What are MIL-PRF-39012 Connectors?

Meet the Connector: MIL-PRF-39012 Connectors

MIL-PRF-39012 connectors bring high reliability to a wide range of RF devices and assemblies such as amplifiers, transceivers, filters, antennas, and more.

Previously referred to as MIL-C-39012, this standard defines the materials, quality conformance, qualification, and verification for coaxial connectors. As industries continue to adopt high-reliability coaxial cable assemblies, MIL-PRF-39012 is increasingly important for manufacturing and sourcing coaxial cable connectors and adapters. Hi-rel coaxial connectors are used with virtually all RF devices and assemblies that require RF transmission line interconnect, other than waveguides. This includes common assemblies, such as amplifiers, transceivers, filters, antennas, mixers, attenuators, combiners/splitters, couplers, and many other devices and components.

MIL-PRF-39012 applies to BNC, N, TNC, SMA, SMC, SMP, SSMP, SOP, OSSP, OSMM, SSMA, SC, QMA, UMCC, SSMT, and MMCX connectors.

MIL-PRF-39012 covers requirements and tests for radio frequency connectors used with flexible RF cables and some other types of coaxial transmission lines. The specification identifies two classes of connectors. Class 1 connectors are intended to provide superior RF performance at specified frequencies, for which all RF characteristics are completely defined. Class 2 connectors are intended to provide mechanical connection within an RF circuit providing specified RF performance.

SV Microwave SMA male connector, R/A for RG-58 Cable

The connectors are also assigned categories, designated by letters A-F:

• Category A connectors are field serviceable and do not require special tools to assemble.
• Category B connectors are non-field serviceable and may be used for original installations only. They require special tools to be assembled and are not stocked or procured by the government.
• Category C connectors are field replaceable solder center contact and require only standard military crimping tools and standard cable stripping dimensions to assemble.
• Category D connectors require only standard military crimp tools for the center contact and outer ferrule, and standard cable stripping dimensions to assemble.
• Category E connectors are field replaceable. They use semi-rigid cables with standard stripping dimensions and standard military tools. Solder is the method of assembly of the connector to the cable outer conductor.
• Category F connectors are field replaceable crimp for semi-rigid cables with standard stripping dimensions and standard military assembly tools. The method of assembly of the connector to the cable is solderless.

Kings (Winchester Interconnect) RF MIL Spec Connectors BNC PLUG available from Mouser Electronics.

Design Notes

MIL-PRF-39012 involves visual, mechanical, and electrical testing in several stages to uphold quality standards. This standard also requires that manufacturing facilities and processes meet quality standards and that the parts covered by the specification can be listed on the Qualified Products List (QPL).

Midwest Microwave/Cinch Connectivity DC to 40GHz Performance Coaxial Adapters available from Mouser Electronics.

Material specifications:

MIL-PRF-39012 QPL connectors all have gold-plated captivated contacts. The gold plating on the captivated contacts ensures a minimized insertion loss and consistent electrical contact over time and exposure to the environment. The center pin must be gold-plated to a standardized depth, adhesion quality, and finish.

Specifications for body plating vary:

• BNC, N, and TNC QPL connectors have silver-plated brass bodies.
• SMA QPL connectors have stainless steel bodies, with passivated finish, except SMA connector bodies or ferrules to be soldered to semi-rigid cable jacket, which are gold plated.
• SMC QPL connectors have gold- or silver-plated bodies.
• M39012 QPL cable connectors are categorized by their cable attachment types and are assigned cable groups defined by the governing agency (DSCC).

Environmental properties: Protective covers (dust caps) and dummy stowage receptacles ensure proper environmental and mechanical protection.

Markets and Applications

Military and Aerospace, Transportation, Industrial

MIL-PRF-39012 connectors are used in military and non-military high-reliability applications, including radar, RF instrumentation and test equipment, transceivers, ruggedized RF/microwave assemblies, SATCOM ground equipment, indoor/outdoor antennas, transportation, and aerospace RF/microwave assemblies.

Amphenol RF BNC Straight Clamp Plug, available from DigiKey

Suppliers

SV Microwave, Winchester Interconnect (available through Mouser Electronics), Cinch Connectivity Solutions, Delta Electronics (available through TTI Inc.), Amphenol RF (available through Mouser Electronics, PEI-Genesis, DigiKey, Powell Electronics), TE Connectivity.

Related products

RF connectors

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