Pub Date : 2002-12-16DOI: 10.1109/ICIMW.2002.1076137
T. Nagashima, H. Sumikura, O. Morikawa, M. Hangyo
A photomixing technique for sub-THz wave generation using multimode laser diode (MLD) has been developed. To date, sub-THz spectra had a comb structure that was not suitable for application to spectroscopy. We succeeded in obtaining the improved spectral shape with broad background by optimizing the spot size of the MLD light on the photomixer in a cross-correlation spectroscopy in the sub-THz region.
{"title":"Improvement of spectral shape of sub-terahertz wave excited by multimode laser diode","authors":"T. Nagashima, H. Sumikura, O. Morikawa, M. Hangyo","doi":"10.1109/ICIMW.2002.1076137","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076137","url":null,"abstract":"A photomixing technique for sub-THz wave generation using multimode laser diode (MLD) has been developed. To date, sub-THz spectra had a comb structure that was not suitable for application to spectroscopy. We succeeded in obtaining the improved spectral shape with broad background by optimizing the spot size of the MLD light on the photomixer in a cross-correlation spectroscopy in the sub-THz region.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78111314","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076226
A. K. Rastogi, S. Hardikar
Approximate conformal mapping technique has been used for analysing the effect of finite substrate thickness on coplanar waveguide (CPW) theoretically. Calculations for impedance and effective dielectric constant are presented for CPWs with finite substrate thickness. Analytical formulations are presented for calculations. Network analytical methods of electromagnetic fields are employed to evaluate the effect of thick metal coating on CPW. Dispersion characteristics of CPW have been plotted for various metallization thicknesses. Effect of thick metal coating on attenuation is also plotted. Increase in metallization thickness of CPW causes an increase in wavelength; due to this fact characteristic impedance and effective dielectric constant decreases.
{"title":"Characteristics of CPW with thick metal coating","authors":"A. K. Rastogi, S. Hardikar","doi":"10.1109/ICIMW.2002.1076226","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076226","url":null,"abstract":"Approximate conformal mapping technique has been used for analysing the effect of finite substrate thickness on coplanar waveguide (CPW) theoretically. Calculations for impedance and effective dielectric constant are presented for CPWs with finite substrate thickness. Analytical formulations are presented for calculations. Network analytical methods of electromagnetic fields are employed to evaluate the effect of thick metal coating on CPW. Dispersion characteristics of CPW have been plotted for various metallization thicknesses. Effect of thick metal coating on attenuation is also plotted. Increase in metallization thickness of CPW causes an increase in wavelength; due to this fact characteristic impedance and effective dielectric constant decreases.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86378959","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076114
J. Dutta, C.R. Jones, V. Parshin
A technique for measuring complex dielectric permittivity in the 118-178 GHz frequency range is suggested. The combination of a high-quality Fabry-Perot resonator, excited by a BWO (backward wave oscillator)-generator, with the good processing capability of a sensitive receiver, based on the Tektronix 2782 spectrum analyzer (using the WM782 (F-G) harmonic mixers), opens the possibility of a new measuring technique.
{"title":"MM wave resonator technique for dielectric investigations","authors":"J. Dutta, C.R. Jones, V. Parshin","doi":"10.1109/ICIMW.2002.1076114","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076114","url":null,"abstract":"A technique for measuring complex dielectric permittivity in the 118-178 GHz frequency range is suggested. The combination of a high-quality Fabry-Perot resonator, excited by a BWO (backward wave oscillator)-generator, with the good processing capability of a sensitive receiver, based on the Tektronix 2782 spectrum analyzer (using the WM782 (F-G) harmonic mixers), opens the possibility of a new measuring technique.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90170197","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076218
G. Nusinovich, M. Yedulla, L. Velikovich, T. Antonsen, A. Vlasov
For quasi-CW operation at the MW level and above, millimeter-wave gyrotrons should operate at very high-order modes. Selective excitation of these modes is an extremely difficult problem. Therefore a proper choice of the start-up scenario, which provides initial excitation of a desired mode and its drive into a high efficiency regime with simultaneous suppression of all undesirable parasitic modes, is very important. This problem was first formulated and studied some time ago (G.S. Nusinovich, Elektronnaya Tekhnika, ser. 1, Elektronika SV Ch, no. 3, pp. 44-49, 1974). Later, important contributions that clarified some issues in this problem were made by E. Borie and B.J. Dicke (Int. J. Infrared Millimeter Waves, vol. 8, pp. 207-226, 1987) and D.R. Whaley et al (IEEE-PS vol. 22, pp. 850-860, 1994). This paper discusses several issues which are important for the orrect understanding of this problem, along with the results of simulations used for analyzing the start-up scenarios in 1 MW, 110 GHz and 140 GHz gyrotrons.
