Method for testing shielding effectiveness of a HEMP/EMI enclosure
A HEMP enclosure includes a recessed coaxial connector interface. The connector interface is located at the bottom of a metallic tube in the chassis wall that functions as a waveguide below cutoff (WBC). The WBC attenuates the electromagnetic pulse threat signal to a benign level when the transmitter enclosure is not inserted for testing. Internal to the chassis, the connector interface includes an omni-directional antenna. A transmitter enclosure includes a wand to plug the transmitter into the connected interface. The transmitter generates an RF signal at a desired frequency range that is then transmitted via a coaxial cable in the wand to the antenna in the chassis.
1 . A HEMP enclosure comprising:
a shielded enclosure case;
a metallic tube disposed to extend from an external opening, internally within the shielded enclosure;
one or more EMI gaskets disposed within the metallic tube; and
wherein the metallic tube is configured to receive a wand structure of a separate transmitting device or receiving device.
2 . The HEMP enclosure of claim 1 , further comprising:
an internal interface disposed at a terminus of the metallic tube distal to the external opening; and
an antenna disposed at an internal terminus of the metallic tube, within the shielded enclosure.
3 . The HEMP enclosure of claim 2 , wherein the metallic tube comprises a waveguide below cutoff.
4 . The HEMP enclosure of claim 1 , wherein the metallic tube comprises a waveguide below cutoff.
5 . A transmitting device for testing HEMP enclosures comprising:
a transmitter;
a wand structure configured to engage a metallic tube of a HEMP enclosure in electronic communication with the transmitter;
an interface disposed at a distal end of the wand structure, the interface configured to engage an internal interface in the metallic tube of the HEMP enclosure; and
one or more EMI gaskets disposed along the wand structure.
6 . The transmitting device of claim 5 , further comprising an antenna disposed at a distal end of the wand structure.
7 . The transmitting device of claim 6 , further comprising one or more EMI gaskets disposed along the wand structure.
8 . A testing system comprising:
A HEMP enclosure comprising:
a shielded enclosure case;
a metallic tube disposed to extend from an external opening, internally within the shielded enclosure; and
one or more EMI gaskets disposed within the metallic tube; and
A transmitting device for testing HEMP enclosures comprising:
a transmitter;
a wand structure in electronic communication with the transmitter, the wand structure comprising an interface disposed at a distal end of the wand structure, the interface configured to engage an internal interface in the metallic tube of the System; and
one or more EMI gaskets disposed along the wand structure.
9 . The system of claim 8 , the HEMP enclosure further comprising:
an internal interface disposed at a terminus of the metallic tube distal to the external opening; and
an antenna disposed at an internal terminus of the metallic tube, within the shielded enclosure.
10 . The system of claim 9 , wherein the metallic tube comprises a waveguide below cutoff.
11 . The system of claim 8 , wherein the metallic tube comprises a waveguide below cutoff.
12 . The system of claim 8 , further comprising one or more EMI gaskets disposed within the metallic tube.
13 . The system of claim 8 , the transmitting device further comprising an antenna disposed at a distal end of the wand structure.
14 . The system of claim 13 , further comprising one or more EMI gaskets disposed along the wand structure.