Computer-controlled scattering measurements in a parallel-plate configuration

This paper describes an instrument developed for the purpose of studying the propagation of microwaves through and scattered by objects of varying dielectric properties. Ultimately, it is hoped that a map of the internal electromagnetic structure of the object can be reconstructed from the measurement of the amplitude and/or the phase of the fields outside the object. For this purpose, the field must be sampled at a large number of points; this is done under computer control using a minicomputer. The geometry of the problem is simplified by performing the measurements in a parallel-plate configuration. The minicomputer controls the data acquisition, storage of the data, and data display. This paper includes a description of the hardware and software components of the system and then illustrates its performance with measured distributions for some object geometries.