Free space measurement of complex permittivity and complex permeability of magnetic materials using open circuit and short circuit method at microwave frequencies

For measurements of dielectric materials, we have developed a free-space measurement system in the frequency range of 8 - 12.5 GHz. The key components of the measurement system are a pair of spot-focusing horn lens antennas, the network analyzer and the coaxial cables. In this project the objective is to analyze and measure the complex reflection coefficients of the dielectric materials such as carbonyl iron powder loaded silicon rubber sheets and PVC using short circuit and open circuit method at microwave frequencies. The thru, reflect and line 2 (LRL) calibration technique were used to eliminate the effects of undesirable multiple reflections. By implementing an algorithm which been derived from open circuit and short circuit which is defined from the transmission line equations the dielectric constants and the complex permeability were calculated from the measured reflection coefficients.