Pub Date : 2008-04-23DOI: 10.1109/COMITE.2008.4569891
R. Lech, Jerzy Mazur
This paper presents a new analysis of a polarizer composed of N sections of frequency selective surfaces (FSS). Each FSS is composed of periodic array of conducting wires. The structure is analyzed with the use of the exact full-wave theory based on the the mode-matching method, and also an efficient numerical technique based on the T- matrix approach and the lattice sums is utilized to investigate the FSSs.
{"title":"Polarization Rotator - Analysis and Design","authors":"R. Lech, Jerzy Mazur","doi":"10.1109/COMITE.2008.4569891","DOIUrl":"https://doi.org/10.1109/COMITE.2008.4569891","url":null,"abstract":"This paper presents a new analysis of a polarizer composed of N sections of frequency selective surfaces (FSS). Each FSS is composed of periodic array of conducting wires. The structure is analyzed with the use of the exact full-wave theory based on the the mode-matching method, and also an efficient numerical technique based on the T- matrix approach and the lattice sums is utilized to investigate the FSSs.","PeriodicalId":306289,"journal":{"name":"2008 14th Conference on Microwave Techniques","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130029385","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 : 2008-04-23DOI: 10.1109/COMITE.2008.4569911
J. Vrba, L. Oppl
Medical applications of microwaves (i.e. a possibility to use microwave energy and/or microwave technique and technology for therapeutical purposes) are a quite new and a very rapidly developing field. Microwave thermotherapy is being used in medicine for the cancer treatment and treatment of some other diseases since early eighties. In this contribution we would like to offer general overview of present activities in the Czech Republic, i.e. clinical applications and results, technical aspects of thermotherapeutic equipment and last but not least, prospective diagnostics based on microwave principals ant technology and instrumentation.
{"title":"Prospective Applications of Microwaves in Medicine","authors":"J. Vrba, L. Oppl","doi":"10.1109/COMITE.2008.4569911","DOIUrl":"https://doi.org/10.1109/COMITE.2008.4569911","url":null,"abstract":"Medical applications of microwaves (i.e. a possibility to use microwave energy and/or microwave technique and technology for therapeutical purposes) are a quite new and a very rapidly developing field. Microwave thermotherapy is being used in medicine for the cancer treatment and treatment of some other diseases since early eighties. In this contribution we would like to offer general overview of present activities in the Czech Republic, i.e. clinical applications and results, technical aspects of thermotherapeutic equipment and last but not least, prospective diagnostics based on microwave principals ant technology and instrumentation.","PeriodicalId":306289,"journal":{"name":"2008 14th Conference on Microwave Techniques","volume":"11 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132025330","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 : 2008-04-23DOI: 10.1109/COMITE.2008.4569957
K. Malaric, I. Bacic
This paper deals with the efficiency of TEM shield. Operator working with TEM cell should be protected from the radiation from inside the cell or from any possible leakage (from the door, i.e.). Theoretical analysis and calculation was used to compare standard materials for the shield with cheaper and more simple solution. Simple aluminium foil placed on a dielectric material is sufficient in obtaining enough shield protection, while still keeping electrical properties of the cell.
{"title":"Efficiency of the Materials used in Building TEM-Cell","authors":"K. Malaric, I. Bacic","doi":"10.1109/COMITE.2008.4569957","DOIUrl":"https://doi.org/10.1109/COMITE.2008.4569957","url":null,"abstract":"This paper deals with the efficiency of TEM shield. Operator working with TEM cell should be protected from the radiation from inside the cell or from any possible leakage (from the door, i.e.). Theoretical analysis and calculation was used to compare standard materials for the shield with cheaper and more simple solution. Simple aluminium foil placed on a dielectric material is sufficient in obtaining enough shield protection, while still keeping electrical properties of the cell.","PeriodicalId":306289,"journal":{"name":"2008 14th Conference on Microwave Techniques","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125145107","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 : 2008-04-23DOI: 10.1109/COMITE.2008.4569948
J. Macháč, J. Fabian, P. Protiva
This paper presents a possible application of an artificial dielectric substrate. The substrate is fabricated as a 2D array of metallic posts separated from the top conductor by a thin dielectric slab. The effective permittivity of a microstrip line fabricated on this substrate depends on the dimensions of the posts, the permittivity of a dielectric material filling the space between the posts, and on the thickness and permittivity of the top dielectric slab. The thinner this slab is and the higher its permittivity is the higher the effective permittivity will be. Due to the high effective permittivity, a substantial reduction in the dimensions of the microwave circuit elements is possible. Two 3 dB branch line couplers were designed, fabricated and measured by applying the microstrip line on this artificial dielectric substrate. They have considerably smaller dimensions than a coupler on a standard substrate.
