What materials are commonly used to make RF couplers

RF Coupler Material Composition

Advanced material selection for optimal signal transfer, impedance matching, and durability across radio frequencies

Conductive Materials

  • Primary Conductors Copper - Standard choice (97% IACS conductivity)
    Applications: Microstrip lines, coaxial inner conductors
    Advantages: Excellent malleability and conductivity
    Silver - High-performance option (105% IACS)
    Applications: Premium couplers
    Considerations: Higher cost limits widespread use
    Aluminum - Lightweight alternative (61% IACS)
    Applications: Aerospace systems, large couplers
    Benefits: Weight reduction with acceptable conductivity
    Gold plating - High-frequency solution
    Applications: >10 GHz systems
    Purpose: Oxidation prevention for stable performance

Dielectric Materials

  • High-Frequency Dielectrics PTFE (Polytetrafluoroethylene)
    Dielectric Constant: 2.1
    Advantages: Minimal signal loss at high frequencies
    Alumina (Al₂O₃)
    Properties: High thermal stability, mechanical strength
    Applications: Extreme temperature/power environments
    FR-4
    Applications: <1 GHz systems
    Benefits: Cost-effective balance of properties

Structural Materials

  • Brass (Copper-Zinc alloy)
    Applications: Outer housings, connectors
    Advantages: Excellent machinability and rigidity
    Stainless Steel
    Applications: Industrial/outdoor couplers
    Properties: Superior corrosion resistance and strength

Material Selection Factors

  • Key considerations for optimal material selection:
    • Operating frequency range
    • Power handling requirements
    • Environmental conditions
    • Cost-performance balance
    High-performance designs prioritize low-loss dielectrics and high-conductivity metals, while balancing mechanical and environmental requirements.