Pub Date : 2010-06-01DOI: 10.1109/FREQ.2010.5556256
I. Avramov, Stephen R Gilbert, Richard C. Ruby
First results on a novel power efficient voltage controlled oscillator (VCO) in the lower GHz range, featuring excellent phase noise, high frequency accuracy and stability are presented. The heart of the VCO is a novel miniature two-pole De-coupled Stacked Bulk Acoustic Resonator (DSBAR) filter recently reported. With its single 180 deg. phase transition over the 1 dB bandwidth, linear phase and maximum 1 dB insertion loss it provides stable single-mode operation over 45 MHz (≈3%) of tuning bandwidth and negligible heat dissipation when operated at incident power levels of 100 mW and higher. The 1,55 GHz laboratory VCO prototypes operate at 5V supply voltage, 50 mA supply current, 15 dBm of output power and >13% efficiency demonstrating −83 and <−180 dBc/Hz phase noise suppression at 1 KHz carrier offset and in the thermal noise region, respectively. VCO with cascaded DSBAR filters for further phase noise reduction are also demonstrated.
{"title":"1.5 GHz voltage controlled oscillator with 3% tuning bandwidth using a two-pole DSBAR filter","authors":"I. Avramov, Stephen R Gilbert, Richard C. Ruby","doi":"10.1109/FREQ.2010.5556256","DOIUrl":"https://doi.org/10.1109/FREQ.2010.5556256","url":null,"abstract":"First results on a novel power efficient voltage controlled oscillator (VCO) in the lower GHz range, featuring excellent phase noise, high frequency accuracy and stability are presented. The heart of the VCO is a novel miniature two-pole De-coupled Stacked Bulk Acoustic Resonator (DSBAR) filter recently reported. With its single 180 deg. phase transition over the 1 dB bandwidth, linear phase and maximum 1 dB insertion loss it provides stable single-mode operation over 45 MHz (≈3%) of tuning bandwidth and negligible heat dissipation when operated at incident power levels of 100 mW and higher. The 1,55 GHz laboratory VCO prototypes operate at 5V supply voltage, 50 mA supply current, 15 dBm of output power and >13% efficiency demonstrating −83 and <−180 dBc/Hz phase noise suppression at 1 KHz carrier offset and in the thermal noise region, respectively. VCO with cascaded DSBAR filters for further phase noise reduction are also demonstrated.","PeriodicalId":344989,"journal":{"name":"2010 IEEE International Frequency Control Symposium","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128524537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-01DOI: 10.1109/FREQ.2010.5556344
M. Huang, C. Klimcak, J. Camparo
For space-qualified vapor-cell atomic clocks, the pressure-shift coefficient describes the frequency change as the device transitions from atmospheric pressure to vacuum. Two processes are known to affect this frequency change: a thermal pathways mechanism and a resonance-cell volume mechanism (i.e., the so-called barometric frequency shift). Here, we focus on the barometric frequency shift, and employ finite element methods to examine how the barometric shift depends on resonance-cell size and wall thickness.
{"title":"Vapor-cell clock frequency and environmental pressure: Resonance-cell volume changes","authors":"M. Huang, C. Klimcak, J. Camparo","doi":"10.1109/FREQ.2010.5556344","DOIUrl":"https://doi.org/10.1109/FREQ.2010.5556344","url":null,"abstract":"For space-qualified vapor-cell atomic clocks, the pressure-shift coefficient describes the frequency change as the device transitions from atmospheric pressure to vacuum. Two processes are known to affect this frequency change: a thermal pathways mechanism and a resonance-cell volume mechanism (i.e., the so-called barometric frequency shift). Here, we focus on the barometric frequency shift, and employ finite element methods to examine how the barometric shift depends on resonance-cell size and wall thickness.","PeriodicalId":344989,"journal":{"name":"2010 IEEE International Frequency Control Symposium","volume":"420 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116530556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-01DOI: 10.1109/FREQ.2010.5556345
T. Niu, M. Palaniapan
In this paper, a 10MHz micromechanical reference oscillator is presented by combining lamé-mode bulk resonator with Q above 200,000 and low noise off-chip interface circuitry. Benefiting from high quality factor as well as large energy storage capability of the bulk resonator, low phase noise performance has been achieved even when the resonator is operating in nonlinear region with a 4Vp-p oscillation output. A clear sine wave output signal is observed and the oscillator shows −138dBc/Hz noise floor and −132dBc/Hz 1kHz away from the carrier, which meets the cellular phase noise requirement of −130dBc/Hz at 1kHz offset for 13MHz GSM reference oscillators. Such oscillator does not require any gain limiting circuitry and hence makes the implementation much simpler and less noisy.
