Microwave response phase control of a graphite microstrip

Interaction between a carbon based low-conductivity graphite microstrip, which is an element of a metamaterial, and incident electromagnetic (EM) waves was investigated in the microwave range of frequency (8-12 GHz). The distribution of the magnetic near-field visualized by a non-contact thermoelastic optical indicator microscope, has three localization centers which vary significantly depending on the conductivity of the graphite microstrip. In the case of high resistance, the EM field was mostly localized near the microstrip. With decrease of resistance, new localization zones of EM field were formed, the intensity of which was constantly increased, and continuously decreased near the microstrip. Analysis of images resulting from the superposition of incident and scattered waves reveals a significant increase in the scattered wave phase-shift due to an increase in the conductivity of the graphite microstrip. A metamaterial consisting of elements with such regulated conductivity can serve as a phasetuning system for radiation control.