Series Inductance Research Articles

Factorized form of the dispersion relations of a traveling wave tube

The traveling tube (TWT) design in a nutshell comprises of a pencil-like electron beam (e-beam) in vacuum interacting with guiding it slow-wave structure (SWS). In our prior studies the e-beam was represented by one-dimensional electron flow and SWS was represented by a transmission line (TL). We extend in this paper our previously constructed field theory for TWTs as well the celebrated Pierce theory by replacing there the standard TL with its generalization allowing for the low frequency cutoff. Both the standard TL and generalized transmission line (GTL) feature uniformly distributed shunt capacitance and serial inductance, but the GTL in addition to that has uniformly distributed serial capacitance. We remind the reader that the standard TL represents a waveguide operating at the so-called TEM mode with no low frequency cutoff. In contrast, the GTL represents a waveguide operating at the so-called TM mode featuring the low frequency cutoff. We develop all the details of the extended TWT field theory and using a particular choice of the TWT parameters we derive a physically appealing factorized form of the TWT dispersion relations. This form has two factors that represent exactly the dispersion functions of non-interacting GTL and the e-beam. We also find that the factorized dispersion relations comes with a number of interesting features including: (i) focus points that belong to each dispersion curve as TWT principle parameter varies; (ii) formation of “hybrid” branches of the TWT dispersion curves parts of which can be traced to non-interacting GTL and the e-beam.

High Quality Factor Miniaturized CMOS Transmission Lines Using Cascaded T-Networks for 60 GHz Millimeter Wave Applications

This work presents an on-chip 60 GHz lumped element transmission line (TL) using cascaded T-networks with a high Quality factor. Each T-network consists of a series inductance with a shunt capacitance at its center. We have derived the design equations for this TL configuration and proved that a TL whose electrical length ≥ 60° achieves additional miniaturization when implemented with three or more cascaded T-networks. The inductance is implemented using a straight wire model with no ground below it, while the capacitance is implemented using a parallel plate model with a grounding pedestal. Both configurations guarantee maximum inductance per unit length and capacitance per unit area to further improve the miniaturization level. A quarter wavelength TL with three cascaded T-networks is fabricated as proof of concept. The measured and simulated results of the fabricated TL have good agreement, and the measured quality factor is 17 at 60 GHz.

Coherence resonance in a memristive map neuron and adaptive energy regulation

Involvement of memristive term and additive physical variables including magnetic flux and charge can enhance the physical description of the biophysical neurons. Neural circuits coupled with memristors can be built and tamed to mimic the intrinsic biophysical characteristics and dynamical properties of biological neurons, and these memristive oscillator models are effective in predicting the mode transition in neural activities and self-organization in collective electric behaviors of neural networks. Any proposal of memristive map neurons requires reliable physical description. For example, the energy definition and self-adaptive working mechanism are crucial to verify the reliability of memristive maps. A capacitive variable is useful to describe the membrane potential, while the complexity of ion channels requires careful evaluation and description by using inductive variables relative to the electromagnetic field. In this work, a charge-controlled memristor is connected to an inductor in series for building a hybrid ion channel, and then a capacitor and a nonlinear resistor are combined to couple the ion channel. As a result, a simple memristive neural circuit is designed to discern the inner effect of electric field and magnetic field synchronously. The energy function is defined and verified with theoretical proof. Furthermore, a linear transformation is applied to convert this memristive neuron into a memristive map with an exact energy description, in which its dynamics and mode transition will be controlled by an adaptive law when its energy is beyond the threshold. Additive noise is imposed to induce coherence resonance, which can be detected by using the statistical analysis and average value for Hamilton energy function during changes in noise intensity. This scheme provides guidance for energy definition in memristive maps and the intrinsic energy regulation mechanism in neural activities is explained from physical and dynamical aspects.

Inverse Class‐E power amplifier with broadband capability at different switch‐off duty ratio

AbstractThe paper explores the investigation of an inverse Class‐E amplifier featuring a series output filter across various switch‐off duty ratios D. Analysis of different duty ratios as a design parameter reveals their impact on peak switch voltage, output power capability, and maximum operating frequency. Notably, it is demonstrated that adjusting the D ratio affects these parameters, with specific emphasis on achieving a maximum normalized switch voltage lower than 2 and an output power capability exceeding 0.1 for D = 0.7. Furthermore, the paper considers both parasitic shunt capacitance and series inductor in the load network, a departure from previous works that solely focused on the series inductor. The proposed circuit is highlighted for its ease of implementation compared with conventional reactance compensation circuits employing parallel resonant circuits, which are challenging to form directly. An innovative approach is introduced to showcase the broadband performance of the inverse Class‐E amplifier. The measured drain efficiency and output power versus input power at 430 MHz are 82% and 45.3 dBm, respectively. A similar performance can be achieved within the frequency range of 380–600 MHz by proper tuning at saturated power. The measurement results demonstrate a maximum high power‐added efficiency (PAE) of 79% and drain efficiency of 82% within this frequency range, accompanied by a gain exceeding 12.0 dB and output power surpassing 44 dBm.

