Pub Date : 2008-05-19DOI: 10.1109/FREQ.2008.4623050
Fuping Wu, Li Gun, Xianhe Huang
The highly precise time synchronization is very important to underwater acoustic (UWA) networks (UANs) and underwater targets and vehicles. It consists of a variable number of sensors and vehicles that are deployed to perform collaborative monitoring tasks over given area. The UANs are envisioned to enable applied widely for oceanographic data collection, pollution monitoring, offshore exploration, disaster prevention, assisted navigation and tactical surveillance applications. In the paper, the main purpose is to provide highly precise time synchronization method for the underwater objects. The general designing scheme, the theory of the underwater orientation and navigation and the method of signal processing were given. The results of the underwater experiments show that the precision of time synchronization are 10 ns, 30 ns for a 100 m (stationary) baseline and a 8 km baseline respectively. The experiments also indicate that the major influence factors are complicated for the underwater time synchronization networks and objects.
{"title":"Study on a new time synchronization method for underwater targets and vehicles","authors":"Fuping Wu, Li Gun, Xianhe Huang","doi":"10.1109/FREQ.2008.4623050","DOIUrl":"https://doi.org/10.1109/FREQ.2008.4623050","url":null,"abstract":"The highly precise time synchronization is very important to underwater acoustic (UWA) networks (UANs) and underwater targets and vehicles. It consists of a variable number of sensors and vehicles that are deployed to perform collaborative monitoring tasks over given area. The UANs are envisioned to enable applied widely for oceanographic data collection, pollution monitoring, offshore exploration, disaster prevention, assisted navigation and tactical surveillance applications. In the paper, the main purpose is to provide highly precise time synchronization method for the underwater objects. The general designing scheme, the theory of the underwater orientation and navigation and the method of signal processing were given. The results of the underwater experiments show that the precision of time synchronization are 10 ns, 30 ns for a 100 m (stationary) baseline and a 8 km baseline respectively. The experiments also indicate that the major influence factors are complicated for the underwater time synchronization networks and objects.","PeriodicalId":220442,"journal":{"name":"2008 IEEE International Frequency Control Symposium","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124332812","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 : 2008-05-19DOI: 10.1109/FREQ.2008.4623059
Jaehyun Lim, Insoo Kim, Kyusun Choi, D. Kenny
A cubic function generator is an essential component in TCXOs to compensate for the frequency variation of quartz resonators during temperature change. The authors present a fully analog CMOS cubic function generator circuit. It is composed of analog variable gain amplifiers and a voltage adder. The circuit generates an exact cubic function that represents a quartz resonatorpsilas frequency versus temperature characteristic. Adjusting the parameters of the cubic wave and adding the higher order terms for more precise control can be done easily in this design. The design is implemented and fabricated in TSMC 0.35 mum technology.
{"title":"A CMOS cubic voltage generator for a temperature compensated crystal oscillator (TCXO)","authors":"Jaehyun Lim, Insoo Kim, Kyusun Choi, D. Kenny","doi":"10.1109/FREQ.2008.4623059","DOIUrl":"https://doi.org/10.1109/FREQ.2008.4623059","url":null,"abstract":"A cubic function generator is an essential component in TCXOs to compensate for the frequency variation of quartz resonators during temperature change. The authors present a fully analog CMOS cubic function generator circuit. It is composed of analog variable gain amplifiers and a voltage adder. The circuit generates an exact cubic function that represents a quartz resonatorpsilas frequency versus temperature characteristic. Adjusting the parameters of the cubic wave and adding the higher order terms for more precise control can be done easily in this design. The design is implemented and fabricated in TSMC 0.35 mum technology.","PeriodicalId":220442,"journal":{"name":"2008 IEEE International Frequency Control Symposium","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123634064","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 : 2008-05-19DOI: 10.1109/FREQ.2008.4623049
M. Hottovy, M. Weiss
Differential delay measurements of two Global Positioning System satellite signal receivers of different manufacture were measured without using geodetic processing software. The two receivers were connected to the same antenna through a splitter, and driven by the same clocks. We obtained the continuous averages of differential delays through the receivers over a period of 128 days. This report will describe the process by which we calculated these averages and will also present the results found for each of the four signal types studied, which are the L1 and L2 carrier phases, and the C1 and P2 code phases.
