SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Yantchev Ventsislav) "

Sökning: WFRF:(Yantchev Ventsislav)

  • Resultat 1-10 av 82
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Anderås, Emil, 1982- (författare)
  • Advanced MEMS Pressure Sensors Operating in Fluids
  • 2012
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Today’s MEMS technology allows manufacturing of miniaturized, low power sensors that sometimes exceeds the performance of conventional sensors. The pressure sensor market today is dominated by MEMS pressure sensors.In this thesis two different pressure sensor techniques are studied. The first concerns ways to improve the sensitivity in the most commonly occurring pressure sensor, namely such based on the piezoresistive technique. Since the giant piezoresistive effect was observed in silicon nanowires, it was assumed that a similar effect could be expected in nano-thin silicon films. However, it turned out that the conductivity was extremely sensitive to substrate bias and could therefore be controlled by varying the backside potential. Another important parameter was the resistivity time drift. Long time measurements showed a drastic variation in the resistance. Not even after several hours of measurement was steady state reached. The drift is explained by hole injection into the buried oxide as well as existence of mobile charges. The piezoresistive effect was studied and shown to be of the same magnitude as in bulk silicon. Later research has shown the existence of such an effect where the film thickness has to be less than around 20 nm. The second area that has been studied is the pressure sensitivity of in acoustic resonators. Aluminium nitride thin film plate acoustic resonators (FPAR) operating at the lowest-order symmetric (S0), the first-order asymmetric (A1) as well as the first-order symmetric (S1) Lamb modes have been theoretically and experimentally studied in a comparative manner. The S0 Lamb mode is identified as the most pressure sensitive FPAR mode. The theoretical predictions were found to be in good agreement with the experiments. Additionally, the Lamb modes have been tested for their sensitivities to mass loading and their ability to operate in liquids, where the S0 mode showed good results.Finally, the pressure sensitivity in aluminium nitride thin film bulk wave resonators employing c- and tilted c-axis texture has been studied. The c-axis tilted FBAR demonstrates a substantially higher pressure sensitivity compared to its c-axis oriented counterpart. 
  •  
2.
  • Anderås, Emil, et al. (författare)
  • Lamb wave resonant pressure micro-sensor utilizing a thin-film aluminium nitride membrane
  • 2011
  • Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 0960-1317 .- 1361-6439. ; 21:8, s. 085010-
  • Tidskriftsartikel (refereegranskat)abstract
    • In this work, pressure sensitivities of aluminium nitride (AlN) thin film plate acoustic resonators (FPAR) operating at the lowest-order symmetric (S0), the first-order asymmetric (A1) as well as the first-order symmetric (S1) Lamb modes are theoretically and experimentally studied in a comparative manner. The finite element method analysis has also been performed to get a further insight into the FPAR pressure sensitivity. The theoretical predictions are found to be in good agreement with the experiment. The S0 Lamb mode is identified as the most pressure-sensitive FPAR mode, while the A1 and S1 modes are found to be much less sensitive. Further, the S0 and the A1 modes exhibit almost equal temperature sensitivities, which can be exploited to eliminate the temperature drift by comparing the resonance frequencies of the latter two modes.
  •  
3.
  • Anderås, Emil, et al. (författare)
  • Thin Film Plate Wave Resonant Sensor for Pressure and Gravimetric Measurements
  • 2011
  • Ingår i: Procedia Engineering 25, Eurosensors XXV. - : Elsevier. ; , s. 571-574
  • Konferensbidrag (refereegranskat)abstract
    • Thin film plate acoustic resonators (FPAR) devices operating in the lowest order symmetric Lamb wave mode (S0),the first order asymmetric Lamb wave mode (A1) and the first order symmetric Lamb wave mode (S1), propagatingin c-oriented aluminum nitride (AlN) membranes on Si were fabricated and tested for their sensitivities to pressureand mass. Systematic data on frequency shifts versus rigid mass (layer) thickness and ambient pressure variations arepresented for the different Lamb wave resonances. Further the ability to work in liquid environment of the S0, A1 andS1 modes, respectively, has been tested in view of Bio-sensor applications.
  •  
4.
  • Anderås, Emil, 1982-, et al. (författare)
  • Tilted c-Axis Thin-Film Bulk Wave Resonant Pressure Sensors With Improved Sensitivity
  • 2012
  • Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 12:8, s. 2653-2654
  • Tidskriftsartikel (refereegranskat)abstract
    • Aluminum nitride thin film bulk wave resonant pressure sensors employing c- and tilted c-axis texture, have been fabricated and tested for their pressure sensitivities. The c-axis tilted FBAR pressure sensors demonstrate substantially higher pressure sensitivity compared to its c-axis oriented counterpart. More specifically the thickness plate quasi-shear resonance has demonstrated the highest pressure sensitivity while further being able to preserve its performance in liquid environment.
