Digital Circuit Boards: Mach 1 GHz

1.20 Glossary

B field (Section 1.13): The B field is the field of magnetic induction. The unit of B field intensity at a point is the tesla. The B field is a vector field, as it has intensity and direction at every point in space. The B field does not change intensity across a boundary when the permeability changes value. When the B field is represented by lines, these lines always form closed loops. The B and H fields are related by permeability B = μ₀μ_R · H, where μ₀ is the permeability of free space or 4π10⁻⁷ and μ_R is the relative permeability.

Capacitance (Section 1.7): The ability of a physical space to store electric field energy. In circuit applications it is the ability of a conductor geometry to store electric field energy (capacitor). If the electric field energy is not contained by conductors, it must be moving at the speed of light. Examples of fields in motion are transmission lines or antennas. Space has a capacitance per unit volume.

Capacitor (Section 1.7): A circuit component designed to store electric field energy.

Charge (Section 1.4): A quantity of electrons (negative charge). The absence of electrons (positive charge). The unit of charge is the coulomb. A coulomb of charge flowing past a point in one second is an ampere.

Charged (Section 1.4): A mass that has an excess or a lack of electrons on its surface.

Current (Section 1.6): The flow of electrons or ions. Electrons can flow in a conductor. Ions can travel in space or in a chemical solution.

D field (Section ...