Input impedance antenna automatic matching system

This paper presents a new design for an input impedance antenna automatic matching system. In order to achieve this main objective, it is necessary to accomplish several intermediate tasks. On the one hand, a study about the implementation of a generic electronically tunable impedance synthesizer is carried out. Then, a prototype based on the research is constructed, and its characteristics and improvements are evaluated. On the other hand, a fully automatic system is developed. The device is integrated inside a commercial handset mobile radio communications equipment, in order to evaluate the improvements achieved with the automatic system. At this point, experimental results about human body influence on the input impedance of helical and monopole antennas are presented for the 380-400 MHz frequency band. Several control methods are studied.