LC Network Research Articles

Modeling and Analysis of N-Branch Hybrid Switched Inductor and Capacitor Converter

This paper proposes a family of N-Branch hybrid switched inductor and capacitor (SLC) converters. With the single circuit, the multi-level output voltage or current could be generated. The proposed converter is suitable both for the voltage source and the current source. The same LC network is reused for different LC branches. The proposed converter is controlled by the phase shift control method with a time domain multiplexing concept. The N level circuit is operated with the same frequency. One cycle period is divided into N small time cycles for each branch. The phase shift for each branch is 360°/N. The load voltage could be changed by modifying the duty cycle of the transistor. When the SLCs work in the resonant condition, the soft switching will be acquired. The power loss of transistors could be sharply reduced. In this paper, a 300 W SLC converter is constructed to verify the theoretical analysis and operation mechanism in the resonant condition and hard switching condition. With the experimental and simulated verification, the soft switching and the stable multi-level output voltage or current are achieved. The proposed SLC converter could be used for the multi-level voltage power supply system, such as the electric vehicle, the electric aircraft, autonomous underwater vehicles (AUVs) and a new energy generation system.

A 28-GHz Doherty Power Amplifier With a Compact Transformer-Based Quadrature Hybrid in 65-nm CMOS

This brief presents a single-ended, two-stage, and symmetric Doherty power amplifier (DPA). A rigorous and closed-form formula is proposed to design the transformer-based quadrature hybrid. The hybrid combines the advantages of flexibility, compactness, and low loss. A non-classic Doherty impedance inverting network is co-designed with the input network for phase matching. Besides, the parasitic parameters of the interconnects and RF pads are used to reduce the value of the inductor in the LC network. Designed and implemented in a 65-nm CMOS process, the fully integrated compact DPA prototype occupies only 0.35 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> active area. The experimental prototype operating at 28 GHz achieves 18.7 % power-added efficiency (PAE) at 6-dB power back-off (PBO). A maximum small-signal gain of 20.4 dB is achieved with a -3-dB bandwidth from 25.6 to 29.4 GHz. A saturated output power ( P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SAT</sub> ) of 17.5 dBm is measured with the peak PAE of 27%. At 6-dB PBO, the DPA prototype increases the efficiency by 2.8 and 1.4 times over a normalized Class-B and Class-A PA, respectively.

Resonant Machine Learning Based on Complex Growth Transform Dynamical Systems.

Traditional energy-based learning models associate a single energy metric to each configuration of variables involved in the underlying optimization process. Such models associate the lowest energy state with the optimal configuration of variables under consideration and are thus inherently dissipative. In this article, we propose an energy-efficient learning framework that exploits structural and functional similarities between a machine-learning network and a general electrical network satisfying Tellegen's theorem. In contrast to the standard energy-based models, the proposed formulation associates two energy components, namely, active and reactive energy with the network. The formulation ensures that the network's active power is dissipated only during the process of learning, whereas the reactive power is maintained to be zero at all times. As a result, in steady state, the learned parameters are stored and self-sustained by electrical resonance determined by the network's nodal inductances and capacitances. Based on this approach, this article introduces three novel concepts: 1) a learning framework where the network's active-power dissipation is used as a regularization for a learning objective function that is subjected to zero total reactive-power constraint; 2) a dynamical system based on complex-domain, continuous-time growth transforms that optimizes the learning objective function and drives the network toward electrical resonance under steady-state operation; and 3) an annealing procedure that controls the tradeoff between active-power dissipation and the speed of convergence. As a representative example, we show how the proposed framework can be used for designing resonant support vector machines (SVMs), where the support vectors correspond to an LC network with self-sustained oscillations. We also show that this resonant network dissipates less active power compared with its non-resonant counterpart.

