Lightning protection spark gaps for cable devices

Patent metadata

Field	Value
Publication number	US-11527870-B2
Application number	US-202117165403-A
Country	US
Kind code	B2
Filing date	Feb 2, 2021
Priority date	Feb 3, 2020
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A spark gap circuit includes a circuit board. The spark gap circuit also includes an input configured to connect to the circuit board and to receive signals. The spark gap circuit also includes a spark gap configured to connect to the circuit board and the input. The spark gap circuit also includes an output configured to connect to the spark gap. The spark gap is configured to cause a return loss between the input and the output to be within a first predetermined range. The spark gap is configured to cause a parasitic capacitance between the input and the output to be within a second predetermined range.

First claim

What is claimed is:

1. A spark gap circuit, comprising:
a circuit board;
an input configured to connect to the circuit board and to receive signals;
a spark gap configured to connect to the circuit board and the input, the spark gap comprising:
a first conducting electrode;
a second conducting electrode that is grounded; and
a dielectric material configured to be positioned within a gap between the first and second conducting electrodes;
a first capacitor configured to connect to the circuit board and the spark gap;
a second capacitor configured to connect to the circuit board and the first capacitor;
an output configured to connect to the circuit board and the second capacitor;
wherein the spark gap is configured to cause a return loss between the input and the output to be within a first predetermined range;
wherein the spark gap is configured to cause a parasitic capacitance between the input and the output to be within a second predetermined range;
wherein the first conducting electrode has a length from about 750 μm to about 2000 μm;
wherein the first conducting electrode has a diameter from about 500 μm to about 1 mm;
wherein the first conducting electrode has a mass from about 1 gram to about 100 grams;
wherein a signal trace extends from the input to the first capacitor;
wherein the first conducting electrode is substantially parallel with the signal trace;
wherein the second conducting electrode comprises a staple with two leads and a cross bar positioned therebetween;
wherein the two leads are substantially perpendicular to the circuit board;
wherein the cross bar is substantially perpendicular to the first conducting electrode and the signal trace;
wherein the cross bar is positioned farther away from the circuit board than the first conducting electrode such that the gap exists therebetween;
wherein a thickness of the gap is from about 150 μm to about 250 μm;
wherein a thickness of the dielectric material is from about 75 μm to about 125 μm;
wherein the dielectric material comprises air, paper, or a combination thereof;
wherein the dielectric material has a relative permittivity from about 1 to about 3;
wherein the first and second capacitors are configured to block direct current (DC) flow therethrough and to provide surge protection;
wherein a voltage rating of the first capacitor is greater than a voltage rating of the second capacitor; and
wherein the output is configured to connect to a cable or a device.

2. The spark gap circuit of claim 1 , wherein the first predetermined range is from about 15 dB to about 40 dB within a cable television (CATV) bandwidth.

3. The spark gap circuit of claim 1 , wherein the second predetermined range is from about 0.01 pF to about 0.05 pF.

4. The spark gap circuit of claim 1 , wherein the first conducting electrode is configured to increase an impedance of the signal trace, as measured by return loss, from about 0.01 dB to about 1 dB.

5. A spark gap circuit, comprising:
a circuit board;
an input configured to connect to the circuit board and to receive signals;
a spark gap configured to connect to the circuit board and the input, the spark gap comprising:
a first conducting electrode;
a second conducting electrode that is grounded; and
a dielectric material positioned within a gap between the first and second conducting electrodes;
a first capacitor configured to connect to the circuit board and the spark gap;
an output configured to connect to the circuit board and the first capacitor;
wherein a signal trace extends from the input to the first capacitor;
wherein the first conducting electrode is substantially parallel with the signal trace;
wherein the second conducting electrode comprises a staple with two leads and a cross bar positioned therebetween;
wherein the two leads are substantially perpendicular to the circuit board;
wherein the cross bar is substantially perpendicular to the first conducting electrode and the signal trace;
wherein the cross bar is positioned farther away from the circuit board than the first conducting electrode such that the gap exists therebetween;
wherein the spark gap is configured to cause a return loss between the input and the output to be within a first predetermined range;
wherein the spark gap is configured to cause a parasitic capacitance between the input and the output to be within a second predetermined range; and
wherein the output is configured to connect to a cable or a device.

6. The spark gap circuit of claim 5 , wherein the first predetermined range is from about 20 dB to about 50 dB within a cable television (CATV) bandwidth.

7. The spark gap circuit of claim 5 , wherein the second predetermined range is from about 0.01 pF to about 0.1 pF.

8. The spark gap circuit of claim 5 , wherein the first conducting electrode is configured to increase an impedance of the signal trace, as measured by return loss, from about 0.01 dB to about 1 dB.

9. The spark gap circuit of claim 5 , wherein the first conducting electrode has a length from about 750 μm to about 2000 μm, wherein the first conducting electrode has a diameter from about 500 μm to about 1 mm, and wherein the first conducting electrode has a mass from about 1 gram to about 100 grams.

10. The spark gap circuit of claim 5 , wherein a thickness of the gap is from about 150 μm to about 250 μm.

11. The spark gap circuit of claim 5 , wherein a thickness of the dielectric material is from about 75 μm to about 125 μm, wherein the dielectric material comprises air, paper, or a combination thereof, and wherein the dielectric material has a relative permittivity from about 1 to about 3.

12. The spark gap circuit of claim 5 , further comprising a second capacitor configured to be connected to the circuit board and the first capacitor.

13. The spark gap circuit of claim 12 , wherein the first and second capacitors are configured to block direct current (DC) flow therethrough and to provide surge protection, and wherein a voltage rating of the first capacitor is greater than a voltage rating of the second capacitor.

14. A spark gap circuit, comprising:
a circuit board;
an input configured to connect to the circuit board and to receive signals;
a spark gap configured to connect to the circuit board and the input;
an output configured to connect to the spark gap;
a first capacitor configured to connect to the circuit board and the spark gap;
a second capacitor configured to connect to the circuit board, the first capacitor, and the output;
wherein the spark gap is configured to cause a return loss between the input and the output to be within a first predetermined range; and
wherein the spark gap is configured to cause a parasitic capacitance between the input and the output to be within a second predetermined range.

15. The spark gap circuit of claim 14 , wherein the first predetermined range is from about 25 dB to about 60 dB within a cable television (CATV) bandwidth.

16. The spark gap circuit of claim 14 , wherein the second predetermined range is from about 0.01 pF to about 0.2 pF.

17. The spark gap circuit of claim 14 , wherein the spark gap comprises:
a first conducting electrode;
a second conducting electrode that is grounded; and
a dielectric material positioned between the first and second conducting electrodes.

18. The spark gap circuit of claim 17 , wherein the first conducting electrode is configured to increase an impedance of a signal trace between the input and the output, as measured by return loss, from about 0.01 dB to abo

Assignees

• Ppc Broadband Inc

Inventors

• Bailey Paul

Classifications

• H01T4/02 Primary

  Details · CPC title

• H01T4/10

  having a single gap or a plurality of gaps in parallel · CPC title

• H01T4/08 Primary

  structurally associated with protected apparatus (with switches H01H9/14; with fuses H01H85/44) · CPC title

• H02H9/06

  using spark-gap arresters · CPC title

• H05K1/116

  Lands, clearance holes or other lay-out details concerning the surrounding of a via · CPC title