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Full-Text Articles in Engineering
Polar Fuzzy Logic Based Power System Stabilizer, D. K. Chaturvedi
Polar Fuzzy Logic Based Power System Stabilizer, D. K. Chaturvedi
D. K. Chaturvedi Dr.
A neuro fuzzy logic based adaptive power system stabilizer (AFPSS) has been developed using angularspeed deviation and angular acceleration as the input variables. It consists of two main parts, namely, fuzzylogic controller (FLC) and generalized neuron (GN) based identifier. The inference mechanism of the fuzzylogic controller is represented by rule-base and a data-base. Three parameters have been introduced to tunethe FPSS. These parameters are decided on the basis of GN-identifier output and present system conditions.This mechanism of tuning the AFPSS makes the fuzzy logic based power system stabilizer adaptive tochanges with the operating conditions. Therefore, the degradation of the system …
Power Handling And Related Frequency Scaling Advantages In Piezoelectric Aln Contour-Mode Mems Resonators, Chengjie Zuo, Matteo Rinaldi, Gianluca Piazza
Power Handling And Related Frequency Scaling Advantages In Piezoelectric Aln Contour-Mode Mems Resonators, Chengjie Zuo, Matteo Rinaldi, Gianluca Piazza
Chengjie Zuo
This paper reports on the analytical modeling and experimental verification of the mechanically-limited power handling and nonlinearity in piezoelectric aluminum nitride (AlN) contour-mode resonators (CMR) having different electrode configurations (thickness field excitation, lateral field excitation, one-port and two-port configurations) and operating at different frequencies (177-3047 MHz). Despite its simplicity, the one-dimensional analytical model fits the experimental behavior of AlN CMRs in terms of power handling capabilities. The model and experiment also confirm the advantage of scaling (i.e. miniaturizing) the AlN CMRs to higher frequencies at which higher critical power density can be more easily attained up to values in excess …
Ultra-Thin Super High Frequency Two-Port Aln Contour-Mode Resonators And Filters, Matteo Rinaldi, Chiara Zuniga, Chengjie Zuo, Gianluca Piazza
Ultra-Thin Super High Frequency Two-Port Aln Contour-Mode Resonators And Filters, Matteo Rinaldi, Chiara Zuniga, Chengjie Zuo, Gianluca Piazza
Chengjie Zuo
This paper reports on the demonstration of a new class of ultra-thin (250 nm thick) Super High Frequency (SHF) AlN piezoelectric two-port resonators and filters. A thickness field excitation scheme was employed to excite a higher order contour extensional mode of vibration in an AlN nano plate (250 nm thick) above 3 GHz and synthesize a 1.96 GHz narrow-bandwidth channel-select filter. The devices of this work are able to operate over a frequency range from 1.9 to 3.5 GHz and are employed to synthesize the highest frequency MEMS filter based on electrically self-coupled AlN contour-mode resonators. Very narrow bandwidth (~ …
Demonstration Of Inverse Acoustic Band Gap Structures In Aln And Integration With Piezoelectric Contour Mode Transducers, Nai-Kuei Kuo, Chengjie Zuo, Gianluca Piazza
Demonstration Of Inverse Acoustic Band Gap Structures In Aln And Integration With Piezoelectric Contour Mode Transducers, Nai-Kuei Kuo, Chengjie Zuo, Gianluca Piazza
Chengjie Zuo
This paper presents the first design and demonstration of a novel inverse acoustic band gap (IABG) structure in aluminum nitride (AlN) and its direct integration with piezoelectric contour-mode transducers. The experimental results indicate that the IABG structure has a stop band from 185 MHz to 240 MHz and is centered around 219 MHz with maximum rejection of 30 dB. The ABG-induced phonon scattering causes a frequency band gap that prohibits the propagation of certain acoustic wavelengths. In this work, the IABG unit cell consists of a high acoustic velocity (V) center material, which is formed by 2-μm-thick AlN sandwiched by …
