1. Overview

Directional couplers are passive devices that sample a portion of RF/IF signal power for monitoring or feedback purposes. They enable signal splitting, reflection measurement, and signal-to-noise ratio optimization. These components are critical in wireless communication systems, RFID infrastructure, and industrial control applications.

2. Major Types and Functional Classification

3. Structure and Components

Typical construction includes: - Precision-machined metal housing (aluminum/copper alloys) - Dielectric substrates (PTFE or ceramic materials) - Coupling slots/apertures (0.1-2.0mm dimensions) - Input/Output ports with SMA/N-Type connectors - Isolation termination resistor (50 matched load) - EMI shielding gaskets

4. Key Technical Specifications

5. Application Fields

Key industries include: - Telecommunications (5G/4G BTS signal monitoring) - RFID systems (UHF/NFC reader sensitivity control) - Industrial IoT (Wireless sensor network optimization) - Medical equipment (MRI RF power management) - Automotive (V2X communication diagnostics)

6. Leading Manufacturers and Products

7. Selection Guidelines

Key considerations: - Frequency bandwidth match (1.5x operating range) - Power handling (1.2x maximum system power) - Directivity requirements (>30dB for precise measurements) - Environmental factors (operating temperature -40 C to +85 C) - Connector type compatibility (SMA vs N-Type) - Cost vs performance tradeoff (planar vs waveguide)

8. Industry Trends

Emerging developments: - Sub-6GHz massive MIMO integration - Advanced packaging for mmWave applications - AI-optimized coupling algorithms - Gallium Nitride (GaN) material adoption - Miniaturization for mobile device integration - Higher directivity (>50dB) research