EMI/EMP Filter Connectors

Mission-critical systems must always maintain signal integrity despite the threat of electromagnetic interference (EMI), radio frequency interference (RFI), and electromagnetic pulse (EMP). Amphenol Aerospace filter connectors are built to provide critical EMI, EMP, and RFI protection for any sensitive system operating in harsh environments and are vital components when engineering your system for electromagnetic compatibility (EMC).

Product D38999 Series III Filter Connectors
D38999 Series III Filter Connectors
High-performance general duty D38999 Series III threaded Filter Connector designed to withstand severe environment applications.
Product D38999 Series II Filter Connectors
D38999 Series II Filter Connectors
Subminiature, environmental-class connectors used where a quick disconnect coupling system is required for blind mating.
Product D38999 Series I Filter Connectors
D38999 Series I Filter Connectors
The filtered LJT Series offers all the design features of Series II plus a 100% “scoop-proof” contact protection design.
Product MIL-DTL-26482 Series I Filters (FPT)
MIL-DTL-26482 Series I Filters (FPT)
Combines the unique design features of the miniature PT Series with an EMI filter.
Product 2M Filters
2M Filters
The versatility of standard 2M connectors with EMI protection to meet the demands of your application.
Product Filter Adapters
Filter Adapters
Present an effective and economical method of introducing EMI/EMP protection to an installed system.
Product MIL-DTL-5015 Filters (FAN)
MIL-DTL-5015 Filters (FAN)
Designed in configurations intermateable and intermountable with MIL-DTL-5015* connectors and provides electromagnetic interference protection for critical circuits.

Transient Protection

Product Diode Connectors
Diode Connectors
Offer the versatility of a standard connector, with transient protection for sensitive circuits, such as TTL Lines.
Product MOV - Metal Oxide Varistor Connectors
MOV - Metal Oxide Varistor Connectors
Offer the versatility of a standard connector, with transient protection for sensitive circuits.

EMI/EMP/RFI Solutions for Every Connector, Every System

Our filtering devices can be utilized on all standard and Mil-Spec circular connectors to provide durable and versatile EMI, EMP, and RFI protection for any system. Amphenol Aerospace has a filtering solution for essential signal in any land, sea, air, or space-based application.


Opting for EMI/EMP/RFI protection at the connector instead of on the board also presents valuable opportunities for weight and space savings in your system. Electing for these safeguards at the connector level also means there is no longer a need to redesign your entire system to incorporate EMI/EMP/RFI protection.

What is EMI?

EMI is when low, medium, or high-frequency electromagnetic signals interfere with a system and cause performance degradation or malfunction. Some sources of EMI include interference from radio waves, stray transmissions, electric power lines or electric motor noise, or interference between electronic components or subsystems within the same system.


It can also happen due to natural causes like lightning, radiation, solar activity, or atmospheric phenomena such as ionospheric disturbances or static electricity buildup.


There are two main types of EMI:


  • Conducted EMI: Occurs when electromagnetic signals are conducted along wires or other conductive paths.
  • Radiated EMI: Occurs when electromagnetic signals travel through the air or a vacuum and are picked up by a system’s input/output lines. It requires no physical connection.

Amphenol filter connectors protect against both conducted and radiated EMI by strategically orienting the internal filtering components to target different threat profiles. 


What is RFI?

Like EMI, RFI is caused by electromagnetic signals, but RFI occurs within the radio frequency spectrum typically in the medium to high-frequency range above 10 kHz. RFI often occurs due to intentional radio transmissions from sources like AM/FM radio broadcasts, television signals, Wi-Fi, cellular networks, and radar systems.

What is EMP?

EMP is a short, intense burst of electromagnetic energy that can severely damage or disable electrical devices and electronic systems. EMPs can be caused naturally by lightning strikes or solar flares or can originate from man-made sources such as EMP weapons or nuclear explosions. Hardening a system against EMP is crucial for all mission-critical systems due to the enormous threat they present.

EMI Low Pass Filter Options

Amphenol EMI filter connectors utilize several types of low-pass filters to filtrate medium and high-frequency interference. These filters utilize capacitors and Planar and Ferrite Inductors to prevent unwanted signal noise which can harm a system’s functionality and performance.



  • Pi Filter: Consists of two planar capacitors with a ferrite inductor installed in between that offers a steep insertion loss curve.
  • C Filter: Consists of a single planar capacitor, a simple and cost-effective design that often exceeds the performance of multi-component configurations.
  • C-L Filter: Consists of a single planar capacitor followed by a ferrite inductor. Best used when the source impedance is greater than the load impedance.
  • L-C Filter: Consists of a ferrite inductor followed by a single planar capacitor. Best used when load impedance is greater than source impedance.
  • T Filter: Consists of two ferrite inductors with a single planar capacitor installed in between. Superior high-frequency performance.


