EMC immunity testing with Parallel Plate Antennas and E/H Field Generators

Low frequencies antennas used for radiated immunity testing in the frequency range 10kHz – 30MHz have a poor radiating pattern uniformity, what negatively impacts the repeatability and reproducibility of the EMC immunity tests.

Parallel plate lines and E/H field generators are very efficient to radiate controlled, reproducible electromagnetic fields with excellent uniformity, making them reliable tools for laboratories and certification bodies.

These systems are recommended for testing of automotive devices (European directive 2004/104/EC, ISO 11451-2), multimedia equipment (EN 55035), mission critical equipment (MIL STD 461, RS103) and others similar EMC immunity testing requiring stable E field exposure.

The typical immunity testing setup for small equipment (up to about 40x40x40cm) can be well performed with a parallel plate antenna. The equipment is installed on a wooden table between the plates. The montena PPL200 parallel plate antenna provides a simple rotating mechanism to switch the polarization without moving the equipment under test.

Strong field intensities of more than 200 V/m can be easily achieved with a 500 W amplifier in the frequency range 10kHz – 30MHz.

For larger equipment or system, such as a full vehicle, we recommend using an E/H field generator. That radiating structure offers an excellent field uniformity over a large test volume.

It is possible to perform the immunity test inside an EMC test chamber or in an open area test site. It is often difficult to turn the EUT to test it in all orthogonal positions. The E/H field generator can be switched from vertical to horizontal polarization by rearranging the line wires and switching the feed transformers.

When feed with 3 kW power amplifiers, E/H field generator can produce more than 200 V/m of field intensity.

By combining robust design with field homogeneity, easy polarization switching, and high adaptability, Montena’s parallel plate antennas and E/H field generators deliver reliable solutions for EMC immunity testing. Their compliance with major standards and practical usability make them indispensable tools for laboratories working with demanding applications.