De-embedding of Contact Pads Parasitics in RFMEMS resonators for 5G Applications

To remove the parasitic reactance in wafer-level measurement of MEMS resonators and derive the relationship between the size of the resonator and how parasitic reactance can affect the performance of the resonator, the line-to-line de-embedding method is applied to the measurement results of resonators with the area of approximate 20000 µm ² and 10000 µm ² . The line-to-line method is found to be efficient in RF measurement, with a small chip area requirement. The parasitic reactance at high frequency mainly consists of resistive and inductive components and helps to reduce the resonance frequency and increase the resonance impedance of the resonator hence reduction in coupling coefficient is observed after de-embedding for all resonators. Moreover, resonators with large device areas tend to be more affected by the parasitic reactance at high working frequency compare to the smaller ones.