{"title":"A low phase noise 10MHz micromechanical lamé-mode bulk oscillator operating in nonlinear region","authors":"T. Niu, M. Palaniapan","doi":"10.1109/FREQ.2010.5556345","DOIUrl":"https://doi.org/10.1109/FREQ.2010.5556345","url":null,"abstract":"In this paper, a 10MHz micromechanical reference oscillator is presented by combining lamé-mode bulk resonator with Q above 200,000 and low noise off-chip interface circuitry. Benefiting from high quality factor as well as large energy storage capability of the bulk resonator, low phase noise performance has been achieved even when the resonator is operating in nonlinear region with a 4Vp-p oscillation output. A clear sine wave output signal is observed and the oscillator shows −138dBc/Hz noise floor and −132dBc/Hz 1kHz away from the carrier, which meets the cellular phase noise requirement of −130dBc/Hz at 1kHz offset for 13MHz GSM reference oscillators. Such oscillator does not require any gain limiting circuitry and hence makes the implementation much simpler and less noisy.","PeriodicalId":344989,"journal":{"name":"2010 IEEE International Frequency Control Symposium","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124717598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-01DOI: 10.1109/FREQ.2010.5556260
Ji Wang, Lijun Yang, Jianke Du, Dejin Huang
An analysis of overtone quartz crystal resonators is required as part of the design process which has been turning out products of higher-order overtone for many years. It has been known that current analysis is generally oversimplified and the trial-and-error approach has been the only choice by engineers as the practical analytical method and tools are not available, but we found that the Mindlin plate equations in the design and analysis of the fundamental thickness-shear type of resonators can be improved and utilized. Through extensive improvements of the Mindlin plate equations, we can now analyze vibrations for mode couplings, electrode effect, optimal sizes, and thermal behavior, among others. Since it has been proven that the Mindlin plate equations can be used for the vibration analysis of plates at the higher-order overtone modes with accurate prediction of frequency and dispersion relations in the vicinity of cut-off frequencies, we have extended the equations to the third-order for the modal behavior and frequency spectra. The results show that earlier knowledge on the proper selection of the sizes of electrode can be theoretically proven from our analysis. In addition, the spatial variation and end effects of displacements, particularly of the working mode, can be used in the optimal selection of a quartz crystal blank. The design changes can be used as a way to improve the resonator performance, which has been increasingly degenerating for higher-order overtone types, to meet more stringent requirements. We now extend the Mindlin plate equations with latest corrections to the fifth-order so the design principle and guidelines can be summarized from analytical results of vibration analysis. As a research objective for years, we are getting improved frequency solutions as expected after extensive improvements and corrections of the Mindlin plate equations, and the frequency spectra and vibration modes will be compared with known fundamental and third-order solutions to extract needed design guidelines.
