Mechanically coupled ring-resonator filter and array (analytical and finite element model)

© The Institution of Engineering and Technology 2016. In this paper, a design of two microelectromechanical systems based devices is carried out using an analytical and finite-element analysis. The first device is mechanically coupled ring-resonator band-pass filter with centre frequency of 4.4 MHz and a small bandwidth of only 36 kHz. Flexural-mode ring resonators have been mechanically coupled using soft mechanical spring for realising the filtering action. Owing to inherent symmetry in the ring structure, simple approach is used to access a low-velocity coupling locations to set a smallest possible bandwidth. The authors also show a reduction in the amplitude of spurious mode by accentuating the filter structure in its fully differential mode inherently present in the structure. Moreover, the effect of the number of the support beams and structural damping on the frequency response of a filter has been analysed. A second device is mechanically coupled ring-resonator arrays with varying number of rings coupled. The mechanical links using short stubs connect each constituent resonator of an array to its adjacent ones at the high-velocity vibrating locations to accentuate the desired mode and reject all other spurious modes. Both analytical and finite-element based simulation results for parameters of the designed structure are found in good agreement.status: publishe