Skip to Main Content
A circuit model for electrically small antennas is introduced that is based on their frequency-dependent polarizabilities. This model is useful for straightforwardly analyzing several different small antenna geometries. A negative permittivity sphere, shell, and spheroid are all analyzed. An inductively loaded dipole, a top-hat loaded dipole, and a spherical sheet impedance are also analyzed. The circuit model provides the antenna's radiation quality factor (Q), radiation efficiency (ηrad), and bandwidth. It also offers insight into the operation of the antenna which can aid and simplify design.