D38999 Contact RF Cable Assemblies

Overview
Amphenol Military & Aerospace’s SV Microwave D38999 Contact RF Cable Assemblies extend standard MIL‑DTL‑38999 circular connectors to carry microwave and millimeter‑wave signals. These pre‑terminated assemblies combine high‑frequency coaxial contacts within a durable, environmentally sealed 38999 interface, allowing existing platforms to transmit RF energy without redesigning the connector layout.

Design and Construction
The assemblies use precision BMA, BMB, SMPM, and SMPS contact systems installed in size 8, 12, and 16 cavities. Each contact is terminated to SMA male connectors using Ø.085 or Ø.141 in cables to maintain tight impedance control and low return loss. Float Mount technology permits small axial movement to reduce stress and preserve impedance alignment under vibration and thermal cycling. All interfaces conform to MIL‑STD‑348 for mechanical intermateability and maintain 50 Ω characteristic impedance.

Variants and Frequency Range
Contact options cover multiple frequency bands and form factors:

• Size 8 BMA and BMB contacts — for medium‑ to high‑power paths to ~22 GHz
• Size 12 SMPM contacts — blind‑mate push‑on design with operation to ~65 GHz
• Size 16 SMPS contacts — ultra‑miniature variant suited for dense layouts to 65 GHz
• Size 20 SV20 series — compact ~40 GHz channels for micro‑density configurations

Integration and Alignment
All pin and socket contacts of the same RF series are intermateable across cable types and support mixed‑diameter cabling within a single shell. These assemblies fit Series I, III, and IV 38999 housings as well as VITA 67.3 SOSA‑aligned layouts, bridging embedded VPX payloads to external system circuits. Standard materials and plating meet defense environment requirements for corrosion and shock resistance.

Applications
Typical uses include airborne radar feedlines, electronic warfare modules, VITA/SOSA embedded computing interfaces, and general mixed‑signal systems migrating from low‑frequency contacts to broadband microwave paths. By utilizing existing 38999 shells, these assemblies simplify system upgrades and reduce connector count while preserving proven mechanical reliability.

Selection Guidance
Choose contact size and series based on desired frequency range and density. Size 8 BMB options favor lower loss at longer runs; size 12 or 16 SMPM/SMPS contacts maximize density and bandwidth for compact modules. Assemblies are available in custom lengths and cable types upon request for specific radar, EW, or mission‑computer integration needs.