Transient Voltage Protection for EMP Defense


To defend against EMP or other abrupt releases of stored energy such as load switching, lightning strikes, or electrostatic discharge (ESD), Amphenol filter connectors are offered in configurations with transient voltage suppression (TVS) diodes or metal oxide varistors (MOVs) that shunt high current spikes to the ground. Amphenol’s transient voltage protection technology meets all aircraft performance requirements and combines traditional environmental protection provided by Mil-Spec connectors.


Block EMI and Address SWaP on eVTOL Aircraft

Electric Vertical Takeoff and Landing (eVTOL) aircraft are poised to bring urban air mobility to cities around the world in the coming years. Large cities are also rife with all sorts of EMI and RFI caused by many types of communications and transmissions as well as power line noise, electronics, and competing systems. 


Electric vehicles like eVTOLs rely heavily on sophisticated avionics and electrical systems for operation and must remain free from EMI and RFI interference in these dense urban environments.


Opting for Amphenol EMI/RFI filter connectors in your eVTOL system not only provides reliable EMI and RFI protection; the weight and space savings offered by Amphenol Filters are also ideal for the weight and space constraints needed in efficient eVTOL platforms.

Maintaining Signal Integrity No Matter the Application

Amphenol Aerospace offers a wide variety of EMI/EMP/RFI filter options to meet almost any customer requirement. Our filter capabilities are available for a variety of Mil-Specs including MIL-DTL-38999, MIL-DTL-5015, MIL-DTO-26482, MIL-DTL-26500, and MIL-DTL-27599, and Amphenol engineers can customize any connector to meet the customers’ specifications.


Filter Connector Key Features

filter connector


  • Military Aircraft
  • Commercial Aircraft
  • Electric Vertical Takeoff and Landing (eVTOL) Aircraft
  • Military Ground Vehicles
  • Radar Equipment
  • Missile Warning Systems
  • Refueling Systems
  • Engine Systems
  • Landing Gear
  • Avionics Systems
Amphenol Filter Advantages
  • Wide range of filter configurations to accurately target specific customer requirements.
  • Filter technology is versatile and can be implemented into any standard circular connector series.
  • Transient Voltage Suppression (TVS) devices can be coupled with our filter technology or act as standalone devices in a connector to target requirements from RTCA-DO-160
  • Dielectric Withstanding Voltages (DWV) upwards of 3kVDC
  • Operating Temperature Range of -55°C to 125°C
  • Reduction in overall weight and space
  • Reduction of solder junctions
  • Greater reliability due to fewer connections
  • Fragile filter elements protected by connector shell
  • Pre-testing from the factory and ready for installation
Composite Weight Savings
  • Meets MIL-DTL-38999 Series III dimensional lengths.
  • Offers the same high performance as its metal counterpart.
  • Lightweight: 17%-70% weight savings over metal.
  • Corrosion Resistant.
  • Offers better environmental performance than its metal counterpart.
  • Durable - 1,500 coupling minimum.
EMP Protection
  • EMP protection using diodes.
  • EMP protection utilizing metal oxide varistors (MOVs).
  • Filtered plug connectors.
  • Glass fused hermetic seal.
  • ESD protection.
  • Combine filtering devices within one connector package.


Contact Options
  • Coaxial, concentric twinax, triax, and quadrax contacts
  • Filter contacts with differing cut-off frequencies
  • Ground, insulated, or filter contacts
  • Thermocouple contacts
  • Diodes or MOV for EMP
Wire Termination Methods
  • Solder cup - wire termination
  • PCB termination (Pre-tinning is available)
  • Solderless wrap
  • Amphenol® UTS (Universal Termination System) allows crimp termination
  • Weld terminal for thermocouple contacts
  • Compliant Pin (press fit) for epoxy
  • Effective and economical method of introducing EMI/EMP protection to an installed system
  • Intermateable with popular Mil-Spec connectors
  • Can be configured for transient protection
  • Space-qualified components available
  • Quick and efficient installation
  • Readily available in MIL-DTL-38999 Series I, II, and III
Transient Protection Options
  • TVS Diodes
  • Metal Oxide Varistors (MOVs)
  • Energy Shunting Assembly (ESA)
  • Electrostatic Discharge (ESD)
  • High Speed
  • Hermetic and High-Speed Hermetic
  • Aquacon
  • Epoxy Sealed
  • Printed Circuit Board Mount