Passive Circuit Research Articles

On the pass- and stop-band optical filtering by passive silicon photonic circuits using square-layout MZI ring(s)

On the pass- and stop-band optical filtering by passive silicon photonic circuits using square-layout MZI ring(s)

Nanoscale on-chip inductors using a linearized meminductive circuit

This work presents a novel RF on-chip inductor that overcomes the problems with conventional large-sized inductors, which cannot be placed in an integrated circuit (IC) for large inductance values. The proposed inductor depends mainly on the meminductor, a new passive circuit element that has memory properties. This new circuit element is argued to be common in the nanoscale, where the dynamical properties of electrons and ions are likely to depend on the history of the system. Being nonlinear, it is shown that, by a suitable arrangement of meminductors and through appropriate initial values for their inductances, we can achieve a linear nanoscale inductor.

Numerical and experimental investigation of the energy harvesting performance of electromechanically coupled piezoelectric prestressed beams subjected to nonlinear vibrations

Τhe piezoelectric energy harvesting from nonlinear vibrating structures has greatly attracted the attention of scientific community over the last decades, as it seems to provide one of the more promising ways for high electromechanical energy conversion. Current study deals with the development of a robust and accurate numerical tool capable of modelling and designing piezoelectric structures undergoing severe nonlinear vibrations. Specifically, a coupled multi-field generalized nonlinear mechanics framework for piezoelectric beams subjected to initial stresses and large rotations, extended to include passive external electric circuits in order to predict the dynamic response of the structure and the power generated at the external resistive load. An experimental setup was also developed providing great correlations with the numerical results in case of a vibrating axially prestressed composite beam under the prebuckling regime. At the end, a computational investigation was performed studying the complex dynamic behavior of the piezoelectric beam, in the postbuckling regime. The model successfully captures the measured energy harvesting response of the beam including additional effects induced by the asymmetric configuration of the piezoelectric film.

Lithium-ion battery equalization circuit and control strategy for photovoltaic energy storage applications

Abstract Solar photovoltaic (PV) is considered a very promising technology, and PV-lithium-ion battery energy storage is widely used to obtain smoother power output. In this paper, we propose a battery equalization circuit and control strategy to improve the performance of lithium-ion batteries. In the equalization circuit, the passive equalization and active equalization circuits are combined, and the active equalization circuit used is simple and has high performance, whereas in the equalization strategy, because the system works 24 h a day, the equalization speed is sacrificed to obtain a smaller temperature rise by adjusting the duty cycle of the passive equalization metal-oxide-semiconductor field-effect transistors and by calculating the state of charge instead of the voltage to obtain better performance. The proposed circuit and strategy can not only achieve the goal of battery equalization, while turning on four batteries at the same time and the temperature rise of passive equalization is only 1°C for ~1.5 h. Compared with the traditional equalization control strategy with 8 mV voltage error, the proposed strategy is only 3 mV, which has better performance.

Sound isolation via temporal modulation material based on piezoelectric elements

The temporal modulation material is investigated to be used as lightweight sound isolation material. This smart composite material consists of a lightweight structure attached with shunted piezoelectric ceramic (PZT) patches. The shunt circuits are connected to the two poles of PZT patches to act as some local electrical resonators to improve the sound isolation. The circuit is composed of operational amplifiers and passive analog circuit elements, so the system is always stable, and the power consumption is low. The metal-oxide-semiconductor field-effect-transistor (MOSFET) is added in the shunt circuit connected to the PZT patches, so the time sequence of the working circuit is controlled with the MOSFET devices in each resonant shunt. The motivation of this study is to improve the sound isolation in the low-to-middle frequency range. The temporal modulation material proposed in this study has many potential applications in environmental acoustics, precise instrument, automotive sector, and aerospace technologies.

A Passive Thyristor-Based Hybrid DC Circuit Breaker

DC circuit breaker (DCCB) is one of the most important technologies for safe and reliable operation of dc grid. And the hybrid DCCB (HCB) is obviously promising in high-voltage application area, because it combines both the advantages of mechanical DCCB and solid-state DCCB. At present, insulated gate bipolar transistors (IGBTs) are generally used for configuring the main breaker branch in the HCB. Compared with IGBTs, thyristors have the merits of ability to bear higher surge current, higher reliability, and lower cost, thus being more economical and reliable when used to replace IGBTs. Right now, several topologies of thyristor-based HCBs have been proposed, but the economy, reliability, control complexity, as well as the operation performance, can still be improved. In this article, a novel passive thyristor-based HCB is proposed. Compared with existing IGBT-based HCBs, the proposed HCB has significant advantages on economy and reliability, due to the application of thyristors for replacing IGBTs. In addition, in the proposed scheme, the required thyristors count is reduced and the additional power supply for capacitor precharging is saved, so the investment and control complexity are both cut down. The feasibility and superiorities of the proposed HCB are validated with scaled-down experiment test and 500-kV-level simulation case study.

