scholarly journals Design and demonstration of acoustically optimized, fully-printed, BST MIM varactors for high power matching circuits

2018 ◽  
Vol 10 (5-6) ◽  
pp. 620-626
Author(s):  
Daniel Kienemund ◽  
Nicole Bohn ◽  
Thomas Fink ◽  
Mike Abrecht ◽  
Walter Bigler ◽  
...  
Keyword(s):  
Quality Factor ◽  
High Power ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Acoustic Resonance ◽  
Power Matching ◽  
Metal Insulator Metal ◽  
The Matrix ◽  
Suppression Technique ◽  
High Power Operation

AbstractThis work addresses the piezoelectric induced reduction of quality factor in fully-printed metal-insulator-metal (MIM) barium strontium titanate (BST) thick film varactors designed for high power operation. An acoustically optimized varactor design is presented and compared to a non-optimized high-power varactor. The design is utilized to present a narrowband acoustic suppression technique based on defined weights. The acoustically optimized varactor consists of 162 varactor cells in a capacitive matrix. The cells in the matrix are interconnectable allowing for a variable unbiased capacitance and power rating. Due to this setup, surface acoustic waves are interrupted, and the reduced size of the cells allows for a reduced BST layer thickness, shifting the acoustic resonance away from the operational frequency. Therefore, an inverted behavior in comparison to the high-power varactor is observed with an increasing quality factor with biasing voltage. Compared to the high-power varactor, the acoustically optimized varactor design shows a 40% increased quality factor in biased state. By applying the narrowband acoustic suppression technique, an increase in quality factor of 145% is achieved compared to the unsuppressed design. In comparison to the high-power varactor, the acoustical suppressed design shows an increase in quality factor of 480% at the first acoustic resonance frequency.

Low loss, fully-printed, ferroelectric varactors for high-power impedance matching at low ISM band frequency

2019 ◽  
Vol 11 (7) ◽  
pp. 658-665
Author(s):  
Daniel Kienemund ◽  
Nicole Bohn ◽  
Thomas Fink ◽  
Mike Abrecht ◽  
Walter Bigler ◽  
...  
Keyword(s):  
High Power ◽  
Power Level ◽  
Impedance Matching ◽  
Input Power ◽  
Low Loss ◽  
Band Frequency ◽  
Power Matching ◽  
Metal Insulator Metal ◽  
Ferroelectric Varactors ◽  
Suppression Technique

AbstractLow loss, ferroelectric, fully-printed varactors for high-power matching applications are presented. Piezoelectric-induced acoustic resonances reduce the power handling capabilities of these varactors by lowering the Q-factor at the operational frequency of 13.56 MHz. Here, a quality factor of maximum 142 is achieved with an interference-based acoustic suppression approach utilizing double metal–insulator–metal structures. The varactors show a tunability of maximum 34% at 300 W of input power. At a power level of 1 kW, the acoustic suppression technique greatly reduces the dissipated power by 62% from 37 W of a previous design to 14.2 W. At this power level, the varactors remain tunable with maximum 18.2% and 200 V of biasing voltage.

HIGH-PERFORMANCE SURFACE TRANSVERSE WAVE RESONATORS IN THE LOWER GHz FREQUENCY RANGE

2000 ◽  
Vol 10 (03) ◽  
pp. 735-792 ◽  
Author(s):  
IVAN D. AVRAMOV
Keyword(s):  
Phase Noise ◽  
Transverse Wave ◽  
High Power ◽  
Acoustic Waves ◽  
Power Efficiency ◽  
Surface Acoustic Waves ◽  
Low Noise ◽  
Propagation Loss ◽  
Range Data ◽  
Frequency Range

Since the first successful surface transverse wave (STW) resonator was demonstrated by Bagwell and Bray in 1987, STW resonant devices on temperature stable cut orientations of piezoelectric quartz have enjoyed a spectacular development. The tremendous interest in these devices is based on the fact that, compared to the widely used surface acoustic waves (SAW), the STW acoustic mode features some unique properties which makes it very attractive for low-noise microwave oscillator applications in the 1.0 to 3.0 GHz frequency range in which SAW based or dielectric resonator oscillators (DRO) fail to provide satisfactory performance. These STW properties include: high propagation velocity, material Q-values exceeding three times those of SAW and bulk acoustic waves (BAW) on quartz, low propagation loss, unprecedented 1/f device phase noise, extremely high power handling ability, as well as low aging and low vibration sensitivity. This paper reviews the fundamentals of STW propagation in resonant geometries on rotated Y-cuts of quartz and highlights important design aspects necessary for achieving desired STW resonator performance. Different designs of high- and low-Q, low-loss resonant devices and coupled resonator filters (CRF) in the 1.0 to 2.5 GHz range are characterized and discussed. Design details and data on state-of-the-art STW based fixed frequency and voltage controlled oscillators (VCO) with low phase noise and high power efficiency are presented. Finally, several applications of STW devices in GHz range data transmitters, receivers and sensors are described and discussed.

