Pub Date : 2007-04-24DOI: 10.1109/RADIOELEK.2007.371689
A. Balalem, J. Macháč, A. Omar
This paper presents compact filters for CPW and microstrip applications. The filter elements are based on quasi-lumped concepts. Moreover, the filters are designed on the both sides of the substrate. Good agreement between the simulated and measured results is achieved.
{"title":"Quasi-Lumped Filters on Doubly Metallized Planar Lines","authors":"A. Balalem, J. Macháč, A. Omar","doi":"10.1109/RADIOELEK.2007.371689","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2007.371689","url":null,"abstract":"This paper presents compact filters for CPW and microstrip applications. The filter elements are based on quasi-lumped concepts. Moreover, the filters are designed on the both sides of the substrate. Good agreement between the simulated and measured results is achieved.","PeriodicalId":446406,"journal":{"name":"2007 17th International Conference Radioelektronika","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123588705","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 : 2007-04-24DOI: 10.1109/RADIOELEK.2007.371658
Josef URBAf, R. Maršálek
The major disadvantage of orthogonal frequency division multiplex (OFDM) is the high peak to average power ratio (PAPR) of the transmitted signal. The main idea of this paper is to use a combination of two appropriate methods. First is the distortionless method using data interleaving. Second is the distortion method of repeated clipping and filtering. This combination expects better PAPR reduction than both separatelly used methods. It is shown that the combination of interleaving with repeated clipping and filtering gives lower PAPR than the repeated clipping and filtering alone.
{"title":"PAPR Reduction by Combination of Interleaving with Repeated Clipping and Filtering in OFDM","authors":"Josef URBAf, R. Maršálek","doi":"10.1109/RADIOELEK.2007.371658","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2007.371658","url":null,"abstract":"The major disadvantage of orthogonal frequency division multiplex (OFDM) is the high peak to average power ratio (PAPR) of the transmitted signal. The main idea of this paper is to use a combination of two appropriate methods. First is the distortionless method using data interleaving. Second is the distortion method of repeated clipping and filtering. This combination expects better PAPR reduction than both separatelly used methods. It is shown that the combination of interleaving with repeated clipping and filtering gives lower PAPR than the repeated clipping and filtering alone.","PeriodicalId":446406,"journal":{"name":"2007 17th International Conference Radioelektronika","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122250437","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 : 2007-04-24DOI: 10.1109/RADIOELEK.2007.371685
A. Labanc
The TESLA-type superconducting accelerating cavities are designed for use in high gradient linear accelerators - operating free electron laser in Hamburg (FLASH) and the future projects X-ray free electron laser (XFEL) and international linear collider (ILC). The cells of these cavities must be precisely aligned to the beam trajectory in order to minimize its unwanted interaction with the acceleration mode as well as beam-excited higher order modes. The eccentricity of cells is measured up to now only mechanically, which has too weak coupling to the electromagnetic field pattern inside of the cavity. In order to increase the precision of measurement and consequently increase the beam stability a contact-less measurement method based on the small perturbation theory was designed and a prototype of measurement setup was built.
{"title":"High Precision Eccentricity Measurement of Accelerating Cavities by Use of the Small Perturbation Theory","authors":"A. Labanc","doi":"10.1109/RADIOELEK.2007.371685","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2007.371685","url":null,"abstract":"The TESLA-type superconducting accelerating cavities are designed for use in high gradient linear accelerators - operating free electron laser in Hamburg (FLASH) and the future projects X-ray free electron laser (XFEL) and international linear collider (ILC). The cells of these cavities must be precisely aligned to the beam trajectory in order to minimize its unwanted interaction with the acceleration mode as well as beam-excited higher order modes. The eccentricity of cells is measured up to now only mechanically, which has too weak coupling to the electromagnetic field pattern inside of the cavity. In order to increase the precision of measurement and consequently increase the beam stability a contact-less measurement method based on the small perturbation theory was designed and a prototype of measurement setup was built.","PeriodicalId":446406,"journal":{"name":"2007 17th International Conference Radioelektronika","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129572988","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 : 2007-04-24DOI: 10.1109/RADIOELEK.2007.371660
V. Wieser, Vladimir Psenak
The mobile radio channel state prediction may be regarded as powerful tool to increase effects of loop power control in mobile radio network based on WCDMA, where the active fast power control is essential. Requirements on the appropriate prediction methods and obtained samples preprocessing include not only accuracy of prediction and low complexity of prediction model (what means easier implementation), but low delays and good modeling properties as well. This article deals with direct prediction of complex channel taps and power prediction by using adaptive and non-adaptive FIR predictor, and drafts the idea of implementation of predictor to the basic power control algorithm.