Passive realization of the fractional‐order capacitor based on fractional‐order inductor and its application

SummaryThis paper investigates a new implementation of a passive fractional‐order capacitor (FOC) based on a single‐component fractional‐order inductor (FOI). The significance of this approach lies in providing the fractional‐order passive circuit to synthesize an FOC, which avoids the approximation that only depends on the integer‐order transfer function and reflects truly the infinite‐dimensional nature of fractional‐order impedance characteristic. For this purpose, the realizable conditions of this passive FOC are obtained and the main ideas of the proposed method are described by examples. The sensitivity of the impedance magnitude and phase angle on required components parameters is also analyzed in order to facilitate the design of the FOC emulator. Furthermore, the bandwidth is extended by modular structures connected in series, and the proposed approach shows an improvement over some previous methods in terms of accuracy. Also, based on the fractional calculus Grünwald–Letnikov definition, a single‐component FOI circuit element is packaged to build simulation circuit in Matlab/Simulink, and the effectiveness of the proposed method are validated by simulated and experimental results. In the application of an FOC, the results from in the series–parallel fractional‐order RLCβ bandreject filter circuit indicate that the fractional‐order counterpart can reduce the ripple and improve the suppression level at a certain frequency, and the peak amplitude and the overshoot decrease initially with decreasing order. Moreover, under the fixed inductance, capacitance, and resistance, the rise time varies almost inversely with order, whereas the setting time is on the decrease as the order is decreasing.

Pulsed Four-Wave Mixing at Telecom Wavelengths in Si3N4 Waveguides Locally Covered by Graphene.

Recently, the nonlinear optical response of graphene has been widely investigated, as has the integration of this 2D material onto dielectric waveguides so as to enhance the various nonlinear phenomena that underpin all-optical signal processing applications at telecom wavelengths. However, a great disparity continues to exist from these experimental reports, depending on the used conditions or the hybrid devices under test. Most importantly, hybrid graphene-based waveguides were tested under relatively low powers, and/or combined with waveguide materials that already exhibited a nonnegligible nonlinear contribution, thereby limiting the practical use of graphene for nonlinear applications. Here, we experimentally investigate the nonlinear response of Si3N4 waveguides that are locally covered by submillimeter-long graphene patches by means of pulsed degenerate four-wave mixing at telecom wavelength under 7 W peak powers. Our measurements and comparison with simulations allow us to estimate a local change of the nonlinearity sign as well as a moderate increase of the nonlinear waveguide parameter (γ∼-10 m-1W-1) provided by graphene. Our analysis also clarifies the tradeoff associated with the loss penalty and nonlinear benefit afforded by graphene patches integrated onto passive photonic circuits, thereby providing some guidelines for the design of hybrid integrated nonlinear devices, coated with graphene, or, more generally, any other 2D material.

Memristor Crossbar Circuit for Ternary Content‐Addressable Memory with Fine‐Tuning Operation

Memristor‐based ternary content‐addressable memory (TCAM) has emerged as an alternative to conventional static random‐access memory (SRAM)‐based TCAM because of its high‐density integration and zero‐static energy consumption. Herein, 0T2R TCAM operation on a 32 × 32 passive memristor crossbar circuit is experimentally verified. The effective margin, which is the difference between the match case and 1‐bit mismatch case, is improved through precise tuning operations. Moreover, the number of mismatch bits and match cases can be accurately detected thanks to the linear relationship between the number of mismatch bits and match‐line current. In addition, the nonideal effects in the passive crossbar array including dynamic voltage drop and sneak current are analyzed through SPICE studies. These results indicate that the proposed TCAM operating conditions can ensure stable TCAM operation in larger arrays.

