2019 URSI Asia-Pacific Radio Science Conference (AP-RASC)最新文献

{"title":"Quad-Band Electrically Small Dual-Polarized ZOR Antenna with Improved Bandwidth using Single-Split Ring Resonators and Spiral Slots Enabled with Reflector for GPS/UMTS/WLAN/WiMAX Applications","authors":"M. Ameen, R. Chaudhary","doi":"10.23919/URSIAP-RASC.2019.8738478","DOIUrl":"https://doi.org/10.23919/URSIAP-RASC.2019.8738478","url":null,"abstract":"An electrically small quad-band metamaterial (MTM) antenna based on the short-ended configuration of zeroth order mode (ZOR) added with a reflector unit cell presented in this paper. The antenna is highly miniaturized due to the ZOR mode and the addition of the CPW backed ground plane. The intended antenna electrical size is $0.094 lambda _{0} times 0.112 lambda _{0} times 0.006 lambda _{0}$ at 1.54 GHz and a physical dimension of $18.5 times 22 times 1.27$ mm3. A bandwidth of 3.89%, 10.11%, 13.48%, and 30.76% is acquired for the four bands centered at 1.54 GHz, 2.57 GHz, 3.48 GHz, and 5.33 GHz and a CP bandwidth of 8.32% is obtained in the fourth band. Moreover, the antenna exhibits a good level of compactness, good axial ratio, good radiation efficiency, and acceptable S11 bandwidth. The intended antenna is the best candidature for use in 1.5 GHz GPS L2 band, 2.6 GHz UMTS, 5.2/5.8 WLAN, and 3.3/3.6 WiMAX applications.","PeriodicalId":344386,"journal":{"name":"2019 URSI Asia-Pacific Radio Science Conference (AP-RASC)","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131503642","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":"Spatiotemporal development of pulsating auroral patch associated with discrete chorus elements: Arase and PWING observations","authors":"M. Ozaki, K. Shiokawa, Y. Miyoshi, K. Hosokawa, S. Oyama, S. Yagitani, Y. Kasahara, Y. Kasaba, S. Matsuda, R. Kataoka, Y. Ebihara, Y. Ogawa, Y. Otsuka, S. Kurita, R. Moore, Y.‐M. Tanaka, M. Nosé, T. Nagatsuma, M. Connors, N. Nishitani, M. Hikishima, A. Kumamoto, F. Tsuchiya, A. Kadokura, T. Nishiyama, T. Inoue, K. Imamura, A. Matsuoka, I. Shinohara","doi":"10.23919/URSIAP-RASC.2019.8738444","DOIUrl":"https://doi.org/10.23919/URSIAP-RASC.2019.8738444","url":null,"abstract":"A one-to-one correspondence between in-situ chorus elements near the equator and rapid luminosity variations of a pulsating auroral patch on the conjugate ground site (Gakona, Alaska) is identified from coordinated observations by the Arase satellite [1] and a ground observation network of PWING (study of dynamical variation of Particles and Waves in the INner magnetosphere using Ground-based network observations) [2]. The spatiotemporal development of the pulsating auroral patch was captured with a 100-Hz sampling imager. The temporal variations of a pulsating auroral patch are associated with not only a train of chorus elements near the equator, but also possibly subpacket structures of the chorus elements with tens of milliseconds. Here we found that the luminosity variations in the well-known few Hz range were observed only at the edge part of the auroral patch in this event, because they were caused by the spatial expansion and contraction of the auroral patch from the center location. The spatial size at the ionosphere (altitude of 110 km) of the auroral patch was approximately 15-km long at the short axis in the magnetic north-south direction and 70-km long at the long axis in the east-west direction of an ellipse. The spatial scale projecting the ionospheric auroral patch to the equatorial plane of the magnetosphere was roughly a circle of 900 km in diameter, which is comparable with a small spatial scale of relativistic electron microbursts. These observations suggest that the pulsating auroral patch associated with chorus elements reflects not only a temporal variation of wave–particle interaction in the magnetosphere, but also a transverse spatial profile (across the geomagnetic field line) of wave–particle interaction. In this presentation, we will present the spatiotemporal variation of the pulsating auroral patch associated with chorus elements in detail.","PeriodicalId":344386,"journal":{"name":"2019 URSI Asia-Pacific Radio Science Conference (AP-RASC)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116533836","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":"Multilayer Absorber Based on Carbon Fibers Loaded Epoxy Foam","authors":"A. Assal, R. Benzerga, A. Sharaiha, A. Harmouch, A. Jrad","doi":"10.23919/URSIAP-RASC.2019.8738390","DOIUrl":"https://doi.org/10.23919/URSIAP-RASC.2019.8738390","url":null,"abstract":"Due to the rapid development of electronics and telecommunications, protection against electromagnetic waves has become an active area of research, and the intensification of protective materials usage is reflecting the market needs and the great demand of such products. The form and composition of electromagnetic absorbers are various and depend on the application under consideration. The