Pull-in instability as an inherently nonlinear and crucial effect continues to become increasingly important for the design of electrostatic MEMS and NEMS devices and ever more interesting scientifically. This review reports not only the overview of the pull-in phenomenon in electrostatically actuated MEMS and NEMS devices, but also the physical principles that have enabled fundamental insights into the pull-in instability as well as pull-in induced failures. Pull-in governing equations and conditions to characterize and predict the static, dynamic and resonant pull-in behaviors are summarized. Specifically, we have described and discussed on various state-of-the-art approaches for extending the travel range, controlling the pull-in instability and further enhancing the performance of MEMS and NEMS devices with electrostatic actuation and sensing. A number of recent activities and achievements methods for control of torsional electrostatic micromirrors are introduced. The on-going development in pull-in applications that are being used to develop a fundamental understanding of pull-in instability from negative to positive influences is included and highlighted. Future research trends and challenges are further outlined.

Electrostatic pull-in instability in MEMS/NEMS: A review

IEEE International Solid-State Circuits Conference

This expanded and thoroughly revised edition of Thomas H. Lee's acclaimed guide to the design of gigahertz RF integrated circuits features a completely new chapter on the principles of wireless systems. The chapters on low-noise amplifiers, oscillators and phase noise have been significantly expanded as well. The chapter on architectures now contains several examples of complete chip designs that bring together all the various theoretical and practical elements involved in producing a prototype chip. First Edition Hb (1998): 0-521-63061-4 First Edition Pb (1998); 0-521-63922-0

The Design of CMOS Radio-Frequency Integrated Circuits: RF CIRCUITS THROUGH THE AGES

Transceiver architecture selection: Review, state-of-the-art survey and case study

We show that graphene-percolated polymer composites exhibit fractional capacitance response in the frequency range of 50 kHz–2 MHz. In addition, it is shown that by varying the loading of graphene within the matrix from 2.5% to 12%, the phase can be controllably tuned from −67° to −31°, respectively. The electrostatic fractional capacitors proposed herein are easy to fabricate and offer integration capability on electronic printed circuit boards.

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Microscale electrostatic fractional capacitors using reduced graphene oxide percolated polymer composites

A 12th-order OTA-C complex filter with a nonconventional frequency tuning for a Bluetooth receiver is implemented in a low-cost mainstream 0.35-/spl mu/m CMOS process. This proposed frequency tuning scheme is simpler than the conventional one based on phased-locked loop (PLL). Furthermore, a high-speed pseudo differential OTA using common-mode feedforward (CMFF) and common-mode feedback (CMFB) strategy is proposed. The filter bandwidth is 1 MHz and is centered at 2 MHz. Image and adjacent channels are attenuated by more than 45 and 27 dB, respectively. The integrated input referred noise is 29 /spl mu/V/sub rms/, and the filter chip dissipates 4.7 mA from a 2.7 V supply. The theoretical and experimental results are in good agreement.

A pseudo differential complex filter for Bluetooth with frequency tuning

This paper studies analytically and numerically the spring softening and hardening phenomena that occur in electrostatically actuated microelectromechanical systems comb drive resonators utilizing folded suspension beams. An analytical expression for the electrostatic force generated between the combs of the rotor and the stator is derived and takes into account both the transverse and longitudinal capacitances present. After formulating the problem, the resulting stiff differential equations are solved analytically using the method of multiple scales, and a closed-form solution is obtained. Furthermore, the nonlinear boundary value problem that describes the dynamics of inextensional spring beams is solved using straightforward perturbation to obtain the linear and nonlinear spring constants of the beam. The analytical solution is verified numerically using a Matlab/Simulink environment, and the results from both analyses exhibit excellent agreement. Stability analysis based on phase plane trajectory is also presented and fully explains previously reported empirical results that lacked sufficient theoretical description. Finally, the proposed solutions are, once again, verified with previously published measurement results. The closed-form solutions provided are easy to apply and enable predicting the actual behavior of resonators and gyroscopes with similar structures.

Nonlinear Dynamics of Spring Softening and Hardening in Folded-MEMS Comb Drive Resonators

A fully integrated CMOS low-IF Bluetooth receiver is presented The receiver consists of a radio frequency (RF) front end, a phase-locked loop (PLL), an active complex filter, a Gaussian frequency shift keying (GFSK) demodulator, and a frequency offset cancellation circuit The highlights of the receiver include a low-power active complex filter with a nonconventional tuning scheme and a high-performance mixed-mode GFSK demodulator The chip was fabricated on a 625-mm/sup 2/ die using TSMC 035-/spl mu/m standard CMOS process -82 dBm sensitivity at 1e-3 bit error rate, -10 dBm IIP3, and 15 dB noise figure were achieved in the measurements The receiver active current is about 65 mA from a 3-V power supply

A 3-V, 0.35-/spl mu/m CMOS Bluetooth receiver IC

A unified system-level design methodology for highly integrated CMOS radio frequency receiver design is introduced. This complete system-level design methodology is targeted to minimize the total power consumption of the receiver. System-level design techniques which can be used to derive the overall receiver radio specifications and study noise and linearity performance of receivers are presented. Then, a few circuit examples of building blocks in receiver signal chain are analyzed to show a linear relationship between power and dynamic range of the blocks. The result is then used to derive the optimal system specification distribution among receiver signal chain building blocks yielding the minimum total receiver power consumption for a given system performance. The theory and an actual CMOS Bluetooth receiver design are compared showing very good agreement.

CMOS RF receiver system design: a systematic approach

Due to the non-idealities of commercial inductors, the demand for a better model that accurately describe their dynamic response is elevated. So, the fractional order models of Buck, Boost and Buck-Boost DC-DC converters are presented in this paper. The detailed analysis is made for the two most common modes of converter operation: Continuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM). Closed form time domain expressions are derived for inductor currents, voltage gain, average current, conduction time and power efficiency where the effect of the fractional order inductor is found to be strongly present. For example, the peak inductor current at steady state increases with decreasing the inductor order. Advanced Design Systems (ADS) circuit simulations are used to verify the derived formulas, where the fractional order inductor is simulated using Valsa Constant Phase Element (CPE) approximation and Generalized Impedance Converter (GIC). Different simulation results are introduced with good matching to the theoretical formulas for the three DC-DC converter topologies under different fractional orders. A comprehensive comparison with the recently published literature is presented to show the advantages and disadvantages of each approach.

Ahmed Emira

Papers

A pseudo differential complex filter for Bluetooth with frequency tuning

Nonlinear Dynamics of Spring Softening and Hardening in Folded-MEMS Comb Drive Resonators

A 3-V, 0.35-/spl mu/m CMOS Bluetooth receiver IC

CMOS RF receiver system design: a systematic approach

Modeling and analysis of fractional order DC-DC converter.