Frequency tuning in electromagnetic bandgap nonlinear transmission lines

Frequency tuning in stopband filters based on nonlinear transmission lines is demonstrated for the first time. The structure is an electromagnetic bandgap (EBG) coplanar waveguide reflector periodically loaded with varactor diodes, acting as tuning elements. By varying the capacitance of the diodes the phase velocity can be tailored, the result being a wide tuning range for the central frequency of the rejected band. It was also found that the EBG-based reflector is able to inhibit harmonic generation under large-signal driving conditions.