Spherical scanned radiation pattern measurement by phase retrieval method

This paper presents spherical scanned radiation pattern measurement by phase retrieval method. We firstly derive near-field to far-field transformation formulas for magnetic near-field distributions measurement, and discuss correct far-field extrapolation using phase retrieval method. A key parameter in this method is to select appropriate probe scanning radius. This paper clarifies optimal distance between two measurement planes by the simulation with a half-wavelength (λ/2) dipole, a 3/2 λ dipole and a handset antenna consisting a folded F-shaped antenna on rectangular ground plane. We also verify the simulation results by measurements.