{"title":"Differential delay between two geodetic gps receivers for L1 and L2 code and carrier signals","authors":"M. Hottovy, M. Weiss","doi":"10.1109/FREQ.2008.4623049","DOIUrl":"https://doi.org/10.1109/FREQ.2008.4623049","url":null,"abstract":"Differential delay measurements of two Global Positioning System satellite signal receivers of different manufacture were measured without using geodetic processing software. The two receivers were connected to the same antenna through a splitter, and driven by the same clocks. We obtained the continuous averages of differential delays through the receivers over a period of 128 days. This report will describe the process by which we calculated these averages and will also present the results found for each of the four signal types studied, which are the L1 and L2 carrier phases, and the C1 and P2 code phases.","PeriodicalId":220442,"journal":{"name":"2008 IEEE International Frequency Control Symposium","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121571339","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 : 2008-05-19DOI: 10.1109/FREQ.2008.4623018
W. Chiu, C. J. Hammond, R. Hammond, L. Harding, E. Hawkins, X. Li, S. Moore, K. Sanders, A. Sleptsov, C. Zhou, M. Cooper
We have employed bulk acoustic wave and surface acoustic wave devices for the sensitive and specific detection of biological agents in complex liquid media. We have produced a robotic liquid delivery system coupled to a multi-layer microfluidic manifold that delivers liquids in a controlled manner to pairs of resonant acoustic sensors in a dasiaUSBpsila type docking station. These resonators were fabricated on a single wafer of piezoelectric material, and a rapid switching process between active areas employed to eliminate cross talk and interference. System performance was enhanced using a proprietary FPGA-based network analyzer with internal digital synthesizer, RF switches and calibration elements. Before the signal was sent to the sensor interface, the impedance of the signal path was transferred to match the sensor interface impedance. The sensors are coated with proprietary planar surface chemistries and polymeric interfaces optimised for biological compatibility, shear modulus and penetration depth to maximise acoustic coupling of a binding signal to the sensor. An optimised elastomeric mounting was developed to minimise the impact of thermal and motional stress on the piezoelectric material, whilst simultaneously providing a sub-microlitre microfluidic dead volume above the sensor. Herein we demonstrate the utility of the system using analytes at each end of the molecular weight range: small molecular weight drug candidates binding to a protein receptor and high molecular weight bacteria binding to an antibody.
{"title":"Resonant acoustic profiling for biological detection and diagnostics","authors":"W. Chiu, C. J. Hammond, R. Hammond, L. Harding, E. Hawkins, X. Li, S. Moore, K. Sanders, A. Sleptsov, C. Zhou, M. Cooper","doi":"10.1109/FREQ.2008.4623018","DOIUrl":"https://doi.org/10.1109/FREQ.2008.4623018","url":null,"abstract":"We have employed bulk acoustic wave and surface acoustic wave devices for the sensitive and specific detection of biological agents in complex liquid media. We have produced a robotic liquid delivery system coupled to a multi-layer microfluidic manifold that delivers liquids in a controlled manner to pairs of resonant acoustic sensors in a dasiaUSBpsila type docking station. These resonators were fabricated on a single wafer of piezoelectric material, and a rapid switching process between active areas employed to eliminate cross talk and interference. System performance was enhanced using a proprietary FPGA-based network analyzer with internal digital synthesizer, RF switches and calibration elements. Before the signal was sent to the sensor interface, the impedance of the signal path was transferred to match the sensor interface impedance. The sensors are coated with proprietary planar surface chemistries and polymeric interfaces optimised for biological compatibility, shear modulus and penetration depth to maximise acoustic coupling of a binding signal to the sensor. An optimised elastomeric mounting was developed to minimise the impact of thermal and motional stress on the piezoelectric material, whilst simultaneously providing a sub-microlitre microfluidic dead volume above the sensor. Herein we demonstrate the utility of the system using analytes at each end of the molecular weight range: small molecular weight drug candidates binding to a protein receptor and high molecular weight bacteria binding to an antibody.","PeriodicalId":220442,"journal":{"name":"2008 IEEE International Frequency Control Symposium","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125300864","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 : 2008-05-19DOI: 10.1109/FREQ.2008.4623065
M. Kumagai, H. Ito, M. Hosokawa, G. Santarelli, C. Locke, J. Hartnett
We have developed a 1 GHz synthesis chain based on a cryogenic sapphire oscillator. The 11.2005 GHz output of the CSO is down-converted for laboratory distribution. The frequency stability of the down-converter itself is 2times10-15 at an averaging time of 1 second. The long-term drift of the CSO is suppressed by referencing it to a hydrogen maser linked to Japan Standard Time. An application of this highly stable reference is absolute frequency measurement of an ultra-narrow clock laser for the optical frequency standard performed using a frequency comb, in which the repetition rate is stabilized by the CSO signal.