An Auxiliary Passive Circuit and Control Design for Wireless Power Transfer Systems in DC Microgrids with Zero Voltage Switching and Accurate Output Regulations

This paper presents an auxiliary passive circuit and control design for wireless power transfer (WPT) systems in DC microgrids to achieve optimal power transfer efficiency while maintain accurate output voltage regulation. An auxiliary inductance is added at the transmitter resonator to form a current sink to ensure zero voltage switching (ZVS) of the primary-side full-bridge inverter with even extremely light load conditions. Moreover, an adaptive proportional–integral (PI) controller is adopted to track the output voltage references by regulating the phase shift angle of the phase shift control for the full-bridge inverter. The coefficients of the adaptive PI controller are determined by the inductance of the auxiliary inductance. Both simulation and experimental results validated the effectiveness of the proposed circuit and control design in achieving optimal efficiency and output voltage regulation for WPT systems in DC microgrids with source and load variations.

Design and Implementation of a Passive Autoranging Circuit for Hybrid FBG-PZT Photonic Current Transducer

In this paper, we present a novel technique for passively autoranging a photonic current transducer (PCT) that incorporates a current transformer (CT), piezoelectric transducer (PZT) and fiber Bragg grating (FBG). Due to the usage of single-mode fiber and FBG, multiple PCTs can be interconnected and distributed over a long distance, for example along a power network, greatly reducing the cost of sensor deployment and offering other unique advantages. The autoranging technique relies on the usage of multiple, serially connected CT burden resistors and associated static MOSFET switches to realize instantaneous shortening of the resistors in response to increasing measured current. This functionality is realized passively, utilizing a modular, μW-power comparator circuit that powers itself from the electrical energy supplied by the CT within a small fraction of the 50/60 Hz cycle. The resultant instantaneous changes in sensor gain will be ultimately detected by the central FBG interrogator through real-time analysis of the optical signals and will be used to apply appropriate gain scaling for each sensor. The technique will facilitate the usage of a single PCT to cover an extended dynamic range of the measurement that is required to realize a combined metering- and protection-class current sensor. This paper is limited to the description of the design process, construction, and testing of a prototype passive autoranging circuitry for integration with the PCT. The two-stage circuitry that is based on two burden resistors, 1 Ω and 10 Ω, is used to prove the concept and demonstrate the practically achievable circuit characteristics. It is shown that the circuit correctly reacts to input current threshold breaches of approximately 2 A and 20 A within a 3 ms reaction time. The circuit produces distinct voltage dips across burden resistors that will be used for signal scaling by the FBG interrogator.

A Lossless Soft-Switching Boost Converter with Passive Auxiliary Circuit

Based on boost topology, a lossless soft-switching passive circuit with a single switch is proposed in this paper. The proposed circuit's power switch achieves approximately zero voltage switching (ZVS) and zero current switching (ZCS) without increasing the number of switches. Due to an auxiliary inductor, the reverse recovery loss of the rectifier diode is significantly reduced. Besides, all auxiliary circuit energy is returned to the power supply without additional energy consumption. Therefore, by using a traditional control method, simple design, and appropriate auxiliary circuit parameters, soft-switching can be realized in a wide voltage and full load range. Moreover, the number of components used in the auxiliary circuit is minimal. This method makes circuit design more manageable and achieves 95.39% high efficiency since the increase of voltage stress is relatively small.

ПРОСТИЙ МЕТОД ПІДВИЩЕННЯ ВИСОКОЧАСТОТНОЇ ПОЗАСМУГОВОЇ СТАБІЛЬНОСТІ РАДІОЧАСТОТНИХ ПІДСИЛЮВАЧІВ

Subject and Purpose. Methods for determining and ensuring the stability of radio frequency (RF) amplifiers have been progressing quite actively over the past decades. However, most of them are not convenient for practical use. Combining analytical and graphical techniques widely accepted at the moment requires a highly skillful user and licensed software. Also, a bad point is the lack of clear algorithms for increasing the out-of-band high-frequency stability of amplifiers, sending us to the procedure of successive approx- imations when an optimal solution for an individual scheme is sought. The present work seeks for a simple method that effectively increases the out-of-band high-frequency stability of RF amplifiers and improves the reliability of signal amplification systems, espe- cially those complex structures that incorporate low-frequency radio telescopes. Methods and Methodology. The parameters of the RF amplifiers and passive circuits are obtained by computer modeling upon the S-parameters given by the manufacturer. The amplifier stability is determined by the K-factor for stability. Results. A simple universal method has been developed to improve the out-of-band high-frequency stability of RF amplifiers. In this method, a stabilization RstabLstab circuit is connected to the amplifier in series with the load. An original procedure has been designed to calculate the stabilization circuit. Also, a metric has been proposed that evaluates the practical margins of the out-of-band high-frequency stability of RF amplifiers and makes it possible to compare them one to another. Finally, the proposed method offers freedom from the licensed software. Conclusions. The proposed method significantly increases the high-frequency stability of RF amplifiers beyond the operating fre- quency range and simplifies the technological requirements for the design. The employment of RF amplifiers is more available almost without compromising their performance in the operating frequency range. The method is simple and easy to apply.

