Pub Date : 2011-04-26DOI: 10.1109/NRSC.2011.5873626
S. Badr, F. Bayoumi, G. Darwesh
The evolution of the World Wide Web (WWW) service has incorporated new distributed multimedia conference applications, powering a new generation of e-services development, and allowing improved interactivity [1]. Most common interactive real-time applications are fault-tolerant but suffer from QoS limitations; low-latency requirements and reliability are cumulative to conference success [2], it may easily absorb all network resources and the subjective quality sensed by users would remain poor if the available resources are used indiscriminately. This paper simulates a network infrastructure design that classifies and prioritizes the real-time traffic in order to improve the performance of the real-time applications, taking into consideration of the performance of non real-time applications. This infrastructure has been designed to present a typical network of a university campus, so that in this way it can be implemented in any campus. In this paper 3 scenarios are suggested first before enabling any QoS mechanism at the routers, second use class based weighted fair queuing using low latency queue (CBWFQ-LLQ) for video traffic and last scenario apply CBWFQ-LLQ for voice. The simulation is conducted using OPNET IT Guru. Simulation results demonstrated that applying LLQ for voice improves the performance of overall real-time and non real-time application.
万维网(WWW)服务的发展已经纳入了新的分布式多媒体会议应用程序，推动了新一代电子服务的发展，并允许改进的交互性[1]。大多数常见的交互式实时应用程序是容错的，但受到QoS限制;低延迟要求和可靠性是会议成功的累积因素[2]，它很容易吸收所有的网络资源，如果不加区分地使用可用资源，用户感知的主观质量就会很差。本文模拟了一种网络基础设施设计，在考虑非实时应用性能的情况下，对实时流量进行分类和优先级排序，以提高实时应用的性能。这个基础设施被设计成一个典型的大学校园网络，这样它就可以在任何校园中实现。本文提出了三种场景，首先在路由器上启用任何QoS机制，其次在视频流量中使用基于类的加权公平排队，使用低延迟队列(CBWFQ-LLQ)，最后在语音流量中使用CBWFQ-LLQ。仿真采用OPNET IT Guru软件进行。仿真结果表明，在语音中应用LLQ可以提高整体实时和非实时应用的性能。
{"title":"QoS adaptation in real time systems based on CBWFQ","authors":"S. Badr, F. Bayoumi, G. Darwesh","doi":"10.1109/NRSC.2011.5873626","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873626","url":null,"abstract":"The evolution of the World Wide Web (WWW) service has incorporated new distributed multimedia conference applications, powering a new generation of e-services development, and allowing improved interactivity [1]. Most common interactive real-time applications are fault-tolerant but suffer from QoS limitations; low-latency requirements and reliability are cumulative to conference success [2], it may easily absorb all network resources and the subjective quality sensed by users would remain poor if the available resources are used indiscriminately. This paper simulates a network infrastructure design that classifies and prioritizes the real-time traffic in order to improve the performance of the real-time applications, taking into consideration of the performance of non real-time applications. This infrastructure has been designed to present a typical network of a university campus, so that in this way it can be implemented in any campus. In this paper 3 scenarios are suggested first before enabling any QoS mechanism at the routers, second use class based weighted fair queuing using low latency queue (CBWFQ-LLQ) for video traffic and last scenario apply CBWFQ-LLQ for voice. The simulation is conducted using OPNET IT Guru. Simulation results demonstrated that applying LLQ for voice improves the performance of overall real-time and non real-time application.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"138 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115675256","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873617
A. K. Aboul-Seoud, E. El-Badawy, A. Mokhtar, W. El-Masry, Mohamed El-Barbry, Alaa El-Din Sayed Hafez
This paper introduces a simple implementation of digital chaotic sequence generator. The implementation is based on using microcontroller ATMGA 16 to generate the chaotic map required for advanced encryption standard (AES) encryption scheme s-box and radar frequency agile control. The implemented circuit is simple, low cost and suitable for use with identification friend or foe (IFF) equipped with data encryption systems. The circuit also can changes the carrier frequency of the transmitted signal based on chaotic map, benefits a security and confidentiality to the radar waveform against Electronic Counter Measurement (ECM). The circuit generates 256 random sequences at different initial conditions and each of them has 256 sequences generated from different bifurcation parameters. The circuit is simulated under Matlab program environment and Proteus circuit simulation program. A security analysis for the implemented circuit is demonstrated. The results show the superiority of the circuit for generating the random sequences forming an efficient s-box for IFF system and radar frequency agility.
