How to Use This Calculator
- Enter the inner conductor radius (a) in millimeters. This is the radius of the center conductor.
- Enter the outer conductor radius (b) in millimeters. This is the radius of the outer shield.
- Enter the relative permittivity (ε_r) of the dielectric material between the conductors. For air, this value is approximately 1.0. For common dielectrics like polyethylene, it's around 2.25-2.5.
- Enter the frequency (MHz) at which you want to calculate the parameters.
- Click the "Calculate" button to compute the impedance, inductance, and capacitance.
- Use the "Reset" button to clear all inputs and start over.
Working Principle
The calculator uses standard formulas for coaxial cables to determine key electrical parameters:
- Impedance (Z₀): Determines how much resistance the cable offers to high-frequency signals. It depends on the dimensions of the cable and the dielectric material.
- Inductance (L): Represents the cable's ability to store energy in a magnetic field. It increases with cable length and depends on conductor geometry.
- Capacitance (C): Represents the cable's ability to store energy in an electric field. It also depends on cable geometry and dielectric material.
Applications
This calculator is useful for:
- Designing RF and microwave systems
- Matching impedance between components
- Understanding signal propagation characteristics
- Selecting appropriate coaxial cables for specific applications
Note: For more complex cable types or materials, additional parameters may be needed. This calculator provides basic calculations for standard coaxial cables with cylindrical symmetry.