Efficient transmitters for phase modulated signals

• US 6,556,054 B1
• Filed: 10/02/2000
• Issued: 04/29/2003
• Est. Priority Date: 10/01/1999
• Status: Expired due to Fees

• Current Assignee: Gas Technology Institute (GTI Energy)
• Original Assignee: Gas Research Institute (GTI Energy)
• Inventors: Goodman, William L., Sweeny, Mark
• Primary Examiner(s): Wells, Kenneth B.
• Application Number:
  US09/677,282
• Time in Patent Office: 939 Days
• Field of Search: 327/108-112, 327/423, 327/587
• US Class Current: 327/110
• CPC Class Codes: E21B 47/125 using earth as an electrical conductor by electromagnetic energy E21B47/13
• CPC Class Codes: H01Q 1/04 Adaptation for subterranean or subaqueous use
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H03C 3/00 Angle modulation H03C5/00, H03C7/00 take precedence
• CPC Class Codes: H03J 5/246 using electronic means H03J5/244 takes precedence

Abstract

A circuit for driving a current into an inductor, which circuit includes at least one main capacitor, a power supply operably connected to the main capacitor, the inductor, and at least two pairs of switches connecting the main capacitor to the inductor, whereby the connection of the main capacitor to the inductor is made in either polarity. Current is driven into the inductor by applying a current to the main capacitor, applying a voltage to the inductor from the main capacitor resulting in generation of inductive energy, and recapturing the inductive energy with the main capacitor at the end of a cycle.

Claims

1. A circuit for driving a current into an inductor comprising:

at least one main capacitor;

a power supply operably connected to said at least one main capacitor;

said inductor; and

at least two pairs of switches connecting said at least one main capacitor to said inductor whereby the connection of said at least one capacitor to said inductor is made in either polarity, each of said switches having an open position and a closed position.

2. A circuit in accordance with claim 1 further comprising at least one tuning capacitor connected in parallel to said at least one main capacitor between said at least one main capacitor and said power supply.

3. A circuit in accordance with claim 2 further comprising switching means for switching said at least one tuning capacitor in and out of said circuit.

4. A circuit in accordance with claim 1, wherein said switches are MOS-FETs.

5. A circuit in accordance with claim 3, wherein said switching means comprises at least two pairs of tuning capacitor switches connecting said power supply to said main capacitor and said tuning capacitor in either polarity.

6. A circuit in accordance with claim 1 further comprising at least one diode connected between said at least two pairs of switches and said at least one main capacitor whereby said at least one diode always charges said at least one main capacitor in a same polarity.

7. A circuit in accordance with claim 1, wherein said at least two pairs of switches are bipolar.

8. A circuit in accordance with claim 1, wherein said at least two pairs of switches are unipolar.

9. A circuit in accordance with claim 1, wherein said inductor is a magnetic antenna.

10. A method for driving a current into an inductor comprising the steps of:

applying a current to a main capacitor;

applying a voltage to said inductor from said main capacitor resulting in generation of inductive energy; and

recapturing said inductive energy with said main capacitor at an end of a cycle, wherein said current and said voltage are measured by a microprocessor which, based upon said measurements, determines when to open and close two pairs of switches connecting said main capacitor to said inductor.

11. A method in accordance with claim 10, wherein said inductor is disconnected from said main capacitor when said current is zero.

12. A method in accordance with claim 11, wherein a length of time during which said inductor is disconnected from said main capacitor is variable.

13. A method in accordance with claim 10, wherein a period of high current is prolonged by shorting said inductor.

14. A method in accordance with claim 10, wherein said inductor is a magnetic antenna.