{"title":"Start-up scenarios in high-power gyrotrons","authors":"G. Nusinovich, M. Yedulla, L. Velikovich, T. Antonsen, A. Vlasov","doi":"10.1109/ICIMW.2002.1076218","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076218","url":null,"abstract":"For quasi-CW operation at the MW level and above, millimeter-wave gyrotrons should operate at very high-order modes. Selective excitation of these modes is an extremely difficult problem. Therefore a proper choice of the start-up scenario, which provides initial excitation of a desired mode and its drive into a high efficiency regime with simultaneous suppression of all undesirable parasitic modes, is very important. This problem was first formulated and studied some time ago (G.S. Nusinovich, Elektronnaya Tekhnika, ser. 1, Elektronika SV Ch, no. 3, pp. 44-49, 1974). Later, important contributions that clarified some issues in this problem were made by E. Borie and B.J. Dicke (Int. J. Infrared Millimeter Waves, vol. 8, pp. 207-226, 1987) and D.R. Whaley et al (IEEE-PS vol. 22, pp. 850-860, 1994). This paper discusses several issues which are important for the orrect understanding of this problem, along with the results of simulations used for analyzing the start-up scenarios in 1 MW, 110 GHz and 140 GHz gyrotrons.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78697648","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076158
T. Tatsukawa, A. Doi, M. Teranaka, H. Takashima, F. Goda, T. Idehara, T. Kanemaki, T. Namba
The development of a millimeter and submillimeter wave catheter for irradiation of the tissues of living bodies is described. The power sources of electromagnetic waves are an impatt oscillator and a gyrotron. A Teflon rod dielectric antenna or a newly designed waveguide vent antenna with a dielectric sheet is used as a launcher for the irradiation. Preliminary measurements on the denaturalization of tissue are performed.
{"title":"Millimeter wave irradiation on living bodies using a catheter waveguide vent - Teflon antennas","authors":"T. Tatsukawa, A. Doi, M. Teranaka, H. Takashima, F. Goda, T. Idehara, T. Kanemaki, T. Namba","doi":"10.1109/ICIMW.2002.1076158","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076158","url":null,"abstract":"The development of a millimeter and submillimeter wave catheter for irradiation of the tissues of living bodies is described. The power sources of electromagnetic waves are an impatt oscillator and a gyrotron. A Teflon rod dielectric antenna or a newly designed waveguide vent antenna with a dielectric sheet is used as a launcher for the irradiation. Preliminary measurements on the denaturalization of tissue are performed.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79099490","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076053
H. Park, E. Mazzucato, T. Munsat, B. Deng, C. Domier, N. Luhmann, M. J. van de Pol, A. Donne
Advances in technology and innovative ideas have enabled visualization of complex turbulence physics in high temperature plasmas, which has been an enduring outstanding transport issue in toroidal devices. Imaging diagnostics based on millimeter waves have a strong potential to capture 2D images of plasma density and temperature fluctuations.
{"title":"Recent progress on turbulence imaging and visualization diagnostics for high temperature plasmas in toroidal devices","authors":"H. Park, E. Mazzucato, T. Munsat, B. Deng, C. Domier, N. Luhmann, M. J. van de Pol, A. Donne","doi":"10.1109/ICIMW.2002.1076053","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076053","url":null,"abstract":"Advances in technology and innovative ideas have enabled visualization of complex turbulence physics in high temperature plasmas, which has been an enduring outstanding transport issue in toroidal devices. Imaging diagnostics based on millimeter waves have a strong potential to capture 2D images of plasma density and temperature fluctuations.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84886606","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076104
G. L. Carr, M. C. Martin, W. R. McKinney, K. Jordan, G. Neil, Gwyn P. Williams
We report the production of high power (20 watts average, /spl sim/1 megawatt peak) broadband THz light based on coherent emission from relativistic electrons. We describe the source, presenting theoretical calculations and their experimental verification. For clarity we compare this source with one based on ultrafast laser techniques.
