Pub Date : 2010-06-21DOI: 10.1109/MSMW.2010.5546058
M. Sakhno, J. Gumenjuk-Sichevska
One of most promising detectors for THz range is the hot electron bolometer on basis of semiconductor compound HgCdTe [1] .Experimental sensitivity is greater than theoretical prediction for such device. The most credible hypothesis is that metallic contacts to the detector play the role of antenna, which is greatly increasing an electric field in the active element. The main probable evidence of this is a strong frequency dependence of the system response similar with those for simple dipole antenna.
{"title":"Electric field enhancement computation for integrated detector of THz range","authors":"M. Sakhno, J. Gumenjuk-Sichevska","doi":"10.1109/MSMW.2010.5546058","DOIUrl":"https://doi.org/10.1109/MSMW.2010.5546058","url":null,"abstract":"One of most promising detectors for THz range is the hot electron bolometer on basis of semiconductor compound HgCdTe [1] .Experimental sensitivity is greater than theoretical prediction for such device. The most credible hypothesis is that metallic contacts to the detector play the role of antenna, which is greatly increasing an electric field in the active element. The main probable evidence of this is a strong frequency dependence of the system response similar with those for simple dipole antenna.","PeriodicalId":129834,"journal":{"name":"2010 INTERNATIONAL KHARKOV SYMPOSIUM ON PHYSICS AND ENGINEERING OF MICROWAVES, MILLIMETER AND SUBMILLIMETER WAVES","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132110986","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 : 2010-06-21DOI: 10.1109/MSMW.2010.5546168
A. Kalenyuk, A. Kasatkin, V. Pan, A. Kurakin, S. Vitusevich
It is well known that high temperature superconductors (HTS) generally reveal a nonlinear dependence of the surface impedance on the input microwave power Zs(Pin) [1,2] unlike to normal metals behavior. This leads to undesirable nonlinear effects (such as: intermodulation distortions, generation of higher harmonics) in HTS passive microwave devices and strongly limits possibilities of their application even for weak microwave signals. On the other hand, strong nonlinear effects in HTS materials can be used for design of active devices, such as microwave power limitters. Similar devices have been elaborated already for application as dc and low-frequency ac current limitters in electric cirquits.
{"title":"Nonlinear attenuation in a long YBCO coplanar transmission line in the vicinity of Tc.","authors":"A. Kalenyuk, A. Kasatkin, V. Pan, A. Kurakin, S. Vitusevich","doi":"10.1109/MSMW.2010.5546168","DOIUrl":"https://doi.org/10.1109/MSMW.2010.5546168","url":null,"abstract":"It is well known that high temperature superconductors (HTS) generally reveal a nonlinear dependence of the surface impedance on the input microwave power Zs(Pin) [1,2] unlike to normal metals behavior. This leads to undesirable nonlinear effects (such as: intermodulation distortions, generation of higher harmonics) in HTS passive microwave devices and strongly limits possibilities of their application even for weak microwave signals. On the other hand, strong nonlinear effects in HTS materials can be used for design of active devices, such as microwave power limitters. Similar devices have been elaborated already for application as dc and low-frequency ac current limitters in electric cirquits.","PeriodicalId":129834,"journal":{"name":"2010 INTERNATIONAL KHARKOV SYMPOSIUM ON PHYSICS AND ENGINEERING OF MICROWAVES, MILLIMETER AND SUBMILLIMETER WAVES","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131802713","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 : 2010-06-21DOI: 10.1109/MSMW.2010.5546047
E. Serov, M. Koshelev, V. Parshin, M. Tretyakov
Investigation of atmospheric gases spectral properties is demanded to develop absorption models. Such models are very important for the global Earth's atmosphere monitoring. Most of atmospheric lines and continuum spectral parameters are obtained in laboratory experiments. Recovered atmospheric parameters accuracy of depends directly on accuracy of laboratory measurements. Parameterization of the continuum absorption, in particular, the water vapor continuum is one of the most difficult problems. The problem is related to yet unknown physical origin of the continuum, its weakness in comparison with absorption in regular discrete lines of water molecule, and general difficulties of the water-related measurements. The water-related continuum broadband measurement by the resonator spectrometer [1] revealed strong influence of water adsorbing on resonator elements on results of the continuum parameters measurements. Analysis [2] of the MM/SubMM continuum measurement methods used in the earlier studies leads to the conclusion that water adsorbing onto mirrors was a common factor influencing the water-related continuum parameters obtained in all well-known laboratory experiments. In all these cases gas cells with multiple reflections of radiation off inner mirrors were used as the most appropriate technique for weak continuum absorption investigation, although the problem of separation of water vapor absorption and absorption by water adsorbed on mirrors was not solved in the experiments. To overcome the problem it was proposed to use the cavity length variation method [1], which permits separation of these two types of absorptions and, as a result, the accuracy of continuum absorption measurements increases.
