Broadband Conductivity Measurement Method up to 110 GHz Using a Balanced-Type Circular Disk Resonator

We propose a method for measuring the electrical conductivity of metallic disks in the microwave and millimeter-wave bands by using a balanced-type circular disk resonator (BCDR). Because only the TM0m0 modes can be selectively excited in the BCDR, this technique provides broadband conductivity measurements from less than 20 GHz up to over 100 GHz with a single resonator by utilizing higher-order mode resonances. To experimentally demonstrate the proposed method, we measure the conductivities of two metallic disks made of brass and SUS and evaluate those uncertainties up to 110 GHz.