{"title":"Mobile Radio Channel State Prediction for Power Control in WCDMA Mobile Network","authors":"V. Wieser, Vladimir Psenak","doi":"10.1109/RADIOELEK.2007.371660","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2007.371660","url":null,"abstract":"The mobile radio channel state prediction may be regarded as powerful tool to increase effects of loop power control in mobile radio network based on WCDMA, where the active fast power control is essential. Requirements on the appropriate prediction methods and obtained samples preprocessing include not only accuracy of prediction and low complexity of prediction model (what means easier implementation), but low delays and good modeling properties as well. This article deals with direct prediction of complex channel taps and power prediction by using adaptive and non-adaptive FIR predictor, and drafts the idea of implementation of predictor to the basic power control algorithm.","PeriodicalId":446406,"journal":{"name":"2007 17th International Conference Radioelektronika","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129436078","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 : 2007-04-24DOI: 10.1109/RADIOELEK.2007.371465
J. Hribik, M. Hruškovic
The designed switch mode power supply source (SMPS) is described. It consists of a net filter, power factor correction (PFC) circuits, pulse width modulation (PWM) controller, driver stage, PWM output stage, output transformer and voltage converter. The PFC principle is described in detail. The PWM output part was designed to deliver output power of the SMPS up to 1200 W. The calculated and the measured parameters of the output pulse transformer and the filter inductor are given. The measured values of the designed SMPS show the efficiency nearly 90% at the half and the maximum output power value.
{"title":"Power Supply Source for Class TD Power Amplifiers","authors":"J. Hribik, M. Hruškovic","doi":"10.1109/RADIOELEK.2007.371465","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2007.371465","url":null,"abstract":"The designed switch mode power supply source (SMPS) is described. It consists of a net filter, power factor correction (PFC) circuits, pulse width modulation (PWM) controller, driver stage, PWM output stage, output transformer and voltage converter. The PFC principle is described in detail. The PWM output part was designed to deliver output power of the SMPS up to 1200 W. The calculated and the measured parameters of the output pulse transformer and the filter inductor are given. The measured values of the designed SMPS show the efficiency nearly 90% at the half and the maximum output power value.","PeriodicalId":446406,"journal":{"name":"2007 17th International Conference Radioelektronika","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117154082","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 : 2007-04-24DOI: 10.1109/RADIOELEK.2007.371709
M. Wiktor
Performance of perfectly matched layer (PML) for evanescent plane waves is examined. According to the model of guidance based on total internal reflection, evanescent waves exists outside the core of the waveguide. In this article the situations where PML can yield significant errors are presented. The results obtained for a simple planar structure can be generalized for analyses of arbitrary open waveguides where the computational domain is terminated by the perfectly matched layer.
{"title":"Examination of Perfectly Matched Layer Performance for Evanescent Waves","authors":"M. Wiktor","doi":"10.1109/RADIOELEK.2007.371709","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2007.371709","url":null,"abstract":"Performance of perfectly matched layer (PML) for evanescent plane waves is examined. According to the model of guidance based on total internal reflection, evanescent waves exists outside the core of the waveguide. In this article the situations where PML can yield significant errors are presented. The results obtained for a simple planar structure can be generalized for analyses of arbitrary open waveguides where the computational domain is terminated by the perfectly matched layer.","PeriodicalId":446406,"journal":{"name":"2007 17th International Conference Radioelektronika","volume":"202 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123039077","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 : 2007-04-24DOI: 10.1109/RADIOELEK.2007.371446
F. Vejražka
GPS is the best-known satellite navigation system in the world. Next to GPS, a Russian system GLONASS is operating, and a European system Galileo is intensively prepared. The first satellite of the Galileo system should be launched in 2009, and the whole system Galileo should start to regularly operate in 2011 or 2012. Both in the community of researchers and in the public, questions about the accuracy, compatibility and helpfulness of those systems are discussed. Those questions are not only of the technical nature but also of the political one. The paper tries to give explanation of the principles of the operation of those systems, and their mutual comparison. At the end of the paper a concept of satellite navigation receiver designed at the Czech Technical University in Prague is sketched.