{"title":"Atmosphere continuum absorption investigation at MM waves","authors":"E. Serov, M. Koshelev, V. Parshin, M. Tretyakov","doi":"10.1109/MSMW.2010.5546047","DOIUrl":"https://doi.org/10.1109/MSMW.2010.5546047","url":null,"abstract":"Investigation of atmospheric gases spectral properties is demanded to develop absorption models. Such models are very important for the global Earth's atmosphere monitoring. Most of atmospheric lines and continuum spectral parameters are obtained in laboratory experiments. Recovered atmospheric parameters accuracy of depends directly on accuracy of laboratory measurements. Parameterization of the continuum absorption, in particular, the water vapor continuum is one of the most difficult problems. The problem is related to yet unknown physical origin of the continuum, its weakness in comparison with absorption in regular discrete lines of water molecule, and general difficulties of the water-related measurements. The water-related continuum broadband measurement by the resonator spectrometer [1] revealed strong influence of water adsorbing on resonator elements on results of the continuum parameters measurements. Analysis [2] of the MM/SubMM continuum measurement methods used in the earlier studies leads to the conclusion that water adsorbing onto mirrors was a common factor influencing the water-related continuum parameters obtained in all well-known laboratory experiments. In all these cases gas cells with multiple reflections of radiation off inner mirrors were used as the most appropriate technique for weak continuum absorption investigation, although the problem of separation of water vapor absorption and absorption by water adsorbed on mirrors was not solved in the experiments. To overcome the problem it was proposed to use the cavity length variation method [1], which permits separation of these two types of absorptions and, as a result, the accuracy of continuum absorption measurements increases.","PeriodicalId":129834,"journal":{"name":"2010 INTERNATIONAL KHARKOV SYMPOSIUM ON PHYSICS AND ENGINEERING OF MICROWAVES, MILLIMETER AND SUBMILLIMETER WAVES","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127657828","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 : 2010-06-21DOI: 10.1109/MSMW.2010.5546015
V. Golikov, O. Lebedeva, A. Castillejos Moreno, D. Munoz Rodriguez, M. Salvador Islas
In this paper we develop a new approach to robust detector in the presence of multiple external interferences with unknown powers and target signal with unknown Doppler frequency. Our approach is based on the generalized likelihood ratio test (GLRT). The basic idea of the so-called projection method is the separation of the overall observation space into orthogonal subspaces; here it is offered to separate the overall space so that on each narrowband source of external interference it would be necessary on one subspace. This paper presents the synthesis and efficiency analysis of a new non-adaptive detection test, which has constant or robust false alarm rate (CFAR or RFAR). The aim of this work is two-fold. On one hand, we assess the detection performance, on the other we analyze their robustness with respect to accrual powers of the narrowband interferences. Numerical simulations attest to the validity of the analysis. The evaluation of its performance shows that the loss measured with respect to the corresponding optimum structure is kept within a few dBs.
