Pub Date : 1900-01-01DOI: 10.1109/ISAPE.2003.1276794
M. Meshram, N. K. Agrawal, B. Sinha, P. S. Misra
This paper present the design, development and characterization of the hexagonal ferrite powder [BaCo/sub 0.5/spl delta//Ti/sub 0.5/spl delta//Mn/sub 0.1/Fe(11.87-/spl delta/)O/sub 19/] at /spl delta/=1.6 as microwave absorber. The hexagonal ferrite powder has been developed by dry attrition and sintering procedure. The developed ferrite powder 60% by weight has been mixed in epoxy resin to form a microwave absorbing paint. This paint was coated on conducting aluminum sheet to study absorption characteristics of linearly polarized TE wave at X band. The experimental and computed results for different coating thickness have been reported. It has been found that it shows the broadband characteristics with minimum absorption of 6.5 dB from 8 to 12 GHz for a coating thickness of 2 mm. These paints are very useful in military application such as RCS reduction, camouflaging of the target and prevention of EMI etc.
{"title":"Characterization of (Co-Mn-Ti) substituted M type barium hexagonal ferrite based microwave absorber at X band","authors":"M. Meshram, N. K. Agrawal, B. Sinha, P. S. Misra","doi":"10.1109/ISAPE.2003.1276794","DOIUrl":"https://doi.org/10.1109/ISAPE.2003.1276794","url":null,"abstract":"This paper present the design, development and characterization of the hexagonal ferrite powder [BaCo/sub 0.5/spl delta//Ti/sub 0.5/spl delta//Mn/sub 0.1/Fe(11.87-/spl delta/)O/sub 19/] at /spl delta/=1.6 as microwave absorber. The hexagonal ferrite powder has been developed by dry attrition and sintering procedure. The developed ferrite powder 60% by weight has been mixed in epoxy resin to form a microwave absorbing paint. This paint was coated on conducting aluminum sheet to study absorption characteristics of linearly polarized TE wave at X band. The experimental and computed results for different coating thickness have been reported. It has been found that it shows the broadband characteristics with minimum absorption of 6.5 dB from 8 to 12 GHz for a coating thickness of 2 mm. These paints are very useful in military application such as RCS reduction, camouflaging of the target and prevention of EMI etc.","PeriodicalId":179885,"journal":{"name":"6th International SYmposium on Antennas, Propagation and EM Theory, 2003. Proceedings. 2003","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128763594","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 : 1900-01-01DOI: 10.1109/ISAPE.2003.1276719
Zhefeng Yu, Zhicheng Zhang, Lezhu Zhou, Wei-Long Hu
In this paper, the interaction between plasma and electromagnetic waves is studied. It demonstrates that high reflection coefficient requires low collision frequency and high plasma density. If its density is overdensed, the scattering characteristics of nonmagnetized collisionless cold plasma and metal conductor are comparable. As an example, the parameters of a plasma sphere with required RCS is given. The scattering characteristics of plasma with a large space scale are also discussed.
{"title":"Numerical research on the RCS of plasma","authors":"Zhefeng Yu, Zhicheng Zhang, Lezhu Zhou, Wei-Long Hu","doi":"10.1109/ISAPE.2003.1276719","DOIUrl":"https://doi.org/10.1109/ISAPE.2003.1276719","url":null,"abstract":"In this paper, the interaction between plasma and electromagnetic waves is studied. It demonstrates that high reflection coefficient requires low collision frequency and high plasma density. If its density is overdensed, the scattering characteristics of nonmagnetized collisionless cold plasma and metal conductor are comparable. As an example, the parameters of a plasma sphere with required RCS is given. The scattering characteristics of plasma with a large space scale are also discussed.","PeriodicalId":179885,"journal":{"name":"6th International SYmposium on Antennas, Propagation and EM Theory, 2003. Proceedings. 2003","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114723517","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 : 1900-01-01DOI: 10.1109/ISAPE.2003.1276634
Li Ping, Liang Chang-hong, Yuan Tao
Aiming at spreading bandwidth of SAR, this paper puts forward a new type of prism radar antenna. The feed based on techniques of CPW is a two-component antenna array liking H printed by dubble plane overlap. The antennas frequency bandwidth gets to 2.2 times frequency and is designed larruping. VSWR within the bandwidth is less than 1.8, gain and the centural frequency is more than 9dBi. The paper analyzes antennas structure, presents VSWR and radiation direction plot by simulation and test. The result indicates: two-component antenna array printed by dubble plane overlap can be the new feed of UHF radar antenna.
