Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005.最新文献

{"title":"Dual-mode SC-cut resonator hysteresis and aging study","authors":"G. Hague, R. Helmbold, D. Malocha","doi":"10.1109/FREQ.2005.1574035","DOIUrl":"https://doi.org/10.1109/FREQ.2005.1574035","url":null,"abstract":"This paper presents recent measurements and theoretical predictions for dual-mode quartz 20 MHz, third overtone, SC-cut resonators. Fabricated lots of such resonators have f-T hysteresis below 50 parts per billion (ppb), with the best resonators demonstrating only a few ppb over the entire temperature range. Process and fabrication control have shown to be critical elements in reducing both hysteresis and mounting stress. Aging rates have also been measured, and the effects of absolute and mode-to-mode differential aging have been modeled. When both modes age at the same rate, no change in the thermometric frequency is predicted. However, the predictions show thermometric errors versus temperature for differential aging rates. These lead to both a \"tilt\" and an offset in the temperature sensing error versus temperature","PeriodicalId":108334,"journal":{"name":"Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005.","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125278411","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}

{"title":"Autonomous characterization of clock drift for timescale improvement at the AHU/APL time and frequency laboratory","authors":"M. Miranian, G. Weaver, M. Reinhart","doi":"10.1109/FREQ.2005.1573929","DOIUrl":"https://doi.org/10.1109/FREQ.2005.1573929","url":null,"abstract":"We have reported on continuous improvements in the capability of our time and frequency laboratory. A substantial portion of our progress in capability was achieved through the incorporation of new clock hardware, improvement in GPS time recovery and coordination of our clocks into the computation of TAI. We have discussed our ensemble of hydrogen maser and cesium beam atomic clocks into a timescale that enables UTC (APL) to be steered within plusmn 30 nanoseconds per month of UTC. The propagation of the APL timescale is based on a modified version of the Percival method, requiring regular characterization of each clock's frequency rate and drift. Here, we discuss our results in an autonomous characterization of the individual clocks contributing to the APL timescale. This improvement in our operation has minimized the need for routine operator timescale maintenance and realizes the advantages in clock estimation using frequency, described by J.A. Barnes and D.W. Allan (1985). We discuss how our approach at characterizing the nonlinear drift observed in our hydrogen masers has aided our attempt to discipline the long term frequency drift behavior of quartz ultra-stable oscillators in the space environment. As in previous reports, we present updated laboratory performance in the form of UTC-UTC(APL)","PeriodicalId":108334,"journal":{"name":"Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005.","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124656082","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}

{"title":"A two-dimensional analysis of surface acoustic waves in finite plates with eigensoluti","authors":"Ji Wang, Jianke Du, Q. Pan","doi":"10.1109/FREQ.2005.1573967","DOIUrl":"https://doi.org/10.1109/FREQ.2005.1573967","url":null,"abstract":"It is generally known that surface acoustic waves, or Rayleigh waves, have different mode shapes in infinite plates. To be precise, there are both exponentially decaying and growing components in plates appearing in pairs, representing symmetric and anti-symmetric modes in a plate. As the plate thickness increases, the combined modes approached to the Rayleigh mode in a semi-infinite solid, exhibiting surface acoustic wave deformation and velocity. As a result, for plates with finite thickness, we need to consider the effect of two modes in the analysis. In this study, the two-dimensional theory for surface acoustic waves in finite plates is extended to include exponentially growing modes in the expansion function, creating a two-dimensional equation system for plates with finite thickness. Since additional expansion functions are also exponential, the two-dimensional equations keep the same appearance, implying the same evaluation and solution procedure. These results are important in the improvement of two-dimensional analysis of surface acoustic waves in finite solids, which are the essential problem in surface acoustic wave resonator analysis and design","PeriodicalId":108334,"journal":{"name":"Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005.","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121130185","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}

