GA-tuned microelectromechanical filters for signal processing

Microelectromechanical systems (MEMS) are the integration of mechanical elements, sensors, actuators, and electronics on a common silicon substrate through the utilization of microfabrication technology. These filters consist of miniature mechanical vibrating elements such as capacitively coupled beams or thin-film bulk acoustic resonators. In this paper, the design of a microelectromechanical series bandpass filter is done by (i) first designing a digital bandpass filter of transfer function H(z), (ii) tuning the digital BPF for minimum order and minimum MSE in the pass-band and stop-band using the genetic algorithm (GA). (iii) relating the tuned digital BPF coefficients with the microelectromechanical filter geometry parameters, (iv) realizing the resultant microelectromechanical filter structure and (v) finally obtaining the frequency response of the microelectromechanical filter. The parameters are tuned using GA to have high Q values. The obtained frequency response of the designed filter promises good performance over the operating frequency range. The different factors that influence the performance of the filter are also discussed in the paper. The obtained frequency response shows that the parameter optimization process is invariant as the coefficients are transformed from the digital to the microelectromechanical domain.