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Wavelength in Coaxial Cable Formula:
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The wavelength in a coaxial cable is the physical distance between successive crests of an electromagnetic wave propagating through the cable. It depends on the frequency of the signal and the relative permittivity (dielectric constant) of the insulating material between the conductors.
The calculator uses the wavelength formula:
Where:
Explanation: The formula shows that wavelength decreases with increasing frequency and increases with higher relative permittivity of the dielectric material.
Details: Calculating wavelength in coaxial cables is essential for designing RF systems, determining cable lengths for impedance matching, avoiding standing waves, and ensuring proper signal transmission at different frequencies.
Tips: Enter frequency in Hz and relative permittivity (typically between 2-3 for common coaxial cables). Both values must be positive numbers.
Q1: Why does relative permittivity affect wavelength?
A: Higher relative permittivity reduces the speed of electromagnetic waves in the dielectric material, which decreases the wavelength for a given frequency.
Q2: What are typical ε_r values for coaxial cables?
A: Common values range from 2.0-2.5 for polyethylene cables to about 2.8-3.0 for foam dielectric cables.
Q3: How does wavelength relate to cable length?
A: Cable lengths are often designed as fractions of wavelength (λ/4, λ/2, etc.) for impedance matching and filtering applications.
Q4: Does this formula work for all frequencies?
A: Yes, the formula is valid for all frequencies where the coaxial cable maintains its fundamental TEM mode of propagation.
Q5: How is this different from free-space wavelength?
A: Free-space wavelength is calculated as c/f, while in coaxial cable the wavelength is shorter due to the dielectric material (c/(f√ε_r)).