Grounded Capacitors Research Articles

Fabrication and Characterization of Aluminum SQUID Transmission Lines

We report on the fabrication and characterization of 50 Ohms, flux-tunable, low-loss, SQUID-based transmission lines. The fabrication process relies on the deposition of a thin dielectric layer (few tens of nanometers) via Atomic Layer Deposition (ALD) on top of a SQUID array, the whole structure is then covered by a non-superconducting metallic top ground plane. We present experimental results from five different samples. We systematically characterize their microscopic parameters by measuring the propagating phase in these structures. We also investigate losses and discriminate conductor from dielectric losses. This fabrication method offers several advantages. First, the SQUID array fabrication does not rely on a Niobium tri-layer process but on a simpler double angle evaporation technique. Second, ALD provides high quality dielectric leading to low-loss devices. Further, the SQUID array fabrication is based on a standard, all-aluminum process, allowing direct integration with superconducting qubits. Moreover, our devices are in-situ flux tunable, allowing mitigation of incertitude inherent to any fabrication process. Finally, the unit cell being a single SQUID (no extra ground capacitance is needed), it is straightforward to modulate the size of the unit cell periodically, allowing band-engineering. This fabrication process can be directly applied to traveling wave parametric amplifiers.

Huge-scale capacitance mass flowmeter in gas/solid two-phase flow with rectangular vertical pipeline

A huge-scale capacitance mass flowmeter in gas/solid two-phase flow is proposed to measure the mass flowrate of rectangular vertical pipeline. The dimension of the sensor section is 2 m in length and 0.5 m in width. Two planes of capacitance electrodes are arranged in the flow direction, and the flow velocity of particle can be obtained by correlating the particle concentration of the two planes. Therefore, the mass flowrate of the particles can be calculated from concentration and velocity of the particles. Simulation and experiment are combined to optimize the sensitivity distribution of the sensor section, so that the fringe effect in the lateral and axial direction can be eliminated. The problem of ground capacitance and temperature drift in the huge-scale sensor are solved. The ac-based capacitance measuring circuit is improved and its performance is tested using this experiment. A gravity experimental setup with a height of 7 m is built to test the performance of the designed capacitance flowmeter. The experimental result has shown that the results from the measuring system are repeatable and therepeatabilityerror is 1.365%. The measurement errors in the mass flowrates of 7.5 kg/s, 16 kg/s, 23.5 kg/s and 33 kg/s are 29.3%, 8.3%, 4.1% and 3.5%, respectively. The results indicate that the measurement system has a satisfying level of measuring accuracy when the flowrate is above 16 kg/s. This measuring method provides a valuable reference for huge scale application.

A Fast and Precise Method for Modeling EMI Source in Two-Level Three-Phase Converter

Currently, frequency-domain electromagnetic interference (EMI) modeling has become the most commonly used method for EMI prediction and filter design. However, because of the unpredictability of the ringing effect in the present frequency-domain EMI modeling methods, the precision of the predicted EMI interference source is notably limited, which results in the inaccuracy of the system level EMI prediction. In order to achieve an accurate EMI prediction, this study presents a systematical study on the interference source of a 10 kVA three-phase bridge converter. The precise mathematical models of the common-mode and differential-mode interference source are constructed. Then, the characteristics of the multiple ringing effect, which is an important part of the interference source, are intensively analyzed. Based on the investigation of interference source, an improved interference source synthesis method is proposed. It can quickly and precisely predict the CM and DM interference source with multiple ringing effect, which can be used to achieve accurate frequency domain EMI prediction. Moreover, the multiple ringing effect is extended for IGBT parasitic parameter measuring. Instead of complicated device-level measurement, the grounding capacitance and junction capacitance can be effectively extracted through the ringing frequency measurement.

A $V$ -Band Low-Power Digital Variable-Gain Low-Noise Amplifier Using Current-Reused Technique With Stable Matching and Maintained OP1dB

This article presents a low-power CMOS digitally controlled variable gain low-noise amplifier (VGLNA) at $V$ -band in a 40-nm LP CMOS process. There are three amplifier stages and three digital gain control bits in this VGLNA. The first stage is a common source amplifier, and the second and third stages are current-reused amplifiers. In order to save dc power and control gain, we use the current-reused technique and add the digital switch between upper and lower transistors. Due to constant dc current, the input impedance of the current-reused stage is stable. Output impedance is stabilized by an ac grounding capacitor at the source terminal of the upper transistor under gain switching. Thus, our proposed VGA can minimize the interstage influence with the previous and following stage and maintain OP1dB due to the constant bias current. By adding a resonated inductor to cancel out the parasitic capacitance of switch transistor, we can keep bandwidth and improve noise figure (N.F.) at the current-reused stages under different gain states. The measured peak gain is 19.8 dB at 59.6 GHz, and lowest N.F. is 5.98 at 63.5 GHz. The gain states are 19.8/15.3/11.5/6.5 dB, respectively, and the measured input/output return loss is stable under different gain states. The IP1dB is increased from −29.5 to −17 dBm, and the OP1dB is nearly constant under different gain states. Total dc power consumption is only 18 mW for 1.1-V supplied voltage. This is the first digital current-reused VGLNA that has good FoM among digital VGLNA, the lowest dc power consumption, and compact die area at $V$ -band.

