outputs of the amplifiers are connected causing an activated amplifier of the two or more amplifiers to load modulate another activated amplifier of the two or more amplifiers.

2. The digital power amplifier of claim 1, wherein the outputs of two of the two or more amplifiers are connected by two signal paths.

3. The digital power amplifier of claim 1, wherein the outputs of two or more amplifiers are connected by a transmission line network.

4. The digital power amplifier of claim 3, wherein the transmission line network is based on a rat-race combiner, wherein the impedances of the transmission lines are altered from those of a standard ring combiner to enable said load modulation.

5. The digital power amplifier of claim 3, wherein the impedances of transmission lines in the transmission line network are selected so that the impedance presented to a first activated amplifier by the combination of the transmission line network and any other activated amplifiers sets the output power of the first activated amplifier so that the first activated amplifier operates in saturation.

6. The digital power amplifier of claim 3, wherein the transmission line networks includes a phase inverter.

7. The digital power amplifier of claim 1, wherein the two or more amplifiers operate in current saturation at different saturation powers.

8. The digital power amplifier of claim 1, configured to receive digital signals for individually activating and deactivating the two or more amplifiers, said signals individually applied as gate bias to transistors of the amplifiers.

9. The digital power amplifier of claim 1, further comprising a signal splitter configured to split the input signal, wherein individual outputs of the splitter are individually connected to inputs of the amplifiers.

10. The digital power amplifier of claim 9, wherein said splitter splits the signal into unequal output signals to operate the amplifiers in saturation.

11. The digital power amplifier of claim 1, wherein the two or more amplifiers are discrete devices.

12. The digital power amplifier of claim 1, wherein the two or more amplifiers and their connections are configured to provide output power levels in saturation optimised for a predetermined signal modulation scheme.

13. A device comprising the digital power amplifier of claim 1, wherein the device is a mobile phone basestation or a DVB transmitter.