A directional coupler is a passive RF component that samples a small portion of signal power from a transmission line without disturbing the main signal flow . Keenlion, a B2B factory, manufactures custom directional couplers across various frequency bands with precise coupling, low insertion loss, and high directivity for demanding RF systems.

Basic Directional Coupler Functions

What exactly is a directional coupler? A directional coupler is basically a design that provides a 4- port network to direct a specific amount of power onto a coupled port for measurement. When an RF signal is applied to the input port, the entire of the signal basically appears at the thru (output) port, with only a small amount of power appearing onto the coupled port in proportion. This allows a design that measures the strength (power) of the RF signals, to monitor for reflected signals, and to assess the health/working of the entire RF transmission system without affecting the main flow of transmitted signals.

How Does a Directional Coupler Achieve Directionality?

A directional coupler operates by creating an electromagnetic coupling between transmission lines. When two transmission lines are placed close together for a length of time (as would be the case in a microstrip or stripline), power is able to couple from the main transmission line to the coupled transmission line. The directivity of a directional coupler is its primary feature, which helps in differentiating the two waves traveling from forward and backward directions. This is precisely why the directivity of directional couplers makes them so important when determining VSWR and measuring reflected power.

Types and Key Parameters

Directional couplers come in various forms: three-port and four-port bi-directional types, as well as dual directional couplers for simultaneous forward and reverse monitoring . Key specifications include coupling factor (the fraction of sampled power), insertion loss (signal reduction through the main path), directivity (isolation between forward and reverse samples), and VSWR . Keenlion offers custom directional couplers with tailored frequency ranges and power handling capabilities. Visit www.keenlion.com to submit your directional coupler RFQ today.

Si Chuan Keenlion Microwave a large selection in narrowband and broadband configurations, covering frequencies from 0.5 to 50 GHz. They are designed to handle from 10 to 30 watts input power in a 50-ohm transmission system. Microstrip or stripline designs are utilized, and optimized for best performance.

We can also customize directional coupler according to your requirements. You can enter the customization page to provide the specifications you need.
https://www.keenlion.com/customization/
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Sichuan Keenlion Microwave Technology Co., Ltd.