A period-based measurement for grounding capacitance meter with arduino using a relaxation oscillator

This paper focus on the development of a simple and low-cost capacitance measurement for Arduino microcontroller. The working principle of the circuit is based on the period changes of the square-wave signal, which is generated by relaxation oscillator, causes by RC values in the circuit. The relaxation oscillator is based on two different types of op-amp, rail-to-rail and comparator. The output frequency of the oscillator is about 2 kHz to 100 kHz. The range of test capacitors is approximately from 1 pF to 33 pF. The percent error of each type of op-amp due to nonlinearity and parasitic capacitance is presented. Finally, the comparison of the experimental results and theoretical analysis as well as precision LCR meter are investigated and discussed.

Voltage Differencing Gain Amplifier-Based Sinusoidal Quadrature Oscillator Using Only Two Grounded Capacitors

Background: This article describes the circuit construction of the sinusoidal quadrature oscillator using two Voltage Differencing Gain Amplifiers (VDGAs) as active devices. Methods: Since the presented oscillator circuit uses only two external grounded capacitors as passive elements, it is quite suitable for monolithic integration point of view. The condition of oscillation and the frequency of oscillation are non-interactive, and can be controlled electronically by tuning two separate biasing currents. Non-ideal analysis and sensitivity performance are also discussed. Results: The feasibility of the designed oscillator is justified by the PSPICE simulation results based on TSMC 0.35-µm CMOS process parameters. Conclusion: The effects of the VDGA non-idealities on the proposed circuit are also provided, and the computer simulations based on TSMC 0.35-mm CMOS model parameters are included to evaluate the performance of the circuit.

Current-Controlled Current-Mode Quadrature Oscillator Using Translinear Current Conveyors

In this paper, a current-mode quadrature oscillator using second-generation current conveyors (CCIIs) is presented. The proposed oscillator consists of two CCIIs, two grounded capacitors and two grounded resistors. The circuit is suitable for integrated circuit implementation by using grounded capacitors. In addition, a new current-controlled current-mode quadrature oscillator using two current controlled second generation current conveyors (CCCIIs) and two grounded capacitors can be obtained by replacing CCIIs and resistors series at X terminals with CCCIIs. The condition of oscillation and frequency of oscillation can be orthogonally controlled. The frequency of oscillation can be controlled by grounded resistors and external bias currents. The proposed circuits have been simulated by SPICE simulations. The simulation results are confirmed the proposed theory.

Four-plate capacitive power transfer system with different grounding connections

In this paper, a four-plate capacitive power transfer (CPT) system with different grounding connections is studied by taking the mutual coupling between the plates and the ground into consideration. A 4 * 4 mutual capacitance matrix model including the ground capacitances is established to accurately describe the coupling relationship between the four plates and the ground. Based on the proposed model, eight grounding connections are identified for effective power transfer among fifteen theoretically possible combinations. The electric field distribution and system output performance of a typical CPT system with two pairs of parallel plates are simulated for different grounding connections. A practical coupling setup consisting of two pairs of vertically placed parallel 300 mm * 300 mm square aluminum plates is built to verify the modeling and analysis. Both simulation and experimental results show the measured output voltage under different grounding connections are in good agreement with the theoretical results. It has been found that the ground has minimal impact on power transfer when one pair of the coupled transmitter and receiver plates are grounded, and the highest voltage gain and the lowest leakage electric field are also achieved under this grounding connection. However, considering the practicality, grounding one transmitter plate is the most suitable connection.

Insulation Monitoring Method for DC Systems with Ground Capacitance in Electric Vehicles

Owing to the influence of ground capacitance in electric vehicles, in the traditional unbalanced electric bridge DC insulation monitoring (DC-IM) method, the voltage of positive and negative electric bridges changes slowly. To calculate the insulation resistances, sampling should be conducted once the voltage of the bridge becomes stable, that will inevitably extend the monitoring cycle. To reduce the monitoring cycle, this study proposes a three-point climbing algorithm, namely, three-bridge voltage sampling with equal sampling intervals, to predict the evolution of the bridge voltage curve. However, due to the existence of sampling errors, the insulation resistances calculated by sampling values will deviate from the actual values. Then, this article also proposes the filter and correction methods of three sampled voltages to improve monitoring accuracy. Through experimental data, the influences of different parameters on the results are verified, and comparisons with the traditional method are shown in the back. The conclusion is that compared with the traditional method, the proposed method can monitor insulation resistance more quickly and ensure fixed monitoring cycles under different ground capacitance values and keep the similar monitoring accuracy.