{"title":"Branch Line Coupler on an Artificial Dielectric Substrate","authors":"J. Macháč, J. Fabian, P. Protiva","doi":"10.1109/COMITE.2008.4569948","DOIUrl":"https://doi.org/10.1109/COMITE.2008.4569948","url":null,"abstract":"This paper presents a possible application of an artificial dielectric substrate. The substrate is fabricated as a 2D array of metallic posts separated from the top conductor by a thin dielectric slab. The effective permittivity of a microstrip line fabricated on this substrate depends on the dimensions of the posts, the permittivity of a dielectric material filling the space between the posts, and on the thickness and permittivity of the top dielectric slab. The thinner this slab is and the higher its permittivity is the higher the effective permittivity will be. Due to the high effective permittivity, a substantial reduction in the dimensions of the microwave circuit elements is possible. Two 3 dB branch line couplers were designed, fabricated and measured by applying the microstrip line on this artificial dielectric substrate. They have considerably smaller dimensions than a coupler on a standard substrate.","PeriodicalId":306289,"journal":{"name":"2008 14th Conference on Microwave Techniques","volume":"312 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134394983","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 : 2008-04-23DOI: 10.1109/COMITE.2008.4569922
L.A. Tejedor-Alvarez, J. Alonso, J. Gonzalez-Martin
Detectors designing is a key aspect for the development of the new millimeter wave systems. In this paper two detectors in microstrip technology are presented. They use zero bias Schottky diodes to detect signals from low frequency to 40 GHz. High sensibility, flat frequency response and ultrabroadband are the main features of these designs. They are also cheap and easy to mount because they have been built using microstrip technology. This paper explains most technological questions which must be taken into account to design such detectors.
{"title":"An Ultrabroadband Microstrip Detector up to 40 GHz","authors":"L.A. Tejedor-Alvarez, J. Alonso, J. Gonzalez-Martin","doi":"10.1109/COMITE.2008.4569922","DOIUrl":"https://doi.org/10.1109/COMITE.2008.4569922","url":null,"abstract":"Detectors designing is a key aspect for the development of the new millimeter wave systems. In this paper two detectors in microstrip technology are presented. They use zero bias Schottky diodes to detect signals from low frequency to 40 GHz. High sensibility, flat frequency response and ultrabroadband are the main features of these designs. They are also cheap and easy to mount because they have been built using microstrip technology. This paper explains most technological questions which must be taken into account to design such detectors.","PeriodicalId":306289,"journal":{"name":"2008 14th Conference on Microwave Techniques","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132526278","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 : 2008-04-23DOI: 10.1109/COMITE.2008.4569930
P. Hazdra, M. Capek
Paper describes development of Iterated Function System (IFS) software tool for the generation and modal analysis of microstrip fractal patches. This tool is able to effectively create almost arbitrary plane fractal and to prepare its shape for further (modal, full-wave) EM calculations.
{"title":"IFS Tool for Fractal Microstrip Patch Antenna Analysis","authors":"P. Hazdra, M. Capek","doi":"10.1109/COMITE.2008.4569930","DOIUrl":"https://doi.org/10.1109/COMITE.2008.4569930","url":null,"abstract":"Paper describes development of Iterated Function System (IFS) software tool for the generation and modal analysis of microstrip fractal patches. This tool is able to effectively create almost arbitrary plane fractal and to prepare its shape for further (modal, full-wave) EM calculations.","PeriodicalId":306289,"journal":{"name":"2008 14th Conference on Microwave Techniques","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134447895","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 : 2008-04-23DOI: 10.1109/COMITE.2008.4569936
K. Wincza, S. Gruszczynski, J. Borgosz
The paper presents an antenna design for use in a nonlinear junction detection device. To achieve wide bandwidth a capacitive feed technique is used in which small probe feed elements are coupled to the radiating patch. In order to minimize the overall antenna size both receiving and transmitting antenna elements have been integrated into one dual-band structure having two separate excitation ports. High isolation between ports is achieved to avoid direct interferences between a transmitter and a receiver. Results of theoretical analysis are presented agree well with the experimental ones.
{"title":"Dual-band Capacitive Feed Antenna for Nonlinear Junction Detection Device","authors":"K. Wincza, S. Gruszczynski, J. Borgosz","doi":"10.1109/COMITE.2008.4569936","DOIUrl":"https://doi.org/10.1109/COMITE.2008.4569936","url":null,"abstract":"The paper presents an antenna design for use in a nonlinear junction detection device. To achieve wide bandwidth a capacitive feed technique is used in which small probe feed elements are coupled to the radiating patch. In order to minimize the overall antenna size both receiving and transmitting antenna elements have been integrated into one dual-band structure having two separate excitation ports. High isolation between ports is achieved to avoid direct interferences between a transmitter and a receiver. Results of theoretical analysis are presented agree well with the experimental ones.","PeriodicalId":306289,"journal":{"name":"2008 14th Conference on Microwave Techniques","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130295301","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 : 2008-04-23DOI: 10.1109/COMITE.2008.4569906
V. De Santis, M. Feliziani
A numerical dosimetry procedure is applied to a biological tissue in order to evaluate the temperature increase produced by RF exposure. The originality of the proposed method regards the application of the bio-heat equation in a vascularized region considering a discrete blood vessel structure which operates as a cooling system in the biological region. First, the blood structure is assumed to be a hydraulic system where a laminate incompressible fluid flows. By this approach the blood velocity in all vessels are computed. Then, the diffusion-convection heat equation is analyzed in a three dimensional domain by a differential numerical method based on the finite difference method. A simple test configuration is finally analysed.