{"title":"The Fifth-order overtone vibrations of crystal plates with corrected higher-order Mindlin plate equations","authors":"Ji Wang, Lijun Yang, Jianke Du, Dejin Huang","doi":"10.1109/FREQ.2010.5556260","DOIUrl":"https://doi.org/10.1109/FREQ.2010.5556260","url":null,"abstract":"An analysis of overtone quartz crystal resonators is required as part of the design process which has been turning out products of higher-order overtone for many years. It has been known that current analysis is generally oversimplified and the trial-and-error approach has been the only choice by engineers as the practical analytical method and tools are not available, but we found that the Mindlin plate equations in the design and analysis of the fundamental thickness-shear type of resonators can be improved and utilized. Through extensive improvements of the Mindlin plate equations, we can now analyze vibrations for mode couplings, electrode effect, optimal sizes, and thermal behavior, among others. Since it has been proven that the Mindlin plate equations can be used for the vibration analysis of plates at the higher-order overtone modes with accurate prediction of frequency and dispersion relations in the vicinity of cut-off frequencies, we have extended the equations to the third-order for the modal behavior and frequency spectra. The results show that earlier knowledge on the proper selection of the sizes of electrode can be theoretically proven from our analysis. In addition, the spatial variation and end effects of displacements, particularly of the working mode, can be used in the optimal selection of a quartz crystal blank. The design changes can be used as a way to improve the resonator performance, which has been increasingly degenerating for higher-order overtone types, to meet more stringent requirements. We now extend the Mindlin plate equations with latest corrections to the fifth-order so the design principle and guidelines can be summarized from analytical results of vibration analysis. As a research objective for years, we are getting improved frequency solutions as expected after extensive improvements and corrections of the Mindlin plate equations, and the frequency spectra and vibration modes will be compared with known fundamental and third-order solutions to extract needed design guidelines.","PeriodicalId":344989,"journal":{"name":"2010 IEEE International Frequency Control Symposium","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129193822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-01DOI: 10.1109/FREQ.2010.5556365
L. Ruppalt, D. McKinstry, K. Lauritzen, A. Wu, Shawn A. Phillips, S. Talisa
In this article, we describe the simultaneous digital measurement of both phase (PM) and amplitude (AM) noise of VHF and microwave sources by the direct digitization of the signal-under-test. Our measurement approach takes advantage of a commercially-available, high-dynamic-range analog-to-digital converter driven by a high-performance clock to digitize the signal-under-test with high fidelity. Following digitization, phase and amplitude fluctuations are extracted and converted to PM and AM noise spectra. Measurement of microwave signals is accomplished by the inclusion of a specially-designed low-noise down-converter to translate the signal frequency to the VHF regime while introducing minimal additional signal noise. Measurements made on this system are shown to be in good agreement with those obtained using a conventional heterodyne mixer system. In addition to speeding the characterization of RF sources by simultaneously measuring both PM and AM signal characteristics, the digital noise measurement approach allows the direct measurement of the PM- and AM-noise spectra of more complex signals, such as pulsed CW waveforms, in both the VHF and microwave regimes.
{"title":"Simultaneous digital measurement of phase and amplitude noise","authors":"L. Ruppalt, D. McKinstry, K. Lauritzen, A. Wu, Shawn A. Phillips, S. Talisa","doi":"10.1109/FREQ.2010.5556365","DOIUrl":"https://doi.org/10.1109/FREQ.2010.5556365","url":null,"abstract":"In this article, we describe the simultaneous digital measurement of both phase (PM) and amplitude (AM) noise of VHF and microwave sources by the direct digitization of the signal-under-test. Our measurement approach takes advantage of a commercially-available, high-dynamic-range analog-to-digital converter driven by a high-performance clock to digitize the signal-under-test with high fidelity. Following digitization, phase and amplitude fluctuations are extracted and converted to PM and AM noise spectra. Measurement of microwave signals is accomplished by the inclusion of a