Concurrent Dual-Band Inverter-Based Low Noise Amplifier (LNA) for WLAN Applications

low noise amplifier (LNA); concurrent; dual-band; inverter-basedIn this paper, a two-stage concurrent dual-band low noise amplifier (DB-LNA) operating at 2.4/5.2-GHz is presented for Wireless Local Area Network (WLAN) applications. The current-reused structure using resistive shunt-shunt feedback is employed to reduce power dissipation and achieve a wide frequency band from DC to-5.5-GHz in the inverter-based LNA. The second inverter-based stage is employed to increase the gain and obtain a flat gain over the frequency band. An LC network is also inserted at the proposed circuit output to shape the dual-band frequency response. The proposed concurrent DB-LNA is designed by RF-TSMC 0.18-µm CMOS technology, which consumes 10.8 mW from a power supply of 1.5 V. The simulation results show that the proposed DB-LNA achieves a direct power gain (S 21 ) of 13.7/14.1 dB, a noise figure (NF) of 4.2/4.6 dB, and an input return loss (S 11 ) of −12.9/−14.6 dBm at the 2.4/5.2-GHz bands.

Narrower Band Matching With Low Quality Factor Values

In this brief, a new approach based on quality factor technique is proposed to design narrower band matching networks. The main idea is to use one series and one parallel lossless one-port LC network between generator and load resistances. In the proposed approach, it is not necessary to use a high quality factor value to get narrower band, it is enough to use the quality factor value defined by generator and load resistances. After explaining the rationale of the new approach, an example is given to compare the performances of the proposed and existing methods in the literature.

Bandwidth Analysis of a Broadband Amplifier with Two-Stage Matching System Using the Smith Chart

This paper describes a novel trace structure for the analysis and design of two-stage Broadband Frequency Low Noise Amplifiers based on standard Smith chart procedures and program algorithm realization. The method allows to put the transistor's S-parameters and details of the source and load networks and to interactively explore the effects of these quantities on design variables such as gain, noise figure and stability. It also facilitates the design of two-element matching networks to transform the source and load impedances to optimum values to achieve the desired gain and noise performance. The extended Smith chart concept is proposed to enable the advanced graphical interpretation of devices containing complex properties. This methodology is based on the Smith chart concept, and makes it easy to deal with devices containing signal sources, nonlinearity, very high Q factors and negative resistances. The concept of explaining the use of the Smith chart in combination with using modern tools as MATLAB scripts is exemplified in graphical forms. Phyton-based program contains the algorithm for parameters calculation. It explains the procedure that must be used to solve the two-stage impedance-matching problem. The point of this proposal is using of Smith chart plane for the graphical processing for its application to oscillator analysis. To demonstrate the effective usage of this methodology an interpretation and analysis of the oscillator, especially in terms of gain, noise and stability, are provided. The practical relevance concludes results of multistage design using impedance matching LC networks for the intersection level. The values of the parameters of the integrated microcircuit confirm the possibility of using the calculation methodology considered in the paper. The proposed solution is validated with extensive RF measurements at 3.5 GHz and is benchmarked against several frequency ranges for noise, stability and gain values. The methodology shown in the paper can be used in the development and design of modern microwave amplifiers, as well as for research and analysis of the efficiency of existing devices.

A Simple Equivalent Circuit Approach for Anisotropic Frequency-Selective Surfaces and Metasurfaces

An equivalent circuit model for Frequency Selective Surfaces (FSS) comprising anisotropic elements is presented. The periodic surface is initially simulated with an arbitrary azimuthal incidence angle and its surface impedance matrix is derived. The impedance matrix is subsequently rotated by an angle $\varphi^{rot}$ on the crystal axes $\chi_1$, $\chi_2$ thus nullifying its extra diagonal terms. The rotation angle $\varphi^{rot}$ is derived according to the spectral theorem by using the terms of the matrix initially extracted. The diagonal terms of the rotated matrix, that is, the impedances $Z_{\chi_1}$ and $Z_{\chi_2}$, are finally matched with simple LC networks. The circuit model representation of the anisotropic element can be used to analyse anisotropic FSSs rotated by a generic azimuth angle. The methodology provides a compact description of generic FSS elements with only five parameters: the lumped parameters of the LC network $L_{\chi_1}$, $C_{\chi_1}$, $L_{\chi_2}$, $C_{\chi_2}$ and the rotation angle $\varphi^{rot}$. The circuit model can take into account the presence of dielectric substrates close to the FSS or a variation of the FSS periodicity without additional computational efforts. The equivalent circuit model is finally applied to the design of two transmitting polarization converts based on anisotropic metasurfaces.