{"title":"A novel absorption resonance for atomic clocks","authors":"D. Phillips, I. Novikova, S. Zibrov, C. Smallwood, A. Taichenachev, V. Yudin, R. Walsworth, A. Zibrov","doi":"10.1109/FREQ.2005.1574031","DOIUrl":"https://doi.org/10.1109/FREQ.2005.1574031","url":null,"abstract":"We report an experimental study of an all-optical three-photon-absorption resonance (known as an \"N-resonance\") and discuss its potential application as an alternative to atomic clocks based on coherent population trapping (CPT). We present measurements of the N-resonance contrast, width and light shift for /sup 87/Rb under various conditions including both D/sub 1/ and D/sub 2/ optical transitions. Under conditions such that first-order light shifts cancel, we observe promising short-term frequency stability (/spl sim/ 1.5 /spl times/ 10/sup -11/ /spl tau//sub - 1/2 /) for an N-resonance on the Di transition of /sup 87/ Rb vapor.","PeriodicalId":108334,"journal":{"name":"Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005.","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125710386","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}

{"title":"Characterizing the performance of GPS disciplined oscillators with respect to UTC(NIT)","authors":"M. Lombardi, A. Novick, V. Zhang","doi":"10.1109/FREQ.2005.1574017","DOIUrl":"https://doi.org/10.1109/FREQ.2005.1574017","url":null,"abstract":"Global Positioning System Disciplined Oscillators (GPSDOs) are now the primary standard of time and frequency at many laboratories and calibration facilities. They are typically accepted as self-calibrating standards, and their users generally assume that they meet the manufacturer's specifications. To gain a better understanding of the actual performance of GPSDOs, this paper presents a method of characterizing both their long and short-term performance that uses the UTC(NIST) time scale as a reference. It then describes how this method is used to characterize four GPSDOs, including two that use an oven controlled quartz oscillator (OCXO) as their time base, and two equipped with a rubidium oscillator. All four devices were simultaneously tested using the same antenna over two 60 d measurement intervals. During the first 60 d measurement, a previously surveyed antenna position was used and the same coordinates were applied to all four devices. During the second 60 d measurement, each GPSDO performed an independent survey of the antenna's position and applied its own coordinates. Both the timing output (1 pulse per second) and the frequency output (10 MHz) of each GPSDO was measured during both 60 d intervals. A low-noise dual mixer time difference system was used to characterize the short-term frequency stability of each device's 10 MHz output, and all measurement results are presented and summarized.","PeriodicalId":108334,"journal":{"name":"Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005.","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128133006","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}

{"title":"Testing of the methods of real-time MTIE calculation","authors":"A. Dobrogowski, M. Kasznia","doi":"10.1109/FREQ.2005.1573965","DOIUrl":"https://doi.org/10.1109/FREQ.2005.1573965","url":null,"abstract":"In this paper the experimental tests of the methods enabling real-time quasi-parallel assessment of maximum time interval error (MTIE) are presented. The idea of real-time quasi-parallel computation of MTIE is introduced first. Then two methods enabling real-time MTIE calculation are described. The results of computation experiments performed using several different data sequences and different computers are included","PeriodicalId":108334,"journal":{"name":"Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005.","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133028854","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}

{"title":"A rubidium frequency standard based on unreal time control approach","authors":"Hui Zhou, W. Zhou, Bayi Qu, Z. Xuan","doi":"10.1109/FREQ.2005.1574000","DOIUrl":"https://doi.org/10.1109/FREQ.2005.1574000","url":null,"abstract":"In conventional rubidium frequency standard and some passive atomic frequency standards the voltage control crystal oscillator VCOCXO exporting the frequency signal of the standards is real time controlled. Because in the locking loop there are frequency transformation circuits, servo amplifier, testing circuits, and physics package, although the output signal of the standards is very accurate and with a good long-term performance, its short-term stability and phase noise performance are poorer than those of VCOCXO. There have been some techniques to filter or control the servo noise, but it is difficult to obtain both good long-term and short-term specifications at the same time. Because a highly stable crystal oscillator not only has a good short-term stability, but also can keep the high accuracy in certain period. Therefore, as an accurate assistant frequency source, the frequency of VCOCXO does not have to be controlled in real time. The unreal time control approach means the servo voltage from the servo amplifier following physics package does not control the frequency of VCOCXO directly. Based on the ability of VCOCXO to keep the accuracy in certain period the control signal can keep unchanged, the good short-term performance of VCOCXO in the standard is taken advantage. In the new rubidium frequency standard, we use microprocessor and I/O units (A/D and D/A converters). This microprocessor can provide the capability of both processing and isolating. It can compare the mean value of output voltage signals of servo amplifier with former voltage signals that control the VCOCXO. The noise of output voltage of servo amplifier can be eliminated through the software processing. The difference between the output voltage signals and the current control voltage signals is related to the regulation value to VCOCXO. The regulation is completed evenly in step according to the least voltage stepping adjusting value in a given adjusting period. This method can guarantee the original stability of VCOCXO and even frequency locking. The rubidium frequency standard can show 1 ~ 2 times 10-12/s stability and better than 5 times10-11/month drift. It is possible to improve its performances further","PeriodicalId":108334,"journal":{"name":"Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005.","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123926849","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}