specially-designed low-noise down-converter to translate the signal frequency to the VHF regime while introducing minimal additional signal noise. Measurements made on this system are shown to be in good agreement with those obtained using a conventional heterodyne mixer system. In addition to speeding the characterization of RF sources by simultaneously measuring both PM and AM signal characteristics, the digital noise measurement approach allows the direct measurement of the PM- and AM-noise spectra of more complex signals, such as pulsed CW waveforms, in both the VHF and microwave regimes.","PeriodicalId":344989,"journal":{"name":"2010 IEEE International Frequency Control Symposium","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123730125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-01DOI: 10.1109/FREQ.2010.5556328
N. Kozlovski, D. Malocha
This paper presents recent results on a NASA program to build a low-loss, multi-sensor, SAW temperature sensor system. Multi-track CDMA tags have been previously studied, which helps to balance the tag reflectivity from chip-to- chip. Normally the IDT's beam extends over all tracks and the bandwidth is the same for all tracks, and there is no significant advantage over a single-track using this approach. Wideband tags using orthogonal frequency coding (OFC) can use multi-frequency chips subdivided into multi-tracks with low loss operation. Each track has one or more chips, with each chip having a different chip frequency. The track-transducer is then designed to operate only over the required frequency bands; making each non-interacting track low loss. The overall transducer embodiment is now tailored for optimum performance for loss, coding and chip reflectivity. If all tracks are electrically in parallel, the overall transducer Q remains the same as a short wideband IDT, but the electrical reflection coefficient is chosen for minimum loss or matching. Measured parallel track OFC S11 response was measured where the reflection coefficient is nearly optimized for minimum unmatched loss. In comparison, for a short wideband transducer of equivalent bandwidth, the reflection coefficient is close to unity with large unmatched loss.
{"title":"Multi-track low-loss SAW tags with flexible impedance matching for passive wireless sensor applications","authors":"N. Kozlovski, D. Malocha","doi":"10.1109/FREQ.2010.5556328","DOIUrl":"https://doi.org/10.1109/FREQ.2010.5556328","url":null,"abstract":"This paper presents recent results on a NASA program to build a low-loss, multi-sensor, SAW temperature sensor system. Multi-track CDMA tags have been previously studied, which helps to balance the tag reflectivity from chip-to- chip. Normally the IDT's beam extends over all tracks and the bandwidth is the same for all tracks, and there is no significant advantage over a single-track using this approach. Wideband tags using orthogonal frequency coding (OFC) can use multi-frequency chips subdivided into multi-tracks with low loss operation. Each track has one or more chips, with each chip having a different chip frequency. The track-transducer is then designed to operate only over the required frequency bands; making each non-interacting track low loss. The overall transducer embodiment is now tailored for optimum performance for loss, coding and chip reflectivity. If all tracks are electrically in parallel, the overall transducer Q remains the same as a short wideband IDT, but the electrical reflection coefficient is chosen for minimum loss or matching. Measured parallel track OFC S11 response was measured where the reflection coefficient is nearly optimized for minimum unmatched loss. In comparison, for a short wideband transducer of equivalent bandwidth, the reflection coefficient is close to unity with large unmatched loss.","PeriodicalId":344989,"journal":{"name":"2010 IEEE International Frequency Control Symposium","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121614475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-01DOI: 10.1109/FREQ.2010.5556297
J. Imbaud, G. Douchet, F. Sthal
Among the crystals belonging to the langasite family, the langatate one (La3Ga5.5Ta0.5O14 also called LGT) seems the best candidate to substitute to the quartz crystal for frequency and time applications. Pairs of LGT crystal resonators prototypes working at 10 MHz have been measured on an advanced phase noise measurement system. The LGT crystal resonators noise has been measured according to various driving power values. Investigations on the amplitude-frequency effect with different LGT crystal resonators were done. Analysis and discussion of the results are presented as conclusions.
