Hertz vector

Summary

A Hertz vector, or polarization potential, is one vector field that yields both the electric potential and the magnetic vector potential by differentiation. The potentials built from it satisfy the Lorenz gauge condition automatically, and Maxwell's equations reduce to one vector wave equation for the Hertz vector. It is a convenient tool for radiation problems, especially for dipole antennas, where it is the field of the source dipole moment delayed in time.