Estimate transmission line behavior using square conductor geometry and dielectric inputs. Compare spacing effects instantly. Save tables, charts, and clean reports for analysis today.
This calculator models two identical square conductors as an equivalent round pair. The equivalent radius is req = a / √π, where a is the square side.
The geometric term is u = acosh(D / (2req)). Here D is the center spacing. This term drives impedance, capacitance, and inductance estimates.
Inductance per meter is L′ = (μ / π)u. Capacitance per meter is C′ = (π ε) / u. Characteristic impedance is Z0 = √(L′ / C′).
Wave velocity is v = 1 / √(L′C′). Delay is length divided by velocity. Wavelength is velocity divided by frequency.
For conductor loss, skin depth is δ = √[1 / (πfμσ)]. AC resistance uses the smaller of full square area and skin-depth area 4aδ. Total attenuation is approximated by conductor and dielectric low-loss terms.
Enter the square side length, conductor spacing, and total line length. Choose matching units for each dimension so the geometry is interpreted correctly.
Set the dielectric constant for the medium surrounding the conductors. Use 1 for air. Increase the value for plastics, laminates, or other insulating materials.
Enter frequency, conductivity, and loss tangent. Conductivity affects resistance. Loss tangent estimates dielectric dissipation. Relative permeability usually remains 1 for nonmagnetic materials.
Press the calculate button. The result block appears under the header and above the form. Use the export buttons to save current outputs.
Review the graph to see how spacing changes impedance. Wider spacing raises impedance for the same conductor size and dielectric condition.
| Case | Side | Spacing | Length | εr | Frequency | Impedance | Delay | Total loss |
|---|---|---|---|---|---|---|---|---|
| Air-spaced copper pair | 8.000 mm | 25.000 mm | 10.000 m | 1.000 | 100.000 MHz | 201.159 ohm | 33.356 ns | 0.044307 dB |
| Low-loss dielectric pair | 10.000 mm | 30.000 mm | 25.000 m | 2.100 | 50.000 MHz | 135.179 ohm | 120.845 ns | 0.107063 dB |
| Higher permittivity pair | 12.000 mm | 40.000 mm | 5.000 m | 4.300 | 10.000 MHz | 100.991 ohm | 34.585 ns | 0.018952 dB |
Greater spacing weakens electric coupling between conductors. That lowers capacitance and raises the geometric term. The result is a higher characteristic impedance.
Closed-form square-bar formulas are less convenient for a compact calculator. The equivalent round model gives practical quasi-static estimates with clear assumptions.
Use 1 for air. Use the material’s relative permittivity when the conductors are embedded or closely surrounded by a dielectric.
Yes. It estimates conductor loss from skin depth and dielectric loss from loss tangent. These are low-loss approximations, not a full field-solver result.
Wave properties still exist in theory, but wavelength and skin-depth behavior become less meaningful. The calculator mainly targets AC and transmission applications.
Accuracy drops when the spacing approaches the equivalent diameter. Very tight geometries often need numerical electromagnetic analysis for stronger confidence.
Conductivity controls metal resistance, especially at higher frequency. Loss tangent captures dielectric heating and energy dissipation in insulating material.
Yes. It is useful for screening conductor sizes, spacings, and dielectrics. Final designs should still be verified against measurements or detailed simulation.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.