{"title":"Design of UHF synthesize aperture radar antenna","authors":"Li Ping, Liang Chang-hong, Yuan Tao","doi":"10.1109/ISAPE.2003.1276634","DOIUrl":"https://doi.org/10.1109/ISAPE.2003.1276634","url":null,"abstract":"Aiming at spreading bandwidth of SAR, this paper puts forward a new type of prism radar antenna. The feed based on techniques of CPW is a two-component antenna array liking H printed by dubble plane overlap. The antennas frequency bandwidth gets to 2.2 times frequency and is designed larruping. VSWR within the bandwidth is less than 1.8, gain and the centural frequency is more than 9dBi. The paper analyzes antennas structure, presents VSWR and radiation direction plot by simulation and test. The result indicates: two-component antenna array printed by dubble plane overlap can be the new feed of UHF radar antenna.","PeriodicalId":179885,"journal":{"name":"6th International SYmposium on Antennas, Propagation and EM Theory, 2003. Proceedings. 2003","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128029346","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 : 1900-01-01DOI: 10.1109/ISAPE.2003.1276702
R. Khanna, R. Saxena
Wireless communication is experiencing the fastest growth in the period of history. The next generation mobile services will offer variable bandwidth, desktop/multimedia with mobility and service personalization. To enable this, new technologies and systems is put in use viz; wideband receivers, advanced power amplifiers, advanced modems, adaptive antenna systems, space time coding techniques, radio resource management etc. The spatial processing is considered to be the last frontier in the battle of improved cellular system technology and smart antennas is emerging as the enabling technique that exploits available resources of the physical layer. The application of adaptive techniques to wireless communication has been shown to offer wide range of benefits including interference rejection, increased coverage and spectral efficiency. The use of adaptive antenna at handset can help in eliminating co-channel interference (CCI), multi-access interference (MAI), multipath fading and other effects has been discussed in various papers. In this paper the use of adaptive antennas in reducing radiation hazards has been discussed. The effect of high frequencies on human head has been discussed by taking a simple model of head i.e. by considering it to be a stack of skin, bone, fat, muscle and brain. The power reaching various tissues of the head has calculated by first considering an omni directional antenna. Next, the power reaching brain by use of adaptive antenna at handset is found. The adaptive antenna is adaptively forming a broad null in the direction of head. The power radiated by adaptive antenna towards head is very small as compared to omni directional antenna. The power absorbed by various tissues of head viz, skin, bone, fat, muscle and brain has been compared for omni directional as well as adaptive antenna. The study has been made at in the range 1 MHz to 10 GHZ. It has been found as frequency increases less power reaches brain. From the model developed it is found that from 1 GHz to 6 GHz, the human head absorbs about 47% of the power. Further it is shown that 6% of the incident power is reaching brain at 1900 MHz as compared to 13% at 900 MHz. At 6 GHz only 0.04% of the incident power is reaching brain. By using adaptive antenna at die handset decreases the power radiated towards human head thereby decreasing the power absorbed by head as now less power is directed towards human head.
{"title":"Adaptive antenna at the cellular mobile handset for reduced deposition of power in human head","authors":"R. Khanna, R. Saxena","doi":"10.1109/ISAPE.2003.1276702","DOIUrl":"https://doi.org/10.1109/ISAPE.2003.1276702","url":null,"abstract":"Wireless communication is experiencing the fastest growth in the period of history. The next generation mobile services will offer variable bandwidth, desktop/multimedia with mobility and service personalization. To enable this, new technologies and systems is put in use viz; wideband receivers, advanced power amplifiers, advanced modems, adaptive antenna systems, space time coding techniques, radio resource management etc. The spatial processing is considered to be the last frontier in the battle of improved cellular system technology and smart antennas is emerging as the enabling technique that exploits available resources of the physical layer. The application of adaptive techniques to wireless communication has been shown to offer wide range of benefits including interference rejection, increased coverage and spectral efficiency. The use of adaptive antenna at handset can help in eliminating co-channel interference (CCI), multi-access interference (MAI), multipath fading and other effects has been discussed in various papers. In this paper the use of adaptive antennas in reducing radiation hazards has been discussed. The effect of high frequencies on human head has been discussed by taking a simple model of head i.e. by considering it to be a stack of skin, bone, fat, muscle and brain. The power reaching various tissues of the head has calculated by first considering an omni directional antenna. Next, the power reaching brain by use of adaptive antenna at handset is found. The adaptive antenna is adaptively forming a broad null in the direction of head. The power radiated by adaptive antenna towards head is very small as compared to omni directional antenna. The power absorbed by various tissues of head viz, skin, bone, fat, muscle and brain has been compared for omni directional as well as adaptive antenna. The study has been made at in the range 1 MHz to 10 GHZ. It has been found as frequency increases less power reaches brain. From the model developed it is found that from 1 GHz to 6 GHz, the human head absorbs about 47% of the power. Further it is shown that 6% of the incident power is reaching brain at 1900 MHz as compared to 13% at 900 MHz. At 6 GHz only 0.04% of the incident power is reaching brain. By using adaptive antenna at die handset decreases the power radiated towards human head thereby decreasing the power absorbed by head as now less power is directed towards human head.","PeriodicalId":179885,"journal":{"name":"6th International SYmposium on Antennas, Propagation and EM Theory, 2003. Proceedings. 2003","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132398108","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 : 1900-01-01DOI: 10.1109/ISAPE.2003.1276797
Li Rulai, Z. Yisheng
The coreless printed circuit board (PCB) transformers have good characteristics at high-frequency. They have the advantages of low costs, very high power density, no magnetic loss. Their structures are simple and easy to be integrated for manufactures. This paper introduces the structure of the coreless PCB transformers; especially an improved calculation of the self and mutual impedances in coreless PCB transformers is given. An experiment proved that the theory calculation is closely coincident with the testing results.
