Epitaxial ZnO piezoelectric thin films for saw filters

This book gives the fundamental principles and device design techniques for surface acoustic wave filters. It covers the devices in widespread use today: bandpass and pulse compression filters, correlators and non-linear convolvers and resonators. The newest technologies for low bandpass filters are fully covered such as unidirectional transducers, resonators in impedance element filters, resonators in double-mode surface acoustic wave filters and transverse-coupled resonators using waveguides.The book covers the theory of acoustic wave physics, the piezoelectric effect, electrostatics at a surface, effective permittivity, piezoelectric SAW excitation and reception, and the SAW element factor. These are the main requirements for developing quasi-static theory, which gives a basis for the non-reflective transducers in transversal bandpass filters and interdigital pulse compression filters. It is also needed for the reflective transducers used in the newer devices. It is a thorough revision of a classic on surface acoustic wave filters first published in 1985 and still in print. It uniquely combines easy-to-understand principles with practical design techniques for all the devices in widespread use today. It includes complete coverage of all the latest devices which are key to mobile phones, TVs and radar systems; and, a new foreword by Sir Eric Albert Ash.

Surface Acoustic Wave Filters: With Applications to Electronic Communications and Signal Processing

Disclosed is a fixation device for spinal fixation. The fixation device includes an elongated body comprising a bone anchor at a distal end. An axially moveable proximal anchor is carried by the proximal end of the fixation device. In one embodiment, the device is inserted through a first vertebra and the bone anchor is rotated into positioned within a second vertebra. The proximal anchor is distally advanced with respect to the bone anchor to provide compression across the first and second vertebra. In other embodiments, the device is used to secure stabilization devices across two or more vertebra.

Method and apparatus for spinal fixation

Diamond has the highest surface acoustic wave (SAW) velocity among all materials and thus can provide much advantage for fabrication of high frequency SAW devices when it is combined with a piezoelectric thin film. Basic SAW properties of layered structures consisting of a piezoelectric material layer, a diamond layer and a substrate were examined by theoretical calculation. Rayleigh mode SAW's with large SAW velocities up to 12,000 m/s and large electro-mechanical coupling coefficients from 1 to 11% were found to propagate in ZnO/diamond/Si, LiNbO/sub 3//diamond/Si and LiTaO/sub 3//diamond/Si structures. It was also found that a SiO/sub 2//ZnO/diamond/Si structure can realize a zero temperature coefficient of frequency with a high phase velocity of 8,000-9,000 m/s and a large electro-mechanical coupling coefficient of up to 4%. >

Theoretical study on SAW characteristics of layered structures including a diamond layer

Physical and structural properties of ZnO sputtered films

A 15 GHz range low insertion loss surface acoustic wave (SAW) filter has been developed using a ZnO/sapphire substrate and IIDT-type electrodes with two external reflectors This filter had an insertion loss of 13 dB, stop-band attenuation of greater than 30 dB and matching impedance of 50 Ω pure resistivity without external matching networks This filter has the smallest insertion loss of all transverse-type GHz-range SAW filters reported previously and it is suitable for use as a RF-stage filter for future 15 GHz range Japanese digital cellular systems

https://iopscience.iop.org/article/10.1143/JJAP.32.2337/pdf

1.5 GHz Low-Loss Surface Acoustic Wave Filter Using ZnO/Sapphire Substrate

The 1.5 and 2.4 GHz range 5IDT-type longitudinally coupled surface acoustic wave (SAW) resonator filters have been developed using ZnO/sapphire substrate. The 1.5 GHz range SAW filter has the minimum insertion loss of 1.0 dB and the relative bandwidth of 2.4% at the insertion loss of 3 dB. The 2.4 GHz range SAW filter has the minimum insertion loss of 1.7 dB and the relative bandwidth of 1.7% at the insertion loss of 3 dB. These filters are suitable for use as RF-stage filters in a personal digital cellular (PDC) system terminal and a wireless local area network (LAN) adapter, respectively.

Quasi-Microwave Band Longitudinally Coupled Surface Acoustic Wave Resonator Filters Using ZnO/Sapphire Substrate

When a zinc oxide piezoelectric crystal film is epitaxially grown on an R-plane sapphire substrate by sputtering, a target containing not more than 45 percent by weight of Cu with respect to the total content of Zn and Cu is employed so that the zinc oxide piezoelectric film contains Cu Thus, it is possible to obtain a zinc oxide piezoelectric crystal film having excellent orientation

Zinc oxide piezoelectric crystal film on sapphire plane

Using the third order harmonic wave of Sezawa-mode which propagates in ZnO films epitaxially deposited on R-plane sapphire, high performance filter which is a low insertion loss of 9 dB at 1.86 GHz has been realized.

http://iopscience.iop.org/article/10.7567/JJAPS.26S2.210/pdf

1.86 GHz SAW Filter

Disclosed herein is a zinc oxide piezoelectric crystal film which is grown on an R-plane sapphire substrate to orient its c-axis in parallel with the substrate surface. In order to improve orientation of the zinc oxide piezoelectric crystal film used is a Zn target for forming the zinc oxide piezoelectric crystal film by sputtering contains not more than 5 percent by weight of nickel or not more than 4.5 percent by weight of iron with respect to Zn.

Jun Koike

Papers

1.5 GHz Low-Loss Surface Acoustic Wave Filter Using ZnO/Sapphire Substrate

Quasi-Microwave Band Longitudinally Coupled Surface Acoustic Wave Resonator Filters Using ZnO/Sapphire Substrate

Zinc oxide piezoelectric crystal film on sapphire plane

1.86 GHz SAW Filter

Zinc oxide piezoelectric crystal film