Comparative Measurements and Inverse Source Technique for Validation of Compact Cylindrical NF Ranges

The spherical near-field antenna measurement system StarLab has evolved to cover the entire frequency band from 800MHz to 18GHz [1, 2, 3]. The system is based on patented probe array technology and the Advanced Modulated Scattering Technique (A-MST) [4, 5]. The StarLab system offers the speed advantages of a probe array, while the mechanical rotation in elevation allows for unlimited angular resolution over the full 3D sphere. By adding a linear scanner, the StarLab system can be converted to a compact cylindrical near field measurement system, as shown in Figure 1. This system is particularly well-suited for measurements of base stationsand other sectorial type array antennas. This paper describes the innovative design aspects of the StarLab portable antenna measurement system, with emphasis on the cylindrical near-field measurement capabilities. The system validation testing has been performed using the inverse source technique [9-11] and with comparative measurement campaigns, including both multiprobe and other traditional (single probe) measurement facilities.