{"title":"The structure and analysis of coreless printed circuit board transformers","authors":"Li Rulai, Z. Yisheng","doi":"10.1109/ISAPE.2003.1276797","DOIUrl":"https://doi.org/10.1109/ISAPE.2003.1276797","url":null,"abstract":"The coreless printed circuit board (PCB) transformers have good characteristics at high-frequency. They have the advantages of low costs, very high power density, no magnetic loss. Their structures are simple and easy to be integrated for manufactures. This paper introduces the structure of the coreless PCB transformers; especially an improved calculation of the self and mutual impedances in coreless PCB transformers is given. An experiment proved that the theory calculation is closely coincident with the testing results.","PeriodicalId":179885,"journal":{"name":"6th International SYmposium on Antennas, Propagation and EM Theory, 2003. Proceedings. 2003","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130131467","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 : 1900-01-01DOI: 10.1109/ISAPE.2003.1276722
W. Chien, C. Chiu
We consider the inverse problem of determining both the shape and the conductivity of a two-dimensional conducting scatterer from a knowledge of the far-field pattern of TM waves by solving the ill posed nonlinear equation. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equations is derived and the imaging problem is reformulated into an optimization problem. Satisfactory reconstructions have been achieved by the genetic algorithm. Numerical results demonstrated that, even when the initial guess is far away from the exact one, good reconstruction has been obtained. Numerical results show that multiple incident directions permit good reconstruction of shape and conductivity.
{"title":"Inverse scattering for shape and conductivity","authors":"W. Chien, C. Chiu","doi":"10.1109/ISAPE.2003.1276722","DOIUrl":"https://doi.org/10.1109/ISAPE.2003.1276722","url":null,"abstract":"We consider the inverse problem of determining both the shape and the conductivity of a two-dimensional conducting scatterer from a knowledge of the far-field pattern of TM waves by solving the ill posed nonlinear equation. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equations is derived and the imaging problem is reformulated into an optimization problem. Satisfactory reconstructions have been achieved by the genetic algorithm. Numerical results demonstrated that, even when the initial guess is far away from the exact one, good reconstruction has been obtained. Numerical results show that multiple incident directions permit good reconstruction of shape and conductivity.","PeriodicalId":179885,"journal":{"name":"6th International SYmposium on Antennas, Propagation and EM Theory, 2003. Proceedings. 2003","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133907433","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 : 1900-01-01DOI: 10.1109/ISAPE.2003.1276627
T. Liu, Wen Xun Zhang
A novel GSM/DCS dual-band single layer patch antenna is presented, it covers the bands of (890-960) MHz for GSM and (1710-1880) MHz for DCS with VSWR /spl les/2. This antenna consists of a ground plane, air layer, and a metal patch layer printed on a thin substrate with lower permittivity. The initial sizes of the antenna are determined by using of transmission line model, then, the performances of antenna are simulated and optimized with Ansoft Ensemble 8.0 software. The bandwidth of 83 MHz for GSM band (9.22 %) and 730 MHz for DCS band (40.56 %) has been obtained. The results of simulation and experiment are compared.
