FREE SPACE MEASUREMENT OF PERMITTIVITY AND PERMEABILITY OF MICROWAVE ABSORBING-SHEETS

Abstract

In this dissertation, a technique based on free space measurement of S-parameters is used to calculate permeability (μ) and permittivity (c) of a plate type material. The measurement setup consists of Network analyzer, coaxial cables, coaxial to rectangular waveguide adapters, rectangular to circular waveguide adapters, two antennas, metal carriage and a sample holder. For generation of focused, plane electromagnetic beam two spot focussing antennas have been designed, fabricated and tested.- Theoretical analysis of calculation of μ and e from the measured S-parameters have been done. For "on-line measurement", a Network Analyzer 8720B has been interfaced with PC 386 for data transfer. To calibrate the system In free space, two techniques have been tried. TRL (Through-Reflect-Line) calibration with the domain gating has been suggested to get better results.