SIST EN 4652-313:2016

Overview

SIST EN 4652-313:2016 is a comprehensive European standard developed by CEN, specifying the technical characteristics and requirements for aerospace-grade coaxial connectors-specifically the Type 3 N interface clamp nut assembly version bulkhead receptacle. These connectors operate at 50 ohms impedance and utilize clamp technology for cable-to-connector assembly. Designed primarily for aerospace applications, this standard ensures uniformity, reliability, and high performance in demanding environments.

Key Topics

• Connector Type and Interface
  The standard defines the Type 3 coaxial connector with an N interface, featuring a clamp nut assembly and bulkhead receptacle configuration. This design supports screwed-on coupling to provide a secure and robust connection.

• Electrical Characteristics

  • Characteristic impedance: 50 Ω
  • Maximum operating frequency: 6 GHz
  • Voltage Standing Wave Ratio (VSWR): ≤ 1.15 up to 6 GHz
  • Maximum insertion loss: 0.04 √f dB (f in GHz)
  • Contact resistance: Initial 1.5 mΩ max for center contact
  • Withstand voltage: 1500 V effective at sea level
  • Insulation resistance minimum: 5000 MΩ

• Mechanical and Environmental Requirements

  • Operating temperature range: −65 °C to +165 °C
  • Tightening torque: Not applicable (clamp nut design)
  • Durability: Minimum 500 mating/unmating cycles
  • Cable retention force: Minimum 180 N for relevant cable groups
  • Water ingress resistance required for both mated and unmated connectors (depending on sealing designation)
  • Resistance against salt mist, sand, dust, low pressure, rapid temperature changes, and fluid immersion specified through rigorous testing

• Materials and Finish

  • Center contact made of gold-plated copper alloy for optimal conductivity
  • PTFE insulators, silicone rubber or silicone fluoride sealings
  • Connector bodies nickel-plated copper alloy for corrosion resistance
  • Polyolefin heat shrink tubing used where applicable

• Test Procedures and Qualification
  The standard references detailed testing protocols derived from EN 2591 series, covering contact resistance, insulation, mechanical endurance, environmental resistance, electrical performance under various conditions, and more to ensure product reliability.

• Designation and Marking
  Connectors are classified and marked according to a structured identification system that includes the connector type, assembly technology, cable group, and impedance rating to facilitate correct selection and traceability.

Applications

• Aerospace Systems
  EN 4652-313 connectors are critical in aerospace electrical and electronic systems requiring rugged, high-frequency, and low-loss coaxial connections. Examples include communication radios, navigation systems, radar, and avionics equipment.

• Defense Equipment
  Due to their reliability under extreme conditions, these connectors are suitable for military aerospace platforms where environmental and mechanical demands are stringent.

• High-Frequency Radiofrequency Transmission
  The standard's adherence to 50 Ω impedance and up to 6 GHz frequency range enables their use in RF signal transmission where precision and minimal signal degradation are necessary.

• Harsh Environment Electronics
  The robust sealing, material selection, and tested resistance against dust, moisture, and temperature variations make the connectors ideal for systems exposed to challenging environments.

Related Standards

• EN 4652-001 – General technical specifications and definitions for aerospace series RF coaxial connectors
• EN 4652-310 – Straight plug version of Type 3 N interface coaxial connectors with clamp nut assembly
• EN 2591 – Aerospace series electrical and optical connection test methods
• EN 2812 – Aerospace series cable stripping methods for electrical cables
• EN 9133 – Quality management system requirements and qualification process for aerospace standard parts
• TR 6058 – Aerospace series cable code identification list

Conclusion

SIST EN 4652-313:2016 defines a stringent product standard for aerospace coaxial connectors with N-type interfaces tailored to high-frequency and high-reliability applications. By adhering to this standard, manufacturers and system integrators ensure interoperability, performance stability, and compliance with aerospace industry requirements-bolstering safety and effectiveness in critical aerospace and defense communications systems.

Keywords: EN 4652-313, aerospace connectors, coaxial connectors, N interface, clamp nut assembly, bulkhead receptacle, 50 ohms, RF connectors, aerospace standards, high-frequency connectors, aerospace electrical components, aerospace cable connectors, EN 4652 standard, aerospace series connectors, coaxial bulkhead receptacle.