Coplanar waveguide structure

The test results suggest that the fuel cell seal variant which contains the coplanar waveguide structure is probably a better candidate than the microstrip variant for the goal of designing a seal that might be indicative of defects or precursors to seal failure, as the sample-to-sample variability is much greater in the microstrip variant. 

Coplanar waveguide structures are used for transmission line-based sensing methods. Booth et al. used the coplanar waveguide structure between the microfluidic channel and the quartz substrate. The microfluidic channel and the transmission line are aligned so that the microwave power propagation and the fluid flow directirui are orthogruial as shown in Fig. 8. As a result, the microwave power experiences three types of transmissirui fines ... 

Microwave in Microfiuidics, Fig. 8 The coplanar waveguide used for characterization of liquids in microchannels [6]. The channel is bonded on top of the coplanar waveguide and fluid flow is perpendicular to the microwave power flow. As a result the transmission line parameters are different in regions covered by PDMS and the channel. The same structure is simulated and the complex permittivity that gives the same results as the measurement is found... 

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