{"title":"A robust detection in the presence of multiple narrowband sources of external interferences with unknown powers","authors":"V. Golikov, O. Lebedeva, A. Castillejos Moreno, D. Munoz Rodriguez, M. Salvador Islas","doi":"10.1109/MSMW.2010.5546015","DOIUrl":"https://doi.org/10.1109/MSMW.2010.5546015","url":null,"abstract":"In this paper we develop a new approach to robust detector in the presence of multiple external interferences with unknown powers and target signal with unknown Doppler frequency. Our approach is based on the generalized likelihood ratio test (GLRT). The basic idea of the so-called projection method is the separation of the overall observation space into orthogonal subspaces; here it is offered to separate the overall space so that on each narrowband source of external interference it would be necessary on one subspace. This paper presents the synthesis and efficiency analysis of a new non-adaptive detection test, which has constant or robust false alarm rate (CFAR or RFAR). The aim of this work is two-fold. On one hand, we assess the detection performance, on the other we analyze their robustness with respect to accrual powers of the narrowband interferences. Numerical simulations attest to the validity of the analysis. The evaluation of its performance shows that the loss measured with respect to the corresponding optimum structure is kept within a few dBs.","PeriodicalId":129834,"journal":{"name":"2010 INTERNATIONAL KHARKOV SYMPOSIUM ON PHYSICS AND ENGINEERING OF MICROWAVES, MILLIMETER AND SUBMILLIMETER WAVES","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131298922","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 : 2010-06-21DOI: 10.1109/MSMW.2010.5546011
F. Gallegos-Funes, B. Carvajal-Gámez, J. López-Bonilla, V. Ponomaryov
In this paper, we present a robust steganographic method for hidden information in the wavelet domain. The proposed method uses the Iterative Center Weighted Median (ICWM) algorithm to estimate the noisy areas of an RGB image. We propose to use the noisy pixels or areas as places to hidden information to provide good invisibility and fine detail preservation of processed images. The proposed method consistently identifies if the wavelets coefficients of an image contains noisy or not, this algorithm works with variances and standard deviations of the same wavelet coefficients of image.
{"title":"Steganographic method based on wavelets and center weighted median filter","authors":"F. Gallegos-Funes, B. Carvajal-Gámez, J. López-Bonilla, V. Ponomaryov","doi":"10.1109/MSMW.2010.5546011","DOIUrl":"https://doi.org/10.1109/MSMW.2010.5546011","url":null,"abstract":"In this paper, we present a robust steganographic method for hidden information in the wavelet domain. The proposed method uses the Iterative Center Weighted Median (ICWM) algorithm to estimate the noisy areas of an RGB image. We propose to use the noisy pixels or areas as places to hidden information to provide good invisibility and fine detail preservation of processed images. The proposed method consistently identifies if the wavelets coefficients of an image contains noisy or not, this algorithm works with variances and standard deviations of the same wavelet coefficients of image.","PeriodicalId":129834,"journal":{"name":"2010 INTERNATIONAL KHARKOV SYMPOSIUM ON PHYSICS AND ENGINEERING OF MICROWAVES, MILLIMETER AND SUBMILLIMETER WAVES","volume":"251 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133752291","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 : 2010-06-21DOI: 10.1109/MSMW.2010.5546063
A. Linkova
Measurement of microstructure characteristics of precipitation is very important for study of process of their formation and progress [1]. Use of the remote sensing methods is also quite interested especially for measurement of particle size of liquid precipitation. That is why the double frequency method for measurement of particle dimensions is quite actual. It was first proposed in the work [2] and then studied in the work [3] for case of solid aerosols. Peculiarity of liquid precipitation is dependence of their permittivity on temperature and operating wavelength. This fact essentially complicates application of double frequency method. So the goal of this paper is analysis of method facilities in the frequency band, which is traditionally used for radio meteorology (8 mm and 3 cm). The most important parameters of the liquid precipitation are water content of unit volume W (g/m3) and intensity of precipitation I (mm/h), which is written for case of monodisperse medium (all particles have the same size) as equations where ref- effective radius of particles, ρ0- particle density ≈ 1 g/cm3, N0- particle concentration 1/m3, V(ref)- particle rate of fall m/s. As it was said the complex permittivity of liquid precipitation depends on temperature and frequency of illuminating field. This dependence is well described by Debye's generalized formulas [4]. Using approximations of monodisperse medium (all particles have the same size) and incoherent scattering the SRCS of scattering volume is σ(ref=N0σp)(σp- RCS of separated particle). As it is known the Rayleigh approximation is not fulfilled for large particles of precipitation for »=8 mm. So it is necessary to use rigorous solution of diffraction problem of electromagnetic field by dielectrical sphere (Mie theory). The numerical simulation of scattering signatures was performed for single spherical drop of water to define the character of dependence of RCS on temperature and wavelength. It was shown the normalized RCS weekly depends on temperature in quite wide range of its variation [−30 °C; 30 °C], especially for larger wavelength. Because of SRCS for monodisperse medium depends on particle concentration and operating wavelength it is reasonably to enter value of differential RCS (DRCS) as ratio of SRCS measured on two wavelength λ1 and λ2, which is single-valued function of particle sizes in some range (workspace)σD=σ0(λ1,r)/σ0(λ2,r). So application of double frequency method of remote sensing permits to measurement of effective particle size of precipitation using approximation of monodisperse medium.
