Tunable Dual-Band Notch Filters with Triangular Sierpinski Resonators for RF MEMS Applications

In this paper, preliminary resonating dual band notch filters potentially driven by SPDT MEMS structures have been studied for X-Band applications. Triangular resonators have been chosen for this work, taking advantage of the tunability provided by the Sierpinski geometry, while maintaining a fixed edge length and varying the internal complexity. In this case, a first-level Sierpinski triangle and a complete metal patch triangle have been used to get two resonating frequencies, 1.5 GHz apart from each other, approximately within the X-Band. An ideal SPDT with technologically emulated MEMS switches (open and closed lines) and a simplified impedance transformer have been used to demonstrate the feasibility of the device, to be implemented with an optimized transformer and real MEMS switches, but still able to explain the principle of operation.