This calculator determines the effective dielectric constant (εeff) and the guide wavelength (λg) of a slot line. These values are essential for designing planar circuits and antennas using open waveguides on substrate.
It is particularly useful to microwave engineers, RF circuit designers, and students working on unconventional transmission structures like slot lines or printed antennas.
Formulas
εeff = (εr + 1) / 2
λg = λo / √(εeff)
where λo = c / f, with c = 3 × 10⁸ m/s and f = frequency in Hz
Explanation of formulas
- εr is the relative permittivity of the substrate material.
- εeff corresponds to the effective permittivity felt by the wave guided on the line.
- λg represents the wavelength of the wave propagating along the slit line, influenced by the substrate.
- These calculations make it possible to adjust the geometry and choice of material for optimal propagation.
Calculation of the guiding wavelength for 10 GHz with εr = 4.4
Input : f = 10 GHz, εr = 4.4
Output : εeff = 2.7, λg ≈ 18.23 mm
Benefits and uses
- Allows you to design and adjust precise slot lines.
- Facilitates the simulation and modeling of planar RF structures.
- Useful for optimizing the size and performance of printed antennas.
- Practical tool for engineers in RF circuit design and microwave research.