Trough and hump phenomenon in a kind of random system

A kind of random system applied simultaneously by the polarizing electric field and microwave field was investigated. The trough and hump phenomenon occurs simultaneously in the transmission spectra at frequency range of 8-12 GHz while microwave scanning the samples. The solid/fluid complex fluid samples are composed of BaTiO₃/silicon oil and microcapsule composite particle/silicon oil. It is seen that the troughs and humps are very similar with photonic band gaps and left-handed metamaterial transmission peaks, which respectively appear in the photonic crystal and left-handed metamaterial. Moreover, the high of troughs and humps also exhibit adjustable characteristics with respect to the external electric field. We think that the trough and hump phenomenon in random system may be originated from the interactions between local oscillation of systems and microwaves field.