A system for determining characteristics of a specific region within an inhomogeneous dielectric specimen by guiding propagation of electric fields through the inhomogeneous dielectric specimen is provided herein. Various embodiments include at least one source of electromagnetic energy for generating electromagnetic waveforms, the electromagnetic waveforms comprising electric fields propagating along a prescribed path that defines a series of spatial regions through which the electric fields propagate. In some embodiments the prescribed path includes electric field modulating elements that determine a rate of electric field propagation along the prescribed path. Some embodiments include a plurality of conductors for guiding the electric field propagation through an inhomogeneous dielectric specimen in the prescribed path, the electric fields spanning between two or more of the plurality of conductors as the electric fields propagate along the prescribed path. In some embodiments the plurality of conductors are external to the inhomogeneous dielectric specimen.
