Antenna miniaturisation and broadband design via a decomposition of structure into conjugated elemental antennas for natural impedance matching

This study introduces a useful technique for an effective antenna design to achieve size miniaturisation or broadband operation. The key idea is the decomposition of the antenna structure into several elemental parts having naturally conjugate input reactance values. Each of the decomposed elemental parts serves as both the matching element and radiator simultaneously, instead of simply being lumped components such as capacitors or inductors. Since the matching element has a reactance conjugate to that of the original antenna, the integrated structure via the connection of these elements in series or parallel will be able to achieve a natural resonance, allowing one to either miniaturise the antenna by using small-sized elements, or achieve a broadband operation if the impedance variations of these elements are similar.