Electrical characteristics of an asymmetric N-step network

We investigated the electrical characteristics of an asymmetric n-step network (including the branch current, node voltage and equivalent resistance). We studied the problem by modeling the differential equation via the method of network analysis, and modeling the constraint equation via the currents of input and output. Aseriesof new analytical formulae are derived by using above methods. As applications of the resistance formula, the equivalent complex impedance of an n-step LC network is discussed in detail, and some interesting characteristics changing with various parameters are revealed.

Quadrupole topological phase and robust corner resonance in Kekulé hexagonal electric circuit

Two-dimensional (2D) quadrupole topological insulators, featured by topologically protected 0D corner modes, have recently attracted tremendous interest in condensed matter and materials physics. Herein, we construct a specific electric circuit made of capacitors and inductors forming a 2D Kekulé hexagonal lattice for quadrupole topological phase and corner modes. Trivial–nontrivial topological phase transition can be controlled by varying capacitance in the circuit, so that distinct topological edge states appear in 1D ribbons and corner states emerge in 0D flakes. We explore the field strength distribution and two-point impedance with respect to excitation frequency, and reveal that the topological corner resonance is robust against size of the LC network and randomness of the capacitors/inductors, a great benefit for experimental detection. Our results enrich the family of designer topoelectrical circuit as a flexible and tunable platform to achieve exotic quantum phases, which may have potential for future telecommunications, signal processing and quantum computing.

Enhancing the performance of defected ground structure type near‐field radiofrequency WPT system by coupled‐line impedance matching

This study reports, for the first time, the use of coupled-line-based impedance matching in wireless power transfer (WPT) system. The transmitter and receiver of the WPT system are realised by microstrip feed line and symmetric coupled line at the top plane. The ground plane is realised with triangular-shaped defect along with the excitation slot mounted by an external capacitor. The defect in the ground plane and the external capacitor regulate the resonant frequency and also enable miniaturisation of the WPT system. The design is augmented with a systematic analytical approach for impedance matching and a simplified design procedure for the WPT system. A novel equivalent circuit model consisting of parallel LC network and coupled lines is also developed for the evaluation of the proposed WPT system design technique. A prototype of the system operating at 300 MHz developed on Rogers RO4350B substrate achieves a peak efficiency of 80% at a transmission distance of 17 mm. An excellent agreement between the measured and the electromagnetic simulated results is a testament of the robustness of the proposed design technique. Furthermore, evaluation of the commonly used WPT-related figure of merit shows significant enhancement when compared to the existing state of the art.

Design and analysis of 73-106 GHz CMOS injection-locked frequency divider

ABSTRACT A 73 ~ 106 GHz divide-by-2 injection-locked frequency-divider (ILFD2) using 90 nm CMOS technology is presented. To achieve a wide locking range, an optimal transistor width ratio of the injection transistor (or mixer) and cross-coupled transistors (CCT) is adopted. To enhance the operation frequency, distributed LC network is used as the load of the CCT. To enhance the input sensitivity, an input power matching network is included in the injection transistor. In addition, for further locking ranging enlargement, the inductive peaking and forward-body-bias techniques are used in the injection transistor for raising its quadrature output current (or conversion gain). The ILFD2 consumes 4.92 mW, and achieves an excellent phase noise of – 106.2 dBc/Hz (at 1 MHz offset from the output frequency of 50 GHz). The ILFD2 achieves a wide locking-range of 33 GHz (73–106 GHz (36.9%)), covering the 77 GHz automotive radar frequency band and the 94 GHz imaging radar frequency band. The ILFD2 can be operated at a low input power of – 60 dBm, one of the best input sensitivities ever reported for a W-band CMOS ILFD2. The core area of the ILFD2 is only 0.014 mm2.

Active Switched Capacitor Network in High Gain DC DC Converter with PI Controller

In this paper, PI controller in the active switched capacitor network is employed to achieve robust control under disturbance by maintaining sustained output voltage for varying input voltage. Active switched capacitor in the high gain DC–DC circuit efficiently increases voltage gain due to the combination of LC network with minimum duty cycle. The proposed circuit is the modification of typical high gain DC converter and modified network is simple in structure due to reduce in number of switch components and the voltage stress on the capacitor, diodes and across switches are reduced compared to base network. This paper presents the design, operation and analysis of the modified topology and the performance comparison with base converter is presented. Simulation is carried out using MATLAB software for the proposed system with and without PI controller and variation in the output voltage between both the circuits is tabulated and comparative analysis is discussed.

