S. Nadri, Linli Xie, Naser Alijabbari, J. Gaskins, B. Foley, P. Hopkins, R. Weikle
{"title":"Steady-state thermal analysis of an integrated 160 GHz balanced quadrupler based on quasi-vertical Schottky diodes","authors":"S. Nadri, Linli Xie, Naser Alijabbari, J. Gaskins, B. Foley, P. Hopkins, R. Weikle","doi":"10.1109/IRMMW-THz.2015.7327482","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2015.7327482","url":null,"abstract":"This work reports on a steady-state thermal analysis of a 160 GHz balanced quadrupler, based on a quasi-vertical varactor Schottky diode process, for high power applications. The chip is analyzed by solving the heat equation via the 3D finite element method. Time-Domain Thermoreflectance (TDTR) was used to measure the thermal conductivity of the different materials used in the model. A maximum anode temperature of 64.9°C was found from the simulation. The addition of an extra beam lead connected to the block, for heat sinking, was found to reduce this maximum temperature to 41.0°C.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"101 11 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83333674","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":"Design and testing of a 900 kW, 140 GHz gyrotron","authors":"S. Cauffman, M. Blank, P. Borchard, K. Felch","doi":"10.1109/IRMMW-THZ.2015.7327573","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327573","url":null,"abstract":"A 140 GHz gyrotron capable of producing output powers up to 900 kW for 1000-second pulses has been developed at CPI. Factory testing demonstrated 1000-second operation at the 25 A CW current limit of the test facility, at which the output power was about 500 kW, and demonstrated 900 kW operation for short pulses. The gyrotron was then shipped to Hefei, China, and installed as part of the electron cyclotron heating and current drive system for the EAST tokamak. Commissioning of the gyrotron at the EAST site is currently in progress, with the goal of demonstrating operation at full parameters (900 kW for 1000-second pulses).","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"11 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78698965","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}
M. Klos, R. Bartholdt, J. Klier, J. Lampin, R. Beigang
{"title":"Photoconductive antennas based on low temperature grown GaAs on silicon substrates for broadband terahertz generation and detection","authors":"M. Klos, R. Bartholdt, J. Klier, J. Lampin, R. Beigang","doi":"10.1117/12.2217505","DOIUrl":"https://doi.org/10.1117/12.2217505","url":null,"abstract":"Summary form only given. We present investigations of photoconductive antennas (PCA) based on low temperature grown GaAs (LT GaAs) on silicon substrates for terahertz (THz) detection and generation. The PCAs consist of 2 μm thick layers of LT GaAs bonded on a high resistivity silicon substrate in order to reduce the intrinsic absorption losses around 8 THz due to a strong phonon resonance in GaAs. Using 20 fs long pump pulses around 800 nm and dipole antennas with dipole length between 20 μm and 60 μm a maximum bandwidth above 10 THz and a maximum dynamic range exceeding 90 dB at 0.5 THz were obtained. The average output power was measured with a calibrated detector to be 5 μW at a repetition rate of 80 MHz.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"14 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78880248","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":"Dispersion compensation of the THz communication channels in the atmosphere","authors":"M. Mandehgar, D. Grischkowsky","doi":"10.1109/IRMMW-THZ.2015.7327833","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327833","url":null,"abstract":"We demonstrate that dispersive compensation can be achieved for the communication channels within the atmospheric THz windows using the long-path THz-TDS system. However, the THz pulse broadening cannot be eliminated due to the bandwidth reduction of the propagating THz pulse due to the frequency dependent absorption of the channels.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"90 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72808822","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}
Quan Li, Xueqian Zhang, Z. Tian, Ranjan Singh, L. Du, J. Gu, C. Ouyang, Jiaguang Han, Weili Zhang
{"title":"Active terahertz modulations based on graphene-silicon hybrid structures","authors":"Quan Li, Xueqian Zhang, Z. Tian, Ranjan Singh, L. Du, J. Gu, C. Ouyang, Jiaguang Han, Weili Zhang","doi":"10.1109/IRMMW-THZ.2015.7327609","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327609","url":null,"abstract":"With simultaneous optical and electrical excitations, we experimentally demonstrate an active modulation of transmitted terahertz waves through a graphene-silicon hybrid structure. A large transmission modulation of 83% was observed. Meanwhile, a “diode” behavior was found in such a structure, where terahertz waves transmits when biased with a positive voltage while attenuates under a low negative voltage.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"30 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72864823","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}
