PROXIMITY FUSE HAVING AN E-FIELD SENSOR

• US 20190331470A1
• Filed: 04/25/2018
• Published: 10/31/2019
• Est. Priority Date: 04/25/2018
• 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: Mercier, Michael N.
• Granted Patent: US 10,935,357 B2
• Time in Patent Office: Days
• CPC Class Codes: F42C 11/06 with time delay by electric circuitry
• CPC Class Codes: F42C 13/003 operated by variations in electrostatic field
• CPC Class Codes: F42C 13/023 using active distance measurement
• CPC Class Codes: F42C 13/08 operated by variations in magnetic field
• CPC Class Codes: G01S 17/46 Indirect determination of position data

Abstract

A proximity fuse includes an electric-field (E-field) sensor to detect electrical disturbances from an object that is external and distinct from a device carrying the proximity fuse. The E-field sensor detects or senses E-fields versus time in order to provide omnidirectional coverage of the device carrying the proximity fuse. When the device carrying the fuse is a missile having warhead, the proximity fuse is connected with detonation logic that detonates the warhead at a desired time to destroy or neutralize the object, which is typically a threat, such as another missile.

Claims

1. A proximity fuse comprising:

an electric-field (E-field) sensor to sense at least one E-field of an object near the E-field sensor;

a detonation time calculator in electrical communication with the E-field sensor that sends a signal to detonate a warhead in response the E-field sensor sensing the E-field of the object; and

detonation logic to detonate the warhead based, at least in part, on the E-field of the object.

2. The proximity fuse of claim 1, further comprising:

a velocity calculator to determine velocity of the warhead;

a comparator that compares electrical signals from the E-field sensor and the velocity of the warhead, and the comparator is electrically connected with the detonation time calculator to determine when to detonate the warhead based on the E-fields of the object.

3. The proximity fuse of claim 2, further comprising:

an impact time calculator that receives signals from the comparator and determines a time to impact and sends the time to impact to the detonation time calculator.

4. The proximity fuse of claim 1, wherein the E-field sensor includes:

an antenna; and

a guard area proximate the antenna to reduce capacitance thereof.

5. The proximity fuse of claim 4, wherein the E-field sensor further includes a differential amplifier with bootstrapping to provide high impedance for the antenna.

6. The proximity fuse of claim 5, wherein the E-field sensor further includes a frequency filter to isolate E-field signals from the object.

7. The proximity fuse of claim 6, wherein the E-field sensor further includes a buffer amplifier to provide high input impedance to the filter frequency filter while providing additional gain and a low impedance source for a voltage measuring device.

8. A countermeasure system for a platform comprising:

a plurality of sensors on the platform to detect an incoming threat wherein the incoming threat generates an electric field (E-field);

a warhead that is deployable from the platform in response to the plurality of sensors detecting the incoming threat; and

a proximity fuse electrically coupled to the warhead, wherein the proximity fuse includes an E-field sensor configured to sense the E-field of the incoming threat versus time to detonate the warhead, via detonation logic, based on the E-field of the incoming threat.

9. The countermeasure system of claim 8, wherein the E-field sensor on the proximity fuse includes:

an antenna; and

a guard area proximate the antenna to reduce capacitance thereof.

10. The countermeasure system of claim 9, wherein the E-field sensor further includes a differential amplifier with bootstrapping to provide high impedance for the antenna.

11. The countermeasure system of claim 10, wherein the E-field sensor further includes a frequency filter to isolate E-field signals from the object.

12. The countermeasure system of claim 11, wherein the E-field sensor further includes a buffer amplifier to provide high input impedance to the filter frequency filter while providing additional gain and a low impedance source for a voltage measuring device.

13. The countermeasure system of claim 12, further comprising:

a countermeasure missile including a guidance system;

wherein the warhead and the proximity fuse are carried by the countermeasure missile to be deployable from the platform in response to the plurality of sensors detecting the incoming threat.

14. The countermeasure system of claim 13, further comprising:

a front end of the countermeasure missile;

wherein the proximity sensor is positioned forward towards the front end from the warhead.

15. A method comprising:

deploying a countermeasure munition in response to detection of a threat object;

sensing an electric field (E-field) of the threat object with an E-field sensor integrated into a proximity fuse on the countermeasure munition; and

detonating the countermeasure munition to eliminate or neutralize the threat object in response a determination, by the E-field sensor, of the E-field of the threat object versus time.

16. The method of claim 15, further comprising:

detecting E-field distortions with an antenna in the E-field sensor; and

reducing capacitance of the antenna with a guard area proximate the antenna and thereby increasing impedance in the antenna.

17. The method of claim 16, further comprising:

processing and filtering, via a filter, unwanted signals from the detected E-field distortions.

18. The method of claim 17, further comprising:

amplifying the detected E-field distortions with a differential amplifier.

19. The method of claim 18, further comprising:

rejecting E-field distortions that are outside a filter range pre-selected to that of the threat object.

20. The method of claim 19, further comprising:

providing a high input impedance to the filter with a buffer amplifier.