{"title":"Improved quality factor for quartz oscillators","authors":"C. A. Adams, J. Kusters, C. M. Sousa","doi":"10.1109/FREQ.1996.559956","DOIUrl":"https://doi.org/10.1109/FREQ.1996.559956","url":null,"abstract":"For the past 17 years, Hewlett-Packard's Santa Clara crystal facility has produced only SC-cut, 10 MHz, 3rd overtone quartz crystals for precision oven-controlled crystal oscillators. Test data on crystals and oscillators form a data base of almost 200,000 units. All of the units are essentially identical. The resonator design, holder design, and basic oscillator design have not changed during this period. This permits a direct comparison of many properties of a quartz resonator as a function of time, material, and the manufacturing processes used. We have found that the Allan Deviation at a tau of 2700 seconds is an excellent predictor of future oscillator performance and is useful as a new quality control parameter. This is especially important for oscillators required to have good time-domain stability for sampling times of 2,000 to 5,000 seconds. Of interest to crystal and oscillator manufacturers is that the new quality control parameter shows strong correlation with many factors important to oscillator users. In particular, we see a strong relationship between the Allan deviation with a tau of 45 minutes (2700 seconds) and frequency jumps, short-term time domain stability, and several mechanical processes in resonator fabrication (especially surface finish). The use of this single parameter is a more reliable indication of overall oscillator performance than the combination of factors previously used.","PeriodicalId":140391,"journal":{"name":"Proceedings of 1996 IEEE International Frequency Control Symposium","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125153336","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":"Cold atoms and cesium fountains at NRC","authors":"J. Boulanger, M. Gagné, R. Douglas","doi":"10.1109/FREQ.1996.560299","DOIUrl":"https://doi.org/10.1109/FREQ.1996.560299","url":null,"abstract":"We present a progress report on laser-cooled cesium atoms at NRC, work which was started a few years ago in order to realize a cesium fountain frequency standard. We selected an acceleration with two-dimensional moving molasses, which can increase both the force and the interaction time by a factor of /spl radic/2 over the more common 1-D molasses scheme. This configuration also allows for trapping and cooling of atoms while previously launched atoms are still moving in the clock section of the system. We report measurements on the number of atoms, temperature, friction coefficient and spring constant of our magneto-optical trap and 1-D molasses for various conditions.","PeriodicalId":140391,"journal":{"name":"Proceedings of 1996 IEEE International Frequency Control Symposium","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115176509","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}
P.A. Senjushenkov, T.V. Hristoforova, B. Mill, V.N. Hristoforov, Y. Pisarevsky
{"title":"Temperature characteristics of langanite bulk wave vibrations","authors":"P.A. Senjushenkov, T.V. Hristoforova, B. Mill, V.N. Hristoforov, Y. Pisarevsky","doi":"10.1109/FREQ.1996.559833","DOIUrl":"https://doi.org/10.1109/FREQ.1996.559833","url":null,"abstract":"Langanite (NGL) is the promising material for FC applications. In present work we measured NGL piezoelectric constants at temperature range -196/spl deg/C-+120/spl deg/C. This results and previous data on temperature dependencies (TD) other constants enabled to make the complete theoretical analysis of thickness vibration parameters of NGL single and double rotation cuts in wide temperature range. Thermally compensated xybl//spl alpha///spl beta/ cuts were theoretically found for several modes. For slow shear mode first and second order temperature coefficients (TC) could be zero simultaneously. From our calculations resonator frequency shift at temperature range could be 2-4 times better than SGL one. High quality NGL single crystals were grown by Czochralski method NGL plane, plano-convex and double-convex plates were prepared and tested at temperature range 15/spl deg/C-120/spl deg/C on fundamental and 3, 5, 7 overtone frequencies. It experimentally suggested zero cuts existence. From above data and possibility to grow high quality single crystals NGL seems to be more promising compare with SGL.","PeriodicalId":140391,"journal":{"name":"Proceedings of 1996 IEEE International Frequency Control Symposium","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115303002","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}