{"title":"A simple 8-bit digital microcontroller implementation for chaotic sequence generation","authors":"A. K. Aboul-Seoud, E. El-Badawy, A. Mokhtar, W. El-Masry, Mohamed El-Barbry, Alaa El-Din Sayed Hafez","doi":"10.1109/NRSC.2011.5873617","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873617","url":null,"abstract":"This paper introduces a simple implementation of digital chaotic sequence generator. The implementation is based on using microcontroller ATMGA 16 to generate the chaotic map required for advanced encryption standard (AES) encryption scheme s-box and radar frequency agile control. The implemented circuit is simple, low cost and suitable for use with identification friend or foe (IFF) equipped with data encryption systems. The circuit also can changes the carrier frequency of the transmitted signal based on chaotic map, benefits a security and confidentiality to the radar waveform against Electronic Counter Measurement (ECM). The circuit generates 256 random sequences at different initial conditions and each of them has 256 sequences generated from different bifurcation parameters. The circuit is simulated under Matlab program environment and Proteus circuit simulation program. A security analysis for the implemented circuit is demonstrated. The results show the superiority of the circuit for generating the random sequences forming an efficient s-box for IFF system and radar frequency agility.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127080525","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873582
A. Abdel-Rahman, A. E. El Dein, M. A. Mostafa
This paper presents a new design of a wide band monopole antenna with excellent impedance matching to enhancement the impedance bandwidth. The impedance bandwidth enhancement is achieved by inserting only one rectangular shape slot on the rectangular patch of the monopole antenna instead of inserting more than one slot on the patch as usual. Also the ground plane (GP) dimensions are very important parameters in the design of these antennas, because of strong dependence of bandwidth on ground plane size. Results and performance optimizations are carried out by using the commercial EM wave simulation program and FDTD technique.
{"title":"Impedance bandwidth enhancement of UWB monopole antenna by using rectangular shaped slot","authors":"A. Abdel-Rahman, A. E. El Dein, M. A. Mostafa","doi":"10.1109/NRSC.2011.5873582","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873582","url":null,"abstract":"This paper presents a new design of a wide band monopole antenna with excellent impedance matching to enhancement the impedance bandwidth. The impedance bandwidth enhancement is achieved by inserting only one rectangular shape slot on the rectangular patch of the monopole antenna instead of inserting more than one slot on the patch as usual. Also the ground plane (GP) dimensions are very important parameters in the design of these antennas, because of strong dependence of bandwidth on ground plane size. Results and performance optimizations are carried out by using the commercial EM wave simulation program and FDTD technique.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125534718","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873583
A. Montaser, K. Mahmoud, H. Elmikati
An internal Ultra-Wideband (UWB) monopole antenna for use in portable wireless communication applications is presented with a compact dimensions. It consists of a radiating patch, a matching stub, and a ground plane. The effect of defected ground plane structure (DGS) is studied in addition to the effect of defected slots in the radiating patch and matching stub on the return loss (S11). The Differential Evolution (DE) algorithm is considered to minimize S11 in the UWB frequency range by determining the appropriate antenna dimensions, the results are compared with other optimization techniques such as Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). Also, the proposed antenna is built into a plastic case (εr = 3), having external dimensions 43.4 × 21.4 × 8.3 mm to study its effect on the radiation parameters.
{"title":"Compact Ultra-Wideband monopole antenna design for wireless communication using differential evolution optimization algorithm","authors":"A. Montaser, K. Mahmoud, H. Elmikati","doi":"10.1109/NRSC.2011.5873583","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873583","url":null,"abstract":"An internal Ultra-Wideband (UWB) monopole antenna for use in portable wireless communication applications is presented with a compact dimensions. It consists of a radiating patch, a matching stub, and a ground plane. The effect of defected ground plane structure (DGS) is studied in addition to the effect of defected slots in the radiating patch and matching stub on the return loss (S11). The Differential Evolution (DE) algorithm is considered to minimize S11 in the UWB frequency range by determining the appropriate antenna dimensions, the results are compared with other optimization techniques such as Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). Also, the proposed antenna is built into a plastic case (εr = 3), having external dimensions 43.4 × 21.4 × 8.3 mm to study its effect on the radiation parameters.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122081172","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873640
S. Mikki, Y. Antar
The goal of this paper is to present the view of the authors on the current status of electromagnetic research, particulary in the engineering and the applied sciences, in order to asses the latent potentials of what has been achieved so far and their germination and subsequent evolvement throughout the near future into concrete research strategies.