Electrical properties of an n-order network with Y circuits

This paper introduces an n-order network model with Y circuits to investigate the electrical properties, and it is an entirely new question that has seldom been addressed in the academic world. We carry out the research by means of building an equivalent model. Firstly, we use Kirchhoff’s law to build a second-order nonlinear recurrence equation model. Secondly, by using variable substitution we transform the nonlinear equation into a linear difference equation. Thirdly, we name the process recurrence transformation of n-order network, called N-RT for short. Based on the linear difference equation, an analytical solution is offered to the problem of the equivalent resistance of the n-order network with Y circuits. This research is going to find specific application in many cases. What’s important, this paper further investigates the equivalent complex impedance of LC network and the electrical properties of complex impedance, and illustrates the oscillation and resonance characteristics of LC network with 3D graphs.

A Broadband Resonant Noise Matching Technique for Piezoelectric Ultrasound Transducers

A novel resonant noise matching technique is proposed to improve the sensitivity and output SNR of ultrasound receivers. Diverse from the power matching, the resonant noise matching technique proposed in this paper applies resonant LC networks to raise the transducers’ input impedance to a high impedance. As a consequence, in addition to the function of improving the output signal strength, the prominent advantage of the resonant noise matching technique is that the passive gain provided by the matching network can reduce equivalently the receiver’s input-referred noise and thus obtain the minimum noise figure. Furthermore, broadband matching which can cover the transducers’ working bandwidth is also developed to reduce the ringing in received signals, which can significantly improve axial resolution in applications of imaging. For this, an accurate electrical model extended from Butterworth Van-Dyke (BVD) model is obtained to co-simulate with the new matching network in the design. Measurement results show that, the output signal is improved by 5 times through the proposed technique, which is 66.7% larger than that of conventional methods. In addition, the sensitivity of the receiver is significantly improved by more than 10.4 dB which is beneficial for piezoelectric ultrasound transducers in a variety of applications.

Hyperchaos, quasi-period and coexisting behaviors in second-order-memristor-based jerk circuit

This paper generalizes a second-order-memristor-based jerk circuit, which is achieved by substituting the first-order memristor contained diode-bridge and RC filter in an existing memristive jerk circuit with a second-order one composed of diode-bridge and LC network. The second-order-memristor-based jerk circuit possesses an unstable saddle-focus and generates complex parameter-dependent dynamics, including hyperchaos, chaos, quasi-period, and period along with coexisting behaviors. The coexistences of symmetric chaotic and quasi-periodic attractors are shown by local attraction basins. Particularly, 2D two-layer-based dynamical maps on the system parameter spaces are employed to perfectly detect complex dynamical behaviors of hyperchaos and quasi-period. Furthermore, hardware breadboard is made for experimental investigations and the measurement results well validate complex parameter-dependent dynamics revealed by the numerical simulations.

28-GHz Passive Frequency Tripler With n-Type Varactors in 45-nm SOI CMOS

A 28-GHz passive frequency tripler for 5G New Radio (NR) is demonstrated in 45-nm SOI CMOS. A symmetric antiparallel pair of series varactor (SAPSV) topology is proposed to reduce the conversion loss (CL) and increase the output power by realizing symmetric $C$ – $V$ curves with only n-type varactors and simplified dc biasing. Compact on-chip LC networks provide 13.6− and 20.1-dBc rejection for fundamental and second harmonics, respectively, from 27.1 to 32.4 GHz (17.8%). The measured minimum CL is 24.3 dB, and the maximum output power is −8 dBm. Conversion loss variation is not more than 3 dB when the input power range varies from 8 to 20 dBm. The tripler only adds a 9.66-dB integrated phase noise measured from 1 to 100 kHz at 28.95 GHz.

