1. What is Skin Depth?

Skin depth (δ) is the depth at which the current density falls to 1/e (about 37%) of its value at the surface in a conductor carrying alternating current. It's a critical parameter in high-frequency electronics and electromagnetic applications.

2. How Does the Calculator Work?

The calculator uses the skin depth equation:

Where:

• \( \delta \) — Skin depth (m)
• \( \rho \) — Resistivity of copper (Ω·m)
• \( \omega \) — Angular frequency (rad/s)
• \( \mu \) — Permeability of copper (H/m)

Explanation: The equation shows that skin depth decreases with increasing frequency, meaning high-frequency currents flow mostly near the surface of the conductor.

3. Importance of Skin Depth Calculation

Details: Skin depth is crucial for designing high-frequency circuits, RF components, and electromagnetic shielding. It affects conductor resistance, inductor Q factor, and transmission line losses.

4. Using the Calculator

Tips: Enter resistivity (default is 1.68×10⁻⁸ Ω·m for copper), angular frequency (ω = 2πf), and permeability (default is 4π×10⁻⁷ H/m for non-magnetic copper). All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: Why is skin depth important for copper conductors?
A: It determines the effective cross-sectional area for high-frequency currents, affecting resistance and power losses.

Q2: How does frequency affect skin depth?
A: Skin depth decreases with the square root of frequency (δ ∝ 1/√f). At higher frequencies, current flows in a thinner layer.

Q3: What's typical skin depth for copper at 1 MHz?
A: About 66 μm (0.066 mm) at room temperature.

Q4: Does temperature affect skin depth?
A: Yes, since resistivity changes with temperature. Warmer copper has greater resistivity and thus slightly larger skin depth.

Q5: When is skin effect negligible?
A: When conductor diameter is much smaller than skin depth at the operating frequency (typically below kHz range for typical wire sizes).