{"title":"Very high power THz radiation from relativistic electrons","authors":"G. L. Carr, M. C. Martin, W. R. McKinney, K. Jordan, G. Neil, Gwyn P. Williams","doi":"10.1109/ICIMW.2002.1076104","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076104","url":null,"abstract":"We report the production of high power (20 watts average, /spl sim/1 megawatt peak) broadband THz light based on coherent emission from relativistic electrons. We describe the source, presenting theoretical calculations and their experimental verification. For clarity we compare this source with one based on ultrafast laser techniques.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74985955","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076120
Zhendong Sun, R. Lees, Li-Hong Xu
A tunable infrared (IR) source has been assembled for high-resolution molecular spectroscopy with application to environmental trace gas detection and investigation of large biomolecules. The source employs a Lamb-dip stabilized CO/sub 2/ laser of Evenson design, with 7-18 GHz microwave (MW) sidebands added via a Cheo modulator to obtain tunable IR radiation over a large fraction of the spectral band. The source will be coupled to a slit-jet molecular beam chamber for ultra-high resolution observations.
{"title":"CO/sub 2/-laser/microwave-sideband tunable IR source for molecular spectroscopy with environmental and biomolecular applications","authors":"Zhendong Sun, R. Lees, Li-Hong Xu","doi":"10.1109/ICIMW.2002.1076120","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076120","url":null,"abstract":"A tunable infrared (IR) source has been assembled for high-resolution molecular spectroscopy with application to environmental trace gas detection and investigation of large biomolecules. The source employs a Lamb-dip stabilized CO/sub 2/ laser of Evenson design, with 7-18 GHz microwave (MW) sidebands added via a Cheo modulator to obtain tunable IR radiation over a large fraction of the spectral band. The source will be coupled to a slit-jet molecular beam chamber for ultra-high resolution observations.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72736928","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076196
S. Pogarsky, V. Chumachenko
The analytical-numerical method of electrical wave diffraction by a bounded sequence of periodical irises in a circular waveguide has been suggested. It is based on the idea of the partial inversion of the diffraction problem operator.
{"title":"Electrical waves diffraction by bounded sequence of periodical irises in circular waveguide","authors":"S. Pogarsky, V. Chumachenko","doi":"10.1109/ICIMW.2002.1076196","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076196","url":null,"abstract":"The analytical-numerical method of electrical wave diffraction by a bounded sequence of periodical irises in a circular waveguide has been suggested. It is based on the idea of the partial inversion of the diffraction problem operator.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74026892","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 : 2002-12-16DOI: 10.1109/ICIMW.2002.1076193
A. K. Rastogi
Whispering gallery mode dielectric resonators (WGMDRs) have high quality factors, compatibility with microwave integrated circuits and reasonable mechanical dimensions even at millimeter wavelength frequencies. A simple theoretical model for predicting resonant frequencies of modes of the WGMDR for microwave and millimeter wave integrated circuits is presented. The un-symmetric field distribution for WGE mode in the axial direction is taken into account. Highly useful modeled results such as the effect of DR, aspect ratio, substrate width, and their dielectric constants on each mode are discussed. The effect of the spacer on frequency of MIC WGMDR is also discussed.
{"title":"Characterization of whispering gallery modes in dielectric resonators","authors":"A. K. Rastogi","doi":"10.1109/ICIMW.2002.1076193","DOIUrl":"https://doi.org/10.1109/ICIMW.2002.1076193","url":null,"abstract":"Whispering gallery mode dielectric resonators (WGMDRs) have high quality factors, compatibility with microwave integrated circuits and reasonable mechanical dimensions even at millimeter wavelength frequencies. A simple theoretical model for predicting resonant frequencies of modes of the WGMDR for microwave and millimeter wave integrated circuits is presented. The un-symmetric field distribution for WGE mode in the axial direction is taken into account. Highly useful modeled results such as the effect of DR, aspect ratio, substrate width, and their dielectric constants on each mode are discussed. The effect of the spacer on frequency of MIC WGMDR is also discussed.","PeriodicalId":23431,"journal":{"name":"Twenty Seventh International Conference on Infrared and Millimeter Waves","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79359805","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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