A Compact Polarization and Pattern Reconfigurable Patch Antenna by Digital Coding Method

A compact array antenna employing polarization and radiation pattern reconfigurable with digital coding method is presented. The antenna unit consists of a square patch loaded by four 1-pf capacitors and four switchable feeding ports which are controlled by a field-programmable gate array (FPGA). By designing the coding modes of the digital radiating units, four different radiation beams with three linear polarization states of (+45 degrees-LP, -45 degrees-LP, and V-LP) can be realized by switching the corresponding coding sequences.