Naturally non-selective handset antennas with good robustness against impedance mistuning

An experimental study on capacitive coupling element based mobile terminal antennas is presented, with focus on impedance detuning caused by the electromagnetic interactions between the antenna and the user of the handset. Robustness against the detuning can be affected both with the design of the coupling element and with the design of the matching circuitry. With a naturally non-selective antenna and a suitable matching circuit design, the impedance detuning can be limited to a moderate level.