Pub Date : 2008-12-01DOI: 10.1109/RFM.2008.4897377
A. Ramli, S. M. Idrus, A. Supa’at
Optical wireless or Free Space Optics (FSO) has received considerable attention as an alternative to existing Radio Frequency (RF) communication system. This is due to the growing demand for wireless broadband communications and congestion on bandwidth of RF spectrum. In optical wireless application, the performance of the receiver is significantly determines the overall performance of optical wireless link. Receiver is required to have large aperture. Accordingly, the detector is required to have a large detection area which produces high photodetector capacitance and limits the receiver bandwidth. In this paper, the front-end optical receiver designs especially for wireless application have been focused where a fundamental requirement is the achievement of wide dynamic range and broad bandwidth. Through a review on reported works, the bootstrapping technique is found effectively reduces the photodetector capacitance associated with the large area photodetector. Consequently, the overall bandwidth of the system can be improved.
{"title":"Optical wireless front-end receiver design","authors":"A. Ramli, S. M. Idrus, A. Supa’at","doi":"10.1109/RFM.2008.4897377","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897377","url":null,"abstract":"Optical wireless or Free Space Optics (FSO) has received considerable attention as an alternative to existing Radio Frequency (RF) communication system. This is due to the growing demand for wireless broadband communications and congestion on bandwidth of RF spectrum. In optical wireless application, the performance of the receiver is significantly determines the overall performance of optical wireless link. Receiver is required to have large aperture. Accordingly, the detector is required to have a large detection area which produces high photodetector capacitance and limits the receiver bandwidth. In this paper, the front-end optical receiver designs especially for wireless application have been focused where a fundamental requirement is the achievement of wide dynamic range and broad bandwidth. Through a review on reported works, the bootstrapping technique is found effectively reduces the photodetector capacitance associated with the large area photodetector. Consequently, the overall bandwidth of the system can be improved.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131224439","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 : 2008-12-01DOI: 10.1109/RFM.2008.4897422
N. Zakaria, A. A. Sulaiman, Muhammad Asyraf Abd Latip
A circular microstrip antenna is designed in order to obtain the required parameter responses from 2.4 GHz-2.5 GHz by using GENESYS software based on the method of cavity model due of simplicity and easier to analyze. This circular patch is fed by microstrip line and RT Duroid 5870 is used with the specified information include the dielectric constant of substrate (isinr = 2.33) the resonant frequency (fr = 2.45GHz) and substrate height (h=0.5 mm). The circular microstrip antenna exhibits appropriate required parameters depend on the feed point position, size of the circular patch and length of the microstrip line. A prototype of a circular microstrip antenna has been built and tested by Vector Network Analyzer. The agreement between the measured and simulated results is slightly differ caused by several factors that would be discussed in result part.
{"title":"Design of a circular microstrip antenna","authors":"N. Zakaria, A. A. Sulaiman, Muhammad Asyraf Abd Latip","doi":"10.1109/RFM.2008.4897422","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897422","url":null,"abstract":"A circular microstrip antenna is designed in order to obtain the required parameter responses from 2.4 GHz-2.5 GHz by using GENESYS software based on the method of cavity model due of simplicity and easier to analyze. This circular patch is fed by microstrip line and RT Duroid 5870 is used with the specified information include the dielectric constant of substrate (isinr = 2.33) the resonant frequency (fr = 2.45GHz) and substrate height (h=0.5 mm). The circular microstrip antenna exhibits appropriate required parameters depend on the feed point position, size of the circular patch and length of the microstrip line. A prototype of a circular microstrip antenna has been built and tested by Vector Network Analyzer. The agreement between the measured and simulated results is slightly differ caused by several factors that would be discussed in result part.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123390527","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 : 2008-12-01DOI: 10.1109/RFM.2008.4897415
U. Okonkwo, R. Ngah, T. A. Rahman
Channel characterization and state information play important role in the realization of optimal performance in communication systems. In mobile communication systems, the channel is realistically nonstationary and is often modeled equivalently as time-frequency integral operator with finite supports in time and frequency, employing the Fourier kernel and fixed window as the analyzing functions which result in poor time-frequency resolution and is unsuitable for representation of nonstationary systems. And as such this form of characterization is not adequate in accurately tracking channel variations especially in fast fading and frequency selective channels. In this paper, we present a method of mobile radio channel characterization and description in the wavelet-domain which promises a better joint time-frequency variations representation assuming nonstationary channel condition and very suitable for mobile broadband communication system.
