No (2400)
Number of found documents:
2400
Tunable Universal Fully-Differential Filter With
Operational Transresistance Amplifier
Polesakova, Zuzana
English
The new single-ended (S-E) second order frequency filter providing transfer function of Low Pass (LP), High Pass (HP), Band Pass (BP), Band Stop (BS) and All Pass (AP) is presented in this paper. The cut-off frequency is tunable up to 3 MHz. Also the fully-differential (F-D) version of the filter is presented and so is the transformation method which is in this case the Signal Flow Graph (SFG). The design filter can be implemented with discretive active devices or as an Integrated Circuit (IC). The features of both S-E and F-D filters are verified using PSpice simulations comparing ideal and behavioral models of the active devices.
Keywords:
Fully-Differential Frequency Filter; Signal Flow Graph; Universal Filter; OTRA
Available in a digital repository NRGL
Tunable Universal Fully-Differential Filter With
Operational Transresistance Amplifier
The new single-ended (S-E) second order frequency filter providing transfer function of Low Pass (LP), High Pass (HP), Band Pass (BP), Band Stop (BS) and All Pass (AP) is presented in this paper. The ...
Reconfigurabe Waveguide Divider
Cupal, Miroslav
English
The design and implementation of the textile integrated waveguide (TIW) switch for ISM band is presented. The traveling electromagnetic wave is controlled by conductive posts with a circular slot. PIN diodes are used for switching electromagnetic wave to two directions. The simulations results are presented as parametric analysis.
Keywords:
TIW; textile integrated waveguide; divider; reconfigurable; textile
Available in a digital repository NRGL
Reconfigurabe Waveguide Divider
The design and implementation of the textile integrated waveguide (TIW) switch for ISM band is presented. The traveling electromagnetic wave is controlled by conductive posts with a circular slot. PIN ...
Influence Of Interferences Caused By Non-Linear
Power Amplifier In Multi-User Generalized
Frequency Division Multiplex Scenario
Harvanek, Michal
English
This article is aimed to the problematic of interferences in multi-user scenarios which can occur in modern mobile communication networks. Hence of new modulation schemes as a Filter Bank Multi Carrier (FBMC), Generalized Frequency Division Multiplex (GFDM) or another modulation scheme with low out of band emission there can occur problems with interferences especially when user equipments are using non-linear power amplifiers. The non-linear system causes radiation into adjacent channel which can lead to interferences with another user transmitting in this channel. This paper explains impact of such interferences to Error Vector Magnitude (EVM) of demodulated signal for different frequency spacing between users and also describe influence of interferences for different signal noise ratio. To remove inter-carrier interferences, the self interference cancellation method is used.
Keywords:
Power amplifier; amplifier modeling; distortion; interferences; FBMC; GFDM; 5G
Available in a digital repository NRGL
Influence Of Interferences Caused By Non-Linear
Power Amplifier In Multi-User Generalized
Frequency Division Multiplex Scenario
This article is aimed to the problematic of interferences in multi-user scenarios which can occur in modern mobile communication networks. Hence of new modulation schemes as a Filter Bank Multi ...
Direct Learning Architecture For Digital
Predistortion With Real-Valued Feedback
Král, Tomáš Král, Jan
English
The power efficiency is a key parameter of modern comunication systems. Efficient nonlinear power amplifiers are linearised using digital predistorters. Conventional predistorters require two ADCs in the feedback. In this paper we have proposed a modification of the direct learning architecture using solely one ADC in the feedback and an RF mixer instead of a quadrature mixer. This allows us to minimise the system complexity and power consumtion and maximise the efficiency. The proposed architecture has been verified experimentally and compared to the conventional digital predistorters. We have shown that it can achieve same linearisation performance as the conventional architecture with two ADCs. Moreover the proposed method outperformed the conventional DPD with indirect learning architecture.
Keywords:
digital predistortion; direct learning architecture; real-valued feedback
Available in a digital repository NRGL
Direct Learning Architecture For Digital
Predistortion With Real-Valued Feedback
The power efficiency is a key parameter of modern comunication systems. Efficient nonlinear power amplifiers are linearised using digital predistorters. Conventional predistorters require two ADCs in ...
Comparison Of Different Approaches To
Adaptation Of Unscented Kalman Filter
For Non-Odometry Slam
Klečka, Jan
English
This paper is aimed at utilizing of an Unscented Kalman filter (UKF) for application on non-odometry SLAM problem. Non-odometry SLAM problem lacks state transitions function for part of state vector so theoretical part of the paper describes the derivation of three proposed modifications. The experimental part then shows experiments which evaluate modifications performance in reference to Extended Kalman filter. Experiments are based on simulation of monocular photogrammetry reconstruction problem.
