A method for measuring the scattering patterns of materials by means of UHF TV broadcasting waves (in the case of oblique incidence)

The authors previously proposed an accurate method for promptly measuring the scattering patterns of materials with low reflectivity (see Proc. Int. Symposium Antennas & Propagation, Japan, vol.4, p.933-6, 1989). It utilizes the concept of determining the far-field scattering pattern of a material from a knowledge of the near-field by using Huygens´s principle. In practical measurements, the UHF TV broadcasting wave (video carrier frequency 669.25 MHz, TM incidence) is used as a main incident wave. In the previous paper, the experimental results in the case of normal incidence were presented and discussed. In this paper, the error on the scattering pattern in the case of oblique incidence is examined. And the experimental results for a metal plate and a zigzag shaped absorber in the case of incident angle 30° are presented and discussed