B. Gaigerov, N. Koshelyaevsky, S. Pushkin, V. Tatarenkov, G. Yolkin
{"title":"The atomic time scale of Russia","authors":"B. Gaigerov, N. Koshelyaevsky, S. Pushkin, V. Tatarenkov, G. Yolkin","doi":"10.1109/FREQ.1996.560306","DOIUrl":"https://doi.org/10.1109/FREQ.1996.560306","url":null,"abstract":"The main aim of this paper is to depict the arrangement of atomic timing in Russia. For many years, time and frequency metrology in Russia have been developed quite separately. That's why it seems to be interesting to compare achievement in such high technology areas, as for example accurate atomic timing, in Russia and leading western countries after more than 30 years independent and competitive development. The paper consists of three parts. The first one depicts mainly housing and maintenance of the instruments, time and frequency intercomparison technology and the individual performances of primary standards and clocks. Then a core of the time algorithm is touched upon. The last part presents results on the Russia national atomic time unit-the second TA(SU)-comparison with the second reproduced by the national primary caesium standard and those of the leading time laboratories abroad and the international time reference system-TAI.","PeriodicalId":140391,"journal":{"name":"Proceedings of 1996 IEEE International Frequency Control Symposium","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114150728","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 spurious reduction technique for high-speed direct digital synthesizers","authors":"L. Kushner, M.T. Ainsworth","doi":"10.1109/FREQ.1996.560276","DOIUrl":"https://doi.org/10.1109/FREQ.1996.560276","url":null,"abstract":"Digital-to-Analog Converters (DACs) are the primary source of spurious in high-speed Direct Digital Synthesizers (DDS), DAC glitches, DC-linearity errors, and digital noise feedthrough can corrupt the DDS output. This paper proposes a balanced-DAC configuration at the DDS output that can dramatically reduce these effects. A pair of single-ended DACs are employed, driven from a set of inverters that generate the out-of-phase drive signals. An on- or off-chip subtractor combines the two out-of-phase DAC outputs, canceling distortion, noise, and glitches. Simulations along with experimental results from an 800 MHz balanced-DAC DDS breadboard are included. Greater than 10 dB reduction in harmonics, aliased-harmonics, and noise floor have been achieved. A monolithic version of this balanced-DAC DDS has been fabricated and is currently in test.","PeriodicalId":140391,"journal":{"name":"Proceedings of 1996 IEEE International Frequency Control Symposium","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116092511","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":"The influence of amateur radio on the development of the commercial market for quartz piezoelectric resonators in the United States","authors":"P. Brown","doi":"10.1109/FREQ.1996.559819","DOIUrl":"https://doi.org/10.1109/FREQ.1996.559819","url":null,"abstract":"In the mid and late 1920s, amateur radio operators were experimenting in great numbers with crystal control of radio transmitters. At the time, most amateurs used home built transmitters made from a combination of purchased and home made parts. The use of quartz crystals by amateurs predated the first U.S. commercial broadcast station to use crystal control. Amateur radio operators were the first sizable commercial market for crystals. Many of the crystal companies of the 1920s and 1930s were founded by amateur radio operators to supply other amateurs.","PeriodicalId":140391,"journal":{"name":"Proceedings of 1996 IEEE International Frequency Control Symposium","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116233664","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":"Low-loss SAW filters on NSPUDT orientations of a Li/sub 2/B/sub 4/O/sub 7/ substrate","authors":"M. Takeuchi, I. Odagawa, M. Tanaka, K. Yamanouchi","doi":"10.1109/FREQ.1996.559865","DOIUrl":"https://doi.org/10.1109/FREQ.1996.559865","url":null,"abstract":"Natural single phase unidirectional transducers (NSPUDT) have attracted much attention for implementing low-loss SAW devices. In this paper, we describe a