In RF and microwave systems, a directional coupler is an essential passive component that enables signal sampling, monitoring, and routing without disturbing the main transmission line. This article explains what a directional coupler is, how it works, and why it's a critical element in modern wireless communication systems.
A directional coupler is a four-port RF device designed to split or combine signals with controlled coupling in a specific direction. It allows a small portion of the input signal to be "coupled" from the main line to a secondary port, typically for monitoring or testing purposes.
Input Port – Where the main RF signal is fed into the coupler.
Output (Through) Port – The main signal continues through this port with minimal insertion loss.
Coupled Port – Receives a small fraction of the input signal.
Isolated Port – Ideally has no signal in the direction opposite to the coupled port (terminated to prevent reflection).
Directional couplers operate on the principle of electromagnetic coupling between transmission lines. They are designed to couple energy traveling in one direction while isolating energy in the reverse direction. This makes them useful for:
Signal monitoring
Power measurement
Feedback loops
System protection
The coupling factor, typically expressed in dB (e.g., 6 dB, 10 dB, 20 dB), determines how much signal is coupled out. A 20 dB directional coupler, for example, will extract 1% of the input power to the coupled port.
Directional couplers are widely used in RF and microwave systems, including:
Base stations and DAS systems
5G and LTE networks
Satellite communication
Test and measurement setups
Public safety and military communication
RFID and IoT systems
In all these applications, directional couplers enable signal sampling, reflected power detection, and system diagnostics without interrupting the main transmission path.
Depending on your application, you may need different types of directional couplers, including:
Single-directional couplers
Bi-directional couplers
Hybrid couplers (90° or 180°)
Stripline or waveguide couplers
Choosing the right RF directional coupler depends on factors like frequency range, power handling, coupling level, and physical size.
At Maniron Electronic, we’ve specialized in the design and manufacturing of RF passive components since 2002. Our directional couplers are built for performance, low insertion loss, and excellent isolation. Whether you need standard models or custom specifications, we support OEM and ODM projects worldwide.
Wide frequency range support (VHF to 6GHz and beyond)
Coupling options: 6 dB, 10 dB, 20 dB, etc.
Customizable connectors and enclosures
Precision-engineered and factory-tested
Do you have any questions ?
Call Us : +86 551 65329702
