Now showing items 1-19 of 19

    • Bandwidth, power and noise considerations in airborne cMUTs 

      Senlik, M.N.; Olcum, S.; Köymen H.; Atalar, Abdullah (2009)
      Capacitive micromachined ultrasonic transducers (cMUTs) offer wider bandwidth in air due to their low mechanical impedances. The impedance mismatch between the air and transducer decreases with the smaller device dimensions ...
    • CMUT array element in deep-collapse mode 

      Olcum, S.; Yamaner F.Y.; Bozkurt, A.; Köymen H.; Atalar, Abdullah (2011)
      Collapse and deep-collapse mode of operations have boosted the pressure outputs of capacitive micromachined ultrasonic transducers (CMUTs) considerably. In this work, we demonstrate a CMUT element operating in the deep-collapse ...
    • Deep-collapse operation of capacitive micromachined ultrasonic transducers 

      Olcum, S.; Yamaner F. Y.; Bozkurt, A.; Atalar, Abdullah (IEEE, 2011)
      Capacitive micromachined ultrasonic transducers (CMUTs) have been introduced as a promising technology for ultrasound imaging and therapeutic ultrasound applications which require high transmitted pressures for increased ...
    • Design and implementation of capacitive micromachined ultrasonic transducers for high power 

      Yamaner F.Y.; Olcum, S.; Bozkurt, A.; Köymen H.; Atalar, Abdullah (2011)
      Capacitive micromachined ultrasonic transducers (CMUTs) have a strong potential to compete piezoelectric transducers in high power applications. In a CMUT, obtaining high port pressure competes with high particle velocity: ...
    • Designing transmitting CMUT cells for airborne applications 

      Ünlügedik, A.; Taşdelen, A.; Atalar, Abdullah; Köymen, H. (Institute of Electrical and Electronics Engineers Inc., 2014)
      We report a new mode of airborne operation for capacitive micromachined ultrasonic transducers (CMUT), in which the plate motion spans the entire gap without collapsing and the transducer is driven by a sinusoidal voltage ...
    • Electrically unbiased driven airborne capacitive micromachined ultrasonic transducer design 

      Unlugedik, A.; Atalar, Abdullah; Kocabas, C.; Oguz H.K.; Koymen H. (2012)
      We present a design method for airborne capacitive micromachined ultrasonic transducers (CMUT). We use an equivalent lumped element circuit to model both electrical and mechanical properties of CMUT and analyze it in ...
    • An equivalent circuit model for transmitting capacitive micromachined ultrasonic transducers in collapse mode 

      Olcum, S.; Yamaner, F. Y.; Bozkurt, A.; Köymen, H.; Atalar, Abdullah (IEEE, 2011)
      The collapse mode of operation of capacitive micromachined ultrasonic transducers (CMUTs) was shown to be a very effective way to achieve high output pressures. However, no accurate analytical or equivalent circuit model ...
    • Equivalent circuit-based analysis of CMUT cell dynamics in arrays 

      Oğuz, H. K.; Atalar, Abdullah; Köymen, H. (IEEE, 2013)
      Capacitive micromachined ultrasonic transducers (CMUTs) are usually composed of large arrays of closely packed cells. In this work, we use an equivalent circuit model to analyze CMUT arrays with multiple cells. We study ...
    • An improved lumped element nonlinear circuit model for a circular CMUT cell 

      Koymen, H.; Atalar, Abdullah; Aydogdu, E.; Kocabas, C.; Oguz, H. K.; Olcum, S.; Ozgurluk, A.; Unlugedik, A. (IEEE, 2012)
      This paper describes a correction and an extension in the previously published large signal equivalent circuit model for a circular capacitive micromachined ultrasonic transducer (CMUT) cell. The force model is rederived ...
    • Interaction between a cMUT cell and a liquid medium around the parallel resonance frequency 

      Senlik, M.N.; Atalar, Abdullah; Olcum, S. (2007)
      In this paper, we present how a capacitive micromachined ultrasonic transducer (cMUT) couples to the immersion medium, based on an accurate parametric model. We show that the velocity of cMUT membrane can be written as a ...
    • Nonuniform membranes in capacitive micromachined ultrasonic transducers 

      Şenlik, Muhammed N (Bilkent University, 2005)
      Capacitive micromachined ultrasonic transducers (cMUT) are used to receive and transmit ultrasonic signals. The device is constructed from many small, in the order of microns, circular membranes, which are connected in ...
    • A novel equivalent circuit model for CMUTs 

      Oguz H.K.; Olcum, S.; Senlik, M.N.; Atalar, Abdullah; Köymen H. (2009)
      A nonlinear equivalent circuit for immersed transmitting capacitive micromachined ultrasonic transducers (CMUTs) is presented. The velocity profile across the CMUT surface maintains the same form over a wide frequency ...
    • Optimizing CMUT geometry for high power 

      Yamaner F.Y.; Olcum, S.; Bozkurt, A.; Koymen H.; Atalar, Abdullah (2010)
      Capacitive micromachined ultrasonic transducers (CMUTs) have demonstratedvarious advantages over piezoelectric transducers. However, current CMUT designsproduce low output pressures with high harmonic distortions. Optimizing ...
    • Radiation impedance and equivalent circuit for immersed CMUT array element 

      Senlik, M.N.; Atalar, Abdullah; Koymen H.; Olcum, S. (2006)
      In this paper, we present equivalent circuit for immersed capacitive micromachined ultrasonic transducers (cMUT), based on an accurate parametric model. We also present an accurate approximation for the radiation impedance ...
    • Radiation impedance of an array of circular capacitive micromachined ultrasonic transducers 

      Senlik, M. N.; Olcum, S.; Köymen, H.; Atalar, Abdullah (IEEE, 2010)
      The radiation impedance of a capacitive micromachined ultrasonic transducer (cMUT) with a circular membrane is calculated analytically using its velocity profile for the frequencies up to its parallel resonance frequency ...
    • Radiation impedance of an array of circular capacitive micromachined ultrasonic transducers in collapsed state 

      Ozgurluk, A.; Atalar, Abdullah; Koymen, H.; Olcum, S. (IEEE, 2011)
      Radiation impedance is one of the important parameters in designing efficient and wideband capacitive micro-machined ultrasonic transducer (CMUT) arrays. It determines how much acoustical power is generated in the surrounding ...
    • Radiation impedance of collapsed capacitive micromachined ultrasonic transducers 

      Ozgurluk, A.; Atalar, Abdullah; Köymen, H.; Olçum, S. (Institute of Electrical and Electronics Engineers, 2012)
      The radiation impedance of a capacitive micromachined ultrasonic transducer (CMUT) array is a critical parameter to achieve high performance. In this paper, we present a calculation of the radiation impedance of collapsed, ...
    • Rayleigh-bloch waves in CMUT arrays 

      Atalar, Abdullah; Köymen, H.; Oğuz, H. K. (Institute of Electrical and Electronics Engineers Inc., 2014)
      Using the small-signal electrical equivalent circuit of a capacitive micromachined ultrasonic transducer (CMUT) cell, along with the self and mutual radiation impedances of such cells, we present a computationally efficient ...
    • Wafer bonded capacitive micromachined underwater transducers 

      Olcum, S.; Oǧuz, K.; Şenlik, M.N.; Yamaner F.Y.; Bozkurt, A.; Atalar, Abdullah; Köymen H. (2009)
      In this work we have designed, fabricated and tested CMUTs as underwater transducers. Single CMUT membranes with three different radii and 380 microns of thickness are fabricated for the demonstration of an underwater CMUT ...