Block Circuit Diagram Research Articles

PRINCIPLES OF DEVELOPMENT OF THE TERAHERTZ BAND TELECOMMUNICATION SYSTEM BASED ON THE TECHNOLOGY OF HARMONIC SIGNAL AS THE INFORMATION CARRIER

Physical principles of introduction and reproduction of the information transmitted using the harmonic signal as the information carrier, are analyzed. Based on the performed theoretical calculations confirmed by the results of modeling, there are formed the principles and rules of determining optimal parameters of the ultra-wideband terahertz frequency range communication system on the basis of the technology of electronics using the harmonic signal as the information carrier. The necessity of using the terahertz frequency band while deploying future super high throughput rate telecommunication systems is reasoned. Analysis of the state-of-the-art problem is performed, the direction of research is selected and the mission is set with regards to creation of the terahertz band broadband access telecommunication system with the Gigabit throughput rate within the operating frequencies range of 130…134 GHz. Characteristics of the signal propagation path and defining of the signal losses under the conditions of the terahertz frequency band radio relay system operation are analyzed. On the basis of the analysis performed it is shown that operation of radio relay links in the terahertz band allows practically disregarding the refraction and interference of the electromagnetic waves reflected from the obstacles in the radio signal propagation domain that occurs primarily under the conditions of a dense urban building. The domains of the terahertz band frequencies, which are most of all suitable for use in the radio relay communication lines, are determined. Physical modeling of the super high data rate former is performed on the basis of the multifrequency multiplexing of the OFDM-modulated digital flows, testing at the experimental stand and the optimization aimed at attaining of the maximal throughput capacity of the channel used for transmission of the digital information of the flow are fulfilled in the Ethernet format using the developed software means. The created software and hardware means allowed attaining, for the first time, the general channel data rate of up to 1.2 Gbps at the full duplex. There are developed the block circuit diagram of the system transceiver path – the frequency converters with subharmonic pumping, the heterodyne using a high-stability setting quartz oscillator with the subsequent circuitry of multiplying and amplifying cascades, the bandpass filter using a thin metal plate in the E-plane of the 1.6×0.8 mm waveguide channel, and the horn-lens antenna.

Generation of 2N + 1-scroll existence in new three-dimensional chaos systems.

We propose a systematic methodology for creating 2N + 1-scroll chaotic attractors from a simple three-dimensional system, which is named as the translation chaotic system. It satisfies the condition a12a21 = 0, while the Chua system satisfies a12a21 > 0. In this paper, we also propose a successful (an effective) design and an analytical approach for constructing 2N + 1-scrolls, the translation transformation principle. Also, the dynamics properties of the system are studied in detail. MATLAB simulation results show very sophisticated dynamical behaviors and unique chaotic behaviors of the system. It provides a new approach for 2N + 1-scroll attractors. Finally, to explore the potential use in technological applications, a novel block circuit diagram is also designed for the hardware implementation of 1-, 3-, 5-, and 7-scroll attractors via switching the switches. Translation chaotic system has the merit of convenience and high sensitivity to initial values, emerging potentials in future engineering chaos design.

Radix-2α/4β Building Blocks for Efficient VLSI’s Higher Radices Butterflies Implementation

This paper describes an embedded FFT processor where the higher radices butterflies maintain one complex multiplier in its critical path. Based on the concept of a radix-r fast Fourier factorization and based on the FFT parallel processing, we introduce a new concept of a radix-r Fast Fourier Transform in which the concept of the radix-r butterfly computation has been formulated as the combination of radix-2α/4β butterflies implemented in parallel. By doing so, the VLSI butterfly implementation for higher radices would be feasible since it maintains approximately the same complexity of the radix-2/4 butterfly which is obtained by block building of the radix-2/4 modules. The block building process is achieved by duplicating the block circuit diagram of the radix-2/4 module that is materialized by means of a feed-back network which will reuse the block circuit diagram of the radix-2/4 module.

Theoretical Analysis and Circuit Verification for Fractional-Order Chaotic Behavior in a New Hyperchaotic System

A novel nonlinear four-dimensional hyperchaotic system and its fractional-order form are presented. Some dynamical behaviors of this system are further investigated, including Poincaré mapping, parameter phase portraits, equilibrium points, bifurcations, and calculated Lyapunov exponents. A simple fourth-channel block circuit diagram is designed for generating strange attractors of this dynamical system. Specifically, a novel network module fractance is introduced to achieve fractional-order circuit diagram for hardware implementation of the fractional attractors of this nonlinear hyperchaotic system with order as low as 0.9. Observation results have been observed by using oscilloscope which demonstrate that the fractional-order nonlinear hyperchaotic attractors exist indeed in this new system.

