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Full-Text Articles in Engineering

Multi-Frequency Pierce Oscillators Based On Piezoelectric Aln Contour-Mode Mems Resonators, Chengjie Zuo, Nipun Sinha, Jan Van Der Spiegel, Gianluca Piazza Sep 2008

Multi-Frequency Pierce Oscillators Based On Piezoelectric Aln Contour-Mode Mems Resonators, Chengjie Zuo, Nipun Sinha, Jan Van Der Spiegel, Gianluca Piazza

Chengjie Zuo

This paper reports on the first demonstration of multi-frequency (176, 222, 307, and 482 MHz) oscillators based on piezoelectric AlN contour-mode MEMS resonators. All the oscillators show phase noise values between –88 and –68 dBc/Hz at 1 kHz offset and phase noise floors as low as –160 dBc/Hz at 1 MHz offset. The same Pierce circuit design is employed to sustain oscillations at the 4 different frequencies, while the oscillator core consumes at most 10 mW. The AlN resonators are currently wirebonded to the integrated circuit realized in the AMIS 0.5 μm 5 V CMOS process. This work constitutes a …


The Dependence Of Measured Modulation Error Ratio On Phase Noise, Ron D. Katznelson Aug 2008

The Dependence Of Measured Modulation Error Ratio On Phase Noise, Ron D. Katznelson

Ron D. Katznelson

This paper reviews the algorithms used by Vector Signal Analyzers to measure Modulation Error Ratio (MER) and derives the explicit functional dependence of measured MER on phase noise of digital transmitters. The modulation error model is introduced and the analytical expression for key estimated parameters required to obtain MER measure are derived. The essential elements of algorithms employed by MER measurement instruments to estimate amplitude scale, frequency offset, and initial phase intercept and the resulting MER are identified. The frequency response of the effective phase-noise rejection filtering action associated with a given measurement epoch is derived. It is shown that …


Hybrid Ultra-Compact 4th Order Band-Pass Filters Based On Piezoelectric Aln Contour-Mode Mems Resonators, Chengjie Zuo, Nipun Sinha, Carlos R. Perez, Rashed Mahameed, Marcelo B. Pisani, Gianluca Piazza Jun 2008

Hybrid Ultra-Compact 4th Order Band-Pass Filters Based On Piezoelectric Aln Contour-Mode Mems Resonators, Chengjie Zuo, Nipun Sinha, Carlos R. Perez, Rashed Mahameed, Marcelo B. Pisani, Gianluca Piazza

Chengjie Zuo

This work reports on the design, fabrication and testing of a new class of hybrid (filter design using combined electrical and mechanical coupling techniques) ultra-compact (800×120 μm) 4th order band-pass filters based on piezoelectric Aluminum Nitride (AlN) contour-mode microelectromechanical (MEM) resonators. The demonstrated 110 MHz filter shows a low insertion loss of 5.2 dB in air, a high out-of-band rejection of 65 dB, a fractional bandwidth as high as 1.14% (hard to obtain when only conventional electrical coupling is used in the AlN contour-mode technology), and unprecedented 30 dB and 50 dB shape factors of 1.93 and 2.36, respectively. All …


Dual Band Dual Polarized Antenna With High Efficiency For Base Transceiver Stations, F. H. Kashani, M. Shahpari, Hossein Ameri Mahabadi Jan 2008

Dual Band Dual Polarized Antenna With High Efficiency For Base Transceiver Stations, F. H. Kashani, M. Shahpari, Hossein Ameri Mahabadi

Hossein Ameri Mahabadi

In this paper new array element for use in dual band dual polarized antenna will be introduced that has high efficiency (more than 95%) and has high isolation in both 900MHz and 1800MHz bands. Also radiation pattern of this antenna is according to IEC recommendation.


A Novel Bandpass Waveguide Filter Structure On Siw Technology, Z. Sotoodeh, B. Biglarbegian, F. Hojat Kashani, Hossein Ameri Mahabadi Jan 2008

A Novel Bandpass Waveguide Filter Structure On Siw Technology, Z. Sotoodeh, B. Biglarbegian, F. Hojat Kashani, Hossein Ameri Mahabadi

Hossein Ameri Mahabadi

Taking the advantage of common waveguide filters and SIW technology, a new filter structure is proposed.This structure can be implemented for various microwave frequencies by choosing appropriate low loss substrates.An example of suggested structure in Ku band is presented in this paper.The filter is designed and simulated on a low loss RT/Duroid 5880 laminate.The resulted filter has a Quality factor around 150.The main advantage of the structure is low size and cost, simplicity in fabrication, and the ability of integration with other elements of the circuit


Boost-Half Bridge Single Power Stage Pwm Dc-Dc Converter For Pem-Fuel Cell Stack, Khairy F. A. Sayed Dr Jan 2008

Boost-Half Bridge Single Power Stage Pwm Dc-Dc Converter For Pem-Fuel Cell Stack, Khairy F. A. Sayed Dr

Khairy F. A. Sayed Dr

This paper presents the design of 1 kW prototype high frequency link boost half bridge inverter-fed DC-DC power converter with bridge voltage-doublers suitable for small scale PEM fuel cell system and its associated control scheme. The operation principle of this converter is described using fuel cell modeling and some operating waveforms and the switching mode equivalent circuits based on simulation results and a detailed circuit operation analysis and soft-switching conditions.


Etude D'Une Centrale Hybride Photovoltaïque - Éolien - Diesel, Djamila Rekioua Pr Jan 2008

Etude D'Une Centrale Hybride Photovoltaïque - Éolien - Diesel, Djamila Rekioua Pr

REKIOUA Djamila Dr

The electrical energy using renewable hybrids are known, medium-term interest thanks to their flexibility vis-à-vis the primary energy sources. The objective of this work is the study of a hybrid central power, which combines two renewable energy sources (wind, solar) with storage and an emergency generator. The management of different energy sources is ensured by a manager who controls the opening and closing switches, depending on weather conditions (illumination, wind speed).