typical absorbing materials used in the anechoic chambers are made of Polyurethane (PU) foam loaded with carbon particles. These absorbers have either flat or pyramidal forms [1]; our targeted form is the flat multilayer absorber. The foam structure of these absorbers gives them a low density but also a high flexibility which induces machining errors. On the other hand, the carbon particles load ensures an absorption in large frequency band but this load is volatile as well so that it can easily escapes from the absorber and threatens human health. Our proposed material [2] is made of epoxy foam (rigid foam) loaded with carbon fibers (nonvolatile load).","PeriodicalId":344386,"journal":{"name":"2019 URSI Asia-Pacific Radio Science Conference (AP-RASC)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133467501","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":"Optimal Power Allocation for Minimizing the Energy Consumption of a NOMA Base Station with Cell DTx","authors":"Rémi Bonnefoi, Haifa Fares, Pierre Bélis, Y. Louët","doi":"10.23919/URSIAP-RASC.2019.8738765","DOIUrl":"https://doi.org/10.23919/URSIAP-RASC.2019.8738765","url":null,"abstract":"In this paper, we consider a base station that jointly employs Non-Orthogonal Multiple Access (NOMA) and Cell Discontinuous Transmission (Cell DTx) in order to reduce its power consumption and we study the problem of optimal power allocation. We show first that this problem is convex and can be solved using only single variable root finding algorithms. Then, we employ numerical simulations in order to assess the performance of the proposed power allocation.","PeriodicalId":344386,"journal":{"name":"2019 URSI Asia-Pacific Radio Science Conference (AP-RASC)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122304281","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":"On the Development of Intense THz sources for nonlinear optics and spectroscopy","authors":"Sunil Kumar","doi":"10.23919/URSIAP-RASC.2019.8738176","DOIUrl":"https://doi.org/10.23919/URSIAP-RASC.2019.8738176","url":null,"abstract":"In last couple of decades, the THz science and technology has made huge leap of progress and THz sources and detectors in limited field strength and frequency bandwidth are being made available commercially for applications in spectroscopy, sensing, imaging and medical diagnostics. This is primarily because of the mature NIR femtosecond laser technology and the coherent nature of the THz radiation allowing researchers to create simple table top experimental tools for their THz studies. However, there is a growing demand for intense THz sources which can allow perform nonlinear optics and spectroscopy and develop new methodologies. For nonlinear THz radiation and matter interaction, one needs typically THz-fields comparable to the atomic fields $(sim 10wedge 6mathrm{V}/$cm) such as those provided by lasers in other regions of the electromagnetic spectrum. Photoconductive antennas based on narrow band-gap materials such as InGaAs have seen a great improvement in their performances in terms of optical-to-THz efficiencies and maximum output pulsed THz radiation powers at frequencies above 1 THz due to the availability of high power laser sources operating at the optical telecommunication wavelengths. Even more powerful THz emitters have generally been developed by using nonlinear optical crystals where optical rectification of intense near infrared femtosecond laser pulses produces broadband THz radiation of field strengths reaching few hundreds of kV/cm to even few thousands kV/cm. Zinc telluride and lithium niobate crystals are very popular in this case [1]. Another popular mechanism for generating strong THz fields is by creating plasma in air and phase mismatch between the fundamental and the second harmonic fields of NIR femtosecond pulses [2]. Hetero-structures of layers of ferromagnetic materials and nonferromagnetic films have recently been used to produce THz radiation by excitation with femtosecond laser pulses [3].","PeriodicalId":344386,"journal":{"name":"2019 URSI Asia-Pacific Radio Science Conference (AP-RASC)","volume":"104 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133173954","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":"Testbed and Experiments for Focused Microwave Thermotherapy","authors":"Kwang-Jae Lee, Jang‐Yeol Kim, S. Jeon, Seong‐Ho Son","doi":"10.23919/URSIAP-RASC.2019.8738132","DOIUrl":"https://doi.org/10.23919/URSIAP-RASC.2019.8738132","url":null,"abstract":"Thermotherapy is a medical treatment based on the specific lesion exposure to high temperature. In the case of therapeutic levels of hyperthermia, moderately elevated temperature to a supra-physiological level (typically $43^{circ}mathrm{C}-45^{circ}mathrm{C})$ provides effect of cellular cytotoxicity that causes tumor necrosis. For many musculoskeletal disorders, the moderately elevated temperature could be useful for the treatment of