Skin Depth Calculator

Skin depth calculator

Skin effect is the tendency of concentration of AC current flow near surface of a conductor. The Skin depth is the depth from the conductor surface at which the current density decreases to 1/e (= 0.3678) of its value near the surface. The skin depth depends upon the operating frequency and resistivity & relative permeability of the material.

This online skin depth calculator calculates the skin depth δ by entering the value of the frequency (GHz), and resistivity ρ (Ω) & relative permeability µr of the material (or entering material type).

What is skin depth?

Skin effect is the uneven distribution of the alternating electric current over the surface of the conductor. This effect increases with the frequency. At high frequencies, such as radio frequency, practically the whole of the currents flows on the surface of the conductor. The current flowing between the outer surface and a level is called skin depth. The skin depth depends upon the operating frequency and resistivity & relative permeability of the material. Usually, the skin depth is measured in nm/µm.

The skin effect can greatly affect the analysis and design of radio-frequency and microwave circuits, transmission lines, waveguides, and antennas. It is one of the primary reasons for preferring high-voltage direct current for long distance power transmission. To reduce the skin effect, designers often replace the solid conductors with tubes which entirely eliminates the core. Hence, maximum current is transmitted without many losses.

Skin effect (current flow near-surface of a conductor) is because of larger inductive reactance in the inner core as compared to the outer section of the conductor.

How to calculate the skin depth?

The skin depth (δ) is calculated by using the following formula.

• Where:
• δ = Skin depth in nm/µm
• f = frequency in MHz
• ρ = Resistivity of the material (Ωm)
• µr = Relative permeability
• µo = Permeability constant = 4π x 10-7 H/m