Novel Lossless Grounded and Floating Inductance Simulators Employing a Grounded Capacitor Based on CC-CFA

Simulation of inductors has been a very popular area of analog circuit research and the alternative choice for realizing inductor-based circuits in integrated circuits. In this paper, lossless, grounded and floating inductor topologies using current-controlled-current-feedback amplifier (CC-CFA) with single grounded capacitor are presented. The proposed topologies can be tuned electronically by changing the biasing current of the CC-CFA. Two topologies for grounded inductor simulator employ two CC-CFA and one grounded capacitor. One topology for floating inductor simulator employs three CC-CFA and one grounded capacitor. The performance of the grounded and floating inductor simulators are demonstrated on resonant circuits. The theoretical analysis is verified by PSPICE simulation results.

Voltage-Mode First-Order Allpass Filter with Grounded Capacitor and Electronic Controllability

Voltage-Mode First-Order Allpass Filter with Grounded Capacitor and Electronic Controllability

Overcoming the Limits of the Charge Transient Fault Location Algorithm by the Artificial Neural Network

In this paper, two algorithms for single-ended fault location are presented with reference to the unearthed sub-transmission Italian grid (with a voltage level of 60 kV). Both algorithms deal with the correlation between the ground capacitance charging frequency of sound phases and the fault position. In the former, the frequency response of a lumped parameter circuit in the Laplace domain is linked to the fault distance. With such a simplified lumped parameter circuit, the average error in locating a phase-to-ground (PtG) short circuit is 5.18% (total overhead line length equal to 60 km). Since this error is too high, another approach is presented. In this second algorithm, the frequency spectra of the transient current waveforms are used as a database for the training of an Artificial Neural Network (ANN). With this approach, the average error decreases significantly up to 0.36%. The fault location accuracies of the two proposed methods are compared in order to reveal their strengths and weaknesses. The developed procedures are applied to a single-circuit overhead line and to a double-circuit one, both modelled in the EMTP-rv environment, whereas the fault location algorithms are implemented in the MATLAB environment (for the ANN-based algorithm, the Deep Learning toolbox is used).

A New Floating Memristor Based on CBTA with Grounded Capacitors

This paper presents a new floating memristor emulator (FME) consisting of only a single current backward transconductance amplifier (CBTA) as the active element and two grounded capacitors. The proposed FME-based on CBTA enjoys some advantages that include minimum active and passive elements without using an analog multiplier circuit and grounded passive elements which are attractive for the integrated circuit. In addition, excluding the DC power supply voltage, it does not use bias voltage and/or bias current. The designed memristor circuit provides incremental and decremental characteristics without changing circuit topology or using a switching mechanism and it is implemented with a minimum of circuit elements. All simulation results for the memristor emulator were obtained as expected when compared with fabricated memristors.

Decay of plasmonic waves in Josephson junction chains

We study the damping of plasma waves in linear Josephson junction chains as well as in two capacitively coupled chains. In the parameter regime where the ground capacitance can be neglected, the theory of the antisymmetric mode in the double chain can be mapped onto the theory of a single chain. We consider two sources of relaxation: the scattering from quantum phase slips (QPS) and the interaction among plasmons related to the nonlinearity of the Josephson potential. The contribution to the relaxation rate $1/\tau$ from the nonlinearity scales with the fourth power of frequency $\omega$, while the phase-slip contribution behaves as a power law with a non-universal exponent. In the parameter regime where the charging energy related to the junction capacitance is much smaller than the Josephson energy, the amplitude of QPS is strongly suppressed. This makes the relaxation mechanism related to QPS efficient only at very low frequencies. As a result, for chains that are in the infrared limit on the insulating side of the superconductor-insulator transition, the quality factor $\omega\tau$ shows a strongly non-monotonic dependence on frequency, as was observed in a recent experiment.

