Green's function and network analysis of quasi-2D SAW ID-tags

A rigorous analysis of surface acoustic wave tags for wireless identification (ID) systems is developed based on Green's function technique and method of moments. The SAW ID-tags can be fabricated using arbitrary finite reflector structures placed in multiple tracks and channels. From the Green's function solutions, the P matrix parameters for the reflector bits and coupling transducer are deduced. These P matrices are cascaded and interconnected using network analysis to account for the resulting quasi-2D structure. To provide more physical insights into the scattering mechanism, the cascaded network is described in terms of the more illuminating global reflection and transmission coefficients. Simulation of prototype SAW tag configuration is carried out. Response in time domain is presented to show the spurious signals due to multiple reflections.