Accurate Extraction of Equivalent Circuit Parameters for RF Inductors and Capacitors Using Decoupling TRL With Generalized Q -Factor Solution

This article presents a method for the precise extraction of equivalent circuit parameters of surface-mounted inductors and capacitors. First, when testing these components using a microstrip fixture structure, in addition to leveraging the existing thru-reflect-line (TRL) calibration kits and algorithms, it is pointed out that the parasitic effects introduced during the fixture testing process need to be further considered. By modeling the parasitic effects circuitally and utilizing the fixture design information and redundant information in the TRL calibration kits, these parasitic effects are further eliminated to restore the true impedance of the surface-mounted circuit components. Subsequently, the equivalent circuit topology models of inductors/capacitors are, respectively, considered asRLCparallel/RLCseries models. To solve the model parameters for different models based on the accurate impedance obtained above. Existing$Q$-factor solutions have significant limitations, such as the need for interpolation, failure to effectively utilize test frequency information and high vulnerability to noise and errors. A generalized$Q$value solution is proposed to address the abovementioned issues. This solution obtains the optimal model parameters by fitting frequency-domain data. The equivalent circuit parameter extraction methods for inductors and capacitors are verified through simulations and practical measurements, demonstrating that the proposed method significantly outperforms traditional and existing approaches.