Shunt Capacitor Banks Online Monitoring Using a Superimposed Reactance Method

A new indicating quantity, named superimposed reactance (SR), is presented in this paper to determine failed capacitor elements’ involved phase and number in shunt capacitor banks (SCBs). The proposed quantity is estimated using available measurements to the unbalance protection function of SCBs numerical protective relays. The proposed SR adopts calibrating factors for element failures online monitoring and can provide live report of the number of failed capacitor elements. The proposed method applications are: faster identifying SCBs faulty units, for fuseless and internally fused designs, and planning preventive/scheduled maintenance for all types of unit designs including externally fused units. With integration of these applications into protection intelligent electronic devices that provide captured and time-tagged event records via communication protocols for HMIs and SCADA systems, outage times would be reduced and smart grids reliability would be improved. The developed algorithm supports three different grounding arrangements, Wye-ungrounded, Wye-grounded via a low ratio current transformer, and Wye-grounded via a grounding capacitor at the SCB neutral point. Comprehensive simulation and fault-location sensing in PSCAD and MATLAB have verified the proposed algorithm performance. Advantages of the proposed method reports over conventional unbalance relaying alarms are also demonstrated using a commercial relay test results comparison.

Analisa Gangguan Arus Lebih Terhadap Kondisi Netral Grounding Resistance Aplikasi PT PLN (Persero) Gardu Induk Lamhotma

The power transformer at the substation serves to deliver power from high voltage to low voltage or vice versa. In the transformer section there is a neutral grounding resistance mounted serially with the secondary neutral on the transformer before connecting to ground / ground that serves to minimize the fault current. One of the disadvantages of the NGR grounding system is when there is a short-circuit one-phase interruption to the ground, the soil disturbance current may be larger than the NGR value limit used. This can cause damage to NGR and other equipment. This study discusses more current fl ows in NGR under normal circumstances with cable channel length 28,215,244 feet and at a 20 kV voltage of ground capacitance with manual calculations obtained Ico = 1.167 A and in case of one-phase disturbance to the ground the greater the current Ig = 4.61 A. To prevent the enlargement of short circuit current one phase of this phase, then the measurement of neutral grounding resistance.

Current Mode Fractional Order Filters Using VDTAs with Grounded Capacitors

Current Mode Fractional Order Filters Using VDTAs with Grounded Capacitors

Current inverting metamutator, its implementation with a new single active device and applications

A new kind of metamutator, namely "Current Inverting Metamutator", its realizations using different types of active blocks and some of its applications like voltage-mode universal biquadratic filter with three input and one output terminals are presented. The proposed circuits can realize all standard filters, namely, low-pass, band-pass, high-pass, notch and all-pass without passive component matching conditions. The proposed circuit offers the features of using grounded capacitors and orthogonal controllability of angular frequency and quality factor. Then a novel realization of metamutator with one active device, additive and differential IC (AD-IC) is proposed and implemented with twelve transistors only. The metamutator with AD-IC has the advantages: (1) of creating new realizations of memristors, capacitance multipliers, inductor simulators, frequency dependent negative resistors which can be used to make IC active filters, (2) less is the number (only one) of active devices, less is the amount of disparity, (3) no need to match passive component values.

Grounded Impedance Simulator Topologies Employing Minimum Passive Elements

In this research three new grounded inductance simulators (GIS) are proposed. In addition, frequency dependent negative resistor (FDNR) and grounded capacitor (GC) simulators are also developed. The voltage differencing current conveyor (VDCC) is utilized in the design. All the developed simulator circuits need a single active block and only two grounded passive components. All the designed simulator circuits are perfectly tunable and did not suffer from passive component matching constraints. To demonstrate the performance of the inductor, FDNR and GC circuits they are employed in designing current mode parallel RLC multifunction filter, low pass third order Butterworth filter and RLC resonance circuits. The VDCC is designed in 0.18μm CMOS technology parameters from TSMC and simulated in P-Spice software to prove the theoretical predictions.

Design of pressure-sensing diaphragm for MEMS capacitance diaphragm gauge considering size effect

MEMS capacitance diaphragm gauge with a full range of (1∼1000) Pa is considered for its wide application prospect. The design of pressure-sensing diaphragm is the key to achieve balanced performance for this kind of gauges. The optimization process of the pressure-sensing diaphragm with island design of a capacitance diaphragm gauge based on MEMS technique has been reported in this work. For micro-components in micro scale range, mechanical properties are very different from that in the macro scale range, so the size effect should not be ignored. The modified strain gradient elasticity theory considering size effect has been applied to determine the bending rigidity of the pressure-sensing diaphragm, which is then used in the numerical model to calculate the deflection-pressure relation of the diaphragm. According to the deflection curves, capacitance variation can be determined by integrating over the radius of the diaphragm. At last, the design of the diaphragm has been optimized based on three parameters: sensitivity, linearity and ground capacitance. With this design, a full range of (1∼1000) Pa can be achieved, meanwhile, balanced sensitivity, resolution and linearity can be kept.