TDK Multilayer Radio Frequency Directional Coupler

Frequency Range: 698MHz～2.62GHz (Compatible with GSM/UMTS/LTE/5G Sub-6GHz and Wi-Fi)Coupling Factor: 25.6dB ±2dB (698–915MHz); 25.6dB ±2.5dB (2300–2620MHz)Insertion Loss: ≤0.2dB (Typical: 0.11dB)Isolation: ≥45dB (Typical: 48dB)Impedance: 50Ω (Standard RF System)Package / Dimensions: 0603 (1.6×0.8×0.6mm), 6-pin SMDOperating Temperature: −40℃ ～ +85℃Environmental Compliance: RoHS compliant, lead-free

2. Application Scope

Primarily used in mobile communication and wireless LAN devices:

• Mobile phones / Base stations: RF front-end for GSM, UMTS, LTE and 5G Sub-6GHz

• Wireless routers / Access Points: Power detection for Wi-Fi 2.4GHz/5GHz bands

• IoT Modules: NB-IoT, Cat.1, Bluetooth / Wi-Fi Combo modules

• Test Instruments: RF signal sampling, power monitoring and VSWR detection

3. Function & Working Principle

The directional coupler acts as an RF signal sampler. It extracts a small portion of power from the main signal at a fixed ratio for measurement and control, without affecting normal transmission of the main channel.

• Main Path (Input → Output): Transmits RF signals with nearly no loss (Insertion Loss ≤0.2dB)

• Coupling Port: Picks up a weak signal at 25.6dB (approx. 1/360 of input power) and feeds it to power detection and feedback circuits

• Isolation Port: Attenuates reverse signals by more than 45dB to avoid interference to the main channel

In short, it accurately samples RF power without disrupting signal transmission, and is widely applied in Automatic Power Control (APC), over-power protection and VSWR alarm systems.

4. Pin Definition (6PIN)

1. Output (Main Output)

2. GND (Ground)

3. Input (Main Input)

4. Coupling (Coupled Output)

5. GND (Ground)

6. 50Ω Terminate (Internal 50Ω Termination)