Advances in Characterising Dielectric Materials at Microwave Frequencies Using Circular Open Waveguides

The dielectric characterisation method using an open circular waveguide radiating into a material is a well‐known method that offers many advantages but also has certain disadvantages that limit its use. The main disadvantages are the presence of multiple solutions during extraction and a calibration method that could be improved. Our studies have led to solutions that allow convergence towards a unitary solution and improvement of the calibration technique for better accuracy on the phase of the structure's reflection coefficient and calibration without specific contacts with the guide flange.