A radio transmitting or receiving antenna which is physically compact
being typically no more than three percent of a wavelength in any
dimension. The antenna comprises two electrical conducting surfaces (2)
and (4) across which radio frequency electric field lines carrying half
the power are arranged to cross radio frequency magnetic field lines
carrying the remaining half power to thereby synthesize and propagate
radio waves. The low impedance coaxial feeder (1) from the transmitter
flows through a set of coils (3A) to (3D) wired in parallel and lying in
a toroidal shape to create a circular RF magnetic field H and then enters
a low impedance tap on a resonant autotransformer used to connect a high
RF voltage and create a curving electromagnetic field E across the
interaction zone in the volume between the upper metal cylinder (4) and
the ground plane (1).