Generating multi-scroll chaotic attractors by thresholding

This Letter proposes a novel thresholding approach for creating multi-scroll chaotic attractors. The general jerk circuit and Chua's circuit with sine nonlinearity are then used as two representative examples to show the working principle of this method. The controlled jerk circuit can generate various limit cycles and multi-scroll chaotic attractors by tuning the thresholds and the width of inner threshold plateau. The dynamic mechanism of threshold control is further explored by analyzing the system dynamical behaviors. In particular, this approach is effective and easy to be implemented since we only need to monitor the threshold variables or their functions and then reset them if they exceed the desired thresholds. Furthermore, two simple block circuit diagrams with threshold controllers are designed for the implementations of 1, 2, 3-scroll chaotic attractors. It indicates the potential engineering applications for various chaos-based information systems.

Theoretical Design and Circuit Implementation of Multidirectional Multi-Torus Chaotic Attractors

This paper introduces a novel fourth-order double-torus chaotic circuit. Based on this basic circuit, a systematic theoretical design approach is proposed for generating 1-Dn torus, 2-D n times m-torus, 3-D n times m times I torus, and 4-D n times m times l times p torus chaotic attractors. This is the first autonomous circuit reported in the literature for generating multidirectional multi-torus (MDMT) chaotic attractors. The dynamical behaviors of these MDMT chaotic systems are further investigated, including equilibrium points, bifurcations, Lyapunov exponents, and Poincare maps. Theoretical analysis shows that the MDMT chaotic attractors can be generated by switching and displacing a basic linear circuit. Finally, a block circuit diagram is designed for hardware implementation of the MDMT chaotic attractors. This is also the first time in the literature to experimentally verify a maximal 1-D 20-torus, a maximal 2-D 5 times 5 torus, and a maximal 4-D 5 times 5 times 3 times 3 torus chaotic attractors.

Multifolded torus chaotic attractors: Design and implementation

This paper proposes a systematic methodology for creating multifolded torus chaotic attractors from a simple three-dimensional piecewise-linear system. Theoretical analysis shows that the multifolded torus chaotic attractors can be generated via alternative switchings between two basic linear systems. The theoretical design principle and the underlying dynamic mechanism are then further investigated by analyzing the emerging bifurcation and the stable and unstable subspaces of the two basic linear systems. A novel block circuit diagram is also designed for hardware implementation of 3-, 5-, 7-, 9-folded torus chaotic attractors via switching the corresponding switches. This is the first time a 9-folded torus chaotic attractor generated by an analog circuit has been verified experimentally. Furthermore, some recursive formulas of system parameters are rigorously derived, which is useful for improving hardware implementation.

Design and implementation of n-scroll chaotic attractors from a general jerk circuit

This paper proposes a novel nonlinear modulating function approach for generating n-scroll chaotic attractors based on a general jerk circuit. The systematic nonlinear modulating function methodology developed here can arbitrarily design the swings, widths, slopes, breakpoints, equilibrium points, shapes, and even the general phase portraits of the n-scroll chaotic attractors by using the adjustable sawtooth wave, triangular wave, and transconductor wave functions. The dynamic mechanism and chaos generation condition of the general jerk circuit are further investigated by analyzing the system stability. A simple block circuit diagram, including integrator, sawtooth wave and triangular wave generators, buffer, switch linkages, and voltage-current conversion resistors, is designed for the hardware implementations of various 3-12-scroll chaotic attractors via switchings of the switch linkages. This is the first time to experimentally verify a 12-scroll chaotic attractor generated by an analog circuit. In particular, the recursive formulas of system parameters and real physical circuit parameters are rigorously derived for the hardware implementations of the n-scroll chaotic attractors. Moreover, the adjustability of the nonlinear modulating function and the rigorous recursive formulas together provide a theoretical principle for the hardware implementations of various chaotic attractors with a large number of scrolls.

The development of eddy-current testing techniques for tube inspection

The paper outlines the need for a high speed method of examining tubes for defects and discusses to what extent eddy-current techniques meet this need. A short history is given of the introduction of eddy current testing used for the examination of solid and hollow cylinders. Eddy current testing principles are explained, together with methods of measuring the effects of variations in a test specimen, with the aid of block circuit diagrams and complex impedance curves. The merits of a.c. and d.c. saturation techniques are dealt with and practical testing equipment which employs phase and modulation analysis is described. The application of phase sensitive devices and modulation analysis techniques is explained and the limitations assessed. The uses of internal probes and surface probes are briefly described.