{"title":"TE/sub 01delta/ mode dielectric resonator coupled with coplanar waveguide","authors":"Jong Hyuk Kim, I. Kim","doi":"10.1109/FREQ.2005.1573924","DOIUrl":"https://doi.org/10.1109/FREQ.2005.1573924","url":null,"abstract":"This paper newly proposes that coupling between a coplanar waveguide (CPW) and a TE01delta mode DR (dielectric resonator) can be realized for a parallel resonant characteristic as a microstrip line. It shows that different place of the DR on a CPW from that of the DR on a microstrip line is required. FEM simulation (HFSS) results in terms of S-parameters agree well with measurement results. Finally, unloaded Q values of the DR coupled with a CPW are compared with those of the DR coupled with a microstrip line. The comparison demonstrates that the DR coupled with a CPW has slightly higher unloaded Q than that coupled with a microstrip line","PeriodicalId":108334,"journal":{"name":"Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005.","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124045001","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}

{"title":"Amplitude-frequency effects in VHF quartz resonators","authors":"W. Horton, G. Hague","doi":"10.1109/FREQ.2005.1574037","DOIUrl":"https://doi.org/10.1109/FREQ.2005.1574037","url":null,"abstract":"Dynamic amplitude-frequency effect measurements made of VHF quartz resonators indicate the presence of two separate mechanisms, the relative contribution of which varies for different cuts. For the SC-cut a step-change in drive level leads to a frequency shift with very short time constant (1 ms) that is presumably the classic direct nonlinear elastic effect. Others such as AT-, BT- and LD-cuts show only a much longer time constant (200 ms), presumably a thermally related indirect nonlinear elastic effect. Near the SC-cut, resonators exhibit a combination of both short- and long-time-constant frequency changes. In some cases the two mechanisms produce frequency shifts in opposite directions. This behavior is problematic for some amplitude-frequency-effect measurement approaches because the measured shift depends on the timing of those measurements. It is not surprising that the SC-cut response shows only the direct nonlinear elastic effect, but it is unexpected that the AT- and BT-cuts appear not to show such effect. These results raise a question as to how these amplitude-frequency effects scale to lower frequencies, what criterion should be used in selecting these characteristics for optimum oscillator phase noise performance and whether it is proper to determine nonlinear elastic constants from AT-cut resonator measurements that assume there is no thermally related effect. LD-cut questions are also raised.","PeriodicalId":108334,"journal":{"name":"Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125711868","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}

{"title":"Laser-incident angle optimization for measuring in-plane mode shapes in piezoelectric resonators with polished surfaces","authors":"Y. Watanabe, S. Goka, H. Sekimoto, T. Yamamoto","doi":"10.1109/FREQ.2005.1573920","DOIUrl":"https://doi.org/10.1109/FREQ.2005.1573920","url":null,"abstract":"Based on an optical reflection model in polished multilayered surfaces, reflectance and transmittance for the incident angle of the laser beam have been analyzed. The analysis demonstrates that the laser incident angle used in the previous experiment is optimum for measuring in-plane mode shapes in polished resonators with gold and chrome electrodes.","PeriodicalId":108334,"journal":{"name":"Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005.","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125147513","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}