1. What is Skin Depth?

Skin depth (δ) is the depth at which the current density has fallen to 1/e (about 37%) of its value at the surface of a conductor carrying alternating current. It's a crucial concept in electromagnetics and electrical engineering.

2. How Does the Calculator Work?

The calculator uses the skin depth equation:

Where:

• \( \delta \) — Skin depth (m)
• \( \rho \) — Resistivity of the conductor (Ω·m)
• \( f \) — Frequency of the AC signal (Hz)
• \( \mu \) — Permeability of the conductor (H/m)

Explanation: The equation shows that skin depth decreases with increasing frequency, permeability, and conductivity (lower resistivity).

3. Importance of Skin Depth Calculation

Details: Skin depth is critical for designing conductors for high-frequency applications, calculating AC resistance, and understanding electromagnetic shielding effectiveness.

4. Using the Calculator

Tips: Enter resistivity in Ω·m, frequency in Hz, and permeability in H/m. The default permeability value is for free space (μ₀ = 4π×10⁻⁷ H/m). All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What's typical skin depth for copper at 50Hz?
A: About 9.35mm (ρ = 1.68×10⁻⁸ Ω·m, μ ≈ μ₀).

Q2: Why does skin depth matter in PCB design?
A: At high frequencies, current flows mostly near the surface, affecting trace resistance and requiring proper design to minimize losses.

Q3: How does temperature affect skin depth?
A: Higher temperatures increase resistivity (ρ), thus increasing skin depth.

Q4: What's the skin effect?
A: The phenomenon where AC current density is highest near the conductor's surface and decays exponentially with depth.

Q5: How is skin depth related to electromagnetic shielding?
A: Thicker shielding materials (several skin depths) are needed for effective attenuation of electromagnetic waves.