Fast Phase Analysis of SAW Delay Lines

Today continuous wave (CW) radar systems have been established as a standard method to interrogate surface acoustic wave (SAW) delay line sensors. They provide an ideal solution with high accuracy and reasonable reading distances for low dynamic measured quantities, which do not change fast in time. But their relatively long reading cycles [1] makes them unsuitable for high dynamic measurements. This paper illustrates a concept of an interrogation principle based on a pulse radar system which allows decreasing the reading cycle of a SAW delay line to a minimum of about 3 mu s given by the physical dimension of the SAW delay line tag itself [2, 3].