An electronic device, such as a mobile radiotelephone, includes a dual
antenna structure with a selectively actuatable phase shifter disposed
therebetween. When the selectively actuatable phase shifter is selected,
signals received by the first and second antennas are substantially out
of phase. When the selectively actuatable phase shifter is not selected,
signals received by the first and second antennas are substantially in
phase. The dual antennas are coupled to a first electrical circuit
disposed in a first section of the device. A second electrical circuit is
disposed within a second section of the device. An impedance element, for
example an inductor, couples the first and second electrical circuits and
is disposed in a substantially symmetric location between the first and
second electrical circuits. Working in combination, when the selectively
actuatable phase shifter is selected, an antenna pattern of the device
becomes substantially azimuthal with a null at a top central location.
When the selectively actuatable phase shifter is not selected, the
antenna pattern becomes substantially uniform with a zenith atop the
upper lobe.