Power waveform synthesis using bilateral devices

• US 5,930,128 A
• Filed: 04/02/1998
• Issued: 07/27/1999
• Est. Priority Date: 04/02/1998
• Status: Expired due to Term

• Current Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Dent, Paul Wilkinson
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): Patel, Rajnikant B.
• Application Number:
  US09/054,060
• Time in Patent Office: 481 Days
• Field of Search: 363/43, 363/49, 363/72, 363/17, 323/271, 323/272, 375/261, 307/82, 307/80, 307/71, 307/60, 330/124 R
• US Class Current: 363/43
• CPC Class Codes: H03F 1/3223 using feed-forward H03F1/3211 takes precedence
• CPC Class Codes: H03F 2200/537 A transformer being used as coupling element between two amplifying stages
• CPC Class Codes: H03F 2200/541 Transformer coupled at the output of an amplifier
• 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 3/72 Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal

Abstract

Waveform synthesizers represent an input waveform as a sequence of numerical codes in a number base, each numerical code comprising a plurality of digits ordered by place significance. A plurality of bilateral amplifiers is provided, a respective one of which is associated with a respective one of the digits. The bilateral amplifiers consume current from the DC power supply and return current to the DC power supply based on the value of the associated digit, to thereby generate an output voltage level that is proportional to the value of the associated digit. The output voltage levels of the plurality of bilateral amplifiers are serially coupled to the load, with a weighting that is based upon the place significance of the associated digit. Waveform synthesizers that are so constructed are capable of theoretical efficiencies of 100% for any signal waveform. These waveform synthesizers may be used efficiently to amplify to a transmit power level or radio signal that varies in amplitude as well as phase. These waveform synthesizers may also be used as a DC-to-AC converter having a sinusoidal output waveform.

Claims

1. Apparatus for synthesizing from an input waveform, an output waveform in a load using a DC power supply, the synthesizing apparatus comprising:

means for representing the input waveform as a sequence of numerical codes in a number base, each numerical code comprising a plurality of digits ordered by place significance;

a plurality of bilateral amplifying means, a respective one of which is associated with a respective one of the digits, for consuming current from the DC power supply and for returning current to the DC power supply based on the value of the associated digit, to thereby generate an output voltage level that is proportional to the value of the associated digit; and

means for serially coupling the output voltage levels of the plurality of bilateral amplifying means to the load, with a weighting that is based upon the place significance of the associated digit.

3. Apparatus according to claim 1 wherein the bilateral amplifying means are at least one of field effect transistors that conduct from source to drain and from drain to source, and bipolar transistors including reverse conduction diodes that conduct in a forward direction through the bipolar transistor and in the reverse direction through the reverse conduction diodes.

4. Apparatus according to claim 1 wherein the input waveform is a DC input waveform, to provide a DC to AC power converter.

5. Apparatus according to claim 3 wherein the output waveform is an approximately sinusoidal output waveform.

6. Apparatus according to claim 1 wherein the number base is binary and wherein the plurality of bilateral amplifying means comprises a plurality of square wave inverters.

7. Apparatus according to claim 1 wherein the number base is ternary and wherein the plurality of bilateral amplifying means comprises a plurality of square wave inverters with zero clamping to generate positive, zero and negative output voltage levels.

8. Apparatus according to claim 1 further comprising at least one linear amplifier that is associated with at least two of the least significant digits to generate a linear output voltage that is proportional to the combined values of the at least two least significant digits, the serially coupling means also serially coupling the linear output voltage to the load.

2. Apparatus according to claim wherein the serially coupling means comprises a plurality of transformers, each having a primary and a secondary, the secondaries being serially coupled to the load, a respective primary being coupled to a respective one of the bilateral amplifying means, the primary-to-secondary turns ratios of the plurality of transformers being proportional to the place significance of the associated digit.

9. Apparatus for synthesizing from an input waveform, an output waveform in a load using a DC power supply, the synthesizing apparatus comprising:

a numerical code generator that represents the input waveform as a sequence of numerical codes in a number base, each numerical code comprising a plurality of digits ordered by place significance; and

a plurality of bilateral amplifiers, a respective one of which is associated with a respective one of the digits, the bilateral amplifiers consuming current from the DC power supply and returning current to the DC power supply based on the value of the associated digit, to thereby generate an output voltage level that is proportional to the value of the associated digit, the output voltage levels of the plurality of bilateral amplifiers being serially coupled to the load, with a weighting that is based upon the place significance of the associated digit.

10. Apparatus according to claim 9 further comprising a plurality of transformers, each having a primary and a secondary, the secondaries being serially coupled to the load, a respective primary being coupled to a respective one of the bilateral amplifiers, the primary-to-secondary turns ratios of the plurality of transformers being proportional to the place significance of the associated digit.

11. Apparatus according to claim 9 wherein the bilateral amplifiers are at least one of field effect transistors that conduct from source to drain and from drain to source, and bipolar transistors including reverse conduction diodes that conduct in a forward direction through the bipolar transistor and in the reverse direction through the reverse conduction diodes.

12. Apparatus according to claim 9 wherein the input waveform is a DC input waveform, to provide a DC to AC power converter.

13. Apparatus according to claim 11 wherein the output waveform is an approximately sinusoidal output waveform.

14. Apparatus according to claim 9 wherein the number base is binary and wherein the plurality of bilateral amplifiers comprise a plurality of square wave inverters.

15. Apparatus according to claim 9 wherein the number base is ternary and wherein the plurality of bilateral amplifiers comprise a plurality of square wave inverters with zero clamping to generate positive, zero and negative output voltage levels.

16. Apparatus according to claim 9 further comprising at least one linear amplifier that is associated with at least two of the least significant digits to generate a linear output voltage that is proportional to the combined values of the at least two least significant digits, the linear output voltage also being serially coupled to the load.

17. A method for synthesizing from an input waveform, an output waveform in a load using a DC power supply, the synthesizing method comprising the steps of:

representing the input waveform as a sequence of numerical codes in a number base, each numerical code comprising a plurality of digits ordered by place significance;

bilaterally amplifying the value of each of the digits, to consume current from the DC power supply and return current to the DC power supply based on the value of the associated digit, and thereby generate a plurality of output voltage levels each of which is proportional to the value of the associated digit; and

serially coupling the plurality of output voltage levels to the load, with a weighting that is based upon the place significance of the associated digit.

18. A method according to claim 17 wherein the input waveform is a DC input waveform, to provide a DC to AC power converting method.

19. A method according to claim 17 wherein the output waveform is an approximately sinusoidal output waveform.

20. A method according to claim 17 further comprising the step of:

linearly amplifying at least two of the least significant digits to generate a linear output voltage that is proportional to the combined values of the at least two least significant digits; and

serially coupling the linear output voltage to the load.