Transient response of interdigital surface wave transducers

Transient response of interdigital surface wave transducers

growth. Values of the single parameter are found for each material which gave gqod agreement between measured data and the model predictions. The para...

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growth. Values of the single parameter are found for each material which gave gqod agreement between measured data and the model predictions. The parameter values differ by an order of magnitude in the two materials, LiNbO, being the more strongly non-linear. Optimizing loss-compensated tines C&hen, L. A. 20 (January 1973) 17

long delay

It is shown that the maximum number of transits through a set of identical losscampensated sections on a monolithic Raleigh wave amplifier is obtained when the net gain maximum is placed at the signal frequency. Net gain and maximum delay data taken over the 100-300 MHz band are in good agreement with the paedictions of simple theory. More than 385 transits around an InSb/LiNbO, device were observed at 200 MHz. By operating the amplifier saturated, a very stable mode of operation with improved S/N ratio was obtained.

Farmelectric non-linearities in transudcer ceramics Wbollet, R. S. LeBlanc, C. L. 20 (January 1973) 24 The effects of static bias stress on ac beihaviour and the changes in performance that occur at high signal levels are considered in the design of ceramic transducers. It is concluded that if the ceramics are to be used at their ultimate power capacity, substantial non-linear effects will have to be tolerated and a non-linear theory will be needed. ultrasonic fading simulation Hayre, H. S. 20 (January 1973) 32 A# bubbles in a water tank are used to simulate rainfall and the associated fading of CW signals using an ultrasonic frequency of 1 MHz. The results show that not only the shape of the probability distrlbution but also the mean and standard deviation vary considerably with azimuthal angle. Furthermore, the nature of such a iurbulent volume is anisotropic as opposed to the isotropic case usually as$umed by researchers. Transient response of interdigital surface wave transducers St@yama, K., Yoshikawa, S. 20 (January 1973) 34 An analysis ot delay lines using interdigital surface wave transducers is presented on an equivalent circuit model. Transmission characteristics in the time domain are attained in terms of time-shift operators of Laplace transform calculus. Two types of transducer configurations are discussed for digital delay-line applications. It becomes evident that the tranp ducer configurations utilizing a phasecode such as the Barker-code or the Golaycode are useful for digital devices. The analytical values of the delay line and oukput response agree well with the experimental results.

ULTRASONICS.

MAY 1973

The interaction of a longitudinal pumping wave and two transverse waves polarized perpendicular to the plane of the wave Efficiency-rating methods for ultrasonic vectors is analysed. The growth rate and cleaning equipment Agranat, B. A., Gutnova, L. B., Lyamshev, L. M. conditions required for transverse waves on the longitudinal wave is taken into 18 (January-March 1973) 285 account. A solution is obtained with stationary amplitudes of the interacting Internal friction and heat release in structural waves. and tool steels subjected to intense ultraTemperature dependence of the velocity sonic vibrations of sound in pure and alloyed quartz Andreev, G. I., Kobtseva, T. E., glasses Mirotvorskii, V. S. Goral’nik, A. S., Kul’bitskaya, M. N., 18 (January-March 1973) 290 Mikhailov, I. G., Fershtat, L. N., An energy method for determining the Shutilov, V. A. internal friction of metals subjected to 18 (January-March 1973) 328 ultrasonic vibrations at frequencies of The acoustical characteristics measured order 20 kHz and strain amplitudes of in the ultrasonic frequency range. are 10m4-lo-’ is described. Curves are given for various grades of pure quartz given for the internal friction of technical glasses prepared by different technologies. iron and steels in various states as funcGlasses alloyed with titanium and vanations of strain amplitude. The effect of dium oxide are also analysed. The alloyed heat treatment on the damping factor glasses exhibit an anomalous influence is investigated. of impurities on the temperature coefficient of the sound velocity. Comprehensive investigation of the acoustical parameters, viscosity and density of n-pentane over a wide pressure interval PATENTS Bellnskii, B. A., Ikramov, Sh. Kh. 18 (January-March 1973) 300 Phonon generation handling and detection North American Rockwell Corp The results of a study on the propagation US patent 3693104 (1972) filed 5 June velocity and coefficient of absorption 1970 of ultrasound, shear viscosity, density

SOVIET PHYSICS-ACOUSTICS

and dielectric constant of n-pentane at high pressures (l-8 000 kg cm-‘) along the 20”) 30” and 40°C isotherms are presented. The results are used to calculate the nanlinear parameters Ra and rud, as well as the activation energies of the shear and bulk viscosities. It was found that at low pressures the contribution of structural relaxation to the bulk viscosity of a normal liquid is small by comparison with the contribution of thermal relaxation, while at high pressures it comprises the main contribution to bulk viscosity. Sound field of an infinite circular cylindrical transducer partially coated with an acoustically compliant layer Vouk, I.V., Grinchenko, V. T., Mayatskii, V. I. 18 (January-March 1973) 308 A rigorous solution is given for the problem of sound radiation by an infinite circular cylindrical transducer part of whose surface is coated with a layer of acoustically complaint material of arbitrary thickness and on whose remaining surface the particle velocity is given. A directivity pattern is calculated and compared with the corresponding experimental pattern;

coefficient of solids at high tempe&res Gitis, M. B., Kopanskii, A. G. 18 (January-March 1973) 320 An apparatus and method of measuring the absorption of ultrasound in solid-state specimens of small dimensions at frequencies between S-100 MHz in the temperature range 20-l 000°C are described.

Ultrasonic distance amplitude correction unit TRW Inc US patent 3690153 (1972) filed 7 December 1970 Ultrasonic scanning apparatus with transducer scanning rate-responsive transmitter Zenith Radio Corp US patent 3690311 (1972) filed 27 May 1971 Ultrasonic thickness gauge Sonic Instruments Inc US patent 3688565 (1972) filed 28 September 1970 Ultrasonic surface roughness indicator Automation Industries Inc US patent 3688569 (1972) filed 16 July 1970 Ultrasonic scanning apparatus McDicken, W. N. US patent 3688564 (1972) filed 1 December 1970 Fluid flowmeter Westinghouse Electric Corp UK patent 1282617 (1972) filed 3 November 1969 Ship’s sonar EM1 Ltd UK patent 1285697 (1972) filed 3 October 1969 Underwater electroacoustic transducer Wyle Laboratories UK patent 1281945 (1972) filed 15 October 1969

Non-linear interaction of one longitudinal and two transverse waves in an isotropic

Pipe measuring apparatus

solid Gol’dberg, Z. A., Grebneva, R. V. 18 (January-March 1973) 324

Vereinigte Deutsche Metallwerke AG UK patent 1285639 (1972) tiled 27 October 1970

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