{"title":"Development of synthesis chains based on a cryogenic sapphire oscillator","authors":"M. Kumagai, H. Ito, M. Hosokawa, G. Santarelli, C. Locke, J. Hartnett","doi":"10.1109/FREQ.2008.4623065","DOIUrl":"https://doi.org/10.1109/FREQ.2008.4623065","url":null,"abstract":"We have developed a 1 GHz synthesis chain based on a cryogenic sapphire oscillator. The 11.2005 GHz output of the CSO is down-converted for laboratory distribution. The frequency stability of the down-converter itself is 2times10-15 at an averaging time of 1 second. The long-term drift of the CSO is suppressed by referencing it to a hydrogen maser linked to Japan Standard Time. An application of this highly stable reference is absolute frequency measurement of an ultra-narrow clock laser for the optical frequency standard performed using a frequency comb, in which the repetition rate is stabilized by the CSO signal.","PeriodicalId":220442,"journal":{"name":"2008 IEEE International Frequency Control Symposium","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130482277","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 : 2008-05-19DOI: 10.1109/FREQ.2008.4622978
M. Takeuchi
LiNbO3 is the substrate most often used in wireless identification tags because of its large electromechanical coupling constant. A single-phase unidirectional transducer (SPUDT) on LiNbO3 is attractive to realize a wireless SAW sensor with reduced size, low insertion loss, low passband ripple, and high degree of linearity of phase. A natural single-phase unidirectional transducer (NSPUDT) produces the directivity even when the geometry is symmetrical. The NSPUDT is good for high frequency sensor applications because of its simple structure with wide electrode width. In this paper, NSPUDT orientations on a LiNbO3 substrate are described. Analytical results of transduction characteristics and COM parameters of the NSPUDT using coupled-mode and perturbation theories are shown. A useful orientation on Euler angle (0deg, 38deg, psi ) cut is obtained for aluminum and copper electrodes.
{"title":"Natural single-phase unidirectional transducers on a LiNbO3 substrate for SAW sensor applications","authors":"M. Takeuchi","doi":"10.1109/FREQ.2008.4622978","DOIUrl":"https://doi.org/10.1109/FREQ.2008.4622978","url":null,"abstract":"LiNbO3 is the substrate most often used in wireless identification tags because of its large electromechanical coupling constant. A single-phase unidirectional transducer (SPUDT) on LiNbO3 is attractive to realize a wireless SAW sensor with reduced size, low insertion loss, low passband ripple, and high degree of linearity of phase. A natural single-phase unidirectional transducer (NSPUDT) produces the directivity even when the geometry is symmetrical. The NSPUDT is good for high frequency sensor applications because of its simple structure with wide electrode width. In this paper, NSPUDT orientations on a LiNbO3 substrate are described. Analytical results of transduction characteristics and COM parameters of the NSPUDT using coupled-mode and perturbation theories are shown. A useful orientation on Euler angle (0deg, 38deg, psi ) cut is obtained for aluminum and copper electrodes.","PeriodicalId":220442,"journal":{"name":"2008 IEEE International Frequency Control Symposium","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122274523","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 : 2008-05-19DOI: 10.1109/FREQ.2008.4623067
J. Nosek, L. Burianova
The influence of electric field on the properties of piezoelectric single domain crystal was precisely specified by means of non-linear electro-elastic differential equations [1]. An equivalent treatment, i.e. using the thermodynamically defined material constants for the thickness shear mode resonators, is presented in this paper. Based on the Tierstenpsilas relations [2], we attempt to specify the 4th order effective elastic stiffness tildec6666 for the Y-cut quartz resonators, and gallium ortho-phosphate (GaPO4) resonators. It was discovered that the nonlinear effective stiffness tildec6666 consists of five basic stiffnesses of the 4th order. The tildec6666 was measured for five different cuts of piezoelectric resonators and the constants A1, A2, A3, A4, A5 were specified for each of the cuts. A system of five equations was obtained. By solving this particular system of equations values of basic elastic stiffnesses of the 4th order c5555, c5556, c5566, c5666, and c6666 were obtained. In addition, the GaPO4 crystals were used to study the nonlinear amplitude-frequency-, and inter-modulation effects, and to determine the tildec6666. The measured data were used for modeling the nonlinear A(F) effect by nonlinear electric equivalent circuit of the BAW GaPO4 resonator vibrating in the thickness-shear mode of vibrations. Additional important nonlinear effect such as influence of the electric field to the SAW velocity was used for design of a new SAW transducer. The basic equations describing this effect are presented in the paper.