Ming Xu, W. Shi, Xiaoqing He, Zhijin Yan, Hong Liu
{"title":"Suppression of high gain GaAs photoconductive semiconductor switch at high electric field","authors":"Ming Xu, W. Shi, Xiaoqing He, Zhijin Yan, Hong Liu","doi":"10.1109/IRMMW-THZ.2015.7327660","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327660","url":null,"abstract":"In order to explore the efficient THz emitter with GaAs photoconductive semiconductor switch (PCSS), it's necessary to achieve the suppression of high gain mode in high electric field. The infrared activation and inhibition of high field domains is achieved and the good hold-off characteristics is obtained with 32 kV.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"35 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86839116","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":"Broadband porous-core bandgap terahertz fiber based on Kagome lattice of air holes","authors":"Xiao Rao, Jintao Fan, Yanfeng Li","doi":"10.1109/IRMMW-THZ.2015.7327628","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327628","url":null,"abstract":"We propose a novel bandgap fiber for the transmission of terahertz (THz) radiation based on a Kagome lattice of air holes. The fiber core comprises a triangular lattice of air holes having the same or a smaller size than the cladding air holes. Numerical simulation of a 19-cell fiber is carried out using finite element method. Proper design of the fiber parameters allows the transmission of broadband THz radiation in the 1.0~2.3 THz range.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"22 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87364446","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}
I. Zotova, N. Ginzburg, M. Glyavin, A. Sergeev, R. Rozental, A. Fokin
{"title":"Non-autonomous regimes in gyrotrons with low-Q resonators","authors":"I. Zotova, N. Ginzburg, M. Glyavin, A. Sergeev, R. Rozental, A. Fokin","doi":"10.1109/IRMMW-THZ.2015.7327703","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327703","url":null,"abstract":"Based on the description of wave propagation by a parabolic equation the time-domain theory of non-autonomous operation of gyrotrons with low-Q resonators has been developed. The influence of external signal is taking into account by modification of boundary condition at resonator output. Developed model can be effectively used for simulations of frequency-locking of gyrotron by external signal in soft and hard operation modes, frequency pooling with reflection from remote load, synchronization of several coupling gyrotrons.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"43 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87392534","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":"Equivalent circuit model based on spectral Green's function representation for photo-conductive slot antennas","authors":"A. Garufo, G. Carluccio, N. Llombart, A. Neto","doi":"10.1109/IRMMW-THZ.2015.7327805","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327805","url":null,"abstract":"Summary form only given. The generation of THz signals resorting to photosensitive semiconductors has been the object of various analysis in the recent years. Typically, such sources consist in a optically pumped semiconductor which is coupled to an antenna to generate THz power. In this paper a theoretical model, based on a spectral Green's function formulation, for infinite slot fed by a THz photoconductor generator is shown. An equivalent circuit model is then derived, which gives a description of the involved THz power generation and radiation mechanisms. Such model is a useful engineering tool for the analysis and the design of photo-conductive slot antennas.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"53 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86282947","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":"Phase calibration of oscilloscopes at low frequencies","authors":"Joo-Gwang Lee, Chihyun Cho","doi":"10.1109/IRMMW-THZ.2015.7327761","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327761","url":null,"abstract":"This paper describes how to calibrate phase response of oscilloscopes, especially at low frequencies from 10 MHz to 1 GHz. The method uses the phase response of a standard mixer calibrated by three-mixer method as the reference phase. We describe basic principles and show results obtained using a balanced mixer and a real-time oscilloscope (1 GHz BW).","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"22 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82699545","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}