  •  
5.
  • Arapan, Lilia, 1974-, et al. (författare)
  • An intermode-coupled thin-film micro-acoustic resonator
  • 2012
  • Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 0960-1317 .- 1361-6439. ; 22:8, s. 085004-
  • Tidskriftsartikel (refereegranskat)abstract
    • A novel concept for the development of thin-film micro-acoustic resonators based on the coupling between different plate acoustic modes was demonstrated. The basic principles for the design and fabrication of intermode-coupled plate acoustic wave resonators on c-textured thin AlN films were presented and first experimental proof of coupling between laterally propagating waves and BAW was demonstrated. The experimental results demonstrate that the grating-assisted intermode coupling can be employed in high-frequency resonators inheriting the low dispersive nature of the S0 mode in combination with the energy localization in the plate bulk typical for the fundamental thickness shear resonance.
  •  
6.
  • Arapan, Lilia, et al. (författare)
  • Highly Mass-Sensitive Thin Film Plate Acoustic Resonators (FPAR)
  • 2011
  • Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 11:7, s. 6942-6953
  • Tidskriftsartikel (refereegranskat)abstract
    • The mass sensitivity of thin aluminum nitride (AlN) film S0 Lamb wave resonators is theoretically and experimentally studied. Theoretical predictions based on modal and finite elements method analysis are experimentally verified. Here, two-port 888 MHz synchronous FPARs are micromachined and subsequently coated with hexamethyl-disiloxane(HMDSO)-plasma-polymerized thin films of various thicknesses. Systematic data on frequency shift and insertion loss versus film thickness are presented. FPARs demonstrate high mass-loading sensitivity as well as good tolerance towards the HMDSO viscous losses. Initial measurements in gas phase environment are further presented.
  •  
7.
  • Arapan, Lilia, et al. (författare)
  • Polymer coated thin film plate acoustic resonators (FPAR) for gas sensing applications
  • 2011
  • Ingår i: 2011 Joint Conference of the IEEE International Frequency Control Symposium and European Frequency and Time Forum Proceedings, San Fransisco, CA, USA. - 9781612841113
  • Konferensbidrag (refereegranskat)abstract
    • Mass sensitivity of thin aluminum nitride (AlN) film S0 plate wave resonators is theoretically and experimentally studied. Here, two-port 888MHz synchronous thin film plate acoustic resonators (FPAR) are micromachined and subsequently coated with plasma-polymerized hexamethyldisiloxane (pp-HMDSO) thin films of various thicknesses. Systematic data on frequency shift and insertion loss versus film thickness are presented in a comparative manner. Measurements in gas phase environment are further presented in a comparative manner.
  •  
8.
  • Arapan, Lilia, et al. (författare)
  • Sensitivity Features of Thin Film Plate Acoustic Wave Resonators
  • 2011
  • Ingår i: IEEE Sensors Journal. - : IEEE Sensors Council. - 1530-437X .- 1558-1748. ; 11:12, s. 3330-3331
  • Tidskriftsartikel (refereegranskat)abstract
    • Thin film plate acoustic resonators devices operating in the lowest order symmetric Lamb wave mode (S0) in coriented aluminum nitride (AlN) membranes on Si were fabricated and tested for their sensitivities to pressure and mass as well as for their ability to work in liquid environment.
  •  
9.
