Proximity-Coupled Graphene-Patch-Based Tunable Single-/Dual-Band Notch Filter for THz Applications

A tunable single-/dual-band notch filter is proposed for THz applications. The filter geometry contains a proximity-coupled graphene patch. The filter structure operates with propagating- and nonpropagating-type transverse magnetic (TM) modes. Different higher-order TMmn (where m and n are integers) modes can be excited in the filter structure by changing the aspect ratio of the graphene patch, thus enabling the filter response to be tuned to obtain single- or dual-band notch characteristics. Appropriate selection of the physical parameters of the filter structure allows the desired response at different frequencies to be obtained. Furthermore, the response of the proposed band notch filter can be tuned over frequency by changing the chemical potential of the graphene.