{"title":"Double frequency sounding of liquid precipitation","authors":"A. Linkova","doi":"10.1109/MSMW.2010.5546063","DOIUrl":"https://doi.org/10.1109/MSMW.2010.5546063","url":null,"abstract":"Measurement of microstructure characteristics of precipitation is very important for study of process of their formation and progress [1]. Use of the remote sensing methods is also quite interested especially for measurement of particle size of liquid precipitation. That is why the double frequency method for measurement of particle dimensions is quite actual. It was first proposed in the work [2] and then studied in the work [3] for case of solid aerosols. Peculiarity of liquid precipitation is dependence of their permittivity on temperature and operating wavelength. This fact essentially complicates application of double frequency method. So the goal of this paper is analysis of method facilities in the frequency band, which is traditionally used for radio meteorology (8 mm and 3 cm). The most important parameters of the liquid precipitation are water content of unit volume W (g/m<sup>3</sup>) and intensity of precipitation I (mm/h), which is written for case of monodisperse medium (all particles have the same size) as equations where r<inf>ef</inf>- effective radius of particles, ρ<inf>0</inf>- particle density ≈ 1 g/cm<sup>3</sup>, N<inf>0</inf>- particle concentration 1/m<sup>3</sup>, V(r<inf>ef</inf>)- particle rate of fall m/s. As it was said the complex permittivity of liquid precipitation depends on temperature and frequency of illuminating field. This dependence is well described by Debye's generalized formulas [4]. Using approximations of monodisperse medium (all particles have the same size) and incoherent scattering the SRCS of scattering volume is σ(r<inf>ef</inf>=N<inf>0</inf>σ<inf>p</inf>)(σ<inf>p</inf>- RCS of separated particle). As it is known the Rayleigh approximation is not fulfilled for large particles of precipitation for »=8 mm. So it is necessary to use rigorous solution of diffraction problem of electromagnetic field by dielectrical sphere (Mie theory). The numerical simulation of scattering signatures was performed for single spherical drop of water to define the character of dependence of RCS on temperature and wavelength. It was shown the normalized RCS weekly depends on temperature in quite wide range of its variation [−30 °C; 30 °C], especially for larger wavelength. Because of SRCS for monodisperse medium depends on particle concentration and operating wavelength it is reasonably to enter value of differential RCS (DRCS) as ratio of SRCS measured on two wavelength λ<inf>1</inf> and λ<inf>2</inf>, which is single-valued function of particle sizes in some range (workspace)σ<inf>D</inf>=σ<inf>0</inf>(λ<inf>1</inf>,r)/σ<inf>0</inf>(λ<inf>2</inf>,r). So application of double frequency method of remote sensing permits to measurement of effective particle size of precipitation using approximation of monodisperse medium.","PeriodicalId":129834,"journal":{"name":"2010 INTERNATIONAL KHARKOV SYMPOSIUM ON PHYSICS AND ENGINEERING OF MICROWAVES, MILLIMETER AND SUBMILLIMETER WAVES","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114999901","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 : 2010-06-21DOI: 10.1109/MSMW.2010.5546151
O. Drobakhin, V. Alekseev, D. Saltykov, A. D. Saltykov
The experimental results have shown possibility to detect signal of plexiglass cylinder situated behind plexiglass slab using multifrequency measurements with synthesizing of 2-D spatial images. This approach has advantages in comparison with single-frequency method.