{"title":"About nonlinear effects in the quartz homeotypes single crystals","authors":"J. Nosek, L. Burianova","doi":"10.1109/FREQ.2008.4623067","DOIUrl":"https://doi.org/10.1109/FREQ.2008.4623067","url":null,"abstract":"The influence of electric field on the properties of piezoelectric single domain crystal was precisely specified by means of non-linear electro-elastic differential equations [1]. An equivalent treatment, i.e. using the thermodynamically defined material constants for the thickness shear mode resonators, is presented in this paper. Based on the Tierstenpsilas relations [2], we attempt to specify the 4<sup>th</sup> order effective elastic stiffness tildec<sub>6666</sub> for the Y-cut quartz resonators, and gallium ortho-phosphate (GaPO<sub>4</sub>) resonators. It was discovered that the nonlinear effective stiffness tildec<sub>6666</sub> consists of five basic stiffnesses of the 4<sup>th</sup> order. The tildec<sub>6666</sub> was measured for five different cuts of piezoelectric resonators and the constants A<sub>1</sub>, A<sub>2</sub>, A<sub>3</sub>, A<sub>4</sub>, A<sub>5</sub> were specified for each of the cuts. A system of five equations was obtained. By solving this particular system of equations values of basic elastic stiffnesses of the 4<sup>th</sup> order c<sub>5555</sub>, c<sub>5556</sub>, c<sub>5566</sub>, c<sub>5666</sub>, and c<sub>6666</sub> were obtained. In addition, the GaPO<sub>4</sub> crystals were used to study the nonlinear amplitude-frequency-, and inter-modulation effects, and to determine the tildec<sub>6666</sub>. The measured data were used for modeling the nonlinear A(F) effect by nonlinear electric equivalent circuit of the BAW GaPO<sub>4</sub> resonator vibrating in the thickness-shear mode of vibrations. Additional important nonlinear effect such as influence of the electric field to the SAW velocity was used for design of a new SAW transducer. The basic equations describing this effect are presented in the paper.","PeriodicalId":220442,"journal":{"name":"2008 IEEE International Frequency Control Symposium","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122311569","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 : 2008-05-19DOI: 10.1109/FREQ.2008.4623071
E. Courjon, G. Ulliac, J. Garcia, V. Pétrini, W. Daniau, S. Ballandras, J. Hauden
In this paper, we present new results on the development of piezoelectric transducers based on periodically poled ferroelectric domains on lithium niobate. The fabrication of test devices operating in the range 17-665 MHz has been achieved on 3" 500 mum thick wafers. These devices have been bonded on silicon and lapped down to a few tens of microns. Guided elliptic as well as partially guided longitudinal modes are excited, yielding phase velocity of about 3800 and 7000 m.s-1 respectively. The experimental responses are compared to the theoretical results. Finally, the temperature coefficients of frequency are measured and simulated by introducing temperature variations in our FEA/BEM code showing a good agreement between both results.
