If you’re familiar with networking and cabling, you may have come across the term “FEXT” or far-end crosstalk. Essentially, this is a phenomenon where crosstalk along a disturbed circuit is in the same direction as the desired signals in that circuit.
To put it simply, FEXT occurs when a signal crosses over from one cable to another cable, at the receiving end of the cable opposite from where the signal was sent. This can cause interference and a loss of signal strength, especially on shorter cables where the signal has traveled a shorter distance.
FEXT can be measured using a crosstalk measurement, which is commonly used in audio systems to determine the amount of signal that crosses over from one channel to another. It’s important to note that FEXT alone doesn’t tell you much, as signals can be attenuated over distance. To get a more meaningful result, the attenuation (insertion loss) is removed from the FEXT result and referred to as equivalent far-end crosstalk (ELFEXT) or Crosstalk Ratio, Far-End (ACRF).
Key Points:
- FEXT is a phenomenon where crosstalk along a disturbed circuit is in the same direction as the desired signals in that circuit, on the opposite end of the cable from where the signal was sent.
- FEXT can cause interference and a loss of signal strength, especially on shorter cables.
- Crosstalk measurements are often used in audio systems to determine the amount of signal that crosses over from one channel to another.
- ELFEXT or ACRF is a more meaningful measurement of FEXT, as it takes attenuation into account.
FAQ:
What is crosstalk?
Crosstalk is an electrical effect that causes a signal to cross over from one cable to another. This can cause interference and a loss of signal strength.
What is FEXT?
Far-end crosstalk, or FEXT, is a type of crosstalk that occurs at the receiving end of the cable opposite from where the signal was sent.
What is ELFEXT?
Equivalent far-end crosstalk, or ELFEXT, is a measurement of FEXT that takes attenuation into account.
Conclusion:
FEXT can cause interference and a loss of signal strength in networking and audio systems. By measuring equivalent far-end crosstalk (ELFEXT or ACRF), the impact of FEXT can be more accurately determined and addressed.
