Linear polarization switchable microstrip array antenna using Magic-T circuit

Recently, the planar antenna technologies have been advancing due to the increasing demands for various wireless applications in the ubiquitous society. Furthermore, reconfigurable planar antennas have attracted much more attentions because of their versatility in various wireless systems in terms of frequency controllability and polarization diversity [1]. In this paper, an orthogonal linear polarization switchable microstrip four-element array antenna is proposed. The proposed antenna having a polarization switching function provides high design flexibility for wide variety of radio systems. In order to switch the polarization, the boundary condition of the array antenna is controlled by me ON/OFF condition of the diodes mounted on each antenna element. Magic-T circuits employing Both-sided MIC technology are effectively used to isolate the switching signal from RF signal [2].