About Surface Current Density
Surface current density is the amount of electric current per unit area flowing across a surface. It is measured in amperes per square meter (A/m²) and is crucial in electromagnetic field theory, conductor analysis, and boundary condition calculations.
Applications
- • Conductor current distribution
- • Electromagnetic boundary conditions
- • Skin effect calculations
- • Eddy current analysis
- • Microwave circuit design
- • Superconductor modeling
Typical Values
- • Copper conductors: 10⁶ to 10⁸ A/m²
- • Aluminum wires: 10⁵ to 10⁷ A/m²
- • Superconductors: 10⁹ to 10¹² A/m²
- • Printed circuit boards: 10⁴ to 10⁶ A/m²
- • Microwave guides: 10³ to 10⁵ A/m²
- • Lightning channels: 10⁷ to 10⁹ A/m²
Boundary Conditions
At conductor boundaries, surface current density relates to the tangential magnetic field discontinuity: K = n × (H₂ - H₁), where K is surface current density, n is the surface normal, and H₁, H₂ are magnetic fields on either side. This boundary condition is essential for electromagnetic field analysis.