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rf coupler

In contemporary wireless communication systems, Directional Coupler are crucial. For signal sources in a transmission line, they offer isolation. The directional coupler must have a large operational bandwidth.

A parameter used to determine a directional coupler's performance is the coupling factor. The ratio of input power to output power is the subject of this factor. A directional coupler, for instance, will have an output port that is 3 dB below the input if the input port has a directivity of 10 dB.

VSWR measurements and electronic warfare are two common uses for directional couplers. However, there are numerous other applications for the directional coupler. The measuring of reflected power is one use case. The amount of reflected power can be observed by a transmitter using a directional coupler.

A front-end stage and a power amplifier module make up a directional coupler. The receiver's input terminal is typically attached to the input port. Lower power levels may be transported via different ports.

An additional power detect circuit may be located in the isolated port of some directional couplers. This circuit may be driven by an RF-switch transistor.

A metal-oxide-semiconductor (MOS) device is an RF switch. The output power is managed by channel resistance.

Directivity of at least 20 dB is provided by an electrically short directional coupler. Mobile applications typically employ these devices.

Consider the type of transmitted power level, the insertion loss, and the frequency range when selecting a directional coupler. The directional coupler should ideally be capable of handling both high and low power and have a wide operating range.

In high-frequency bands, loose coupling between the primary and secondary coils can aid in lowering insertion loss. However, technological advancements might make much shorter separation distances possible.

An excessive amount of power loss may occur if the coupling is too strong. A directional coupler's strength can be changed to lessen this impact. Another option for a directional coupler is to be set up as a stripline. The solder pins or a tiny container are two packaging options for the directional coupler.


Symmetrical coupler

Different applications call for the employment of symmetrical rf coupler. It is intended to reduce the connected line's surface gradient. This gradient lowering contributes to lowering the insertion loss.

Because they enable monitoring and control of the reflected and transmitted power, these couplers are crucial in RF systems. They give the system feedback to identify over-voltage or excessive VSWR. These couplers are frequently used for reflected power measurement, VSWR analysis, waveform monitoring, and spectrum monitoring.

A symmetrical coupler has a single polarized input and output, in contrast to asymmetrical lines. As a result, the gadget can work either way. These couplers, however, cannot be used to adjust the frequency of the directed wave. Instead, they are placed close to the antenna to pick up the transmitted or reflected wave.

The structure of the directional coupler needs to be theoretically and physically corrected in order to guarantee that it has good directivity. Depending on the application, the coupling factor is selected. A directional coupler can often be set up with coupling coefficients between -20 and -40 dB.

Typically, the distance between the coupled lines is changed to alter the coupling level. Next, the coupling value is calculated. The structure is not adequately compensated if the value is less than the design.

The coupler construction must have a low insertion loss and a high power handling in the main line in order to establish adequate isolation between signal ports. As a result, the tuning planes must be passed by the PCB's dielectric substance.

A quasi-static design is a more reliable place to start for full-wave designs for high frequencies. In this instance, a chassis is suspended over a coupler. Because of the static architecture, the DC block's center frequency is moved downward by 0.2 GHz.

It is challenging to achieve enough directivity. The coupling factor of the directional coupler must be better than -20 dB in both directions in order to achieve acceptable directivity. The coupler can also work in the opposite direction.

Numerous RF design and testing applications require directional couplers. Although they might have different configurations, they usually have three accessible ports. A coupled port samples the reflected wave, while input and transmitted ports sample the forward wave.

Why choose Hefei Topwave rf coupler?

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