Chamber Array Antenna Layout for Compact OTA Measurements

An optimized irregular planar array antenna layout with uniform excitation of antenna elements is presented for Random-LOS OTA (Random Line-Of-Sight Over-The-Air) characterization setups. A plane wave is synthesized within a cylindrical 3D test zone at 2.7 GHz, which can be scaled to mmWave frequencies. The obtained thinned array achieves a 52% reduction of the number of elements and a 45% aperture size as compared to a uniform fully populated planar array with an inter-element distance of 0.93 \lambda, which is the optimum distance through [\lambda / 2,\lambda] based on the presented cost function at this paper. The obtained maximum phase deviation and the maximum field amplitude deviation from the average field distribution in the 3D test zone of the proposed optimized chamber array antenna layout are approximately 6.4° and 3.9 dB, respectively. The numerical computation of the radiation pattern of a 10 \times 10 element uniform planar array antenna as AUT (Antenna Under Test) placed within the test zone was performed too. Results show a rather good agreement between the radiation pattern to that obtained assuming far-field conditions