{"title":"Galileo and the Other Satellite Navigation Systems","authors":"F. Vejražka","doi":"10.1109/RADIOELEK.2007.371446","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2007.371446","url":null,"abstract":"GPS is the best-known satellite navigation system in the world. Next to GPS, a Russian system GLONASS is operating, and a European system Galileo is intensively prepared. The first satellite of the Galileo system should be launched in 2009, and the whole system Galileo should start to regularly operate in 2011 or 2012. Both in the community of researchers and in the public, questions about the accuracy, compatibility and helpfulness of those systems are discussed. Those questions are not only of the technical nature but also of the political one. The paper tries to give explanation of the principles of the operation of those systems, and their mutual comparison. At the end of the paper a concept of satellite navigation receiver designed at the Czech Technical University in Prague is sketched.","PeriodicalId":446406,"journal":{"name":"2007 17th International Conference Radioelektronika","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131654676","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 : 2007-04-24DOI: 10.1109/RADIOELEK.2007.371421
T. Dostál, R. Sotner
The paper presents a voltage-mode second-order multifunctional filter (low-pass, high-pass, bandpass and band-reject) having one input and four low impedance outputs. The proposed circuit employs as basic building blocks operational transconductance amplifiers, namely LM 13700, OPA 660 and or LT 1228. Their transconductance can be continuously controlled by an auxiliary current. It gives the possibility to control electronically the parameters of realized filters. The workability of the given universal biquad has been confirmed by PSpice simulations.
{"title":"Multifunctional Tuned Second-order ARC Filter with Commercially Available Transconductors","authors":"T. Dostál, R. Sotner","doi":"10.1109/RADIOELEK.2007.371421","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2007.371421","url":null,"abstract":"The paper presents a voltage-mode second-order multifunctional filter (low-pass, high-pass, bandpass and band-reject) having one input and four low impedance outputs. The proposed circuit employs as basic building blocks operational transconductance amplifiers, namely LM 13700, OPA 660 and or LT 1228. Their transconductance can be continuously controlled by an auxiliary current. It gives the possibility to control electronically the parameters of realized filters. The workability of the given universal biquad has been confirmed by PSpice simulations.","PeriodicalId":446406,"journal":{"name":"2007 17th International Conference Radioelektronika","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126623826","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 : 2007-04-24DOI: 10.1109/RADIOELEK.2007.371707
P. Vagner, M. Kasal
A novel microstrip lowpass filter utilizing defected ground structure (DGS) units is presented in this paper. A DGS unit is simulated with different physical dimensions in order to show variation of effective inductance and capacitance. Next, a lowpass filter using proposed DGS unit is designed. A method for determining dimensions of microstrip structure and DGS units is proposed. Influence of dimensions of the microstrip structure on filter characteristics is investigated and simulated. Filters of various orders are simulated as well. Selected filter is simulated and experimentally verified.
{"title":"Design of Microstrip Lowpass Filter Using Defected Ground Structure","authors":"P. Vagner, M. Kasal","doi":"10.1109/RADIOELEK.2007.371707","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2007.371707","url":null,"abstract":"A novel microstrip lowpass filter utilizing defected ground structure (DGS) units is presented in this paper. A DGS unit is simulated with different physical dimensions in order to show variation of effective inductance and capacitance. Next, a lowpass filter using proposed DGS unit is designed. A method for determining dimensions of microstrip structure and DGS units is proposed. Influence of dimensions of the microstrip structure on filter characteristics is investigated and simulated. Filters of various orders are simulated as well. Selected filter is simulated and experimentally verified.","PeriodicalId":446406,"journal":{"name":"2007 17th International Conference Radioelektronika","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122832888","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 : 2007-04-24DOI: 10.1109/RADIOELEK.2007.371653
J. Surda, S. Lovas, J. Púc̆ik, M. Jus
Spectral analysis belongs to widely used method for biomedical data exploration. In order to interpret spectrum correctly, prior knowledge how various phenomena affect the spectrum of analyzed signal is desirable. Spectrum of ECG signal is affected by waveform component shapes, their time positions within cardiac cycle as well as by regularity of heart period. This paper deals with effect of heart rate variability on ECG signal spectrum. Three representations are proposed to model variable heart timing in the case of normal sinus rhythm (pulse process with time jitter, random inter-pulse interval and integral pulse frequency modulation model). Properties of corresponding spectra are theoretically studied and compared with real-world signals from PhysioBank data archive.
{"title":"Spectral Properties of ECG Signal","authors":"J. Surda, S. Lovas, J. Púc̆ik, M. Jus","doi":"10.1109/RADIOELEK.2007.371653","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2007.371653","url":null,"abstract":"Spectral analysis belongs to widely used method for biomedical data exploration. In order to interpret spectrum correctly, prior knowledge how various phenomena affect the spectrum of analyzed signal is desirable. Spectrum of ECG signal is affected by waveform component shapes, their time positions within cardiac cycle as well as by regularity of heart period. This paper deals with effect of heart rate variability on ECG signal spectrum. Three representations are proposed to model variable heart timing in the case of normal sinus rhythm (pulse process with time jitter, random inter-pulse interval and integral pulse frequency modulation model). Properties of corresponding spectra are theoretically studied and compared with real-world signals from PhysioBank data archive.","PeriodicalId":446406,"journal":{"name":"2007 17th International Conference Radioelektronika","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129116937","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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