Keywords:
Unscented Kalman filter; UKF; SLAM; Recurrent estimation
Available in a digital repository NRGL
Comparison Of Different Approaches To
Adaptation Of Unscented Kalman Filter
For Non-Odometry Slam
This paper is aimed at utilizing of an Unscented Kalman filter (UKF) for application on non-odometry SLAM problem. Non-odometry SLAM problem lacks state transitions function for part of state vector ...
Virtual Batch Manufacturing
Benešl, Tomáš
English
This paper describes a possible way to create digital twin of a batch production process. This virtual model of the batch system can be used for testing ISA-88 and ISA-95 with a virtual or real PLC without real system. There is also a possible use for education in labs with PLCs to show a behavior of a batch actors (valve, mixer, heater etc.) and ways to control, which can be tested in the virtual manufacturing system.
Keywords:
ISA-95; ISA-88; Siemens; PLC; Step7; C#; Virtual manufacturing; Industry 4.0
Available in a digital repository NRGL
Virtual Batch Manufacturing
This paper describes a possible way to create digital twin of a batch production process. This virtual model of the batch system can be used for testing ISA-88 and ISA-95 with a virtual or real PLC ...
Semi-Global Solutions To Mixed-Type Functional
Differential Equations
Vážanová, Gabriela
English
The purpose of this paper is to give sufficient conditions for existence of right semi-global solutions to mixed-type functional differential equations. We also give an example to illustrate applicability of the result.
Keywords:
semi-global solutions; mixed-type functional differential equations; delayed argument; advanced argument; monotone iterative method
Available in a digital repository NRGL
Semi-Global Solutions To Mixed-Type Functional
Differential Equations
The purpose of this paper is to give sufficient conditions for existence of right semi-global solutions to mixed-type functional differential equations. We also give an example to illustrate ...
Hybrid Microphone Preamplifier With Variable
Selection Of Amplifier Technology
Musil, Tomáš
English
This paper deals with the design of a studio level hybrid microphone pre-amplifier using a vacuum tube and semiconductor technology. The pre-amplifier circuit also contains an analog VU meter, 48 V phantom power supply, variable high pass filter, phase inverter switch and adjustable stage input impedance. This paper also deals with the design of a multi-voltage power supply unit and microprocessor controller unit ensuring completely automatic amplifier functions. The end of the paper is dedicated to a characteristics measurement determining its parameters.
Keywords:
Vacuum tube; phantom power; microphone; microprocessor; operational amplifier; preamplifier; triode; heating
Available in a digital repository NRGL
Hybrid Microphone Preamplifier With Variable
Selection Of Amplifier Technology
This paper deals with the design of a studio level hybrid microphone pre-amplifier using a vacuum tube and semiconductor technology. The pre-amplifier circuit also contains an analog VU meter, 48 V ...
Optical Fibers Forming For Optical Sensors
Research
Jelínek, Michal
English
We present development of new methods and techniques of the splicing and shaping optical fibers with focusing to development new sensors. We developed new techniques of splicing for standard Single Mode (SM) and Multimode (MM) optical fibers and optical fibers with different diameters in the wavelength range from 532 to 1550 nm. Together with development these techniques we prepared other techniques to splicing and shaping special optical fibers like as Polarization-Maintaining (PM) or hollow core Photonic Crystal Fiber (PCF) and theirs cross splicing methods with focus to minimize backreflection and attenuation. Splicing special optical fibers, especially PCF fibers with standard telecommunication and other SM fibers, can be done by light adjustment of our developed techniques.
Keywords:
microstructured fibers; optical sensors; shaping optical fibers; splicing optical fibers; tapering optical fibers
Available in a digital repository NRGL
Optical Fibers Forming For Optical Sensors
Research
We present development of new methods and techniques of the splicing and shaping optical fibers with focusing to development new sensors. We developed new techniques of splicing for standard Single ...
Application Of Optimization Algorithms To
The Genome Assembly
Jugas, Robin
English
The paper results from development of new sequencing methods together with the need of suitable genome assembly algorithms. It combines the genomic signal processing, correlation techniques and optimization algorithms for solving assembly task. Genomic signals are made by conversion of letter-based DNA into the form of digital signal, thus the methods of digital signal processing can be applied. Possible overlaps between reads converted into signals are found by computing correlation coefficient similarly to cross-correlation. We acquire similarity matrix and the task is to find the path through it achieving minimum distance criterion. For the task, the two optimization techniques were employed: ant colony optimization (ACO) and simulated annealing (SA). The result implies the possibility of using the ACO at the task of creating path through similarly to graphtheory-based algorithms.
Keywords:
bioinformatics; genome assembly; genomic signal processing; optimization tec
Available in a digital repository NRGL
Application Of Optimization Algorithms To
The Genome Assembly
The paper results from development of new sequencing methods together with the need of suitable genome assembly algorithms. It combines the genomic signal processing, correlation techniques and ...
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