This paper deals with state estimation of micro tunable capacitor subjected to nonlinear electrostatic force. For this end a nonlinear observer has been designed for state estimation of the structure.  Necessary and sufficient conditions for construction of the observer are presented. Stability of the observer is checked using Lyapunov theorem. Observer design is based on converting of differen...

In this paper a novel method is proposed for construction of an exponential observer for nonlinear system. The presented method is based on direct solution of dynamic error without any linearzing of nonlinear terms. Necessary and sufficient conditions for construction of direct observer are presented. Stability of the observer is checked using Lyapunov theorem. Also the ability of this observer...

We present results on the development a new micro electromechanical parallel plate tunable capacitor with a wide tuning range. Different from conventional parallel plate tunable capacitors, this new tunable capacitor consists of one suspended movable top plate and two fixed plates. One fixed plate and the top plate form the variable capacitor, while the other, together with the top plate, is us...

We present results on the development of a novel micromachined parallel-plate tunable capacitor with a wide tuning range. Different from conventional two-parallel-plate tunable capacitors, this novel tunable capacitor consists of one suspended top plate and two fixed bottom plates. One of the two fixed plates and the top plate form a variable capacitor, where as the other fixed plate and the to...

Microwave application of ferroelectrics is very promising for electrically tunable microwave devices based on the electric field dependence of the dielectric permittivity. Tunable filters and controllable phase shifters are successfully designed as integrated circuits based on multilayer structures containing thin epitaxial ferroelectric (FE) film. As a rule lumped ferroelectric capacitors are ...

In this paper, we have proposed and designed the new structure of a RF-MEMS voltage tunable capacitor, which have two-movable parallel plates using electrostatic method and can be fabricated by the MEMS technology. Capacitance of the designed voltage tunable capacitor has from 1.0pF to 1.48pF as the applied bias voltage from 0.5V to 2.52V. The effective area and the distance of the capacitor pl...

In this work a new design of a t u n a b l e c a p a c i t o r b a s e d o n microelectromechanical system (MEMS) technology is presented. The design of high Qtunable capacitor has been accomplished through bulk micromachining process with all metal microstructure. A standard IC fabrication process (HP.5μ) is used to carry out the tunable capacitor. The main features of this high-Q MEMS tunable...

In wireless communication systems, passive elements including tunable capacitors and inductors often need high quality factor ( -factor). In this paper, we present the design and modeling of a novel high -factor tunable capacitor with large tuning range and a high -factor vertical planar spiral inductor implemented in microelectromechanical system (MEMS) technology. Different from conventional ...

This paper reports on the development of a micromachined parallel-plate tunable capacitor with a wide tuning range. Different from conventional two-parallel-plate tunable capacitors, this tunable capacitor consists of one suspended top plate and two fixed bottom plates. One fixed plate and the top plate form a variable capacitor, while the other one provides necessary electrostatic actuation. A...

A tunable dual-band inverted F antenna (IFA) is presented in this paper. By placing a LC resonator on the radiating arm, dual-band characteristic is achieved. Especially, the capacitor in the resonator is a tunable thin-film BST capacitor, which has a 3.3:1 tuning ratio. The capacitance of the BST capacitors can be tuned by an external DC bias voltage. By varying the capacitance, both the lower...