Edinburgh Napier University

  This paper presents an approach to implement an automatically tuning antenna for optimising power transfer suitable for software defined radio (SDR). The automatic tunability of the frequency selective antenna is achieved by a closed-loop automatic antenna tuning network comprising of an impedance sensor and control unit. The sensor provides the control unit with data on the transmit or receive power, and the an algorithm is used to impedance of a T-network of LC components to optimize the antenna impedance to maximise power transmission or reception. The effectiveness of the proposed tuning algorithm in terms of impedance matching and convergence on the optimum matching network values is shown to be superior compared with the conventional tuning algorithm.