Properties of acoustic plate modes in YZ LiNbO₃.

Properties of acoustic plate modes (APMs) in YZ LiNbO₃ were calculated and measured. It was found that these modes have a dominant longitudinal component of mechanical motion concentrated near both surfaces of a plate. A delay line with double-electrode interdigital transducers (IDTs) was used for the measurements.

Scattering matrix approach to SHAPM delay line with long interdigital transducers on BT-cut quartz.

Transfer function of a shear horizontal acoustic plate mode (SHAPM) delay line with long interdigital transducers (IDTs) was derived using the scattering matrix method. Analytical expressions for the admittance, scattering coefficients, and reflection coefficient of the periodic electrodes of the IDT, derived previously for SAWs, were used for numerical calculations. By matching the measured and calculated amplitude responses, the velocity, electromechanical coupling coefficient, and reflection coefficient of an aluminum electrode on BT-cut quartz were determined.

Determination of mass density, dielectric, elastic, and piezoelectric constants of bulk GaN crystal.

Mass density, dielectric, elastic, and piezoelectric constants of bulk GaN crystal were determined. Mass density was obtained from the measured ratio of mass to volume of a cuboid. The dielectric constants were determined from the measured capacitances of an interdigital transducer (IDT) deposited on a Z-cut plate and from a parallel plate capacitor fabricated from this plate.

Properties of shear horizontal acoustic plate modes in BT-cut quartz.

Properties of shear horizontal acoustic plate modes (SHAPMs) in BT-cut quartz were calculated and measured. A delay line with a long interdigital transducer, deposited on -50.5°YX90°-oriented quartz plate, was used for the measurements.

Properties of SAW synchronous two-port resonators on GdCa₄O(BO₃)₃ crystal.

Surface acoustic wave (SAW) synchronous two-port resonators were fabricated and measured on several orientations of the GdCa₄O(BO₃)₃ crystal. Resonance frequencies, insertion losses, and unloaded quality factors of the resonators, measured at room temperature, were in the ranges of about 432.3 to 437.

STW two-port asynchronous resonator on BT-cut quartz.

A surface transverse wave (STW) 2-port asynchronous resonator on BT-cut (-50.5 degrees YX90 degrees) quartz was fabricated, measured, and calculated. At a frequency of about 332.

SAW synchronous multimode resonator with gold electrodes on quartz.

A surface acoustic wave synchronous multimode resonator with gold electrodes on ST-cut quartz was designed, fabricated, and measured. At a frequency of about 194.3 MHz, an insertion loss of about 14 dB, and loaded and unloaded quality factors of 11,500 and 14,500, respectively, were obtained.

STW in-line acoustically coupled resonator filter on quartz.

The scattering-matrix method was used for design of a surface transverse wave (STW) in-line acoustically coupled resonator filter on quartz. In this filter, two one-port STW resonators were coupled by means of a center reflector, grating phase shifters were placed between interdigital transducers and reflectors, and the pass band of the filter was located near the center frequency of the reflectors. At a frequency of about 509 MHz, insertion loss of about 5 dB and a 3 dB bandwidth of about 0.

Design of SAW synchronous resonators on ST cut quartz.

Surface acoustic wave (SAW) resonators on ST cut quartz, with synchronous placement of the interdigital transducers (IDT), were designed, fabricated, and measured. The basic structure of the resonators was a two-port one. The one-port resonators were obtained by parallel connection of the two IDT or by short circuiting one of them.

Application of synchronous two-port resonators for measurement of SAW parameters in piezoelectric crystals.

The synchronous two-port resonator can be used for the determination of SAW parameters, including velocity, electromechanical coupling coefficient, and reflection coefficient of one strip. These parameters can be determined from a comparison between the measured and calculated transfer functions of the resonator. Using this technique, the SAW free surface velocity of the 45 degrees XZ-cut of lithium tetraborate (Li(2)B(4)O(7)) crystal was found to be equal to 3436 m/s.

Scattering matrix approach to one-port SAW resonators.

The scattering matrix method was used to derive an expression for the reflection coefficient of a one-port SAW resonator. This expression was applied to calculations of an input admittance of a synchronous resonator on ST-cut quartz. Very good agreement was obtained between calculated and measured parameters of the resonator.

Design and properties of STW asynchronous resonators on quartz.

In a surface transverse wave (STW) asynchronous resonator, grating phase shifters are placed between interdigital transducers and reflectors to obtain the incident and reflected waves in phase, and the resonance frequency is located near the center frequency of the reflectors. In this paper, the scattering matrix method is used for design of such resonators with one dominant longitudinal mode. At a frequency of about 509.

Scattering matrix approach to STW resonators.

The scattering matrix method was used for the analysis of surface transverse wave (STW) resonators on quartz. An expression for the transfer function of the resonators with different numbers of electrodes in the reflectors was derived. It was found that, for a proper ratio of these numbers, the spurious signal level below the resonance frequency can be lowered.

Scattering analysis of two-port SAW resonators.

Linear equations derived from the scattering matrix approach to the two-port resonator were solved, and analytical expressions for the normalized SAW amplitudes were obtained. Asynchronous and synchronous resonators were analyzed numerically. It was shown that the output of the two-port resonator is a sum of two signals.

Surface acoustic wave two resonator filter using synchronous coupling interdigital transducers.

A surface acoustic wave (SAW) two resonator filter with coupling interdigital transducers (IDTs) located inside the reflectors, was designed, fabricated, and tested. In the filter, electrodes of the coupling IDTs are in spatial synchronism with the reflectors' electrodes. The filter, fabricated on ST-cut quartz, had a center frequency of 302.

Admittance matrix of a surface acoustic wave interdigital transducer.

The admittance matrix of a surface acoustic wave interdigital transducer (IDT) is derived from the impulse response model and circuit theory. It is shown, that Y(23)=Y(13) for a symmetrical IDT and Y(23)-Y(13) for an antisymmetrical one. A simple algorithm for the input admittance calculation of apodized IDTs is given.