{"title":"Transmission line model analysis: a novel GSM/DCS dual-band single layer patch antenna","authors":"T. Liu, Wen Xun Zhang","doi":"10.1109/ISAPE.2003.1276627","DOIUrl":"https://doi.org/10.1109/ISAPE.2003.1276627","url":null,"abstract":"A novel GSM/DCS dual-band single layer patch antenna is presented, it covers the bands of (890-960) MHz for GSM and (1710-1880) MHz for DCS with VSWR /spl les/2. This antenna consists of a ground plane, air layer, and a metal patch layer printed on a thin substrate with lower permittivity. The initial sizes of the antenna are determined by using of transmission line model, then, the performances of antenna are simulated and optimized with Ansoft Ensemble 8.0 software. The bandwidth of 83 MHz for GSM band (9.22 %) and 730 MHz for DCS band (40.56 %) has been obtained. The results of simulation and experiment are compared.","PeriodicalId":179885,"journal":{"name":"6th International SYmposium on Antennas, Propagation and EM Theory, 2003. Proceedings. 2003","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131716385","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 : 1900-01-01DOI: 10.1109/ISAPE.2003.1276737
Tang Wei, Qingliang Li, Zhensen Wu, Peinan Jiao
In this paper, the ADI-FDTD algorithm is applied to simulate scattering of three-dimensional objects. A few key techniques include the introduction of an incident plane wave, connective boundary condition between total-field zone and scattering-field zone and near-to-far field transformation are discussed. It is shown from the numerical result that the computation time of the ADI-FDTD algorithm is only 1/6 that of the conventional FDTD method with the same accuracy.
{"title":"ADI-FDTD algorithm for three-dimensional scattering analysis","authors":"Tang Wei, Qingliang Li, Zhensen Wu, Peinan Jiao","doi":"10.1109/ISAPE.2003.1276737","DOIUrl":"https://doi.org/10.1109/ISAPE.2003.1276737","url":null,"abstract":"In this paper, the ADI-FDTD algorithm is applied to simulate scattering of three-dimensional objects. A few key techniques include the introduction of an incident plane wave, connective boundary condition between total-field zone and scattering-field zone and near-to-far field transformation are discussed. It is shown from the numerical result that the computation time of the ADI-FDTD algorithm is only 1/6 that of the conventional FDTD method with the same accuracy.","PeriodicalId":179885,"journal":{"name":"6th International SYmposium on Antennas, Propagation and EM Theory, 2003. Proceedings. 2003","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130792509","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 : 1900-01-01DOI: 10.1109/ISAPE.2003.1276724
Wang Jun
A new target recognition procedure is developed. In order to efficiently obtain feature vectors for target discrimination, the closed-form expression of geometrical wave fronts is also derived to provide efficient and accurate computation. Then, the resulting low dimensional feature vectors, obtained by the developed extractor, are identified using the well-known artificial neural networks (ANNs) classifier. In the illustrative experiments. three thin-wire targets are discriminated. The results show that the presented scheme gives successful automatic target recognition (ATR) in the low SNR with low computational costs. Therefore, the proposed technique has a significant potential for use in ATR.
{"title":"Radar target imaging and identification using the advanced inverse scattering technique","authors":"Wang Jun","doi":"10.1109/ISAPE.2003.1276724","DOIUrl":"https://doi.org/10.1109/ISAPE.2003.1276724","url":null,"abstract":"A new target recognition procedure is developed. In order to efficiently obtain feature vectors for target discrimination, the closed-form expression of geometrical wave fronts is also derived to provide efficient and accurate computation. Then, the resulting low dimensional feature vectors, obtained by the developed extractor, are identified using the well-known artificial neural networks (ANNs) classifier. In the illustrative experiments. three thin-wire targets are discriminated. The results show that the presented scheme gives successful automatic target recognition (ATR) in the low SNR with low computational costs. Therefore, the proposed technique has a significant potential for use in ATR.","PeriodicalId":179885,"journal":{"name":"6th International SYmposium on Antennas, Propagation and EM Theory, 2003. Proceedings. 2003","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131163994","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 : 1900-01-01DOI: 10.1109/ISAPE.2003.1276824
Bingyu Li, S. Zhang
Ray-tracing method was used to simulate the characteristic of wide band radio wave transmission in tunnel. The simulation results showed that the root-mean-square delay spread /spl tau//sub rms/ caused by multipath propagation fade varied with the communication distance in tunnel. Therefore the correlation bandwidth of the channel was connected with the communication distance in tunnel. The attenuation caused by multipath propagation fade varied with the communication distance too.
{"title":"The influence of communication distance on multipath channel characteristic of tunnel","authors":"Bingyu Li, S. Zhang","doi":"10.1109/ISAPE.2003.1276824","DOIUrl":"https://doi.org/10.1109/ISAPE.2003.1276824","url":null,"abstract":"Ray-tracing method was used to simulate the characteristic of wide band radio wave transmission in tunnel. The simulation results showed that the root-mean-square delay spread /spl tau//sub rms/ caused by multipath propagation fade varied with the communication distance in tunnel. Therefore the correlation bandwidth of the channel was connected with the communication distance in tunnel. The attenuation caused by multipath propagation fade varied with the communication distance too.","PeriodicalId":179885,"journal":{"name":"6th International SYmposium on Antennas, Propagation and EM Theory, 2003. Proceedings. 2003","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133497491","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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