Inta's free space nrl arch system and calibration for absorber material characterization

摘要

In order to measure the performance of microwave absorbing materials a broadband free-space measurement system was constructed in INTA. The system is a kind of NRL Arch that give us the possibility of measurements in different configurations. It comprises a set of dielectric loaded rectangular waveguide antennas, coaxial cables, vector analyzer, sample support and a computer. A TRL calibration technique in the plate near field is developed taking advantage of the calibration functions implemented in the network analyzer and the time domain gating. We introduce the use of typical RCS calibration standards as the calibration reflect standards. It gives us the possibility of performing the near field free space calibration in the same way that it is usually done in waveguide, but for directions different to the normal. This calibration allows us to check the edge diffraction behaviour of the samples in the measurement and is thought to be adecuated for thin materials.