A CPW T-Resonator Technique for Electrical Characterization of Microwave Substrates

The microstrip T-resonator is a well established tool for determining broadband electrical properties of microwave materials, namely effective dielectric constant and attenuation. In this paper finite ground coplanar waveguide (CPW) T-resonators on high resistivity silicon are presented and evaluated. The multi-moding seen in CPW T-junctions is effectively eliminated through the use of gold wire bonds. The calibration independence of the CPW T-resonator technique is demonstrated and the predicted impedance independence of the CPW “T” is experimentally validated. The electrical property results obtained using the T-resonator on high resistivity silicon substrates are in good agreement with data from other characterization techniques. The CPW T-resonator is thus shown to provide rapid and accurate characterization of integrated microwave substrates.