Development of an Adaptive Tuning Algorithm for Antennas

Autor : Felix Erckenbrecht
Betreuer : Prof. Dr.-Ing. Stefan Witte
Typ : Master
Forschungsbereich : Industrial Wireless
Kurzbeschreibung :

This thesis describes the theoretical concept, development and evaluation of an adaptive tuning algorithm for automatic antenna tuning units. Intended for applications in the frequency range between 1.5 and 30 MHz, the developed algorithm combines a deterministic and iterative approach for maximum flexibility and adaptivity. Methods known from fuzzy logic and fuzzy set theory are applied to successfully deal with inherent uncertainties of the measurement and matching processes. Yet existent deviations and errors are detected within a subsequent verification and corrected by the iterative part of the algorithm. The deterministic part is based on a mathematical model of the antenna tuning unit, specifically developed for the algorithm within this thesis. During the development of the model, special attention was paid to the representation of the inductances, seen as the most critical component.

The aim of the algorithm development is to attain an impedance match within shortest time, with the only input data, besides the frequency, being the complex reflection coefficient, determined by a directional coupler. Verification and evaluation of the developed algorithm is performed in the end to reveal if the set aims could be achieved. During these test it is also discovered which parts of the algorithm and the model are subject for further investigations and improvements.

Kontakt : Prof. Dr.-Ing. Stefan Witte