  • Arapan, Lilia, 1974- (författare)
  • Thin Film Plate Acoustic Resonators for Frequency Control and Sensing Applications
  • 2012
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The recent development of the commercially viable thin film electro-acoustic technology has triggered a growing interest in the research of plate guided wave or Lamb wave components owing to their unique characteristics. In the present thesis i) an experimental study of the thin film plate resonators (FPAR) performance operating on the lowest symmetrical Lamb wave (S0) propagating in highly textured AlN membranes versus a variety of design parameters has been performed. The S0 mode is excited through an Interdigital Transducer and confined within the structure by means of reflection from metal strip gratings. Devices operating in the vicinity of the stop-band center exhibiting a Q-value of up to 3000 at a frequency around 900MHz have been demonstrated. Temperature compensation of this type of devices has been studied theoretically and successfully realized experimentally for the first time. Further, integrated circuit-compatible S0 Lamb based two-port FPAR stabilized oscillators exhibiting phase noise of -92 dBc/Hz at 1 kHz frequency offset with feasible thermal noise floor below -180 dBc/Hz have been tested under high power for a couple of weeks. More specifically, the FPARs under test have been running without any performance degradation at up to 27 dBm loop power. Further, the S0 mode was experimentally demonstrated to be highly mass and pressure sensitive as well as suitable for in-liquid operation, which together with low phase noise and high Q makes it very suitable for sensor applications; ii) research in view of FPARs operating on other types of Lamb waves as well as novel operation principles has been initiated. In this work, first results on the design, fabrication and characterization of two novel type resonators: The Zero Group Velocity Resonators (ZGVR) and The Intermode-Coupled Thin Film Plate Acoustic Resonators (IC-FPAR), exploiting new principles of operation have been successfully demonstrated. The former exploits the intrinsic zero group velocity feature of the S1 Lamb mode for certain combination of design parameters while the latter takes advantage of the intermode interaction (involving scattering) between S0 and A1 Lamb modes through specially designed metal strip gratings (couplers). Thus both type of resonators operate on principles of confining energy under IDT other than reflection.
  •  
10.
  • Arapan, Lilia, et al. (författare)
  • Thin film plate acoustic resonators for integrated microwave power oscillator applications
  • 2011
  • Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 47:7, s. 452-453
  • Tidskriftsartikel (refereegranskat)abstract
    • Two-port film plate acoustic resonators (FPAR) devices operating on the lowest order symmetric Lamb wave mode (S0) in C-oriented AlN membranes on Si were fabricated and tested for their power handling capabilities in a feedback-loop power oscillator circuit. The FPAR was operated at an incident power level of 24 dBm for several weeks without performance degradation. Its flicker noise constant was calculated from close-in phase noise data as αR=2.1×10^−36/Hz. The results indicate that IC-compatible S0 FPARs are well suited for integrated microwave oscillators with thermal noise floor (TNF) levels below −175 dBc/Hz.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 82
Typ av publikation
tidskriftsartikel (40)
konferensbidrag (39)
doktorsavhandling (2)
patent (1)
Typ av innehåll
refereegranskat (75)
övrigt vetenskapligt/konstnärligt (6)
populärvet., debatt m.m. (1)
Författare/redaktör
Yantchev, Ventsislav (76)
Katardjiev, Ilia (61)
Bjurström, Johan (14)
Enlund, Johannes (14)
Arapan, Lilia (11)
Wingqvist, Gunilla (10)
visa fler...
Martin, David (8)
Johansson, Linda (5)
Johansson, Stefan (4)
Yantchev, Ventsislav ... (4)
Anderås, Emil (3)
Strashilov, Vesselin ... (3)
Avramov, Ivan (3)
Olsson, Jörgen, 1966 ... (2)
Olsson, Jörgen (2)
Anderås, Emil, 1982- (2)
Arapan, Lilia, 1974- (2)
Alexieva, Gergana (2)
Rosén, Daniel (2)
Plessky, V (2)
Moreira, Milena (2)
Lin, Chih-Ming (2)
Pisano, Albert (2)
Andersson, Henrik (1)
Lloyd Spetz, Anita (1)
Smith, Ulf (1)
Kustanovich, Kiryl, ... (1)
Petrov, Ivan (1)
Verona, Enrico (1)
Avramov, Ivan D (1)
Radeva, Elisaveta (1)
Radeva, Ekaterina (1)
Yantchev, Ventsislav ... (1)
Katardjiev, Ilja, Pr ... (1)
Iborra, Enrique, Pro ... (1)
Jesorka, A (1)
Clement, M (1)
Engelmark, Fredrik (1)
Iriarte, Gonzalo Fue ... (1)
Martin, David M. (1)
Ivanov, Ivan (1)
Olsson, Jorgen (1)
Liljeholm, Lina (1)
Felmetsger, Valery (1)
Chen, Yung-Yu (1)
Bjurström, J (1)
Mirea, T. (1)
DeMiguel-Ramos, M. (1)
Olivares, J. (1)
Iborra, E. (1)
visa färre...
Lärosäte
Uppsala universitet (81)
Kungliga Tekniska Högskolan (1)
Linköpings universitet (1)
Chalmers tekniska högskola (1)
Språk
Engelska (82)
Forskningsämne (UKÄ/SCB)
Teknik (41)
Naturvetenskap (2)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy