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High Frequency Postgraduate Student Colloquium, 2004最新文献

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PLL frequency synthesis in on-board satellite L-band front-end 星载卫星l波段前端锁相环频率合成
High Frequency Postgraduate Student Colloquium, 2004 Pub Date : 2004-11-30 DOI: 10.1109/HFPSC.2004.1360364
M. Zamazal
{"title":"PLL frequency synthesis in on-board satellite L-band front-end","authors":"M. Zamazal","doi":"10.1109/HFPSC.2004.1360364","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360364","url":null,"abstract":"A new concept of local oscillator signal generation in an L-band front-end is presented. The front-end is designed as part of the new AMSAT phase 3E satellite. High reliability and low power consumption of the receiver is required. For slow rate data transmissions such as telemetry PSK, highly stable local oscillators in the double conversion receiver are required as well as retuning of the first oscillator. The conventional solution uses a stable quartz oscillator with frequency multipliers. The invention of the receiver design consists in replacement of frequency multipliers by the double PLL synthesizer synchronized by an ultra stable oscillator positioned on-board the satellite.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"39 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114117378","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}
引用次数: 1
Spatio-spectral normalisation for ultra wideband antenna dispersion 超宽带天线色散的空间频谱归一化
High Frequency Postgraduate Student Colloquium, 2004 Pub Date : 2004-11-30 DOI: 10.1109/HFPSC.2004.1360359
W. Malik, Christopher J. Stevens, D. Edwards
{"title":"Spatio-spectral normalisation for ultra wideband antenna dispersion","authors":"W. Malik, Christopher J. Stevens, D. Edwards","doi":"10.1109/HFPSC.2004.1360359","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360359","url":null,"abstract":"The frequency variance of antenna characteristics may result in severe signal distortion in an ultra wideband communications system. We identify the antenna parameters important in the context of propagation and channel modelling, and analyse their variation with frequency. The group delay, VSWR, impedance and radiation pattern of omni-directional UWB antennas are studied over a range of frequencies. We propose a spatio-spectral normalisation scheme to isolate the effect of the antenna from the channel, which can be useful in channel measurements. We anticipate that higher SNR can be obtained with the proposed angular compensation technique.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114643542","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}
引用次数: 7
Microwave tomographic imaging based on real data 基于真实数据的微波层析成像
High Frequency Postgraduate Student Colloquium, 2004 Pub Date : 2004-11-30 DOI: 10.1109/HFPSC.2004.1360349
A. Fontes, J.-L. Hu, Z. Wu, H. McCann, L.E. Davies
{"title":"Microwave tomographic imaging based on real data","authors":"A. Fontes, J.-L. Hu, Z. Wu, H. McCann, L.E. Davies","doi":"10.1109/HFPSC.2004.1360349","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360349","url":null,"abstract":"Tomographic systems using X-rays, capacitance, electrical resistance or electrical impedance have already been developed. This paper presented a new kind of tomographic system, the microwave tomographic system. The system consists of new imaging cells with air or water as a background medium, transmitting and receiving antennas matched to air or water, and an existing network analyser. On the other hand, a new nonlinear programming technique, the sequential quadratic programming method is introduced for the image reconstruction, which demonstrates the efficiency of the new system.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126898359","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}
引用次数: 0
Comparative analysis of the performance of MIMO techniques [mobile communications] MIMO技术[移动通信]性能比较分析
High Frequency Postgraduate Student Colloquium, 2004 Pub Date : 2004-11-30 DOI: 10.1109/HFPSC.2004.1360355
M. C. Mtumbuka, D. Edwards
{"title":"Comparative analysis of the performance of MIMO techniques [mobile communications]","authors":"M. C. Mtumbuka, D. Edwards","doi":"10.1109/HFPSC.2004.1360355","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360355","url":null,"abstract":"This paper presents a comparative analysis of three multiple-input multiple-output (MIMO) techniques. It is observed that the spatial MIMO technique slightly out-performs both the polarisation and joint spatial and polarisation MIMO systems. But, owing to the fact that the orthogonal polarisation MIMO antennas are co-located, the resulting compact set makes the polarisation MIMO technique attractive for future designs of high-speed high-capacity mobile communications systems.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127623818","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}
引用次数: 0
Printed planar monopole antenna with electromagnetically coupled elements 印刷平面单极天线与电磁耦合元件
High Frequency Postgraduate Student Colloquium, 2004 Pub Date : 2004-11-30 DOI: 10.1109/HFPSC.2004.1360358
J.A. Evans, F. L. Lerma, M. Ammann
{"title":"Printed planar monopole antenna with electromagnetically coupled elements","authors":"J.A. Evans, F. L. Lerma, M. Ammann","doi":"10.1109/HFPSC.2004.1360358","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360358","url":null,"abstract":"In this paper, the addition of an EM-coupled element to the printed planar monopole antenna is investigated. While remaining simple to construct, modifications to the EM-coupled element are shown to reduce the lower edge frequency of the 10 dB impedance bandwidth by up to /spl sim/19% (280 MHz at 1.5 GHz). The radiation patterns for these antennas are characteristic of monopole antennas - i.e. omnidirectional in the azimuth plane with a null at the zenith - and are consistent within +/- 2 dB across their useful impedance bandwidths. By optimizing the feed arrangements on these antennas a 10 dB impedance bandwidth ratio of over 3:1 can be achieved. This technique yields the ability to construct a smaller antenna, in comparison to a simple printed planar monopole antenna, for a given frequency range. The antennas considered in this paper operate between 1.3 and 5.5 GHz, making them suitable for numerous mobile and portable applications. Measured results are compared to antenna simulations using transmission line modelling.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133867642","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}
