Method to optimize a tuning network for mobile terminal antennas

In this paper we present a method to optimize a tuning circuit for an electrically small antenna with regard to the total efficiency (matching and losses) of the entire system consisting of antenna and tuning network. The method aims on optimizing the throughput through the tuning network rather than optimizing only the matching to the 50 Omega transceiver module. This is especially important for small antennas with a small radiation resistance which might be in the order of the parasitic loss components of the lumped SMA tuning elements. Furthermore, the proposed method is developed in a way that does not require measurements of the radiated power of the antenna after each optimization step in order derive the radiated efficiency of the entire system. The method is validated and tested in designing a FM radio antenna integrated into a mobile terminal. Regarding the fact that this is a paper which is about fundamentals we use a 50 Omega source at FM radio frequencies.