low-loss SAW filter on NSPUDT orientation of a Li/sub 2/B/sub 4/O/sub 7/ substrate previously reported by authors. Since the unidirectionality of NSPUDT is inherent to the substrate orientation, it is necessary to make the receiving transducer unidirectional in the opposite direction for obtaining a low-loss filter using two transducers with reverse directivity. A new transducer configuration to reverse the directivity of an NSPUDT substrate is proposed which utilizes reflector banks within the ladder transducer. The configurations has the advantage in that it can be fabricated through a single level and a single metallization with minimum electrode width of /spl lambda//4. The details of NSPUDT orientations on a Li/sub 2/B/sub 4/O/sub 7/ substrate are shown with experimental verifications. The principle of operation of reversal of directivity transducer (RDT) is describe. The 200 MHz band low-loss SAW transversal filter with minimum insertion loss below 3 dB and low passband ripple is demonstrated with a theoretical filler response using coupling-of-modes theory.","PeriodicalId":140391,"journal":{"name":"Proceedings of 1996 IEEE International Frequency Control Symposium","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123247702","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":"Effect of drift on TOTALDEV","authors":"D. Howe, K.J. Lainson","doi":"10.1109/FREQ.1996.560271","DOIUrl":"https://doi.org/10.1109/FREQ.1996.560271","url":null,"abstract":"Estimates of the frequency stability of clocks and oscillators are given by statistics of frequency fluctuations. At long-term averaging times, TOTALDEV is a recommended statistic over ADEV, the Allan deviation. Simulation of common noise types with drift are used to compare TOTALDEV and ADEV. Comparisons show that the response of TOTALDEV is consistent at long term with drift taken out whereas the response of ADEV is not.","PeriodicalId":140391,"journal":{"name":"Proceedings of 1996 IEEE International Frequency Control Symposium","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130169941","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}
Y. Shibata, N. Kuze, M. Matsui, K. Kaya, M. Kanai, T. Kawai
{"title":"SAW properties of LiNbO/sub 3/ and LiTaO/sub 3/ films grown by pulsed laser deposition","authors":"Y. Shibata, N. Kuze, M. Matsui, K. Kaya, M. Kanai, T. Kawai","doi":"10.1109/FREQ.1996.559835","DOIUrl":"https://doi.org/10.1109/FREQ.1996.559835","url":null,"abstract":"LiNbO/sub 3/ and LiTaO/sub 3/ films are deposited on sapphire and AlN/sapphire substrates using Ar-F excimer laser ablation. The deposition and structure of the films are investigated systematically. The structure of the films is analyzed by X-ray pole figure, high-resolution X-ray diffraction and transmission electron microscopy. The results of these analysis indicate that deposited films are extremely high-quality epitaxial films. As-grown LiNbO/sub 3/ and LiTaO/sub 3/ films are sufficiently piezoelectric to fabricate SAW devices. The experimental data of SAW velocity (Vs) and electromechanical coupling coefficients (k/sup 2/) almost coincide with the calculated data.","PeriodicalId":140391,"journal":{"name":"Proceedings of 1996 IEEE International Frequency Control Symposium","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127699721","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 voltage controlled oscillator using low temperature co-fired ceramics","authors":"M.D. O'Hearn","doi":"10.1109/FREQ.1996.560249","DOIUrl":"https://doi.org/10.1109/FREQ.1996.560249","url":null,"abstract":"A description of a voltage controlled oscillator (VCO) fabricated using Low Temperature Co-fired Ceramics (LTCC) is given. The capacitors and inductors that adjust the oscillation frequency are multilayer structures buried in the substrate. With phase-locked loop (PLL) techniques the VCO is suitable for a local oscillator used in 900 MHz cellular and cordless systems. A complete frequency synthesizer module that includes the digital phase comparator and dividers, loop filter, and VCO show that buried components is possible in LTCC and the module has exceptional performance with a reduction in size. Included is the module's measured data.","PeriodicalId":140391,"journal":{"name":"Proceedings of 1996 IEEE International Frequency Control Symposium","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116193213","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}