{"title":"Fundamental Research directives in applied electromagnetics","authors":"S. Mikki, Y. Antar","doi":"10.1109/NRSC.2011.5873640","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873640","url":null,"abstract":"The goal of this paper is to present the view of the authors on the current status of electromagnetic research, particulary in the engineering and the applied sciences, in order to asses the latent potentials of what has been achieved so far and their germination and subsequent evolvement throughout the near future into concrete research strategies.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128617265","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873588
S. Zainud-Deen, M. Ibrahim, A. Botros
In this paper, some applications of metamaterial superstrates for directivity enhancement of cylindrical dielectric resonator antenna (CDRA) over curved ground plane are investigated. Three different types of superstrates, viz., split ring resonator (SRR), S-shape, and cubic high dielectric resonator (CHDR) are discussed. The metamaterial structure is used as a lens to improve the directivity of CDRA with small half-power beamwidth, wide impedance bandwidth, and matched input impedance. All analysis and simulations throughout this paper were carried out using the finite element method (FEM) and compared with that calculated with finite integration technique (FIT) method.
{"title":"High-directive dielectric resonator antenna over curved ground plane using metamaterials","authors":"S. Zainud-Deen, M. Ibrahim, A. Botros","doi":"10.1109/NRSC.2011.5873588","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873588","url":null,"abstract":"In this paper, some applications of metamaterial superstrates for directivity enhancement of cylindrical dielectric resonator antenna (CDRA) over curved ground plane are investigated. Three different types of superstrates, viz., split ring resonator (SRR), S-shape, and cubic high dielectric resonator (CHDR) are discussed. The metamaterial structure is used as a lens to improve the directivity of CDRA with small half-power beamwidth, wide impedance bandwidth, and matched input impedance. All analysis and simulations throughout this paper were carried out using the finite element method (FEM) and compared with that calculated with finite integration technique (FIT) method.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127576310","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873602
N. El-Fishawy, M. Zahra, M. Ebrahim, Mostafa M. El-gamala
The IEEE 802.16 standard defines wireless broadband access technology called Worldwide Interoperability for Microwave Access (commonly called fixed WiMAX). WiMAX introduces several interesting advantages including variable and high data rate, last mile wireless access, point to multipoint communication, large frequency range, and Quality of Service (QoS) for various types of applications. IEEE 802.16e amendment defines mobile WiMAX which includes the fixed WiMAX features plus other features like mobility. However, the actual version of the standard does not define a Medium Access Control (MAC) scheduling architecture in uplink as well as downlink direction. Efficient scheduling design is left for designers and thus providing QoS for IEEE 802.16 Broadband Wireless Access (BWA) system is a challenge for system developers. A scheduling algorithm should take into account the WiMAX QoS classes and service requirements. Cross-layer scheduler which designed for WiMAX networks assign a priority function for every service. The priority functions take into account many parameters like channel conditions, service classes, delay, and throughput. In this paper, the scheduling algorithms will be classified, and a modification in cross-layer scheduling algorithm will be proposed to improve the scheduling performance.
{"title":"Modified cross-layer scheduling for mobile WiMAX networks","authors":"N. El-Fishawy, M. Zahra, M. Ebrahim, Mostafa M. El-gamala","doi":"10.1109/NRSC.2011.5873602","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873602","url":null,"abstract":"The IEEE 802.16 standard defines wireless broadband access technology called Worldwide Interoperability for Microwave Access (commonly called fixed WiMAX). WiMAX introduces several interesting advantages including variable and high data rate, last mile wireless access, point to multipoint communication, large frequency range, and Quality of Service (QoS) for various types of applications. IEEE 802.16e amendment defines mobile WiMAX which includes the fixed WiMAX features plus other features like mobility. However, the actual version of the standard does not define a Medium Access Control (MAC) scheduling architecture in uplink as well as downlink direction. Efficient scheduling design is left for designers and thus providing QoS for IEEE 802.16 Broadband Wireless Access (BWA) system is a challenge for system developers. A scheduling algorithm should take into account the WiMAX QoS classes and service requirements. Cross-layer scheduler which designed for WiMAX networks assign a priority function for every service. The priority functions take into account many parameters like channel conditions, service classes, delay, and throughput. In this paper, the scheduling algorithms will be classified, and a modification in cross-layer scheduling algorithm will be proposed to improve the scheduling performance.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125721021","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873596
Mohammed Torad, Ahmed El Qassas, Hadia Al Henawi
In this paper a comparative study between LTE and WiMAX, the two leading wireless broadband technologies, is introduced. The performance metrics used for the evaluation are the response time and the throughput derived from OPNET modeler release 16 system level simulator. To perform the comparison 4 scenarios were developed the first two are for 7 cell LTE and 7cell WiMAX networks while the second two are for 19 cell LTE and 19cell WiMAX networks. The numerical results are obtained for links between mobiles at fixed relative positions in the four scenarios. Through this analysis we found that LTE networks gave shorter response time than WiMAX. The throughput is also compared and results showed that WiMAX outperformed LTE in this respect.