Bifurcation analyses and hardware experiments for bursting dynamics in non-autonomous memristive FitzHugh-Nagumo circuit

In this paper, a non-autonomous memristive FitzHugh-Nagumo (FHN) circuit is constructed using a second-order memristive diode bridge with LC network. For convenience of circuit implementation, an AC voltage source is adopted to substitute the original AC current stimulus. Stimulated by the slowly varying AC voltage source, the number, locations and stabilities of the equilibrium points slowly evolve with the time, which are thus indicated as the AC equilibrium points. Different sequences of fold and/or Hopf bifurcations are encountered in a full period of time series evolutions, leading to various kinds of chaotic or periodic bursting activities. To figure out the related bifurcation mechanisms, the fold and Hopf bifurcation sets are mathematically formulated to locate the critical bifurcation points. On this basis, the transitions between the resting and repetitive spiking states are clearly illustrated by the time series of the AC equilibrium points and state variables, from which Hopf/subHopf, Hopf/Hopf, and Hopf/fold bursting oscillations are identified in the specified parameter regions. Finally, based on a fabricated hardware circuit, the experimental measurements are executed. The results verify that the presented memristive FHN circuit indeed exhibits complex bursting activities, which enriches the family of memristor-based FHN circuits with bursting dynamics.

Infinitely many coexisting conservative flows in a 4D conservative system inspired by LC circuit

Conservative chaotic flows, a category of incompressible chaos, are usually generated from dynamical systems without dissipation. The existing results on conservative chaos are almost reported in mathematical models of coupled ordinary differential equations, but rarely raised in circuit models. This paper proposes a four-dimensional conservative chaotic system inspired by inductor–capacitor (LC) circuit. It is implemented by replacing two RC networks in Wien bridge oscillator with two LC networks. The circuit has only one piecewise nonlinearity featured by the saturation output characteristic of operational amplifier and is likely to be the simplest such model. With dimensionless equations, the conservative nature of the system is analysed. Both theoretical analyses and numerical simulations confirm the system is conservative. Particularly, with fixed system parameters, infinitely many coexisting periodic, quasiperiodic and chaotic flows are observed. The PSIM circuit simulations and DSP-based hardware experiments demonstrate the findings. Finally, pseudorandom number generator based on the conservative chaotic system is designed to generate high-quality pseudorandom bits.

Folded Leafy Cube: A Derivative For High Performance Computing

In this paper, Folded Leafy cube (FLC) structure is derived from LC network to have better performance parameters. The Folding technique reduces the average node distance. FLC is suitable for very large scale computing system due to comparatively lesser link complexity. Interconnection network are backbone of Big data system. In future attempts will be made to suggests better routing and fault tolerance to make FLC is suitable for high performance and Big data.

Повышение пропускной способности ограничителей перенапряжений в составе вакуумных выключателей постоянного тока

One of the problems that must be solved when short-circuit currents breakdown in a DC vacuum circuit breaker is the dissipation of electromagnetic energy stored in the inductance of the Lc network and brought by the source at the time of the current breakdown, as well as limiting the overvoltages on the circuit breaker elements. The high level of overvoltages U»Lсdi/dt is due to the rapid fall of the di/dt trip current in the network with inductance Lc, which, for example, in traction networks of electrified rail transport reaches 15 mH. To solve this problem, a nonlinear overvoltage arrestors (NOA) is used, which is installed parallel to the circuit breaker and provides for the overvoltage limiting and also serves to absorb electromagnetic energy stored in the inductance of the network. The amount of absorbed energy should not exceed the amount of energy dissipated into the outer space. Otherwise, there will be a constant increase in the temperature of the arrester and its subsequent thermal destruction. The energy absorbed in the arrester unit when the current is breakdown (Ibr2Lc/2) depends on the breakdown current Ibr and the inductance of the network Lc. The energy dissipated depends on the design of the arrester unit and the mass of the supply tires. The balance between absorbed and dissipated energy determines the throughput of the arrester unit without degrading it. The throughput of surge arresters with high current pulses is determined by its ability to withstand the max supply tires. The balance between absorbed and dissipated energy determines the throughput of the arrester unit without degrading it. The throughput of surge arresters with high current pulses is determined by its ability to withstand the maximum value of current pulses with duration of several milliseconds. This paper presents the results of numerical simulation and experimental research of ways to increase the throughput of an oxide-zinc (ZnO) surge arrester as part of a DC vacuum circuit breaker.