{"title":"Passive noise analyses on langatate crystal resonators","authors":"J. Imbaud, G. Douchet, F. Sthal","doi":"10.1109/FREQ.2010.5556297","DOIUrl":"https://doi.org/10.1109/FREQ.2010.5556297","url":null,"abstract":"Among the crystals belonging to the langasite family, the langatate one (La3Ga5.5Ta0.5O14 also called LGT) seems the best candidate to substitute to the quartz crystal for frequency and time applications. Pairs of LGT crystal resonators prototypes working at 10 MHz have been measured on an advanced phase noise measurement system. The LGT crystal resonators noise has been measured according to various driving power values. Investigations on the amplitude-frequency effect with different LGT crystal resonators were done. Analysis and discussion of the results are presented as conclusions.","PeriodicalId":344989,"journal":{"name":"2010 IEEE International Frequency Control Symposium","volume":"173 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114906237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-01DOI: 10.1109/FREQ.2010.5556288
Fang Cheng, Xiaochun Lu, Tao Han, Ji Wang
Transponder satellite positioning system uses common business geostationary orbit communication satellites to combine the navigation satellite constellation. We first obtain the observation data of navigation signal. By disposing these data, we analyze different error sources which could impact the timing accuracy, then calculate the signal frequency windage from navigation satellites that has the possibility to greatly impact the capability of user receivers. What's more, the evaluations on timing and velocity measurement performances of transponder satellite positioning system are given.
{"title":"Performance evaluation on time and frequency transfer of transponder satellite positioning system","authors":"Fang Cheng, Xiaochun Lu, Tao Han, Ji Wang","doi":"10.1109/FREQ.2010.5556288","DOIUrl":"https://doi.org/10.1109/FREQ.2010.5556288","url":null,"abstract":"Transponder satellite positioning system uses common business geostationary orbit communication satellites to combine the navigation satellite constellation. We first obtain the observation data of navigation signal. By disposing these data, we analyze different error sources which could impact the timing accuracy, then calculate the signal frequency windage from navigation satellites that has the possibility to greatly impact the capability of user receivers. What's more, the evaluations on timing and velocity measurement performances of transponder satellite positioning system are given.","PeriodicalId":344989,"journal":{"name":"2010 IEEE International Frequency Control Symposium","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114723041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-01DOI: 10.1109/FREQ.2010.5556360
Zhong Wang, Tao Guo, Ke Deng, Xuzong Chen
We have theoretically and experimentally proven that the transient transmitted laser power through a typical Λ system atomic cell near Coherent Population Trapping resonance presents as a damping oscillation. The oscillating frequency is identical to the frequency detuning from the atomic hyperfine splitting. Based on the transient coherent population trapping (TCPT) phenomenon, we have proposed an atomic clock in which the standard frequency is obtained by compensated the TCPT oscillating frequency to the RF modulating frequency. Therefore we do not need to lock the RF frequency. There will be advantages for atomic clock miniaturization and stabilization.
{"title":"An atomic clock based on the transient coherent population trapping detuning oscillation phenomenon","authors":"Zhong Wang, Tao Guo, Ke Deng, Xuzong Chen","doi":"10.1109/FREQ.2010.5556360","DOIUrl":"https://doi.org/10.1109/FREQ.2010.5556360","url":null,"abstract":"We have theoretically and experimentally proven that the transient transmitted laser power through a typical Λ system atomic cell near Coherent Population Trapping resonance presents as a damping oscillation. The oscillating frequency is identical to the frequency detuning from the atomic hyperfine splitting. Based on the transient coherent population trapping (TCPT) phenomenon, we have proposed an atomic clock in which the standard frequency is obtained by compensated the TCPT oscillating frequency to the RF modulating frequency. Therefore we do not need to lock the RF frequency. There will be advantages for atomic clock miniaturization and stabilization.","PeriodicalId":344989,"journal":{"name":"2010 IEEE International Frequency Control Symposium","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121694073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-01DOI: 10.1109/FREQ.2010.5556306
Jinxiang Shen, Ji Wang, Jianke Du, Dejin Huang
