What is coupling factor in RF?
Coupling coefficient or coupling factor: The coupling coefficient is the ratio of the input power to the power at the coupled port, in dB, when the coupler is properly terminated at all ports. This is one of the prime characteristics of the directional coupler.
How do you calculate coupling ratio?
The coupling ratio is calculated from the measured insertion loss. Coupling ratio (in %) is the ratio of the optical power from each output port (A and B) to the sum of the total power of both output ports as a function of wavelength.
What is excess loss in coupler?
Excess loss is the ratio of the optical power launched at the input port of the coupler to the total optical power measured from all output ports, expressed in dB.
What is coupling in directional coupler?
The Coupling factor of a directional coupler is the ratio of incident power to the forward power, measured in dB.
How many types of directional couplers are there?
There are different types of directional couplers like single, dual directional, coaxial, waveguide and even combination types.
What are the parameters of directional coupler?
5.8: Directional Coupler
| Parameter | Ideal | Typical |
|---|---|---|
| Coupling, C | − | 3−40 dB |
| Transmission, T | |√1−1/C2| | −0.5 dB |
| Directivity, D | ∞ | 40 dB |
| Isolation, I | ∞ | 40 dB |
What is a 90 degree hybrid?
A 90 degree hybrid coupler is a four-port device that is used either to equally split an input signal into two paths with a 90 degree phase shift between them or to combine two signals while maintaining high isolation between them.
What is the phase difference for the output of directional couplers?
They are four port devices that split an input signal equally between two output ports with a 90 degree phase difference between them.
What is perfect coupling?
Perfect Coupling or 100% Mutual Coupling When entire magnetic field produced by one coil links or couples with the other coil then it is said that coupling between the coils is perfect or 100 % mutual coupling between the coils.
How do you calculate the insertion loss of a coupler?
Insertion loss (in dB) is the ratio of the input power to the output power from each leg of the coupler as a function of wavelength. It captures both the coupling ratio and the excess loss. The coupling ratio is calculated from the measured insertion loss.
What is directivity of RF coupler?
Editorial Team – everything RF The Directivity in a coupler is the ratio between the input signal at the coupled port and the unwanted reflected signal at the coupled port. It is a measure of how well the coupler isolates two opposite-traveling (forward and reverse) signals at the coupled port.
How do you measure directional coupler?
Measurement Procedure
- Connect the spectrum analyzer inputs to the isolated and coupled ports on the directional coupler.
- Set the low-end frequency on your source and input this into the feedline.
- Measure the magnitude of the wave voltages at the coupled and isolated ports.
When would you use a hybrid coupler?
Hybrid Couplers are passive devices used to perform many functions, including splitting and combining signals in amplifiers, switching circuits, and antenna beam-forming networks used in a wide range of commercial and military applications where power or frequency needs to be monitored, leveled, alarmed or controlled.
How do you choose a directional coupler?
The magnitude of the output signal of dual directional couplers should be equal to the magnitude at the input port minus the magnitude of the signal sampled by the coupler. An ideal directional coupler samples only a signal that is transmitted in a single direction.