EMC — Tool
Standards placement checks
Enter your test geometry once and check the MIL-STD-461G RE103 minimum measurement distance, RS103 illumination coverage and antenna positions, plus a separate Fraunhofer-distance engineering check useful when planning DO-160 Section 20 work.
Test geometry
λ = —. RE103 rule applied: —.
Where these rules come from
RE103 measures an antenna-connected transmitter's spurious emissions. MIL-STD-461G gives the distance rules this page applies: at or below 1.24 GHz, use the greater of 2D²/λ and 3λ; above 1.24 GHz, use 2D²/λ when 2.5D < d, otherwise use (D+d)²/λ.
RS103 requires the antenna at least 1 m from the setup boundary. From 2 MHz to below 200 MHz, boundaries over 3 m use multiple positions based on the boundary length divided by 3 and rounded up. From 200 MHz upward, position count is instead governed by placing the relevant EUT enclosure and cable length inside the antenna's 3 dB beamwidth. The high-frequency count below is therefore a coverage-width planning estimate.
DO-160 Section 20 uses a pre-calibrated field and section-specific setup requirements. The 2D²/λ result shown here is a separate Fraunhofer engineering check; it is not presented as a replacement test distance from the standard.
As always: these checks encode the headline geometry rules to speed up planning. The standard you're testing to — and your lab's accredited procedure — take precedence over anything on this page.