How Are Radiated Susceptibility Tests Performed?
The susceptibility of a device to electromagnetic fields is
typically tested by placing the device on a test bench, placing an antenna some
distance from the device, and sending a controlled signal to the antenna. Tests are performed inside shielded
enclosures to protect personnel from potentially hazardous field levels and to
prevent interference with RF communication systems and nearby electronic
equipment. The arrangement of the device and its cables is carefully
controlled to standardize the test and to make test results as repeatable as
possible. The test bench is typically constructed of non-conductive
material and may be covered with aluminum or copper as required by the
regulatory agency. Likewise, the test antenna distance from the device and
height above ground plane are controlled. For large devices, such as
equipment racks and vehicles, the equipment is generally configured in a manner
equivalent to its final installation. Field levels to which the device is
subjected are usually monitored during testing using a field probe that is
located at the device under test, with a remote display located near the test
operator.
The general arrangement of test equipment for method RS103 of MIL-STD-461E is shown in
the following figure, as an example.
With regard to the RS Analyst radiated
susceptibility model, the EUT represents either the left-hand circuit or right-hand circuit. The LISNs represent
the other (right-hand or left-hand) circuit. The power leads represent the
Conductors.
Another radiated susceptibility model could be constructed where the EUT
represents the left-hand
circuit, the Simulation and Monitoring Equipment outside the shielded
enclosure represents the right-hand circuit., and the cabling between the
EUT and the Simulation and Monitoring Equipment represents the Conductors.
Whenever there are more than one power conductor pair or
signal conductor pair that comprise the device under investigation, an
equivalent number of radiated susceptibility models are required to fully
characterize the system.
More:
 Radiated Susceptibility Controls
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