{"title":"Characterization of guided modes excited by periodically poled transducers on Si","authors":"E. Courjon, G. Ulliac, J. Garcia, V. Pétrini, W. Daniau, S. Ballandras, J. Hauden","doi":"10.1109/FREQ.2008.4623071","DOIUrl":"https://doi.org/10.1109/FREQ.2008.4623071","url":null,"abstract":"In this paper, we present new results on the development of piezoelectric transducers based on periodically poled ferroelectric domains on lithium niobate. The fabrication of test devices operating in the range 17-665 MHz has been achieved on 3\" 500 mum thick wafers. These devices have been bonded on silicon and lapped down to a few tens of microns. Guided elliptic as well as partially guided longitudinal modes are excited, yielding phase velocity of about 3800 and 7000 m.s-1 respectively. The experimental responses are compared to the theoretical results. Finally, the temperature coefficients of frequency are measured and simulated by introducing temperature variations in our FEA/BEM code showing a good agreement between both results.","PeriodicalId":220442,"journal":{"name":"2008 IEEE International Frequency Control Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129741906","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 : 2008-05-19DOI: 10.1109/FREQ.2008.4623029
M. McCorquodale
Self-referenced, trimmed and temperature-compensated radio frequency (RF) CMOS LC, or harmonic oscillators (CHOs) are presented as high-accuracy and low-jitter monolithic frequency generators. CHOs are discussed within the context of recent efforts toward replacement of piezoelectric frequency references with silicon MEMS technology. In contrast, CHOs are self-referenced solid-state oscillators which can be fabricated in a standard microelectronic process technology. The CHO architecture and recent implementations are presented. Frequency- and time-domain performance of CHOs is reported and compared to the incumbent piezoelectric oscillators and emerging MEMS-referenced synthesizers. It is shown that CHOs achieve frequency error as low as plusmn26 ppm over 90degC and 1/6th the period jitter of MEMS-referenced synthesizers at the same frequency.
{"title":"Self-referenced, trimmed and compensated RF CMOS harmonic oscillators as monolithic frequency generators","authors":"M. McCorquodale","doi":"10.1109/FREQ.2008.4623029","DOIUrl":"https://doi.org/10.1109/FREQ.2008.4623029","url":null,"abstract":"Self-referenced, trimmed and temperature-compensated radio frequency (RF) CMOS LC, or harmonic oscillators (CHOs) are presented as high-accuracy and low-jitter monolithic frequency generators. CHOs are discussed within the context of recent efforts toward replacement of piezoelectric frequency references with silicon MEMS technology. In contrast, CHOs are self-referenced solid-state oscillators which can be fabricated in a standard microelectronic process technology. The CHO architecture and recent implementations are presented. Frequency- and time-domain performance of CHOs is reported and compared to the incumbent piezoelectric oscillators and emerging MEMS-referenced synthesizers. It is shown that CHOs achieve frequency error as low as plusmn26 ppm over 90degC and 1/6th the period jitter of MEMS-referenced synthesizers at the same frequency.","PeriodicalId":220442,"journal":{"name":"2008 IEEE International Frequency Control Symposium","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129899721","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 : 2008-05-19DOI: 10.1109/FREQ.2008.4622960
E. Ivanov, M. Tobar
We demonstrated the possibility of "real time" noise measurements at microwave frequencies with spectral resolution ~ 8 dB below the standard thermal noise limit. This was achieved by combining the principles of microwave circuit interferometry with signal recycling and minimizing the influence of various technical noise sources on the measurement processes.
{"title":"Noise measurements beyond the standard thermal noise limit","authors":"E. Ivanov, M. Tobar","doi":"10.1109/FREQ.2008.4622960","DOIUrl":"https://doi.org/10.1109/FREQ.2008.4622960","url":null,"abstract":"We demonstrated the possibility of \"real time\" noise measurements at microwave frequencies with spectral resolution ~ 8 dB below the standard thermal noise limit. This was achieved by combining the principles of microwave circuit interferometry with signal recycling and minimizing the influence of various technical noise sources on the measurement processes.","PeriodicalId":220442,"journal":{"name":"2008 IEEE International Frequency Control Symposium","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132923912","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：