{"title":"Comparison between LTE and WiMAX based on system level simulation using OPNET modeler (release 16)","authors":"Mohammed Torad, Ahmed El Qassas, Hadia Al Henawi","doi":"10.1109/NRSC.2011.5873596","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873596","url":null,"abstract":"In this paper a comparative study between LTE and WiMAX, the two leading wireless broadband technologies, is introduced. The performance metrics used for the evaluation are the response time and the throughput derived from OPNET modeler release 16 system level simulator. To perform the comparison 4 scenarios were developed the first two are for 7 cell LTE and 7cell WiMAX networks while the second two are for 19 cell LTE and 19cell WiMAX networks. The numerical results are obtained for links between mobiles at fixed relative positions in the four scenarios. Through this analysis we found that LTE networks gave shorter response time than WiMAX. The throughput is also compared and results showed that WiMAX outperformed LTE in this respect.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129963201","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873641
A. Tewfik
The wide proliferation of wireless services and applications with increasing bandwidth needs is rapidly creating a spectrum shortage. However, the problem is caused primarily by inefficient legacy spectrum allocation and utilization policies, so that even when some applications suffer from lack of bandwidth, there is idle capacity in the band they are using or other bands. The FCC, ITU and other regulatory organizations have adopted, or are exploring, alternative spectrum usage policies and regulations to address the issue. The new policies and regulations support an open spectrum policy implemented by cognitive radios and overlay transmissions implemented via ultrawideband technology and/or cognitive radios. This talk describes a revolutionary approach for addressing spectrum scarcity and unlocking hidden communication capacity thereby increasing the reach and utility of wireless connectivity. The non-traditional communication technique studied in this research effort detects transmission opportunities that occur when incumbent primary users enjoy signal to noise ratio values that are higher than the minimum value required to maintain their quality of service. It then judicially exploits these opportunities while preserving the current quality of service of the primary users.
{"title":"Proactive transmit opportunity detection in cognitive radio networks","authors":"A. Tewfik","doi":"10.1109/NRSC.2011.5873641","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873641","url":null,"abstract":"The wide proliferation of wireless services and applications with increasing bandwidth needs is rapidly creating a spectrum shortage. However, the problem is caused primarily by inefficient legacy spectrum allocation and utilization policies, so that even when some applications suffer from lack of bandwidth, there is idle capacity in the band they are using or other bands. The FCC, ITU and other regulatory organizations have adopted, or are exploring, alternative spectrum usage policies and regulations to address the issue. The new policies and regulations support an open spectrum policy implemented by cognitive radios and overlay transmissions implemented via ultrawideband technology and/or cognitive radios. This talk describes a revolutionary approach for addressing spectrum scarcity and unlocking hidden communication capacity thereby increasing the reach and utility of wireless connectivity. The non-traditional communication technique studied in this research effort detects transmission opportunities that occur when incumbent primary users enjoy signal to noise ratio values that are higher than the minimum value required to maintain their quality of service. It then judicially exploits these opportunities while preserving the current quality of service of the primary users.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"171 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114764701","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873587
S. Zainud-Deen, N. A. El-Shalaby, K. Awadalla
Characteristics of hemispherical dielectric resonator antenna (DRA) mounted on or embedded in spherical ground plane are discussed in this paper. Curvature effects on radiation characteristics of hemispherical DRA are evaluated using the finite element method and the finite integration technique. The co-polarization and the cross-polarization characteristics are analyzed. The structure of a superstrate-loaded hemispherical DRA is treated. The superstrate layer is loaded directly on the hemispherical DRA. The results obtained for the reflection coefficient, the input impedance and the radiation pattern in different planes are analyzed as functions of ground sphere radius and superstrate permittivity.
{"title":"Hemispherical dielectric resonator antenna mounted on or embedded in spherical ground plane with a superstrate","authors":"S. Zainud-Deen, N. A. El-Shalaby, K. Awadalla","doi":"10.1109/NRSC.2011.5873587","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873587","url":null,"abstract":"Characteristics of hemispherical dielectric resonator antenna (DRA) mounted on or embedded in spherical ground plane are discussed in this paper. Curvature effects on radiation characteristics of hemispherical DRA are evaluated using the finite element method and the finite integration technique. The co-polarization and the cross-polarization characteristics are analyzed. The structure of a superstrate-loaded hemispherical DRA is treated. The superstrate layer is loaded directly on the hemispherical DRA. The results obtained for the reflection coefficient, the input impedance and the radiation pattern in different planes are analyzed as functions of ground sphere radius and superstrate permittivity.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"490 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116170606","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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