引用次数: 3
EMI shielding of woven carbon fibre composites 编织碳纤维复合材料的电磁干扰屏蔽
High Frequency Postgraduate Student Colloquium, 2004 Pub Date : 2004-11-30 DOI: 10.1109/HFPSC.2004.1360389
S. Rea, D. Wylie, D. Linton, E. Orr, J. McConnell
{"title":"EMI shielding of woven carbon fibre composites","authors":"S. Rea, D. Wylie, D. Linton, E. Orr, J. McConnell","doi":"10.1109/HFPSC.2004.1360389","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360389","url":null,"abstract":"The shielding effectiveness of two woven carbon fibre composite (CFC) materials has been calculated using plane wave shielding theory and effective medium theory. Both methods provide the same shielding result. Measurements of the shielding effectiveness using an X-band waveguide show similar levels of shielding to that of aluminium. The high shielding level is due to the large concentration of carbon in both composite samples (50.5%).","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132941626","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}
引用次数: 13
Novel base-band envelope load pull architecture [RF device testing] 新型基带包络负载拉架构[射频设备测试]
High Frequency Postgraduate Student Colloquium, 2004 Pub Date : 2004-11-30 DOI: 10.1109/HFPSC.2004.1360378
T. Williams, J. Benedikt, P. Tasker
{"title":"Novel base-band envelope load pull architecture [RF device testing]","authors":"T. Williams, J. Benedikt, P. Tasker","doi":"10.1109/HFPSC.2004.1360378","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360378","url":null,"abstract":"The paper presents a novel active load-pull architecture capable of providing a constant broadband load with varying drive conditions that is unconditionally stable thus overcoming for the first time many of the problems associated with existing active load pull architectures.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129758612","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}
引用次数: 7
An automated small-signal parameter extraction technique for HBTs using ICCAP 基于ICCAP的hbt小信号参数自动提取技术
High Frequency Postgraduate Student Colloquium, 2004 Pub Date : 2004-11-30 DOI: 10.1109/HFPSC.2004.1360377
S. Chitrashekaraiah, C. N. Dharmasiri, A. Rezazadeh
{"title":"An automated small-signal parameter extraction technique for HBTs using ICCAP","authors":"S. Chitrashekaraiah, C. N. Dharmasiri, A. Rezazadeh","doi":"10.1109/HFPSC.2004.1360377","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360377","url":null,"abstract":"This work presents an automated toolkit for the extraction of small-signal parameters of heterojunction bipolar transistors (HBTs) using Agilent's IC evaluation characterisation and analysis program (ICCAP). On-wafer S-parameters of a 16/spl times/20 /spl mu/m/sup 2/ InGaP/GaAs double HBT (DHBT) for different bias conditions are measured and analysed over a wide temperature range, -25/spl deg/C to +110/spl deg/C. These measured data are used in the extraction of small-signal parameters and compared with ADS simulations to verify and validate the developed small-signal extraction toolkit.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122095162","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}
引用次数: 7
Behavioural modelling of RF power amplifiers using modified Volterra series in the time domain 使用改进的Volterra系列在时域中的射频功率放大器行为建模
High Frequency Postgraduate Student Colloquium, 2004 Pub Date : 2004-11-30 DOI: 10.1109/HFPSC.2004.1360381
John Dooley, B. O'Brien, Thomas J. Brazil
{"title":"Behavioural modelling of RF power amplifiers using modified Volterra series in the time domain","authors":"John Dooley, B. O'Brien, Thomas J. Brazil","doi":"10.1109/HFPSC.2004.1360381","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360381","url":null,"abstract":"This paper presents a new method for the extraction of a behavioural model of an RF power amplifier using the complex envelope representations of the input and output signals in the time domain. A quasi-memory less model is extracted, and used to represent the nonlinearities of the device. The coefficient values are estimated for Volterra filters which are added in parallel to characterise the memory effects of the device. Compared with classic memoryless models, this model provides a more accurate prediction of the actual power amplifier output signal in both the time and frequency domains.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114050455","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}
引用次数: 8
Performance analysis of the photoparametric up-converter using harmonic balance techniques 基于谐波平衡技术的光参量上变换器性能分析
High Frequency Postgraduate Student Colloquium, 2004 Pub Date : 2004-11-30 DOI: 10.1109/HFPSC.2004.1360341
S. M. Idrus, R. Green
{"title":"Performance analysis of the photoparametric up-converter using harmonic balance techniques","authors":"S. M. Idrus, R. Green","doi":"10.1109/HFPSC.2004.1360341","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360341","url":null,"abstract":"The photoparametric amplifier (PPA) operation is based on the non-linear CV characteristics of a photodiode and therefore, the mechanism constituting gain is highly non-linear and different to that in a conventional amplifier/mixer chain. A PPA has been successfully modelled and simulated using a nonlinear microwave simulator to perform harmonics balance analysis, which represented the photodiode model and nonlinear dynamic capacitance behaviour. The simulation predicted a PPA up-conversion gain as high as 27.57 dB, and this agreed with conventional theoretical analysis. In this article, the theory of operation, the device structure of the PPA, and its characteristic are presented.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128748272","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}
引用次数: 5
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