A radio antenna arrangement disposed in the conductive surface of a vehicle consisting
of a substantially rectangular aperture having aperture length L and width B, wherein
said aperture length L is sufficiently small so that the self-resonant frequency
of the aperture is greater than the center frequency of the operating frequency
range. There is a capacitive tuning element disposed in the aperture for tuning
the aperture to a resonant frequency to approximately the center frequency of the
operating frequency range. The capacitive tuning element serves as capacitive connection
between the edges of the aperture, and is formed as a low-inductance element, so
that due to the residual inductive effect, the remaining magnetic reactive power
is as small as possible relative to the magnetically generated reactive power from
the magnetic fields in the aperture. An input coupling element is also disposed
in the aperture for coupling the antenna connection point to the resonance like
high electromagnetic fields.
