MIL-STD-461 for Military EMC testing:

MIL-STD-461 is an EMC testing standard that evaluates the features of electronic, electrical, and electromechanical equipment & subsystems belonging to the Department of Defense (DoD). MIL-STD-461 is a foundation for numerous international EMI standards and is widely adopted, forming the basis for other EMI specifications globally.

MIL-STD-461 is particularly well-suited for items with no larger electronic enclosures than an equipment rack, discrete electrical interconnections between enclosures, and electrical power input derived from prime power sources.

MIL-STD-461 has undergone several revisions. These are

• MIL-STD-461A (1968)
• MIL-STD-461B (1980)
• MIL-STD-461C (1986)
• MIL-STD-461D (1993)
• MIL-STD-461E (1999)
• MIL-STD-461F (2007)
• MIL-STD-461G (2015)

 What are its specifications?

The MIL-STD-461 has specified particular Aircraft/Air Force, Navy, and Ground Force tests. The test procedures are denoted in an alphanumeric coding system. The table below delineates the categorization of tests as either fully applicable or applicable on a restricted basis, along with those necessitating documentation.

Categorization of Tests

 The frequency ranges for the tests mentioned in the table are as follows:

• Conducted emissions: 10 kHz to 40 GHz
• Radiated emissions: 30 MHz to 18 GHz
• Conducted susceptibility: 10 kHz to 18 GHz
• Radiated susceptibility: 30 MHz to 18 GHz

The limits for additional susceptibility tests are as follows:

ESD susceptibility: 2 kV to 30 kV

LITS susceptibility: 50 A to 100 A

What are the test methods of MIL-STD-461?

Conducted Emissions Tests (CE): These tests involve the measure of the amount of electromagnetic interference (EMI) that travels along wires and cables.

• CE101: Audio Frequency Currents & Power Leads - Ensures that electromagnetic emissions from the Equipment Under Test (EUT) stay within specified limits for power input leads, including returns. For power leads, the specified range is from 30Hz to 10kHz.
• CE102: Radio Frequency Potentials & Power Leads - Ensures that electromagnetic emissions from the EUT stay within specified limits for power input leads, including returns. The frequency range of this test is 10 kHz to 10 MHz.
• CE106: Antenna Port - Verifies that conducted emissions at the EUT's antenna port do not exceed specified requirements. The antenna ports may be of transmitters, receivers and amplifiers. The frequency range for this test is between 10 kHz to 40 GHz.

Conducted Susceptibility (CS) Tests: These tests measure how susceptible electronic equipment is to EMI from other devices via wires and cables.

• CS101: Power Leads - Determines the EUT's ability to withstand signals coupled onto input power leads. It applies to equipment and subsystem AC with current draws up to 30 A per phase and DC input power leads (excluding returns), within the frequency range of 30 Hz to 150 kHz. For DC-operated Equipment Under Test (EUT), this test covers the frequency range of 30 Hz to 150 kHz. In the case of AC-operated EUTs, it applies from the second harmonic of the EUT power frequency up to 150 kHz.
• CS103: Antenna Port & Intermodulation - Identifies intermodulation products caused by undesired signals at the EUT's antenna input ports. These tests span a frequency range of 15 kHz to 10 GHz.
• CS104: Antenna Port & Rejection of Undesired Signals - Detects spurious responses due to undesired signals at the EUT's antenna input ports. Tests occur in the range of 30 Hz to 20 GHz.
• CS105: Antenna Port & Cross-Modulation - Identifies cross-modulation products due to undesired signals at the EUT's antenna ports. It applies exclusively to receivers that typically handle amplitude-modulated RF signals, as specified in the specific procurement specification. The test covers a frequency range from 30 Hz to 20 GHz.
• CS109: Transients & Power Leads - Ensures the EUT can withstand structural currents. This test covers a frequency range of 60 Hz to 100 kHz. Handheld equipment is exempt from this test.
• CS114: Bulk Cable Injection - Ensures the EUT can withstand RF signals coupled onto associated cabling. The tests are performed from 10 kHz to 200 MHz for all interconnecting cables, including power cables.
• CS115: Bulk Cable Injection & Impulse Excitation - Verifies the EUT's ability to withstand impulse signals on associated cabling.
• CS116: Damped Sinusoidal Transients, Cables and power Leads - Ensures the EUT can withstand damped sinusoidal transients on associated cables and power leads. This test requirement specifies a frequency range of from 10 kHz to 100 MHz.
• CS117: Lightning-Induced Transients, Cables & Power Leads - Verifies the EUT's ability to withstand lightning transients on associated cables and power leads. It pertains to interconnecting cables used with safety-critical equipment, including full power cables and individual high-side power leads. It also applies to non-safety-critical equipment if their interconnecting cables or electrical interfaces are integrated with or linked to safety-critical equipment. In some cases, it may be extended to equipment serving non-safety critical roles when explicitly outlined by the procuring authority.
• CS118: Personnel-Borne Electrostatic Discharge - Ensures the EUT can withstand personnel-borne electrostatic discharge (ESD) while powered up.

Radiated Emissions (RE) Tests: These tests measure the amount of EMI that travels through air as EM waves.

• RE101: Magnetic Field - Verifies that magnetic field emissions from the EUT and its electrical interfaces meet specified requirements in the range of 30Hz to 100kHz.
• RE102: Electric Field - Verifies that electric field emissions from the EUT and associated cabling meet specified requirements.
• RE103: Antenna Spurious & Harmonic Outputs - Ensures that radiated spurious and harmonic emissions from transmitters do not exceed specified limits.

Radiated Susceptibility (RS) Tests determine how susceptible electronic equipment is to EMI from other devices via the air.

• RS101: Magnetic Field - Determines the EUT's ability to withstand radiated magnetic fields.
• RS103: Electric Field - Evaluate the ability of the EUT and associated cabling to withstand electric fields. The frequency range for RS103 testing is as follows:

• RS105: Transient Electromagnetic Field - Examines the EUT enclosure's resilience to transient electromagnetic fields.

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