A planar switched-beam antenna with compact size

A planar pattern reconfigurable patch antenna is proposed. The proposed antenna is a circular array composed of three radiating elements, and each element can generate a horizontally polarized main beam with a half-power beamwidth of about 135 degrees. To switch the beam direction, a single-pole three-through circuit is designed on the same printed circuit board as the radiating elements, and the total area of the integrated planar antenna is a circular shape of diameter 0.37 lambda 0. A prototype operated at 2.45 GHz is constructed, and the measured results demonstrate that the pattern reconfigurable antenna can give three steerable beams in the E plane, and the gain and the front-to-back ratio of each beam are 3.2 dBi and 15 dB, respectively; moreover, an operation bandwidth of more than 10% is also achieved. Simulated analyses are also performed to explain the antenna performances mentioned above, and they have good agreements with the experimental data.