Resonant power converter for radio frequency transmission and method

• US 20040037363A1
• Filed: 03/04/2003
• Published: 02/26/2004
• Est. Priority Date: 03/04/2002
• Status: Active Grant

• Current Assignee: STMicroelectronics NV
• Original Assignee: STMicroelectronics NV
• Inventors: Norsworthy, Steven R., Norsworthy, Ross W.
• Granted Patent: US 7,924,937 B2
• Time in Patent Office: Days
• US Class Current: 375/259
• CPC Class Codes: H03C 3/40 using two signal paths the outputs of which have a predetermined phase difference and at least one output being amplitude-modulated
• CPC Class Codes: H04B 1/04 Circuits

Abstract

A resonant power converter for ultra-efficient radio frequency transmission and associated methods. In one exemplary embodiment, the invention is digitally actuated and uses a combination of a noise-shaped encoder, a charging switch, and a high-Q resonator coupled to an output load, typically an antenna or transmission line. Energy is built up in the electric and magnetic fields of the resonator, which, in turn, delivers power to the load with very little wasted energy in the process. No active power amplifier is required. The apparatus can be used in literally any RF signal application (wireless or otherwise), including for example cellular handsets, local- or wide-area network transmitters, or even radio base-stations.

Claims

1. A resonant power converter comprising:

a pulse input source adapted to generate a plurality of pulses;

a resonator operatively coupled to said pulse input source and having a resonant frequency at or substantially near a carrier frequency; and

a transmission medium operatively coupled to said resonator'"'"'s output and adapted to transmit a plurality of RF signals;

wherein said resonator is further adapted to selectively reinforce at least portions of a plurality of said generated pulses so as to optimize the efficiency of said power converter.

2. A digitally actuated resonant power (DARP) converter comprising:

a noise-shaping encoder for receiving digital data at a clock rate F_c/L₁ where L₁ is a multiple of a carrier frequency F_c and encoding said digital data;

a power supply, having a frequency at or substantially near DC;

a resonator having a resonant frequency at or substantially near said carrier frequency F_c;

a load impedance coupled to said resonator for receiving energy stored in said resonator; and

a charging switch, said charging switch coupled to said noise-shaping encoder, said power supply, said resonator, and a clock having a clock rate L₂F_c, where L₂ is a multiple of said carrier frequency F_c, said charging switch adapted to;

(i) receive encoded data from said noise-shaping encoder;

(ii) sample the voltage or current of said power supply; and

(iii) deliver said power supply voltage or current samples to said resonator.

3. A resonant power converter comprising:

a pulse input source adapted to generate a plurality of pulses;

a resonator operatively coupled to said pulse input source and having a resonant frequency;

noise shaping encoder apparatus operatively coupled to said resonator and being configured to suppress quantization noise at least at one frequency; and

a transmission medium operatively coupled to said resonator'"'"'s output and adapted to transmit a plurality of RF signals.

4. The converter of claim 3, wherein said noise shaping encoder apparatus is of the first-order.

5. A method of processing a plurality of data in an RF communications system, comprising:

filtering said data; and

encoding said data such that quantization noise generated by said act of encoding is distributed substantially outside at least one frequency band of interest.

6. The method of claim 5, further comprising separating said data into first and second components before said acts of filtering and encoding.

7. The method of claim 6, wherein said act of separating into first and second components comprises separating into I and Q components.

8. The method of claim 6, further comprising:

quadrature modulating said encoded first and second components to form first and second modulated signals; and

combining said signals.

9. The method of claim 5, further comprising quadrature modulating said filtered data before said act of encoding.

10. The method of claim 9, further comprising separating said data into first and second components before said act of filtering and modulating, and then combining said quadrature modulated and filtered signals before said encoding.

11. A digital power converter architecture useful in an RF device, comprising:

at least one first component adapted for data processing; and

at least one second component adapted for RF signal generation;

wherein said at least one first component is rendered in a first process different than a second process in which said at least one second component is rendered.

12. The architecture of claim 11, wherein said first process comprises CMOS, and said second process comprises a Group III-V compound semiconductors process.

13. The architecture of claim 11, wherein said at least one first component comprises a digital processor, and said at least one second component comprises at least one modulator and noise shaping encoder.

14. The architecture of claim 13, wherein said at least one first component is disposed on a CMOS device, and said at least one second component is disposed on a GaAs device.

15. The architecture of claim 14, further comprising serial-to-parallel and parallel-to-serial logic between said at least one first and second components.

16. A resonator architecture useful with an RF circuit, comprising:

a first resonator receiving input signals;

a second resonator operatively coupled to and receiving signals from the output of said first resonator and generating a second output to a receiver; and

a load impedance disposed between said first and second resonators adapted to facilitate transmission and/or reception of RF signals.