HIGH POWER BIPOLAR PULSE GENERATORS

• US 20100231278A1
• Filed: 03/13/2009
• Published: 09/16/2010
• Est. Priority Date: 03/13/2009
• Status: Active Grant

• Current Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Original Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Inventors: London, Simon
• Granted Patent: US 8,004,120 B2
• Time in Patent Office: Days
• US Class Current: 327/171
• CPC Class Codes: H03K 3/53 by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback H03K3/335 takes precedence
• CPC Class Codes: H03K 3/78 Generating a single train of pulses having a predetermined pattern, e.g. a predetermined number
• CPC Class Codes: H03K 3/86 Generating pulses by means of delay lines and not covered by the preceding subgroups

Abstract

A bipolar pulse generator is implemented in a simple structure while providing a high efficiency design having a relatively low total size, while still allowing access by fibers used to control a photoconductive switch that activates the generator. The bipolar pulse generator includes a stacked Blumlein generator structure with an additional transmission line connected to a load at its near end and short-circuited at its distal end. An extra transmission line is positioned between the Blumlein generator'"'"'s structure and the load provides specified limited gap between positive and negative sub-pulses. The bipolar pulse generator further includes a bended Blumlein generator structure, in which an existing intrinsic “stray” transmission line is used to provide the bipolar pulse. Still further, bipolar pulse generator includes stepped transmission lines, with additional switches positioned between steps, which are charged by different voltages.

Claims

1. A bipolar pulse generator comprising:

a load;

a first transmission line connected to the load at its near end and short circuited at its distal end;

a transmission-line based Marx generator structure connected to the load through a second transmission line;

wherein the transmission-line based Marx generator structure includes a plurality of charged transmission lines each connected to a corresponding switch and charging element; and

wherein the electrical length of the first transmission line is equal to the sum of the electrical length of each of the charged transmission lines and the length of the second transmission line.

2. A bipolar pulse generator as claimed in claim 1, wherein a gap is provided between positive and negative sub-pulses that is equal to double the transit time of second transmission line.

3. A bipolar pulse generator comprising:

a stacked Blumlein charging structure including n identically first charged transmission lines with switches at their near ends, and n oppositely charged second transmission lines with the same length and characteristic impedances as for the first transmission lines;

an addition non-charged transmission line connected at its near end to an output of the charging structure and at its distal end to a load; and

a further transmission line connected at its near end to the load and short-circuited at its distal end.

4. A bipolar pulse generator as claimed in claim 3, wherein the additional non-charged transmission line has a specified electrical length t1 and characteristic impedance equal to 2nZ0, where Z0 is a characteristic impedance of each of the first charged transmission lines and the second charged transmission lines, the load impedance is equal to nZ0, and the characteristic impedance of the further transmission line is the same as the additional non-charged transmission line.

5. A bipolar pulse generator as claimed in claim 4, wherein the electrical length of the further transmission line is equal 2t+t1, where t is an electrical length of each of the first charged transmission lines and the second charged transmission lines.

6. A bipolar pulse generator comprising:

a charging structure comprising a stacked Blumlein-type structure including n≧

2 identically first charged transmission lines with switches at their near ends and n−

1 oppositely charged second transmission lines with the same length and characteristic impedances as for the first transmission lines, at least one step transmission line coupled to the output of the stacked Blumlein-type structure charged as first charged transmission lines and one additional oppositely charged transmission line;

a load connected to the charging structure; and

an additional transmission line that is connected to the load at its near end and short-circuited at its distal end.

7. A bipolar pulse generator comprising:

a double Blumlein unipolar pulse generator structure including transmission lines;

a first transmission line with a time delay connected between the output of the double Blumlein unipolar pulse generator structure and a load;

a second transmission line connected to the load at its near end and short-circuited at its distal end.

8. A bipolar pulse generator as claimed in claim 7, wherein a characteristic impedance of each of the first and second transmission lines is twice the impedance of the load and four times the impedance of the transmission lines of the pulse generator structure.

9. A bipolar pulse generator as claimed in claim 7, wherein the second transmission line comprises two intrinsic transmission lines formed by outer conductors of first and second transmission lines of the pulse generator structure and by a folded outer conductor of a third transmission line of the pulse generator structure, wherein the two intrinsic transmission lines are connected in series relative to load.

10. A bipolar pulse generator as claimed in claim 7, further comprising at least one additional double Blumlein unipolar pulse generator structure connected in series with the double Blumlein unipolar pulse generator.

11. A bipolar pulse generator comprising:

a multi-step transmission line structure including a plurality of stepped transmission lines, wherein at least two of the stepped transmission lines are charged to different voltages;

a load connected to the multi-step transmission line structure;

a transmission line have a near end connected to the load and a distal end short-circuited; and

at least two switches, wherein one switch is positioned at the near end of the first step and at least one switch positioned between steps.