Paralleled Variable Inductor Phase-Shifted Full-Bridge Converter With Full-Load Range ZVS and Low Duty Cycle Loss

This paper presents a new phase-shifted full-bridge topology using a new variable inductor. In this topology, a variable inductor is connected in parallel with a near-ideal transformer. The ZVS of the switches is achieved over the full load range using the parallel current provided by the variable inductor. And the adjustable parallel current reduces conduction losses. Under the orthogonal DC magnetic potential, the variable inductor has similar characteristics to the saturated inductor, which is beneficial to reduce the conduction loss caused by the parallel current. Since the topology has no series inductor and the leakage inductor is extremely small, the proposed converter has the advantages of extremely small duty cycle loss, larger transformer turns ratio, smaller primary current stress, smaller secondary voltage stress, and smaller output current ripple, which are beneficial to improve the efficiency and frequency of the converter. An experimental platform was established. Theoretical analysis and experimental verification were carried out.

Barium Strontium Titanate-based multilayer ceramic capacitors with excellent energy storage and charge-discharge performance

Energy storage capacitors for advanced pulse power systems and high-power electric devices is a kind of important electronic components, the demand continues to grow, specifications are constantly being upgraded, and performance boundaries are continuously being pushed. Multilayer ceramic capacitors (MLCCs) for energy storage applications have received increasing attention due to the advantages of ultralow equivalent series inductance, equivalent series resistance, good frequency characteristics, strong voltage overload ability, and stable operability at high temperatures. However, the relatively low energy storage density significantly limits its broader applications. Here, 0.4Ba0.55Sr0.45TiO3-0.4Bi0.5Na0.5TiO3-0.2SrZrO3 (0.4BST-0.4BNT-0.2SZ) relaxor ferroelectric MLCCs are prepared at different heating rates. Excellent recoverable energy storage density of 10.3 J cm−3 and high energy efficiency of 93 % are achieved in fast-fired MLCCs under the electric field of 106.3 V μm−1. The impedance spectroscopy and thermally stimulated depolarization current technologies are employed to investigate the conductance mechanism of MLCCs, and the results can explain the effect of heating rate on the performance of MLCCs. In addition, the charge-discharge performances of fast-fired MLCCs are also thoroughly investigated, exhibiting great thermal and fatigue stability.

A simple LC circuit with a parallel diode

An inductor in series or parallel with a capacitor is a well known electrical circuit that allows the voltage and current to oscillate sinusoidally with time. If a diode is inserted in parallel with the inductor, then the current in the inductor will remain approximately constant with time.

Miniaturized filtering equal/unequal Wilkinson power dividers

In this paper, two miniaturized Wilkinson power dividers with equal and unequal power division ratios capable of suppressing spurious harmonics over a wide frequency range are presented. First, an asymmetric high-low impedance resonator with coupled open-stubs and folded structure is employed to design the equal power divider. Then, how connecting an inductor in series with the introduced resonator can lead to affecting the transmission coefficient of the power divider branch and achieving an unbalanced power division ratio at output ports, is analytically clarified. In the third step, a combination of the resonator with folded structure and the inductor is utilized to design an unequal 2:1 divider. To validate the performed analysis, two equal and unequal Wilkinson power dividers at 900 MHz are fabricated and measured. Regarding S31, both dividers can suppress the 4th to 13th spurious frequencies and with respect to S21 of the unequal case, the 2nd-harmonic to 14th-harmonic are omitted. The occupied areas of the equal and unequal structures are 7.35 mm × 18.9 mm and 7.5 mm × 17.9 mm, respectively, which indicate almost 84 % size reduction in each case.

3D printed circularly polarized implantable antenna with wideband impedance matching

Abstract This article proposes a slot-loaded circularly polarized implantable antenna with wide bandwidth at 2.45 GHz, i.e., Industrial, Scientific, and Medical (ISM) band. This antenna is established with a compact size of 44.52 mm3 based on 3D printing technology, and biocompatible material MED610 is adopted for human safety consideration. During the design, unilaterally shorted patch antenna loaded with T-slot is adopted, obtaining two closely spaced orthogonal modes with miniaturized antenna size. More importantly, to obtain wide impedance matching, a spiral slot is introduced around the feed, forming an L-section network consisted of a parallel capacitor and a series inductor. As a result, a wide circular polarization bandwidth of 28.7 % is realized for the proposed antenna. The measured results are well agreed with simulated results.