{"title":"Multifrequency radar images of electrodynamics objects located behind dielectric layer in millimeter wave range","authors":"O. Drobakhin, V. Alekseev, D. Saltykov, A. D. Saltykov","doi":"10.1109/MSMW.2010.5546151","DOIUrl":"https://doi.org/10.1109/MSMW.2010.5546151","url":null,"abstract":"The experimental results have shown possibility to detect signal of plexiglass cylinder situated behind plexiglass slab using multifrequency measurements with synthesizing of 2-D spatial images. This approach has advantages in comparison with single-frequency method.","PeriodicalId":129834,"journal":{"name":"2010 INTERNATIONAL KHARKOV SYMPOSIUM ON PHYSICS AND ENGINEERING OF MICROWAVES, MILLIMETER AND SUBMILLIMETER WAVES","volume":"427 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115999253","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 : 2010-06-21DOI: 10.1109/MSMW.2010.5546172
A. Kalenyuk, A. I. Rebikov, A. Kasatkin, V. Pan
Certainly, the dip emergence in the resonator with NLE and the decay emergence in the line with NLE are of the same nature. One can see a full analogy between IL(Pin) dependence for the line and ILdip(Pin) dependence for the resonator with NLE (ILdip - insertion losses in the dip of AFC dependence). The rapid initial decrease in the dip on AFC dependence for resonators with NLE corresponds to the first step on the IL(Pin) dependence, obtained for the lines with NLE. Our measurements have revealed the linear dependencies ILdip(Pin)∼Pin and IL(Pin)∼Pin for resonators and lines, correspondingly (Pin is measured in dbm). The rapid increase of the dip on resonator AFC curves, as well as the rapid increase of the line decay with the input power increase, can be explained by a rapid increase of the NLE surface resistance, caused by its transition from superconducting to the normal state. The heat origin of these effects is supported by observations of hysteretic behavior of the IL(Pin) dependence, measured in the line with NLE. Coincidence of the critical current density values, obtained from microwave and dc transport measurements, indicate that penetration of microwave induced Abrikosov vortices is responsible for the YBCO film heating and its subsequent transition to the normal state, contrary to the suggested model of Josephson weak links [8]. Calculations, performed in the work [5], show that the NLE transition to the normal state proceeds not abruptly, but through formation of resistive domains, causing strong rise of the line decay, when the input power slightly increases.
{"title":"Nonlinear HTS lumped elements in microwave transmission and resonance circuits","authors":"A. Kalenyuk, A. I. Rebikov, A. Kasatkin, V. Pan","doi":"10.1109/MSMW.2010.5546172","DOIUrl":"https://doi.org/10.1109/MSMW.2010.5546172","url":null,"abstract":"Certainly, the dip emergence in the resonator with NLE and the decay emergence in the line with NLE are of the same nature. One can see a full analogy between IL(Pin) dependence for the line and ILdip(Pin) dependence for the resonator with NLE (ILdip - insertion losses in the dip of AFC dependence). The rapid initial decrease in the dip on AFC dependence for resonators with NLE corresponds to the first step on the IL(Pin) dependence, obtained for the lines with NLE. Our measurements have revealed the linear dependencies ILdip(Pin)∼Pin and IL(Pin)∼Pin for resonators and lines, correspondingly (Pin is measured in dbm). The rapid increase of the dip on resonator AFC curves, as well as the rapid increase of the line decay with the input power increase, can be explained by a rapid increase of the NLE surface resistance, caused by its transition from superconducting to the normal state. The heat origin of these effects is supported by observations of hysteretic behavior of the IL(Pin) dependence, measured in the line with NLE. Coincidence of the critical current density values, obtained from microwave and dc transport measurements, indicate that penetration of microwave induced Abrikosov vortices is responsible for the YBCO film heating and its subsequent transition to the normal state, contrary to the suggested model of Josephson weak links [8]. Calculations, performed in the work [5], show that the NLE transition to the normal state proceeds not abruptly, but through formation of resistive domains, causing strong rise of the line decay, when the input power slightly increases.","PeriodicalId":129834,"journal":{"name":"2010 INTERNATIONAL KHARKOV SYMPOSIUM ON PHYSICS AND ENGINEERING OF MICROWAVES, MILLIMETER AND SUBMILLIMETER WAVES","volume":"129 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129808988","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 : 2010-06-21DOI: 10.1109/MSMW.2010.5545981
S. Vitusevich
We presented a systematic study of the impact of a layer structure design on the performance of AlGaN/GaN high electron mobility transistor structures. The new mechanism of strain relaxation by twisted nanocolumns was revealed. The experimentally obtained results were found to be in good agreement with the proposed model. Device layer structures were optimized to obtain a minimum overheating temperature at high dissipated power in HEMT channels. It was shown that the room-temperature spectra can be used to determine the activation energy of the traps. In addition, the impact of layer structure design on the properties of the 1/f flicker noise was studied and the phase noise performance of test microwave HEMT-based oscillators was discussed. The noise and capacitance spectroscopy of double-barrier RTDs were found to be a powerful and sensitive tool for the exploration of transport features and structural quality. The results can be used to design AlN/GaN RTD-FETs with optimized layout, to conduct a more efficient analysis of resonant tunneling processes, and to improve the peak-to-valley ratio of NDR regions.
