Loop Antennas

Low-Frequency Magnetic Loop Antennas

Loop antennas are low frequency loop-shaped antennas used for measuring electromagnetic fields. This loop design makes it practical for use in EMC applications where measuring radiated immunity or emissions is important.

In order to have a complete test setup it is useful to have an RF preamplifier operating at the same frequency range as the loop antenna, as well as a spectrum analyzer. With this test setup, analyzing test results for radiated emissions allows for meeting certain test standards specified by FCC, CISPR, MIL-STD, and EN.

Loop antenna selection is driven by the requirements of the applicable test standard. Active loop antennas are typically used for radiated emissions measurements, including MIL-STD-461 RE103, whereas passive loop antennas are commonly utilized for radiated immunity testing under standards such as MIL-STD-461 RS103.