A surface acoustic wave (SAW) resonators are widely used for frequency selection in mobile and wireless transmission systems [1]. SAW devices consist of piezoelectric substrate, interdigital transducers (IDT) and reflectors deposited on top of the substrate [2]. When voltage is applied at the electrodes, it generates electric fields, which produces piezoelectric strains propagating in both directions as shown in Fig. 1(b). Thus, surface acoustic waves are generated through inverse piezoelectric effect [3]. The fundamental resonance frequency is determined by velocity of the acoustic wave and the wavelength as shown in (1). Therefore, the design of the IDT is critical to determine the GHz resonance frequency as shown in Fig. 1.
Discrete SAW resonators suffer from lossy interfacing and consume large area [4]. In this work, SAW resonator was developed ZnO piezoelectric material on silicon [2] to enable integration of the SAW resonator with the integrated circuits. The resonator’s IDTs were formed using metal layers present in standard 0.35 μm CMOS process to realize a 1 GHz resonator. The important parameters that affect the performance of the SAW resonator are the electromechanical coupling coefficient, k2, high quality factor, Q and low insertion loss. This paper studies the effect of different ZnO piezoelectric thickness and different distance of input and output transducer, Lc to the electromechanical coupling coefficient of the SAW resonator. Finite element simulations of the ZnO SAW resonator were conducted using COMSOLTM. A 2D geometry of SAW resonator was drawn under the piezoelectric model. Two analyses were applied: eigen frequency analysis, frequency domain analysis. A harmonic excitation was applied as sinusoidal wavefor...
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...onance frequency are trapped inside the cavity to ensure maximum reflection when the IDT is placed an integer number of half wavelength.
By varying the thickness of the piezoelectric thin film, the phase velocity of the acoustic wave also will be varied. Fig. 5 shows the SAW velocity dispersion of the surface acoustic wave resonator for normalized thickness of ZnO piezoelectric material. There is a slight decrease of phase velocity at normalized thickness of ZnO between 0.35 to 0.95.The phase velocity increases with increasing of ZnO thickness at a range from 3150 m/s to 3650 m/s.
The finding shows that the effective normalized thickness of ZnO piezoelectric layer between 0.63<(hzno/λ)<0.78 and the nearest distance of input and output transducer (Lc =1.6 um) provides highest electromechanical coupling coefficient to improve the performance of the CMOS SAW resonator.
The purpose of this experiment was to determine whether if the sound is affected when it travels through different length pipes. The method used to do this experiment was created by using 5 different PVC pipes in the lengths of 10, 20, 30, 40, and 50 centimeters. Then, using a tuning fork, sound will be produced on one end of the PVC pipe and measured with a decimeter on the other end. This experiment was recorded using 5 trials for each independent level and the average decibels (dB) for each pipe length were recorded.
waves were reflected back to the transducer as they crossed interfaces of different acoustic impedance. More simply, the ultrasound bounced off the
that The Speckled Band is a product of its time as there is a lot of
A transducer is a mechanism that changes one form of energy to another form. A toaster is a transducer that turns electricity into heat; a loudspeaker is a transducer that changes electricity into sound. Likewise, an ultrasound transducer changes electricity voltage into ultrasound waves, and vice versa. This is possible because of the principle of piezoelectricity, which states that some materials (ceramics, quartz, and others) produce a voltage when deformed by an applied pressure. Conversely, piezoelectricity also results in production of a pressure whe...
Sounds are produced by the vibrations of material objects, and travel as a result of
... Physics." .::. The Pysics of Electric Guitars :: Physics. N.p., n.d. Web. 26 May 2014. .
Micro Electro-Mechanical Systems (MEMS) is the integration of mechanical elements, sensors, actuators and electronics on a common silicon substrate using microfabrication techniques. MEMS are a hot area of research because they integrate sensing, analyzing and responding on the same silicon substrate hence promising realization of complete systems-on-a-chip. As MEMS are manufactured using batch fabrication techniques similar to IC technology, MEMS are expected to deliver high functionality at low prices.
... middle of paper ... ... Designs, C. & B. 2013. ProSonic Acoustic Cubes -. [online] Available at: http://www.customaudiodesigns.co.uk/acoustic-cubes.htm [Accessed: 1 Dec 2013].
The carbon transmitter uses carbon granules between metal plates called, electrodes, with one consisting of a thin diaphragm that moves by pressure from sound waves and transmits them to the carbon granules. These electrodes conduct electricity flowing through the carbon. The sound waves hit the diaphragm, causing the electrical resistance of the carbon to vary. The electronic transmitter is composed of a thin disk of metal-coated plastic held above a thick, hollow metal disk. This plastic disk is electrically charged, and creates an electric field.
Fingering and Acoustic Schematic. n.d. Diagram. University of New South Wales, Faculty of Science. Academic Press, 2001. Web. 13 Sept. 2011.
... middle of paper ... ... References Fletcher, N., Martin, D. and Smith, J. (2008) Musical instruments, in AccessScience, McGraw-Hill Companies, Retrieved November 25, 2011 from http://www.accessscience.com.ezproxy.hacc.edu. Henderson, T. (2011). The 'Standard'.
Produced sound from speakers has become so common and integrated in our daily lives it is often taken for granted. Living with inventions such as televisions, phones and radios, chances are you rarely ever have days with nothing but natural sounds. Yet, few people know the physics involved in the technology that allows us to listen to music in our living room although the band is miles away. This article will investigate and explain the physics and mechanism behind loudspeakers – both electromagnetic and electrostatic.
When particles are fired at the wall with both slits open, they are more likely to hit the detector in one specific area, whereas waves interfere with each other creating an interference pattern.
waves are further divided into two groups or bands such as very low frequency (
"Properties of sine waves." University of Manitoba. University of Manitoba, 2010. Web. 29 Nov. 2013. .