Challenges in Measurement of Low-Value ESL and ESR of High-Performance PFN Capacitors for Klystron Modulator

In the high voltage line type pulse modulators, Pulse Forming Network (PFN) capacitors are one of the important components. These capacitors operate at peak kilo ampere current range and at repetition rate in the range of a few hundred hertz. The performance of these capacitors is critical w.r.t. overall system performance, and they are required to operate at high power density and low losses with high reliability. The Equivalent Series Inductance (ESL) and Equivalent Series Resistance (ESR) are two critical parameters that affect the performance of these capacitors. PFN modulator demands a capacitor of very low ESL and ESR for reliable operation and generation of high-voltage pulses. Higher ESR value adversely affects the performance of the capacitor by raising its temperature and thus deteriorating its life. ESL value does not directly affect life, but it affects the quality of high voltage pulse. In RRCAT, the PFN capacitors purchased from Indian manufacturers were showing high-temperature rise and failures. Therefore, new capacitors were designed to have lower ESL and ESR values. Measurement of ESL and ESR is important to evaluate the performance of the capacitors. The low value of these parameters makes their measurement a challenging task and requires special techniques. For low values of ESL and ESR (less than 100 mΩ) measurement, a differential measurement technique was used in which modification and different layouts were explored to improve the repetitive accuracy of the measurements. The differential ESR and ESL measurement techniques with more emphasis on the low-value ESR measurement will be discussed in the paper.

Triple-band and polarization-insensitive rectifying metasurface with flexible substrate

A flexible triple-band and polarization-insensitive rectifying metasurface (RMS) is presented in this article. The surface consists of three parts: a periodic metal unit with integrated diodes, a DC filter composed of series inductor and parallel capacitor, and a load resistor. Due to the direct integration of rectifying diodes and interconnected branches within and between the units, complex matching networks can be eliminated and the overall structure is simplified. A 6 × 6 array is fabricated and measured. The results show that at a low input power of 0 dBm, the RMS has efficiency of 51.81%, 44.25%, and 42.01% at 2.9 GHz, 5.2 GHz, and 5.77 GHz, respectively. The efficiency remains consistent under different polarization angles, demonstrating the polarization insensitivity property of RMS. Additionally, the flexible substrate enables high efficiency in the S-band and Wi-Fi bands even under a certain range of bending, revealing its superior flexibility and adaptability. Therefore, it is well suited for ambient energy harvesting and wireless self-powered miniaturized internet of things devices.

Realization of nth Order Wave Active Low-Pass Filter Using Differential Difference Current Conveyor

A wave active filter (WAF) based on a differential difference current conveyor (DDCC) is presented in this paper. An active filter formation depends entirely on wave quantity processing. The wave method is demonstrated for the basic wave active elements (WAEs) of active filters such as a series inductor and a shunt capacitor. The novelty of the proposed work is that the mathematical operations required to implement the wave active components, such as lossy integration-subtraction; subtraction; summation and inverter, are performed using the DDCC as an analog building block (ABB). Designing WAFs of lower to higher-order is extremely challenging, i.e., great motivation to propose a WFA using a CMOS-based DDCC for lower and higher-order low-pass Butterworth filter topologies. Additionally, the filter performances are verified through noise analysis, percentage total harmonic distortion (%THD) and Monte Carlo analysis. The proposed WFA is theoretically verified for [Formula: see text]th order low-pass Butterworth filter designs ([Formula: see text]) using DDCC-based WAEs and validated using SPICE simulations with [Formula: see text]m TSMC CMOS technology parameters for DDCC, operating on [Formula: see text][Formula: see text]V.

