A mobile terminal can include a printed circuit board with a reference
voltage conductor, an antenna coupled to the first side of the printed
circuit board, and a parasitic resonator coupled to the second side of
the printed circuit board. More particularly, the parasitic resonator can
be connected to the printed circuit board by first and second couplings,
which provide first and second impedances, respectively, between the
parasitic resonator and the reference voltage conductor. The impedances
can be of different values, and can be provided by discrete impedance
components. The resonant frequency of the parasitic resonator can be
adjusted by altering the impedances of the first and second couplings.