Tri-polarized Antenna Research Articles

A Tripolarization Antenna Fed by Proximity Coupling and Probe

The design and characterization of a conformal tripolarization antenna with three independent ports and three orthogonal polarizations is presented. The antenna uses both proximity (slot) coupling and probe-fed ports to reduce isolation and improve polarization purity. The measured bandwidth of the -10-dB return loss is found to be 190 MHz (2.4-2.59 GHz). Measurements across the working bandwidth also show that the isolations among the three ports are better than -16 , -30 , and -40 dB, respectively. Design parameters and experimental results are presented.

On the degrees of freedom in linear array systems with tri-polarized antennas

In this paper, we provide a theoretical, simulation and experimental characterization of the performance of linear arrays of tri-polarized dipole antennas in multiple input multiple output (MIMO) systems in terms of degrees of freedom and channel capacity. Specifically, we formulate three distinct approaches, theoretical and experimental, that lead to the conclusion that linear arrays of tri-polarized dipole antennas employed at the transmit and receive end of a MIMO system can achieve a three-fold increase in channel capacity with respect to analogous arrays of linearly polarized antennas.

Degrees of Freedom in Multiple-Antenna Channels: A Signal Space Approach

Multiple-antenna systems that are limited by the area and geometry of antenna arrays, are considered. Given these physical constraints, the limit on the available number of spatial degrees of freedom is derived. The commonly used statistical multiple-input multiple-output (MIMO) model is inadequate. Antenna theory is applied to take into account the area and geometry constraints, and to define the spatial signal space so as to interpret experimental channel measurements in an array-independent but manageable description of the physical environment. Based on these modeling strategies, for a spherical array of effective aperture A in a physical environment of angular spread |/spl Omega/| in solid angle, the number of spatial degrees of freedom is shown to be A|/spl Omega/| for uni-polarized antennas and 2A|/spl Omega/| for tri-polarized antennas. Together with the 2WT degrees of freedom for a system of bandwidth W transmitting in an interval T, the total degrees of freedom of a multiple-antenna channel is therefore 4WTA|/spl Omega/|.