A tunable filter based on dumbbell metamaterial

摘要

In this paper, based on the metamaterial principle of phase compensation, the broadband and high integration filter is designed. And by using the varactor diode loading technology to change the electromagnetic parameters (relative permittivity and relative permeability), the filter can be tunable in frequency. A dumbbell shaped slot metamaterial filter is designed in this paper. The measured results show that: the filter can be continuously tunable in the X band by loading varactor diode on the unit structure. when the varactor diode increases from 0.1pF to 0.7pF, the center frequency of the filter is decreased from 11.0GHz to 9.1GHz, the bandwidth is 25% (8.7GHz-11.2GHz), and the return loss minimum is 17dB, the insertion loss maximum is 1.2dB.