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This paper presents a new characterization method to measure the RF power handling of capacitive RF MEMS switches. Historically, the RF power handling was characterized by analyzing the pull-in and release voltage shift under several RF power settings. However, this technique is problematic especially because of possible charging under high DC voltages. We present a new measurement setup that includes...
This paper presents a trimming correction technique to calibrate the offset in capacitive readout circuits of MEMS sensors. The technique relies on a N-bit digital voltage divider which allows to implement an equivalent variable capacitor with sub-femto Farad step variations. To reduce area occupation, a hybrid approach entailing both resistive and capacitor voltage dividers is introduced. Design...
This paper presents the energy analysis of capacitive adiabatic logic (CAL) based on gap-closing MEMS devices. CAL uses variable capacitance components instead of transistor elements to have a new balance between on- and off-state losses. Ultra-low power consumption in CAL requires an energy efficient way for charging and discharging of the variable capacitance. First, we investigate “pure” electrical...
Piezoelectric harvesters have been subject to a growing interest in recent years as they can provide a clean source of energy. To extract the power from the harvester, power conditioning circuits are required. In this article, a circuit is proposed to meet the requirements of relatively high efficiency, low voltage operation, good load regulation and sufficient DC output voltage. A combined cross-coupled...
This paper investigates a class of electrical generators based on capacitors and diodes, with two capacitors being variable. Their main characteristics are a symmetrical structure and that they produce two outputs with the same polarity. The simplest version is analyzed in more detail, although in an approximate way, and generalizations of it are obtained, identified with a particular form of two-phase...
We report on a tunable terahertz bandpass filter based on a cross-shaped slot resonator with a reconfigurable roll-up micro structures. The built-in capacitors within the resonator are electrostatically actuated to shift the resonant frequency.
This paper presents a switched-bias MEMS microphone preamplifier for an ultra-low-power voice interface. A switched-MOSFET periodically changes the MOSFET between strong inversion and accumulation to inherently reduce 1/f noise. In addition, a proposed coupling capacitor allows the microphone to benefit from a high bias voltage while the preamp can use a low VDD. The preamp achieves 7.3μVrms input...
This paper presents a Capacitive-to-Digital Converter (CDC) for MEMS sensors using a time-encoding approach. A common CDC needs an intermediate Capacitive-to-Voltage (CV) stage to perform such a conversion. Instead, this architecture directly transforms the sensor capacitor quantity to a digital value. Additionally it is intended to give flexibility at reduced chip area. The proposed solution maps...
This demonstration shows a variable-capacitance electrostatic generator made with 3D-printing techniques powering loads through a DC/DC converter. The generator is similar in structure to a microelectromechanical device, and forms an unstable electrostatic generator when connected to a 2-phase diode-capacitor voltage multiplier. As load, a simple bidirectional digital wireless communication system...
This paper presents an ultra-low-power low-noise Capacitively-coupled Chopper Instrumentation Amplifier (CCIA). A current-reuse telescopic topology in the first stage along with a recycling folded-cascode topology in the second stage consumes net bias current of 26μΑ with enhanced efficiency and achieves an input-referred noise power-spectral-density of 12.77nV/√Hz. The proposed CCIA is chopped at...
21st Century has seen a paradigm shift in use of technology and the thoughts of using the natural sources for energy has led to thinking of using the energy wasted around us, in technical term, we can say harvesting of the energy. The paper aims at covering various techniques used in harvesting energy with focus on cantilever based energy harvesting. Interestingly the vibrations can be captured and...
This paper presents a power management system of self-supplied wireless sensor node based on MEMS electret vibrational energy harvester. The storage and control policy of the management circuit is optimized for small ambient excitation conditions to reduce power dissipation and avoid failure in wireless data transmissions. Live acceleration data collected from a bridge as well as simulation results...
This paper presents a wideband distributed coplanar waveguide (CPW) phase shifter for S-band operation. A 3-bit distributed MEMS transmission line (DMTL) phase shifter is developed by periodically loading MEMS shunt switches on a CPW transmission line (TL). A total of 105 MEMS shunt switches are utilized in the design to provide phase shifts of 0°, 45°, 90°, 135°, 180°, 225°, 270° and 315° at 2.45...
This paper presents a robust triangular-electrode based (TEB) capacitive detection method for MEMS gyroscopes. The TEB method utilizes the inherent nonlinearity of TEB variable-area sense capacitor to measure the amplitude and the phase of mechanical motion, and the derived amplitude and phase are independent of such system parameters as the carrier voltage, the nominal sense capacitance, the gain...
In this paper, a wideband distributed coplanar waveguide (CPW) phase shifter has been designed for S-band operation. The phase shifter is developed on a high impedance CPW transmission line periodically loaded with microelectro-mechanical system (MEMS) shunt switches. To reduce the insertion loss due to the transmission line, a 525 µm high resistivity silicon substrate (ρ=10 kΩ·cm) and 2 µm thick...
Micro-electro-mechanical frameworks (MEMS) Technology has risen as a key methodology for building low-misfortune stage shifters, which is crucial for cutting edge radar and correspondence frameworks. This MEMS innovation is utilized as a part of stage shifters, which are vital for advanced telecom, car, and protection applications. The principle idea here is to evacuate every single existent capacitance...
We report multiphysics simulation results for paraffin variable capacitors integrated with bent slot antenna to form a frequency reconfigurable structure. Paraffin is a phase change material that its solid-to-liquid transition exhibits a 15% volumetric change. In addition to its mechanical properties, paraffin is an organic low-dielectric-loss material (tan δ = 0.003, εr = 2.26 at 300 GHz) which is...
A novel MEMS variable capacitor having two level suspended beams is proposed. The addition of another beam considerably extends the maximum possible displacement, which in turn increases the capacitor tuning range. The tuning was simulated using CoventorWare and found to be 670%. The achievable tuning range far exceeds that of traditional MEMS variable capacitors of the same type. The proposed MEMS...
This paper presents the implementation of a MEMS tunable inductor using admittance J-inverters and a variable capacitor. The tunable inductor circuit consists of two inductors, two fixed capacitors and a variable capacitor. The MEMS tunable inductor has been fabricated using the CRONOS MUMPs® Process. Design details and results are presented for a tunable inductor designed to operate over a bandwidth...
A study is presented about some structures of electrical generators based on variable capacitors, suitable for energy harvesting applications, and compatible with construction as microelectromechanical systems. In the discussed structures, part of the generator has as function the generation of a high biasing voltage, and another part, a capacitive divider where one of the capacitors is variable,...
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