Where does the inductive component of the shunt come from?
Where does the inductive component of the shunt come from? The shunt conductor is a three-dimensional entity. Under the action of high-frequency current, the distribution of the current in the conductor obviously shows a skin effect, and most of the current flows on the surface of the conductor. The high-frequency transformation of the surface current generates an alternating magnetic field inside and outside the conductor, and the direction of the magnetic field is perpendicular to the direction of the current flowing through the conductor. A changing magnetic field induces current in the direction of the conductor current. In the presence of induced current, the voltage across the shunt will contain a part of the induced voltage in addition to the voltage occupied by the internal resistance of the shunt.
Cylindrical conductor shunt, if the diameter of the shunt conductor is much smaller than the length, the induced voltage caused by the skin effect has little effect, otherwise, it will affect the measurement results.
The shunt of the sheet conductor also has a similar phenomenon, which is mainly concentrated in the width direction, which is called the edge effect. If the width is small enough, it will also weaken the effect of edge effects.
The shunt is also made into other shapes to reduce the skin effect, such as making the conductor into a barrel shape, or a large barrel with a small barrel. These structures can reduce the shunt caused by the skin effect to a certain extent. The effect of the inductor inductance on the measurement results. However, the complex cross-sectional structure will bring about a significant increase in cost.