{"title":"AlGaN/GaN microwave transistors for wireless communication systems and advanced nanostructures for high-speed sensor applications","authors":"S. Vitusevich","doi":"10.1109/MSMW.2010.5545981","DOIUrl":"https://doi.org/10.1109/MSMW.2010.5545981","url":null,"abstract":"We presented a systematic study of the impact of a layer structure design on the performance of AlGaN/GaN high electron mobility transistor structures. The new mechanism of strain relaxation by twisted nanocolumns was revealed. The experimentally obtained results were found to be in good agreement with the proposed model. Device layer structures were optimized to obtain a minimum overheating temperature at high dissipated power in HEMT channels. It was shown that the room-temperature spectra can be used to determine the activation energy of the traps. In addition, the impact of layer structure design on the properties of the 1/f flicker noise was studied and the phase noise performance of test microwave HEMT-based oscillators was discussed. The noise and capacitance spectroscopy of double-barrier RTDs were found to be a powerful and sensitive tool for the exploration of transport features and structural quality. The results can be used to design AlN/GaN RTD-FETs with optimized layout, to conduct a more efficient analysis of resonant tunneling processes, and to improve the peak-to-valley ratio of NDR regions.","PeriodicalId":129834,"journal":{"name":"2010 INTERNATIONAL KHARKOV SYMPOSIUM ON PHYSICS AND ENGINEERING OF MICROWAVES, MILLIMETER AND SUBMILLIMETER WAVES","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127048183","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 : 2010-06-21DOI: 10.1109/MSMW.2010.5545979
Y. Kulikov, V. Frolov
We present some results of microwave measurements of ozone number density variations in the mesosphere (in the ionospheric D-region at altitudes of ∼ 60 km) under conditions when the ionosphere was pumped by high-frequency powerful radio waves radiated by the Sura heating facility, which is located near Nizhny Novgorod, Russia (coordinates: 56.15°N, 46.13°E). Determination of the ozone number density in the upper atmosphere was made using the method of the ground-based microwave radiometry, which is based on spectral measurements of thermal atmospheric emissions detected in the frequency range of the ozone radiation. The decrease of microwave emission intensity for the ozone line in HF-pumped atmosphere was first revealed.
{"title":"Influence of HF powerful radio waves on the ozone number density in the earth's atmosphere","authors":"Y. Kulikov, V. Frolov","doi":"10.1109/MSMW.2010.5545979","DOIUrl":"https://doi.org/10.1109/MSMW.2010.5545979","url":null,"abstract":"We present some results of microwave measurements of ozone number density variations in the mesosphere (in the ionospheric D-region at altitudes of ∼ 60 km) under conditions when the ionosphere was pumped by high-frequency powerful radio waves radiated by the Sura heating facility, which is located near Nizhny Novgorod, Russia (coordinates: 56.15°N, 46.13°E). Determination of the ozone number density in the upper atmosphere was made using the method of the ground-based microwave radiometry, which is based on spectral measurements of thermal atmospheric emissions detected in the frequency range of the ozone radiation. The decrease of microwave emission intensity for the ozone line in HF-pumped atmosphere was first revealed.","PeriodicalId":129834,"journal":{"name":"2010 INTERNATIONAL KHARKOV SYMPOSIUM ON PHYSICS AND ENGINEERING OF MICROWAVES, MILLIMETER AND SUBMILLIMETER WAVES","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130030337","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：