Layered structures of piezoelectric films are the core of recently emerged film acoustic resonators of both film bulk acoustic resonators (FBAR) and surface mounted resonators (SMR). As products of film acoustic wave resonators are being accepted in telecommunication applications, notable advantages and acceptable performance have been subjected to possible improvements with structures, materials, and other modifications to meet demands for miniaturized devices from the preferred manufacturing process. These improvements, as the products are already sophisticated with the manufacturing process and design techniques, have to be made with the combination of analytical model and actual fabrication. For practical applications as a frequency control element in circuits, we need to have the electrical parameters from design and actual products, but we can rarely obtain the estimation before we make actual measurement like the resistance, capacitance, and the quality factor. With the known functioning mechanism and energy loss mechanism of acoustic wave resonators, we have been able to formulate the wave propagation in resonators with viscosity of materials for solutions which can be used for the estimations of electrical parameters. Such a procedure has been established for bulk acoustic wave resonators of both traditional quartz crystal and film bulk acoustic wave types, and the key issue is now the determination of the viscosity, which usually is not the ideal value we can obtain from material testing. Not hard to imagine, the dominant energy loss, or the viscosity, is from the bonding process of layers which brought contamination and surface modification which play more important roles in the overall performance of a typical resonator. With these principles and experiences, we start with a surface mounting resonator model with viscous piezoelectric layers. Following the familiar procedure for the viscosity consideration, a complex system of wave propagation equations are obtained, and the vibration frequency, which is no longer real-valued, the deformation, and electrical fields are obtained. Our focus is on the effect of the viscosity on the vibration frequency and wave propagation. With the known major properties such as the quality factor, we can obtain a relatively good estimation of the dominant viscosity in the piezoelectric layer, which in turn will be essential for the calculation of other electrical parameters as we have done for FBAR type. Of course, the usual structure of surface wave resonators with discrete electrodes (IDTs) will result in more complicated formulations which will be our focus the future studies
{"title":"The propagation of Rayleigh waves in layered piezoelectric structures with viscosity","authors":"Jinxiang Shen, Ji Wang, Jianke Du, Dejin Huang","doi":"10.1109/FREQ.2010.5556306","DOIUrl":"https://doi.org/10.1109/FREQ.2010.5556306","url":null,"abstract":"Layered structures of piezoelectric films are the core of recently emerged film acoustic resonators of both film bulk acoustic resonators (FBAR) and surface mounted resonators (SMR). As products of film acoustic wave resonators are being accepted in telecommunication applications, notable advantages and acceptable performance have been subjected to possible improvements with structures, materials, and other modifications to meet demands for miniaturized devices from the preferred manufacturing process. These improvements, as the products are already sophisticated with the manufacturing process and design techniques, have to be made with the combination of analytical model and actual fabrication. For practical applications as a frequency control element in circuits, we need to have the electrical parameters from design and actual products, but we can rarely obtain the estimation before we make actual measurement like the resistance, capacitance, and the quality factor. With the known functioning mechanism and energy loss mechanism of acoustic wave resonators, we have been able to formulate the wave propagation in resonators with viscosity of materials for solutions which can be used for the estimations of electrical parameters. Such a procedure has been established for bulk acoustic wave resonators of both traditional quartz crystal and film bulk acoustic wave types, and the key issue is now the determination of the viscosity, which usually is not the ideal value we can obtain from material testing. Not hard to imagine, the dominant energy loss, or the viscosity, is from the bonding process of layers which brought contamination and surface modification which play more important roles in the overall performance of a typical resonator. With these principles and experiences, we start with a surface mounting resonator model with viscous piezoelectric layers. Following the familiar procedure for the viscosity consideration, a complex system of wave propagation equations are obtained, and the vibration frequency, which is no longer real-valued, the deformation, and electrical fields are obtained. Our focus is on the effect of the viscosity on the vibration frequency and wave propagation. With the known major properties such as the quality factor, we can obtain a relatively good estimation of the dominant viscosity in the piezoelectric layer, which in turn will be essential for the calculation of other electrical parameters as we have done for FBAR type. Of course, the usual structure of surface wave resonators with discrete electrodes (IDTs) will result in more complicated formulations which will be our focus the future studies","PeriodicalId":344989,"journal":{"name":"2010 IEEE International Frequency Control Symposium","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116968165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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