A high-gain wideband balun-LNA with multiple noise-optimized technique

This article reports a high-gain wideband low-noise amplifier (LNA) with single ended input and differential output for multi-standard wireless receiver operating in 0.2 to 7 GHz. The proposed balun-LNA is cascode structure with common-gate–common-source (CG–CS) balun load to achieve single to differential conversion. Focusing on improving the voltage gain, bandwidth and noise performance at the same time, several techniques are implemented in this balun-LNA. A current source is added shunting CG stage to relieve voltage headroom and improve gain and linearity. Wideband input matching is achieved by active shunt-shunt resistive feedback, together with the input series inductor. Moreover, feedforward and current-reuse technique are introduced to further optimize the noise performance. The proposed LNA has a measured voltage gain of 26 dB which is nearly 6 dB higher than other balun-LNA with same supply and process. Moreover, the minimum noise figure (NF) is 2.0 dB owing to multiple noise-optimized technique. The achieved input power at 1 dB gain compression point (IP1 dB) is −14 dB m at 1 GHz and input return loss (S11) is better than −10 dB across entire operating frequency range. IIP3 and IIP2 achieve −7 dBm and 25 dBm respectively, measured at 1 GHz. The power consumption is 15.5 mW at 1.2 V supply. The LNA is fabricated in 130 nm CMOS process and the active area is 0.097 mm2. The LNA achieves high voltage gain and wide operating frequency range with low NF, which can be reflected from the figure of merit (FOM) of 23.1.

Design and analysis of impedance matching for a radial standing wave piezoelectric ultrasonic motor.

Impedance matching circuits are capable of tuning and wave filtering, which is beneficial to performance improvement of piezoelectric ultrasonic motors. At present, impedance matching for piezoelectric ultrasonic motors is usually realized through a series inductance, which has the problem of poor wave filtering effect. Different from the previous series inductance matching method for ultrasonic motors, a series inductance and capacitance matching method is proposed for a radial standing wave piezoelectric ultrasonic motor. The series capacitance is added to adjust the quality factor of the resonance tank so that a desired wave filtering effect can be obtained. The values of the series inductance and capacitance are derived based on the Butterworth-Van Dyke model of the piezoelectric ultrasonic motor. Simulations are conducted to verify the feasibility of the proposed matching method. Finally, the waveforms of voltages and currents as well as torque-speed curves of the motor are measured. The results validate the proposed matching method. In addition, the previous series inductance matching method is compared. The results show that the proposed series inductance and capacitance matching method not only achieves tuning function but also obtains a significantly improved wave filtering effect. Moreover, the torque-speed characteristics of the motor are also improved with the proposed matching method.

Research on tunable bandgap characteristics of the phononic crystal duct with piezoelectric thin plates for the broad noise reduction

To achieve adjustable mid-low frequency noise reduction characteristics in pipeline systems, one hybrid phononic crystal duct with piezoelectric thin plates is proposed. Firstly, phononic crystal duct model with Helmholtz mufflers and built-in piezoelectric thin plates is established to reduce low-to-mid frequency noise in the duct. The theoretical transmission loss is verified using simulation methods, revealing the sound attenuation law and bandgap mechanism. Under the shunting effect of the RLC circuit, three locally resonant bandgaps are generated: the mechanical locally resonant band gap introduced by the thin plate, acoustic locally resonant band gaps caused by the Helmholtz muffler cavity structure, and the electromechanical locally resonant band gaps dominated by the shunting circuit. By adjusting the shunting circuit, the acoustic impedance of the piezoelectric thin plate can be controlled, and then the acoustic characteristics of low and medium frequencies will change. For the shunting circuit composed of inductance, capacitance and resistance in series, the inductance and capacitance can adjust the position of the three band gaps; the negative capacitance can effectively enhance the tunability of the electromechanical locally resonant band gap, which is helpful to obtain the low-frequency band gap; while resistance primarily affects the magnitude of acoustic attenuation within the bandgap. Subsequently, based on the analysis of the noise characteristics of the air-assisted system of one fuel cell vehicle, one hybrid phononic crystal duct with compact structures is designed to achieve a broadband duct noise reduction of 330 Hz–4000 Hz.

Grounded synthetic series lossy inductor simulator circuits employing single current differencing buffered amplifier

SummaryIn this communication, two new positive lossy series inductor simulator circuits using single current differencing buffered amplifier (CDBA), one capacitor, and three resistors are presented. In both the proposed circuits, the inductance value is independently controllable through a grounded resistor, which may be implemented using a voltage‐controlled resistor (VCR), facilitating electronic tuning. Moreover, one of the circuits presented utilizes the intrinsic resistance (internal resistance available at input ports p and n) of the CDBA, thereby enabling electronic control and establishing the inductor simulator as canonical. Both the circuits are analyzed for non‐ideal behavior by taking into account the parasitic elements of CDBA and compared with their ideal counterparts. To demonstrate the efficacy of the proposed series RL simulator circuits, SPICE simulations are performed using CMOS CDBA, and the performance of the proposed circuits is evaluated by designing a lead compensator. The simulation and experimental results of the proposed circuits, along with the application examples employing CDBA realized with the off‐the‐shelf available IC AD844, have also been corroborated.

