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.

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.

scholarly journals Correlation of BAW and SAW properties of langasite at elevated temperatures

2015 ◽  
Vol 4 (2) ◽  
pp. 331-340 ◽  
Author(s):  
M. Schulz ◽  
E. Mayer ◽  
I. Shrena ◽  
D. Eisele ◽  
M. Schmitt ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Acoustic Waves ◽  
Elevated Temperatures ◽  
Surface Acoustic Waves ◽  
Propagation Loss ◽  
Bulk Acoustic Wave ◽  
Coupling Coefficients ◽  
Data Set ◽  
Acoustic Wave Devices ◽  
Bulk Acoustic Wave Resonators

Abstract. The full set of electromechanical data of langasite (La3Ga5SiO14) is determined in the temperature range from 20 to 900 °C using differently oriented bulk acoustic wave resonators. For data evaluation a physical model of vibration is developed and applied. Thereby, special emphasis is taken on mechanical and electrical losses at high temperatures. The resulting data set is used to calculate the properties of surface acoustic waves. Direct comparison with experimental data such as velocity, coupling coefficients and propagation loss measured using surface acoustic wave devices with two different crystal orientations shows good agreement.

A low noise, high power efficiency supply regulator for near-field power delivery

2010 ◽  
Vol 66 (2) ◽  
pp. 177-187 ◽  
Author(s):  
Peter Harrington ◽  
Sudipto Chakraborty ◽  
Bertan Bakkaloglu
Keyword(s):  
High Power ◽  
Power Efficiency ◽  
Near Field ◽  
Low Noise ◽  
Power Delivery ◽  
High Power Efficiency

scholarly journals MHz-Order Surface Acoustic Wave Thruster for Underwater Silent Propulsion

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 419
Author(s):  
Naiqing Zhang ◽  
Yue Wen ◽  
James Friend
Keyword(s):  
Acoustic Waves ◽  
Power Efficiency ◽  
Acoustic Radiation ◽  
Surface Acoustic Waves ◽  
Acoustic Streaming ◽  
Input Power ◽  
Image Velocimetry ◽  
Underwater Propulsion ◽  
Propulsion Force ◽  
Order Surface

High frequency (MHz-order) surface acoustic waves (SAW) are able to generate intense fluid flow from the attenuation of acoustic radiation in viscous fluids as acoustic streaming. Though such flows are known to produce a force upon the fluid and an equivalent and opposing force upon the object producing the acoustic radiation, there is no convenient method for measuring this force. We describe a new method to accomplish this aim, noting the potential of these devices in providing essentially silent underwater propulsion by virtue of their use of the sound itself to generate fluid momentum flux. Our example employs a 40 MHz SAW device as a pendulum bob while immersed in a fluid, measuring a 1.5 mN propulsion force from an input power of 5 W power to the SAW device. Supporting details regarding the acoustic streaming profile via particle image velocimetry and an associated theoretical model are provided to aid in the determination of the propulsion force knowing the applied power and fluid characteristics. Finally, a simple model is provided to aid the selection of the acoustic device size to maximize the propulsion force per unit device area, a key figure of merit in underwater propulsion devices. Using this model, a maximum force of approximately 10 mN/cm 2 was obtained from 1 W input power using 40 MHz SAW in water and producing a power efficiency of approximately 50%. Given the advantages of this technology in silent propulsion with such large efficiency and propulsion force per unit volume, it seems likely this method will be beneficial in propelling small autonomous submersibles.

scholarly journals Phase Noise of SAW Delay Line Magnetic Field Sensors

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5631
Author(s):  
Phillip Durdaut ◽  
Cai Müller ◽  
Anne Kittmann ◽  
Viktor Schell ◽  
Andreas Bahr ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Noise ◽  
Acoustic Waves ◽  
Delay Line ◽  
Magnetic Hysteresis ◽  
Surface Acoustic Waves ◽  
Deep Understanding ◽  
Operating Conditions ◽  
Magnetic Field Sensors ◽  
Noise Characteristics

Surface acoustic wave (SAW) sensors for the detection of magnetic fields are currently being studied scientifically in many ways, especially since both their sensitivity as well as their detectivity could be significantly improved by the utilization of shear horizontal surface acoustic waves, i.e., Love waves, instead of Rayleigh waves. By now, low-frequency limits of detection (LOD) below 100 pT/Hz can be achieved. However, the LOD can only be further improved by gaining a deep understanding of the existing sensor-intrinsic noise sources and their impact on the sensor’s overall performance. This paper reports on a comprehensive study of the inherent noise of SAW delay line magnetic field sensors. In addition to the noise, however, the sensitivity is of importance, since both quantities are equally important for the LOD. Following the necessary explanations of the electrical and magnetic sensor properties, a further focus is on the losses within the sensor, since these are closely linked to the noise. The considered parameters are in particular the ambient magnetic bias field and the input power of the sensor. Depending on the sensor’s operating point, various noise mechanisms contribute to f0 white phase noise, f−1 flicker phase noise, and f−2 random walk of phase. Flicker phase noise due to magnetic hysteresis losses, i.e. random fluctuations of the magnetization, is usually dominant under typical operating conditions. Noise characteristics are related to the overall magnetic and magnetic domain behavior. Both calculations and measurements show that the LOD cannot be further improved by increasing the sensitivity. Instead, the losses occurring in the magnetic material need to be decreased.

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