pathology. The mild thermotherapy provides physiological benefits as increasing blood flow and pain relief [1].","PeriodicalId":344386,"journal":{"name":"2019 URSI Asia-Pacific Radio Science Conference (AP-RASC)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124947857","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 of conformal aperture coupled microstrip patch antenna on cylindrical bodies with circular polarization","authors":"S. Narke, D. Gharpure, S. Ananthakrishnan, C. Bhattacharya","doi":"10.23919/URSIAP-RASC.2019.8738303","DOIUrl":"https://doi.org/10.23919/URSIAP-RASC.2019.8738303","url":null,"abstract":"In this paper, circularly polarized aperture coupled rectangular microstrip patch antenna for X-band application is proposed. Whenever planar antenna is conformed to cylindrical surface, antenna characteristics such as circular polarization gets disturbed. Proposed antenna design is printed on polyimide $(varepsilon_{r}=3.5)$ substrate separated by cross slotted ground plane. The conformal antenna design is simulated in CST microwave studio and is under fabrication.","PeriodicalId":344386,"journal":{"name":"2019 URSI Asia-Pacific Radio Science Conference (AP-RASC)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122049205","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":"Transfer Reinforcement Learning based Framework for Energy Savings in Cellular Base Station Network","authors":"Shreyata Sharma, S. Darak, A. Srivastava","doi":"10.23919/URSIAP-RASC.2019.8738418","DOIUrl":"https://doi.org/10.23919/URSIAP-RASC.2019.8738418","url":null,"abstract":"Last few years have witnessed an exponential upsurge in data intensive applications over the communication networks. Energy saving is one of the major aspects in such networks wherein the increased traffic load entails deployment of a large number of base stations (BSs). In this paper, a BS switching scheme is proposed which exploits reinforcement learning (RL) for dynamic sectorization of BSs to increase the energy efficiency of cellular networks. Furthermore, previously estimated traffic statistics is exploited through the process of transfer learning for further improvement in energy savings and speeding up the learning process. The superiority of the proposed framework is depicted through simulations and relevant mathematical analysis. Compared to conventional ON/OFF scheme, proposed framework offers around 40% lower average energy consumption for cellular networks with low to moderate loads.","PeriodicalId":344386,"journal":{"name":"2019 URSI Asia-Pacific Radio Science Conference (AP-RASC)","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127277476","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":"Comparison between empirical and physical models of the topside ionospheric-plasmaspheric electron content above Antarctica","authors":"N. Bergeot, V. Pierrard, F. Darrouzet, J. Chevalier","doi":"10.23919/URSIAP-RASC.2019.8738318","DOIUrl":"https://doi.org/10.23919/URSIAP-RASC.2019.8738318","url":null,"abstract":"As the polar regions are Earth’s windows to outer space, the Antarctic continent provides a unique opportunity for scientific research that cannot be performed at mid-and low-latitude regions. Moreover, the polar ionosphere-plasmasphere system, especially over Antarctica, is not well understood as compared to other regions due to a lack of experimental observations. Consequently, one of the present challenges of the Space Weather community is to better characterize the climatological behavior of the polar ionosphere and plasmasphere separately in response to variations in the solar activity at high latitudes.","PeriodicalId":344386,"journal":{"name":"2019 URSI Asia-Pacific Radio Science Conference (AP-RASC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131125061","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":"An Improved T-Junction Power Divider Using Linearly Tapered Microstrip Lines","authors":"Ramanand Sagar Sangam, R. S. Kshetrimayum","doi":"10.23919/URSIAP-RASC.2019.8738357","DOIUrl":"https://doi.org/10.23919/URSIAP-RASC.2019.8738357","url":null,"abstract":"In this paper, a T-junction power divider using linearly tapered microstrip lines (MSLs) has been proposed; where the line to port 3 has also been tapered for achieving higher power dividing ratio between the output ports (ports 2 and 3). A method for theoretical analysis of the power divider has been presented approximately. The proposed T-junction power divider exhibits power dividing ratio of more than 10 dB over a broad frequency range of 1.7-5 GHz. The design is simulated in two different EM solvers (HFSS and CST) and their results are in well agreement with each-other which validate the same.","PeriodicalId":344386,"journal":{"name":"2019 URSI Asia-Pacific Radio Science Conference (AP-RASC)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133909312","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}