Class E power amplifier circuit and associated transmitter circuits

• US 20050218977A1
• Filed: 02/24/2005
• Published: 10/06/2005
• Est. Priority Date: 02/25/2004
• Status: Active Grant

• Current Assignee: Queen's University Belfast (Queen's University)
• Original Assignee: Queen's University Belfast (Queen's University)
• Inventors: Fusco, Vincent Francis, Brabetz, Thorsten
• Granted Patent: US 7,321,263 B2
• Time in Patent Office: Days
• US Class Current: 330/10
• CPC Class Codes: H03F 3/2176 Class E amplifiers

Abstract

A class E power amplifier circuit comprising an active device, a DC blocking element and an oscillating element, wherein the oscillating element is driven by a voltage signal.

Claims

1. A class E power amplifier circuit comprising an active device, a DC blocking element and an oscillating element, wherein the oscillating element is driven by a voltage signal.

2. A class E power amplifier circuit as claimed in claim 1 wherein the oscillating element is a LC resonant circuit connected in parallel with the active device and in series with the DC blocking element.

3. A class E power amplifier circuit as claimed in claim 1 wherein the class E power amplifier circuit comprises a load resistor connected in parallel to the oscillating element.

4. A class E power amplifier circuit as claimed in claim 3 wherein the oscillating element forces a sinusoidal voltage over the load resistor and the active device.

5. A class E power amplifier circuit as claimed in claim 1 wherein the class E power amplifier circuit comprises a first inductor connected in series with the active device.

6. A class E power amplifier circuit as claimed in claim 5 wherein the first inductor is connected in series with the DC blocking element.

7. A class E power amplifier circuit as claimed in claim 6 wherein the DC blocking element comprises a RF choke and first capacitor.

8. A class E power amplifier circuit as claimed in claim 1 wherein the active device is switched from an “

ON”

state in which the active device operates as a closed switch to an “

OFF”

state in which the active device operates as an open switch wherein the switching operation is controlled by a RF signal.

9. A class E power amplifier circuit as claimed in claim 8 wherein the switching activity of the active device stimulates a sinusoidal voltage in the oscillating element.

10. A class E power amplifier circuit as claimed in claim 9 wherein when the active device is in its “

ON”

state, a current flows through the switch and sinusoidal voltage developed in the oscillating element is dropped across the load resistor.

11. A class E power amplifier circuit as claimed in claim 8 wherein when the active device is in its “

OFF”

state, a current flows through the load resistor and the voltage developed by the oscillating element is dropped exclusively across the active device.

12. A signal transmission circuit comprising a class E power amplifier circuit as claimed in claim 1.

13. A phase modulated signal transmission circuit comprising a phase modulator and a class E power amplifier circuit as claimed in claim 1.

14. A phase shift keying signal transmission circuit comprising a phase shift keying modulator and a class E power amplifier comprising an active device, a DC blocking element and an oscillating element, wherein the oscillating element is driven by a voltage signal.

15. A circuit as claimed in claim 14 wherein the phase shift keying signal transmission circuit incorporates an analogue signal source connectable to a class E power amplifier bias voltage control means so that the analogue signal source modulates the output from the phase shift keying modulator.

16. An amplitude modulated signal transmission circuit comprising an amplitude modulator and a class E power amplifier comprising an active device, a DC blocking element and an oscillating element, wherein the oscillating element is driven by a voltage signal.

17. A circuit as claimed in claim 16 wherein the amplitude modulated signal transmission circuit comprises an input signal splitting means and a voltage control means wherein the input signal splitting means splits a digital input signal into a series of multiple bit words, wherein at least one bit of a resulting word is transmitted to the voltage control means to control the bias voltage of the class E power amplifier and wherein the remaining bits of the resulting word are transmitted to the amplitude modulator for amplification by the class E power amplifier.

18. A circuit as claimed in claim 16 wherein the amplitude modulated signal transmission circuit is a quadrature amplitude modulated signal transmission circuit.