Gap Waveguide Technology: An Overview of Millimeter-Wave Circuits Based on Gap Waveguide Technology Using Different Fabrication Technologies

With the fast development of next-generation wireless communication and radar sensing, the millimeter-wave frequency band is becoming more and more important due to its rich spectrum, wide bandwidth, and ability to support the miniaturization of antennas and circuits <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</xref> , <xref ref-type="bibr" rid="ref2" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[2]</xref> , <xref ref-type="bibr" rid="ref3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[3]</xref> , <xref ref-type="bibr" rid="ref4" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[4]</xref> . High-performance, low-loss, and low-cost millimeter-wave circuits and modules are the key elements for wireless front-end systems. For planar transmission lines, such as microstrip lines and coplanar waveguides, they are very easy to integrate with other circuits for low-cost and low-profile physical designs. However, the high insertion loss and radiation loss from planar transmission lines limit their applications at the millimeter-waveband. As for rectangular and cylindrical waveguides, their main application is in the areas of low loss and high power handling, but their 3D structure is difficult to integrate with other planar passive and active circuits. The substrate-integrated waveguide (SIW) is a better way to merge the advantages of planar transmission lines and rectangular waveguides, but it still suffers from dielectric losses at the millimeter-wave frequency range.

A Simple 36-Pulse Rectifier With Passive Pulse-Tripling Circuit at the DC Side

A series-connected 36-pulse rectifier with passive pulse-tripling circuit (PPTC) on the dc side is proposed in this article. The proposed rectifier consists of a series-connected 12-pulse rectifier and a PPTC. The PPTC includes a passive current forming network, a single-phase auxiliary transformer with dual secondary windings and two auxiliary single-phase rectifiers (ASRs). One ASR in PPTC is connected in series with the load to directly modulate the output current of rectifier bridges. The other ASR in PPTC is connected in parallel with the load to modulate the output current of rectifier bridges according to the relationship between its input voltage and load voltage. Composite modulation of the two ASRs increases the pulse number of the rectifier from 12 pulses to 36 pulses. The resulting rectifier obtains an approximate sinusoidal input current with less than 5% THD. Only a few low-capacity passive components are sufficient given the absence of active components in the proposed scheme. The proposed scheme presents advantages of simple circuit structure, easy implementation, and high reliability. Detailed analysis and experimental results are provided to verify the effectiveness of the proposed scheme.

Input-Reflectionless Quasi-Elliptic-Type Single- and Dual-Band Bandpass Filters Based on Passive Channelized Principles

An approach to design quasi-elliptic-type planar filters with single- and dual-band bandpass transfer functions and input-absorptive capabilities is presented. Two-branch channelized passive circuit configurations are exploited for this purpose, in which the low-order reflective-type filtering profile of their branches is converted into the desired sharp-rejection input-reflectionless filtering action in the overall circuit. This is achieved by means of fully-destructive and frequency-selective transversal signal-interference effects at the total input and output accesses of the channelized filter, respectively. The theoretical operational principles of the proposed concept of single/dual-passband input-reflectionless two-branch channelized filter are detailed, along with design considerations for their RF transmission-line-based implementation. Besides, its generalization to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\boldsymbol {N}$ </tex-math></inline-formula> -channel architectures is also analyzed. Furthermore, as the fundamental elements of the devised channelized filtering philosophy to increase selectivity, alternative solutions to realize their output phase-delay sections for a more-flexible control of the transmission zeros in the overall transfer function are discussed. For experimental-demonstration purposes, two microstrip proof-of-concept prototypes are developed and measured. They consist of 3-GHz single-band and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.58/3.43$ </tex-math></inline-formula> -GHz dual-band designs with input-quasi-reflectionless spectral ratio above 2.5:1 and 3:1, respectively.

