Emitech adds in-house electromagnetic pulse immunity testing

The Emitech Group has introduced an electromagnetic pulse immunity testing facility at Montigny-le-Bretonneux, near Paris, allowing defence and aerospace electronics to undergo RS105 qualification within the group's own laboratories.

The installation supports RS105 testing under MIL-STD-461H and the corresponding NRS03 method defined by NATO's AECTP-500 requirements. Previously outsourced, the test was the final MIL-STD-461H procedure that Emitech could not perform internally, making the new capability an extension of its existing electromagnetic compatibility testing services.

Announced on 10 November 2026, the facility combines an 80 kV high-voltage pulse generator, a six-metre parallel-plate transmission line, and measurement equipment designed to characterise high-amplitude electromagnetic fields lasting only a few nanoseconds.

The system can generate peak electric field strengths reaching 50,000 V/m, with a rise time of approximately two nanoseconds and a pulse width of approximately 23 nanoseconds. The installation is housed within a large shielded chamber and can be dismantled for deployment in other suitable test facilities.

Military electronics can be exposed to electromagnetic disturbances through their enclosures, cabling, and electrical interfaces. Equipment installed on aircraft, surface vessels, vehicles, and other platforms may operate within structures that provide limited shielding against external fields.

When a programme specifies resistance to electromagnetic pulse effects, the equipment must be assessed against the appropriate disturbance conditions. Rapid changes in an external electromagnetic field can induce unwanted voltages and currents within conductive structures, creating the possibility of interference with electronic circuits.

Depending on the equipment design and disturbance level, the resulting effects may include interrupted communications, incorrect sensor readings, processing errors, temporary loss of function, or damage to susceptible components. The level of protection required is established by the applicable equipment and programme specifications.

RS105 addresses radiated susceptibility to a transient electromagnetic field, typically representing the fast component of a nuclear electromagnetic pulse. Unlike conducted susceptibility methods that introduce disturbances through electrical connections, RS105 exposes equipment to a defined external field.

The test requires the equipment to operate while the pulse is applied. Its behaviour is monitored during and after exposure so that interruptions, changes in output, and recovery characteristics can be evaluated against the programme's acceptance criteria.

Emitech's pulse generator energises a parallel-plate transmission line, commonly described as a stripline. The arrangement establishes the required field within a defined test volume, while a measurement chain verifies the pulse characteristics.

The electric field specification must be distinguished from the generator's electrical output. The 80 kV figure describes the high-voltage pulse generator, while the 50,000 V/m limit describes the maximum electric field produced within the test arrangement.

Pulse shape is central to the method. Emitech specifies a rise time between 1.8 and 2.8 nanoseconds and a full width at half maximum of 23 ± 5 nanoseconds. These parameters determine how rapidly the field develops and how long it remains above half its peak amplitude.

A rapid rise introduces substantial high-frequency content, affecting how the disturbance couples into conductive structures. The resulting currents and voltages depend on the geometry of the equipment, its electrical interfaces, the construction of the enclosure, and the surrounding electromagnetic environment.

Consequently, a test cannot be defined by field amplitude alone. The waveform, equipment orientation, operating condition, and location within the test volume all influence whether the exposure reproduces the requirements of the relevant standard.

Emitech's transmission line provides a test volume approximately 1,000 mm long, with available width ranging from 750 to 1,000 mm and height ranging from 340 to 450 mm according to position. The dimensions of the equipment under test must therefore be assessed before a qualification programme is accepted.

Equipment orientation can also affect the usable space and the resulting electromagnetic coupling. A housing or cable arrangement may respond differently when the same field is applied along different axes, making the specified test orientations important to the overall assessment.

The installation supports electric field levels between 1,000 and 50,000 V/m, allowing test conditions to be selected according to the applicable equipment specification. The maximum capability is not necessarily required for every programme.

Using a demountable arrangement provides flexibility in the allocation of laboratory space. Emitech reports that the transmission line can be installed in approximately two hours and dismantled in one hour, provided a suitable shielded chamber is available.

The company offers a standard two-day test arrangement, incorporating installation, calibration, testing, and dismantling. The final programme duration remains dependent on the equipment dimensions, required field levels, operating procedures, and number of test configurations.

Julien Floch, EMC, Electrical and Lightning Test Engineer at the Emitech Group, said: “RS105 was the last MIL-STD-461H test that we did not carry out ourselves.”

With the capability now installed internally, Emitech can coordinate a complete MIL-STD-461H test programme through its own facilities. Previously, customers requiring RS105 exposure had to use a separate laboratory, introducing another scheduling dependency into equipment qualification.

The facility also strengthens Emitech's coverage of NATO AECTP-500. NRS03 addresses electromagnetic pulse susceptibility under the relevant NATO procedures, although the specific revision and test conditions must be established by each qualification programme.

Individual equipment qualification should not be confused with complete platform protection. Satisfying RS105 requirements for one electronic unit does not establish that the entire aircraft, vessel, installation, or associated cable network is resistant to every electromagnetic pulse effect.

External connections, installation geometry, enclosure interfaces, and system-level protection arrangements may introduce additional requirements. Those must be evaluated through the relevant platform specifications and other applicable test methods rather than inferred from the results of a single equipment-level exposure.

Emitech employs approximately 680 people across 18 sites and forecasts turnover of €78.1 million for 2026. The new installation forms part of the group's continued investment in electromagnetic compatibility and qualification testing infrastructure.

The RS105 facility is available at Montigny-le-Bretonneux, with feasibility assessments addressing equipment dimensions, installation configuration, required field strength, and operating criteria. Its demountable construction also allows deployment in other shielded chambers that satisfy the necessary dimensional and technical requirements.