Design and implementation a novel single switch high gain DC-DC converter based on coupled inductor with low-ripple input current

A novel high-gain and high-efficiency direct current to direct current (DC-DC) converter is introduced in this paper. The presented converter is suitable for low-voltage renewable energy resources such as photovoltaic (PV) and fuel cell (FC). The existence of series inductance with the input source ensures continuous and low-ramp input current, which is important for extracting maximum power from resources. Using coupled inductor technology and an intermediate capacitor in the suggested converter leads to a high gain voltage. In the presented topology for recovering energy from the leakage inductor, reducing voltage stress on the power switch, and so decreasing overall converter losses, a passive clamp circuit is used. The suitable operation range of duty cycle in the converter, besides the leakage inductor, decreases the problem of reverse recovery in diodes. The low value of the leakage inductor and the low volume and cost of the proposed converter are due to the low turn ratio of the coupled inductor. Details of the operation principles of the proposed converter have been discussed in this paper. The presented simulation and laboratory prototype results verify the theoretical analysis and performance of the suggested topology.

An integrated LNA‐phase shifter in 65 nm CMOS for Ka‐band phased‐array receivers

SummaryIn this paper, a vector‐sum phase shifter (VSPS) integrated with a wideband high‐gain low‐noise amplifier (LNA) for Ka‐band phased‐array receivers is presented. The digitally controlled VSPS based on the RF phase shifting architecture consists of a modified I/Q signal generator with additional inductor resonance and a programmable variable gain amplifier (VGA) based on Four 3 × 4 transistor arrays. Besides the reduced parasitic effect of the I/Q signal generator, an Equidistant Contraction Technology (ECT) is used in the VGA, to maintain higher phase shift accuracy of the VSPS. A multistage LNA with series inductor peaking is adopted to fulfill the flat wideband gain, where LC resonance networks are used as interstage matching to compensate for gain roll‐off at a higher frequency. Based on simulations in 65 nm CMOS technology, the presented LNA‐Phase shifter has achieved an average NF of 3.24–3.66 dB, and an average gain of 13.1–23.6 dB. Moreover, an RMS phase error of 1.1–12.6°, an RMS gain error of 4.2–5.6 dB, and an RMS magnitude error of 2.1–2.8 dB are maintained across 27–40 GHz, with a 360° phase shift coverage in steps of approximately 2.8125°. The chip consumes 16.83 mW from a 1.2 V supply voltage, and the occupied area is 0.65 mm2.

A Multilevel Boost Converter with Reduced Inductor Current

DC–DC converters are gaining attention due to their importance in key applications like renewable energy generation. A desirable feature in new DC–DC converters is a reduction in the size, which can be achieved with a reduction in the energy stored in the inductors. This article introduces a new step-up DC–DC converter topology with the following advantages: (i) a larger relation of duty cycle vs. voltage gain compared with the classical boost topology and (ii) an inductor with smaller current and smaller inductance (for the same power conversion characteristics) compared to the traditional boost converter. The smaller inductor current is an advantage against many step-up topologies with the inductor in series with the input (and then the input and the inductor currents are equal). The necessary inductance to achieve a certain current ripple is also reduced compared to the classical boost topology. This results in an inductor with a smaller amount of stored energy, lower inductance, and lower current. The proposed topology can be scaled to have a full family of large-voltage-gain converters. This paper presents the mathematical analysis, simulations, and experiments to assess the benefits of the proposition.

Fabrication of molecularly imprinted polymer‐based interdigital sensor for L‐ascorbic acid

The level of L‐ascorbic acid (AA) in various natural and artificial foods, medicines and other substances must be determined for biological and agricultural purposes. In this study, an AA‐imprinted poly (methacrylic acid)‐based receptor was synthesized by thermal free‐radical bulk polymerization for the detection of ascorbic acid using the methacrylic acid as monomer, ethylene glycol dimethacrylate (EGDMA) as cross‐linker, and azobisisobutyronitrile (AIBN) as initiator, in the presence of a porogenic solvent dimethyl sulfoxide (DMSO). The synthesized molecularly imprinted polymer (MIP) was used as a receptor. Immobilization of the receptor layer on IDEs provided a suitable sensor for AA detection by measuring changes in electrical parameters including inductance, capacitance, and resistance with the help of LCR meter. In the series and parallel inductance, the lowest detection limits were 0.13 and 0.001 ppm, respectively. While, for series and parallel capacitance, the lowest detection limits were 0.01548 and 1.3698 ppm, respectively. In the case of resistance, the lowest limit of detection was 0.0076 and 0.08121 ppm in series and parallel, respectively. The imprinted polymer‐based sensor showed sensitivity, selectivity, and reversibility for ascorbic acid.