CSRR DGS-Based Bandpass Negative Group Delay Circuit Design

The unfamiliar negative group delay (NGD) circuit is the less familiar function for most of RF and microwave design engineers. Among the existing types, the bandpass (BP) NGD type circuits are the most convenient for the wireless communication microwave technology. Therefore, it is particularly important to explore different microwave circuit topologies operating as BP-NGD function. An innovative design of BP-NGD topology constituted by defected ground structure (DGS) with complementary split ring resonator (CSRR) is developed in the present paper. The DGS-based BP-NGD structure design method is introduced in function of the CSRR geometrical elements followed by S-parameter parametric analyses. As proof-of concept (POC), the design method of the proposed BP-NGD passive fully distributed circuit is described. The effectiveness of the BP-NGD structure and the test feasibility are investigated by implementing two different prototypes represented by single- and double-wing DGS passive circuits. It is observed that significant BP-NGD function performances were validated by well-correlated simulations and measurements showing -1.9 ns NGD value around the center frequency, 2.46 GHz over 31 MHz NGD bandwidth. In addition, the tested BP-NGD prototypes present insertion loss better than 4 dB and reflection loss better than 16.7 dB. Because of its potential integration, the investigated BP-NGD circuit is potentially useful for the communication system performance improvement for example via delay effect reduction in the RF and microwave devices.

Low-Loss and High-Confinement Photonic Platform based on Germanium-on-Insulator at Mid-Infrared Range for Optical Sensing

We experimentally demonstrate a low-loss Ge-on-insulator (Ge-OI) passive waveguide with low absorptive yttrium oxide (Y <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) as an insulator for a photonic platform using a wafer-bonding technology at mid-infrared (MIR) wavelength. The lowest propagation losses of 0.84 dB/cm for a channel waveguide (ChW) and 1.79 dB/cm for a slot waveguide with a slab under the slot (s-SlW) were obtained in fundamental transverse-electric (TE) mode at 4.2 μm wavelength. We also designed additional passive circuits such as grating couplers and mode converters for the implementation of the platform. For an optical gas sensor using the platform, the narrow core width of the ChWs and nanoscale of slot gap of the s-SlWs have been derived based on the numerical design toward high optical confinement, and these were fabricated and systematically analyzed to minimize the propagation loss. From the comparison for loss measurement between a nitrogen (N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) ambient and a carbon dioxide (CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) containing normal atmosphere at 4.2 μm wavelength, as a consequence, narrow ChW and s-SlW showed quite high additional optical loss by the CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> absorption, revealing high potential as an optical gas sensor. In conclusion, we believe that this Ge-OI platform can be a very promising candidate for the optical sensor in terms of low-loss and high-confinement properties.

Hybrid UPQC for Power Quality Management of Renewable Energy Penetrated System

Severe voltage sag and radiation pollution is an obstacle for low-voltage intermediate-requirement requiring power facilities, like optical semi conduct, data storage, and precision equipment, like pharmaceuticals and pharmaceuticals, where radiation is involved. As more voltage and economic as well as becoming slower and more difficult to maintain, current equipment is now needed to have higher energy capability. Achieving bi-links for bi-side operation in a medium-voltage condition power-supply application. The first step, followed by the study of a three-phase equivalent circuit and mathematical model, reveals the underlying mechanism of harmonic suppression and voltage control combined with sequence-shunt act phasing and shunt HAPF for continuous phase synthesis (CPS) and the different discrete control and CPS (p-p/Discrete Fourier Transform and Differential Mode Digital Filtration are considered for series, which uses the sliding fourier Phase Lock Loop and its sychronous shunt capability are implemented. The L-C series-filter and passive double-resonant circuits (PDR) are then discussed, along with the key circuit components of the design, the series inductor (LL) circuit, the PDR passive low-pass, and the passive double resonant circuit design for applying the induct filtering. After all, the proof of results in the high voltage delivery validation in MATLAB/Simulink, IHUPC has been demonstrated, 10kV distribution now is supported. With these effects, it being effective in regulating voltage and current and dynamic power generation, the simulation results show the performance of dynamic grid voltage &amp; current regulation and dynamic load-harmonic regulation.

Electronic System of Remote Optical Control of LiNbO3 Mach-Zehnder Modulator Operating Point

A system for integrated optical LiNbO3 Mach–Zehnder modulator operating point remote control and stabilization was developed. It consisted of a conventional telecom photodiode and a passive electronic circuit at the bias input of the modulator. Light from an amplitude-modulated laser was used to remotely set the output voltage of the electronic circuit at the bias input of the Mach–Zehnder modulator. Information regarding the current operating point that had been provided with feedback system implementation was taken from DC values of high frequency photodetector currents. Efficient remote control of the modulator operating point over 1 km of a single-mode optical fiber, which multiplexes an optical carrier at 1550 nm and a low frequency control signal with a peak power of 2 mW at 1310 nm, was demonstrated. The results could be of interest for antenna remoting, radio-over-fiber (RoF) technology, and other applications with broadband optical transmission from remote sources in a distributed network.