Circular Antenna Array With Beam Direction and Polarization Control

In this paper, a circular antenna array is presented for indoor communication. The antenna array consists of 8 dual-polarization antenna elements. At first, the circular antenna array is fed identically, an azimuthal omnidirectional pattern is obtained. Next, the circular antenna array is fed with an optimized distribution of excitations (ODEs) that is calculated with a constrained method of maximum power transmission efficiency (CMMPTE), an azimuthal directional pattern with maximum possible directional gain and desired polarization state is obtained. Experimental and simulation results indicate that the average gain of the omnidirectional pattern ranges from 1.1 to 1.9 dBi for different polarization states, and the maximum gain of the directional pattern is about 9.3dBi for different polarization states with gain fluctuation less than 0.1dB in the azimuth plane. The reported circular array antenna is featured by high directional gain, 360° azimuthal beam continuously scanning, and desired beam polarization state, and it may have potential applications in indoor communications.