{"title":"EMF Exposure: A Numerical Model to Predict the Temperature Increase in Biological Vascularized Tissues","authors":"V. De Santis, M. Feliziani","doi":"10.1109/COMITE.2008.4569906","DOIUrl":"https://doi.org/10.1109/COMITE.2008.4569906","url":null,"abstract":"A numerical dosimetry procedure is applied to a biological tissue in order to evaluate the temperature increase produced by RF exposure. The originality of the proposed method regards the application of the bio-heat equation in a vascularized region considering a discrete blood vessel structure which operates as a cooling system in the biological region. First, the blood structure is assumed to be a hydraulic system where a laminate incompressible fluid flows. By this approach the blood velocity in all vessels are computed. Then, the diffusion-convection heat equation is analyzed in a three dimensional domain by a differential numerical method based on the finite difference method. A simple test configuration is finally analysed.","PeriodicalId":306289,"journal":{"name":"2008 14th Conference on Microwave Techniques","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133429381","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 : 2008-04-23DOI: 10.1109/COMITE.2008.4569895
L. Dudás, P. Kovacs, R. Seller
Our aim is to develop a microwave antenna whose radiation pattern is electronically controlled. The radiation pattern of an antenna is determined by the Fourier-transform of the complex illumination function on the antenna aperture. This radiation pattern is mechanically fixed so its alteration is impossible. Therefore we construct an antenna system of several antenna elements. All elements are actuated by separate transmitters; we control the amplitude and the phase of the supplying currents of the antenna elements. This way, we are able to control the radiation pattern of the antenna system. The control is computerized so that there is a possibility to change the radiation pattern quickly. The novelty of our antenna system is the realization in X and UMTS band.
{"title":"Digital Beamforming - Linear and Planar Array","authors":"L. Dudás, P. Kovacs, R. Seller","doi":"10.1109/COMITE.2008.4569895","DOIUrl":"https://doi.org/10.1109/COMITE.2008.4569895","url":null,"abstract":"Our aim is to develop a microwave antenna whose radiation pattern is electronically controlled. The radiation pattern of an antenna is determined by the Fourier-transform of the complex illumination function on the antenna aperture. This radiation pattern is mechanically fixed so its alteration is impossible. Therefore we construct an antenna system of several antenna elements. All elements are actuated by separate transmitters; we control the amplitude and the phase of the supplying currents of the antenna elements. This way, we are able to control the radiation pattern of the antenna system. The control is computerized so that there is a possibility to change the radiation pattern quickly. The novelty of our antenna system is the realization in X and UMTS band.","PeriodicalId":306289,"journal":{"name":"2008 14th Conference on Microwave Techniques","volume":"13 9-10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131451423","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 : 2008-04-23DOI: 10.1109/COMITE.2008.4569901
V. Bilik, J. Bezek
Two effects limiting high-power performance of a 2.45-GHz R26-waveguide stub tuner have been investigated by means of electromagnetic simulation: electric breakdown and microwave power dissipation in tuning stub. In the case of electric breakdown, increasing rounding radius of the stub edge from 1 mm to 4 mm was found to decrease maximum electric field strength 2.25- times, leading to fivefold increase of tuner power-handling capacity. Estimation of power dissipated in the tuning stub, based on average surface current density and stub conductivity, shows that stub overheating is not the most critical limiting factor. The described methodology can be applied to any type of waveguide and tuning stub structure.
{"title":"Investigation of High-Power Limits of Stub Tuners by Means of Electromagnetic Simulation","authors":"V. Bilik, J. Bezek","doi":"10.1109/COMITE.2008.4569901","DOIUrl":"https://doi.org/10.1109/COMITE.2008.4569901","url":null,"abstract":"Two effects limiting high-power performance of a 2.45-GHz R26-waveguide stub tuner have been investigated by means of electromagnetic simulation: electric breakdown and microwave power dissipation in tuning stub. In the case of electric breakdown, increasing rounding radius of the stub edge from 1 mm to 4 mm was found to decrease maximum electric field strength 2.25- times, leading to fivefold increase of tuner power-handling capacity. Estimation of power dissipated in the tuning stub, based on average surface current density and stub conductivity, shows that stub overheating is not the most critical limiting factor. The described methodology can be applied to any type of waveguide and tuning stub structure.","PeriodicalId":306289,"journal":{"name":"2008 14th Conference on Microwave Techniques","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131273567","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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