Equivalent-Circuit Modelling of Chassis Radiator

The comparison of the characteristics of a flat dipole and the rectangular chassis eigen-mode leads to the concept of the chassis radiator as a flat dipole with completely filled, short-circuited terminal area. The equivalent circuit for the chassis radiator is derived from the flat dipole equivalent circuit by exclusion of the parasitic feed inductor and shunt capacitance and by short-circuiting the de-embedded terminals. In employing equivalent circuit elements based on measured impedance of a flat dipole, the partitioning of parasitic and "dipole" inductance is achieved by application of the theoretical resonance (eigen-) frequency of the chassis mode. In a more general equivalent circuit model the impedance level can be chosen arbitrarily, only enforcing the theoretical resonance frequency and Q-factor of the chassis mode.