the backward radiation, or to shape the radiation beam. Here,
the investigations will be extended to cases of the antennas
surrounded fully or partially by metallic sidewalls. The
antennas with reflectors are proposed to improve their
radiation properties. The CPW-fed slot antenna backed with
the reflector radiates in the broadside direction when the beam
peak is 00. However, due to the reflector, the antennas have
not the uni-directional beam peak at 0° when the antennas
with reflectors operated at 2100 MHz (Fig. 3(b)). Fig. 3(b)
and (c) have multi-lobed patterns. In Fig. 3(b), the antennas
with a 100mm x 100mm reflector and the infinite reflector
have 2 front-lobed patterns at about 600 and 3000, which are
separated by a null along the '
00 axis.