Analysis of interference patterns in acoustic photomicrographs

1989 ◽  
Vol 47 ◽  
pp. 370-371
Author(s):  
Donna A. Downs ◽  
Aly El-Shiekh ◽  
Paul A. Tucker ◽  
John C. Russ
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Specimen Surface ◽  
Wave Reflections ◽  
Reflected Light ◽  
Longitudinal Acoustic Wave ◽  
The Matrix ◽  
Surface Irregularities ◽  
The Waves ◽  
Scanning Acoustic Microscope

Images from the Scanning Acoustic Microscope (SAM) have been used previously to study fiber orientations in opaque matrices. SAM images are superficially similar to reflected light images. They also frequently exhibit interference patterns which can be used for quantitative analysis. These patterns arise at discontinuities near or intersecting the specimen surface, and result from interference between acoustic waves reflecting from subsurface boundaries and from the specimen surface. For the case of fibers intersecting a planar surface, the position of the interference fringes gives the orientation of the fiber with respect to the surface, and the shape of the fringes indicates any surface irregularities. Thus, if the fiber shape and orientation are known and if the waves are determined to be longitudinal, then fringe spacings can be used to calculate the velocity and attenuation of the longitudinal acoustic wave in the matrix surrounding the fiber.This technique was applied to graphite-epoxy composites, imaged in the SAM at a frequency of 1.2 GHz. First it was determined that other waves, such as shear waves, surface-skimming longitudinal waves, and surface acoustic waves (Rayleigh waves) were not present in the composite. Their addition to the interference pattern would have disrupted the interpretation of the object’s shape and surface features from the longitudinal fringes and complicated the solutions for wave reflections.

scholarly journals Holographic measurement of surface acoustic wave parameters in crystals

2019 ◽  
Vol 5 (3) ◽  
pp. 107-114
Author(s):  
Michael E. Gusev ◽  
Yuri N. Zakharov
Keyword(s):  
Holographic Interferometry ◽  
Acoustic Waves ◽  
High Frequency ◽  
Surface Acoustic Waves ◽  
Measuring System ◽  
Wide Field ◽  
Frequency Multiplication ◽  
The Matrix ◽  
Specialized Technique ◽  
Holographic Measurement

The theoretical basis of a specialized technique for applying digital holographic interferometry to measure the parameters of surface acoustic waves is presented, a measuring system for visualization and quantitative analysis of the parameters of ultralow-amplitude high-frequency oscillations arising in electronic devices using surface acoustic waves is developed, and experimental results of the study of surface acoustic waves in crystals of lithium niobate are obtained. In this case, to ensure the possibility of recording precision double-exposure interferograms of high-frequency surface acoustic waves, a picosecond pulsed laser with two-stage frequency multiplication was used as a radiation source, and to increase the spatial resolution of the system with the possibility of observing a wide field of view, an adjustable optical zoom of the incoming image was applied to the matrix input (based on charge-coupled devices) of the recording camera and digital zoom was used for obtained interferogram. We achieved the measuring sensitivity of the surface acoustic waves amplitude and spatial-temporal resolution allowing visualization and measurement of surface acoustic waves with amplitudes of the order of 1 nm and frequencies of the order of 10 MHz, which is far beyond the capabilities of standard methods of holographic interferometry.

Characterization of RF Sputtered ZnO Piezoelectric Films Using Transmission Electron Microscope

1975 ◽  
Vol 33 ◽  
pp. 86-87
Author(s):  
Kemining W. Yeh ◽  
Richard S. Muller ◽  
Wei-Kuo Wu ◽  
Jack Washburn
Keyword(s):  
Integrated Circuit ◽  
Acoustic Waves ◽  
New Technology ◽  
Surface Acoustic Waves ◽  
Electromechanical Properties ◽  
Leading Role ◽  
Saw Devices ◽  
Transmission Electron ◽  
High Degree

Considerable and continuing interest has been shown in the thin film transducer fabrication for surface acoustic waves (SAW) in the past few years. Due to the high degree of miniaturization, compatibility with silicon integrated circuit technology, simplicity and ease of design, this new technology has played an important role in the design of new devices for communications and signal processing. Among the commonly used piezoelectric thin films, ZnO generally yields superior electromechanical properties and is expected to play a leading role in the development of SAW devices.

Attenuation of surface acoustic waves by quantum dots

1998 ◽  
Vol 77 (5) ◽  
pp. 1195-1202
Author(s):  
Andreas Knabchen Yehoshua, B. Levinson, Ora
Keyword(s):  
Quantum Dots ◽  
Acoustic Waves ◽  
Surface Acoustic Waves
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