{"title":"Wavelet-domain channel characterization for mobile broadband communication systems","authors":"U. Okonkwo, R. Ngah, T. A. Rahman","doi":"10.1109/RFM.2008.4897415","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897415","url":null,"abstract":"Channel characterization and state information play important role in the realization of optimal performance in communication systems. In mobile communication systems, the channel is realistically nonstationary and is often modeled equivalently as time-frequency integral operator with finite supports in time and frequency, employing the Fourier kernel and fixed window as the analyzing functions which result in poor time-frequency resolution and is unsuitable for representation of nonstationary systems. And as such this form of characterization is not adequate in accurately tracking channel variations especially in fast fading and frequency selective channels. In this paper, we present a method of mobile radio channel characterization and description in the wavelet-domain which promises a better joint time-frequency variations representation assuming nonstationary channel condition and very suitable for mobile broadband communication system.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115384724","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 : 2008-12-01DOI: 10.1109/RFM.2008.4897373
M. H. Jusoh, N. Ya'acob, H. Saad, A. A. Sulaiman, N. Baba, R. A. Awang, Z. I. Khan
The ionospheric Total Electron Content (TEC) measurements were investigated at Universiti Teknologi Malaysia, UTMJ on 20 February - 20 March 2007. The observation was made 14 days before earthquake and 14 days after earthquake. TEC is extracted using GPS dual frequency data which in RINEX format that supplied by JUPEM (Jabatan Ukur dan Pemetaaan Malaysia). In order to reveal possible earthquake precursor through the changes variation of TEC reading, Southern Sumatra Indonesia earthquake that happened on 6th March 2007 is chosen as a study case. The results show that satellite facilities may detect earthquake precursors in ionosphere 5-11 days or a few hours before main shock and various grounds based or satellite observation have shown strong perturbation of the ionosphere after earthquake. The results show a good agreement with other researchers who studied other earthquakes.
2007年2月20日至3月20日，马来西亚科技大学(UTMJ)对电离层总电子含量(TEC)的测量进行了研究。观测分别在震前14天和震后14天进行。TEC是使用由JUPEM (Jabatan Ukur dan pemetaan Malaysia)提供的RINEX格式的GPS双频数据提取的。为了通过TEC读数的变化变化揭示可能的地震前兆，本文选择2007年3月6日发生的印度尼西亚苏门答腊岛南部地震作为研究案例。结果表明，卫星设施可在主震前5 ~ 11天或数小时探测到电离层的地震前兆，各种地面观测或卫星观测均显示出地震后电离层的强烈扰动。研究结果与其他研究其他地震的研究人员的结果很一致。
{"title":"Earthquake prediction technique based on GPS dual frequency system in equatorial region","authors":"M. H. Jusoh, N. Ya'acob, H. Saad, A. A. Sulaiman, N. Baba, R. A. Awang, Z. I. Khan","doi":"10.1109/RFM.2008.4897373","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897373","url":null,"abstract":"The ionospheric Total Electron Content (TEC) measurements were investigated at Universiti Teknologi Malaysia, UTMJ on 20 February - 20 March 2007. The observation was made 14 days before earthquake and 14 days after earthquake. TEC is extracted using GPS dual frequency data which in RINEX format that supplied by JUPEM (Jabatan Ukur dan Pemetaaan Malaysia). In order to reveal possible earthquake precursor through the changes variation of TEC reading, Southern Sumatra Indonesia earthquake that happened on 6th March 2007 is chosen as a study case. The results show that satellite facilities may detect earthquake precursors in ionosphere 5-11 days or a few hours before main shock and various grounds based or satellite observation have shown strong perturbation of the ionosphere after earthquake. The results show a good agreement with other researchers who studied other earthquakes.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114790299","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 : 2008-12-01DOI: 10.1109/RFM.2008.4897382
A. Al-hetar, A. Supa’at, A. .. Mohammad, I. Yulianti
A thermal analysis and structure of ridge and buried (conventional) single mode waveguides with a metal heater are presented. The numerical simulation shows the power consumption of the present ridge waveguide is almost a third of that for conventional one and the response time is half of that of the conventional one.
{"title":"Thermal analysis for ridge and buried waveguides with a metal heater","authors":"A. Al-hetar, A. Supa’at, A. .. Mohammad, I. Yulianti","doi":"10.1109/RFM.2008.4897382","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897382","url":null,"abstract":"A thermal analysis and structure of ridge and buried (conventional) single mode waveguides with a metal heater are presented. The numerical simulation shows the power consumption of the present ridge waveguide is almost a third of that for conventional one and the response time is half of that of the conventional one.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123213383","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 : 2008-12-01DOI: 10.1109/RFM.2008.4897383
K. Yazbek, O. Harfoush
We aim to design a microwave synthesizer using a PLL and taking into account the EMC/EMI problems. These problems are more important when using two synthesizers in a communication system, one for the transmitter with direct frequency modulation of the oscillator (VCO), and another as a local oscillator for the receiver. EMC/EMI issues have been treated in this work from a practical point of view: layout, type of used components, and distribution of power supply.
