Antenna Tuning Closed Loop Implementation Using S-Matrix Approach

Nowadays, modern communication systems like mobile phones use antennas that are compact, multi-band, located inside the mobile phone and regularly covered by hand or head. In the meanwhile, the space allocated to them tends to decrease due to the needs of other components and the struggle for reduced overall device size. Furthermore, mobile antennas are very difficult to be fully matched. Up to 80% of energy delivered to antenna returns back and disappears as heating, resulting, amongst others, in call drops, mobile phone heating and higher battery consumption. As a result, the traditional radiating performance goals of antennas are becoming increasingly challenging. In this paper a novel implementation of an antenna tuning closed loop model is presented using Scattering Matrix (S-matrix) approach. This approach uses an antenna tuner as a centric tuning element, it is based on the S-matrix that is a universal metric and achieves a significant improvement in impedance matching and return loss.