Aln Contour-Mode Resonators For Narrow-Band Filters Above 3 Ghz, Matteo Rinaldi, Chiara Zuniga, Chengjie Zuo, Gianluca Piazza
Aln Contour-Mode Resonators For Narrow-Band Filters Above 3 Ghz, Matteo Rinaldi, Chiara Zuniga, Chengjie Zuo, Gianluca Piazza
Chengjie Zuo
This paper reports on the design and experimental verification of a new class of thin-film (250 nm) Super High Frequency (SHF) laterally-vibrating piezoelectric microelectromechanical (MEMS) resonators suitable for the fabrication of narrow-band MEMS filters operating at frequencies above 3 GHz. The device dimensions have been opportunely scaled both in the lateral and vertical dimensions in order to excite a contour-extensional mode of vibration in nano features of an ultra-thin (250 nm) Aluminum Nitride (AlN) film. In this first demonstration two-port resonators vibrating up to 4.5 GHz were fabricated on the same die and attained electromechanical coupling, kt2, in excess of …
Demonstration Of Inverse Acoustic Band Gap Structures In Aln And Integration With Piezoelectric Contour Mode Wideband Transducers, Nai-Kuei Kuo, Chengjie Zuo, Gianluca Piazza
Demonstration Of Inverse Acoustic Band Gap Structures In Aln And Integration With Piezoelectric Contour Mode Wideband Transducers, Nai-Kuei Kuo, Chengjie Zuo, Gianluca Piazza
Chengjie Zuo
This paper presents the first design and demonstration of a novel inverse acoustic band gap (IABG) structure in aluminum nitride (AlN) and its direct integration with contour-mode wideband transducers in the Very High Frequency (VHF) range. This design implements an efficient approach to co-fabricate in-plane AlN electro-acoustic transducers with bulk acoustic waves (BAWs) IABG arrays (10x10). The IABG unit cell consists of a cylindrical high acoustic velocity (V) media, which is held by four thin tethers, surrounded by a low acoustic velocity matrix (air). The center media is formed by 2-μm-thick AlN, which is sandwiched by 200-nm-thick top and bottom …
1.05 Ghz Mems Oscillator Based On Lateral-Field-Excited Piezoelectric Aln Resonators, Chengjie Zuo, Jan Van Der Spiegel, Gianluca Piazza
1.05 Ghz Mems Oscillator Based On Lateral-Field-Excited Piezoelectric Aln Resonators, Chengjie Zuo, Jan Van Der Spiegel, Gianluca Piazza
Chengjie Zuo
This paper reports on the first demonstration of a 1.05 GHz microelectromechanical (MEMS) oscillator based on lateral-field-excited (LFE) piezoelectric Aluminum Nitride (AlN) contour-mode resonators. The oscillator shows a phase noise level of –81 dBc/Hz at 1 kHz offset frequency and a phase noise floor of –146 dBc/Hz, which satisfies the GSM requirements of Ultra High Frequency (UHF) local oscillators (LO). The circuit was fabricated in the AMIS 0.5 μm CMOS process, with the oscillator core consuming only 3.5 mW static power. A simple two-mask process was used to fabricate the LFE AlN resonators from 843 MHz to 1.64 GHz with …
Novel Biconical Antenna Configuration With Directive Radiation, M. Shahpari, F. H. Kashani, Hossein Ameri Mahabadi
Novel Biconical Antenna Configuration With Directive Radiation, M. Shahpari, F. H. Kashani, Hossein Ameri Mahabadi
Hossein Ameri Mahabadi
In this paper a novel biconical antenna geometry has been proposed that has directive radiation pattern, higher gain and enhanced front to back ratio. Wide band performance is another characteristic of this new antenna.
Assemble A Ku-Band Frequency Synthesizer, Hossein Ameri Mahabadi, M. Moghavvemi
Assemble A Ku-Band Frequency Synthesizer, Hossein Ameri Mahabadi, M. Moghavvemi
Hossein Ameri Mahabadi
This straightforward design shows how to assemble commercial components into a low-noise 14.4-to-15.5-GHz frequency synthesizer with 625-kHz tuning steps for digital microwave radio systems.
Solar References, Djamila Rekioua