{"title":"Practical EMC considerations in designing PCB for RF and microwave communications systems","authors":"K. Yazbek, O. Harfoush","doi":"10.1109/RFM.2008.4897383","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897383","url":null,"abstract":"We aim to design a microwave synthesizer using a PLL and taking into account the EMC/EMI problems. These problems are more important when using two synthesizers in a communication system, one for the transmitter with direct frequency modulation of the oscillator (VCO), and another as a local oscillator for the receiver. EMC/EMI issues have been treated in this work from a practical point of view: layout, type of used components, and distribution of power supply.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127323694","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 : 2008-12-01DOI: 10.1109/RFM.2008.4897434
M. Rahim, M. Salleh, O. Ayop, T. Masri
This paper described the design and implementation of switch beam antenna array system operating at 2.4 GHz frequency band. In this paper, four beam patterns are generated by incorporated with four dielectric antenna array and butler matrix. The PIN diode worked as a swicth while the PIC microcontroller used to control the beam pattern by setting the time delay between the beams. The result showed that the multibeam radiation pattern can be produced using this system.
{"title":"Switched beam antenna system design","authors":"M. Rahim, M. Salleh, O. Ayop, T. Masri","doi":"10.1109/RFM.2008.4897434","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897434","url":null,"abstract":"This paper described the design and implementation of switch beam antenna array system operating at 2.4 GHz frequency band. In this paper, four beam patterns are generated by incorporated with four dielectric antenna array and butler matrix. The PIN diode worked as a swicth while the PIC microcontroller used to control the beam pattern by setting the time delay between the beams. The result showed that the multibeam radiation pattern can be produced using this system.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125683338","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 : 2008-12-01DOI: 10.1109/RFM.2008.4897414
F. Bin Idris, S. Ariffin
Mobile IPv6 (MIPv6) is a protocol that is proposed for the future of the mobile Internet access. The aim of MIPv6 is provide uninterrupted connection while being mobile. VoIP has stringent delay requirement and to improve the performance of VoIP, handoff latency must be keep as low as possible. In this paper the implementation of Fast Handover Mobile IPv6 (FMIPv6) is modeled and simulated using NS2. The performance is analyzed for typical PCM G.711 voice coding scheme for both MIPv6 and FMIPv6.
{"title":"Handoff latency of voice over internet protocol in Mobile IPv6","authors":"F. Bin Idris, S. Ariffin","doi":"10.1109/RFM.2008.4897414","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897414","url":null,"abstract":"Mobile IPv6 (MIPv6) is a protocol that is proposed for the future of the mobile Internet access. The aim of MIPv6 is provide uninterrupted connection while being mobile. VoIP has stringent delay requirement and to improve the performance of VoIP, handoff latency must be keep as low as possible. In this paper the implementation of Fast Handover Mobile IPv6 (FMIPv6) is modeled and simulated using NS2. The performance is analyzed for typical PCM G.711 voice coding scheme for both MIPv6 and FMIPv6.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114207064","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 : 2008-12-01DOI: 10.1109/RFM.2008.4897371
M.F. Abdul Khalid, M. A. Haron, A. Baharudin, A. A. Sulaiman
The main objective of this project is to design a spiral antenna at a frequency range between 2.4 to 2.5 GHz. The spiral antenna is fed by a microstrip line and RT Duroid 5870 is used with dielectric constant, epsivr and thickness, tsub of 2.33 and 0.5 mm respectively. For the spiral antenna design and simulation, the Genesys software is utilised. A prototype of a circular microstrip antenna is fabricated and measured. Simulated results like return loss, VSWR and input impedance are compared with those obtained from measurements where good agreements are shown.
{"title":"Design of a spiral antenna for Wi-Fi applications","authors":"M.F. Abdul Khalid, M. A. Haron, A. Baharudin, A. A. Sulaiman","doi":"10.1109/RFM.2008.4897371","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897371","url":null,"abstract":"The main objective of this project is to design a spiral antenna at a frequency range between 2.4 to 2.5 GHz. The spiral antenna is fed by a microstrip line and RT Duroid 5870 is used with dielectric constant, epsivr and thickness, tsub of 2.33 and 0.5 mm respectively. For the spiral antenna design and simulation, the Genesys software is utilised. A prototype of a circular microstrip antenna is fabricated and measured. Simulated results like return loss, VSWR and input impedance are compared with those obtained from measurements where good agreements are shown.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126523003","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 : 2008-12-01DOI: 10.1109/RFM.2008.4897428
T. Prakoso, R. Ngah, T. A. Rahman
Antenna return loss and gain as function of frequency are not readily accommodated in many communication system software. This paper proposes solution to the problem by representing the antenna in two-port network s-parameter. The representation exploits the analogy between antenna and two port network. Simulation using communication system software shows that the proposed method is validated.
{"title":"Representation of antenna in two-port network s-parameter","authors":"T. Prakoso, R. Ngah, T. A. Rahman","doi":"10.1109/RFM.2008.4897428","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897428","url":null,"abstract":"Antenna return loss and gain as function of frequency are not readily accommodated in many communication system software. This paper proposes solution to the problem by representing the antenna in two-port network s-parameter. The representation exploits the analogy between antenna and two port network. Simulation using communication system software shows that the proposed method is validated.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126295490","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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