Search

In this paper, jerk function for a transient process of RL circuit is investigated. Some new concepts such as time rate of change of induced emf, time rate of change of displacement current, and Appell function have been introduced for the flrst time in electromagnetic jerky dynamics. The problems on Appell function of several simple models in electromagnetic jerky dynamics are discussed. In the last conclusions and remarks are also presented.

In this paper, structural sound and vibration control using passive and semi-active shunt piezoelectric damping circuits is presented. A piezoelectric patch with an electrical shunt circuit is bonded to a base structure. When the structure vibrates, the piezoelectric patch strains and transforms the mechanical energy of the structure into electrical energy, which can be effectively dissipated by the shunt circuit. Hence, the shunt circuit acts as a means of extracting mechanical energy from the base structure. First, different types of shunt circuits (such as RL series circuit, RL parallel circuit and RL-C circuit), employed in the passive damping arrangement, are analyzed and compared. By using the impedance method, the general modelling of different shunt piezoelectric damping techniques is presented. The piezoelectric shunt circuit can be seen as additional frequency-dependence damping of the system. One of the primary concerns in shunt damping is to choose the optimal parameters for shunt circuits. In past efforts most of the proposed tuning methods were based on modal properties of the structure. These methods are used to minimize the response of a particular structural mode whilst neglecting the contribution of the other modes. In this study, a design method based on minimization of the sound power of the structure is proposed. The optimal parameters for shunt circuits are obtained using linear quadratic optimal control theory. In general, the passive shunt circuit techniques are an effective method of modal damping. However, the main drawback of the passive shunt circuit is that the shunt piezoelectric is very sensitive to tuning errors and variations in the excitation frequency. To overcome this problem, the pulse-switching shunt circuit, a semi-active continuous switching technique in which a RL shunt circuit is periodically connected to a bonded piezoelectric patch, is introduced as structural damping. The switch law for pulse-switching circuit is discussed based on the energy dissipation technique. Compared with a standard passive piezoelectric shunt circuit, the advantages of the pulse-switching shunt circuit is a small required shunt inductance, a lower sensitivity to environmental changes and easier tuning. Very low external power for the switch controller is required so it may be possible to extract this energy directly from the vibration of the structure itself. Numerical simulations are performed for each of these shunts techniques focusing on minimizing radiated sound power from a clamped plate. It is found that the RL series, RL parallel and pulse-switching circuits have basically the same control performance. The RL–C parallel circuit allows us to reduce the value of the inductance L due to the insertion of an external capacity C. However, the control performance will be reduced simultaneously. The pulse-switching circuit is more stable than RL series circuit with regard to structural stiffness variations. Finally, experimental results are presented using an RL series/parallel shunt circuit, RL-C parallel shunt circuit and pulse-switching circuit. The experimental results have shown that the vibration and noise radiation of a structure can be reduced significantly by using these shunt circuits. The theoretical and experimental techniques presented in this study provide a valuable tool for effective shunt piezoelectric damping.

A low voltage detection circuit for a capacitance sensor is important for connection to a low voltage digital circuit interface. We studied two different charge-balanced capacitance–voltage (C–V) conversion circuits configurations; the operational amplifier and the inverter amplifier. Both capacitance detection circuits were designed using 0.35 μm CMOS circuitry technology. Both amplifiers used in the detection circuits were not affected by offset voltage. The current consumption for capacitance detection circuit was reduced from 250 μA at Vdd 3.3 V to 38 μA at Vdd 1.3 V by switching from an operational amplifier to an inverter amplifier. These circuits were packaged with one-side-electrode-type fluid-based inclination sensors on ceramic substrates. The size of the sensor is ∅ 4.0 mm × 1.0 mm and pure propylene carbonate was used as electrolyte. Changes in temperature did not affect the output voltage of the sensor between −10 °C and 50 °C. This results show that the inverter amplifier used in the detection circuit was not affected by offset voltage and the output voltage Vm is depends only on capacitor ratio. The capacitance detection circuit using the inverter amplifier shows a high-sensitivity of about 7 mV/deg over the operational amplifier at Vdd 1.3 V. The response time, resolution and minimum moving angle of sensor were 0.7 s, 0.86° and 0.4°, respectively, at Vdd 1.3 V for the inverter amplifier type of capacitance detection circuit.

In this paper, a formalism to calculate parasitic capacitances on planar coils is proposed. This analysis is based on experimental results through RL circuits where the inductors are coils built in...

To compensate voltage error of the channel selecting filter, a current comparison type voltage tuning circuit is designed. Because the proposed current comparison type voltage tuning circuit is not need to attach another subcircuit, the chip size can be reduced, therefore the proposed circuit is very useful in the low voltage and low power channel filter. We used three channels including bluetooth communication system as application circuits of the proposed tuning circuit. As the results of HSPICE simulation using CMOS technology verify that the proposed tuning circuit respectively can be operated in , and in three channel.

Damping of elastic strain waves in an aluminum bar by means of a pair of piezoelectric members bonded to the bar and loaded by an external RL circuit is studied. Experimental results are compared with theoretical results based on a three-port impedance model for the laminated piezoelectric bar element (PBE). According to this model, the PBE is viewed as a linear system with one electrical and two mechanical ports at which interactions with external devices, e.g., the external parts of the aluminum bar, can take place. The two constitutive equations of the piezoelectric material, the dynamics of the piezoelectric members and the bar, and the dynamics of the resistive-inductive load are taken into account. The experimental results are below the theoretical ones by a few percent for the reflected and transmitted strain waves, by 6–11% for the voltage and current generated, and by 12–19% for the power and energy delivered to the load. This indicates that there are energy losses in the PBE and the external parts of the bars that have not been accounted for in the model. Such losses may be due to, e.g., viscoelastic shear, dielectric losses and generation of bending waves.

This paper describes a novel high-Q active inductor circuit configuration composed of an operational transconductance amplifier (OTA) and an input RC network. Due to the phase rotation made by the input RC network, the active inductor circuit provides high-Q inductive impedance at higher frequencies. According to circuit simulation with design-kit of a 90-GHz-fT SiGe HBT technology, an inductance of more than 0.53nH and Q of more than 80 can be obtained at quasi-millimeter-wave frequency, 24GHz. The Q value is tunable by controlling the transconductance of the OTA. These features are also ensured by means of measurements of fabricated active inductor circuit. Since the active inductor circuit needs small chip area, which is 25% of a conventional passive inductor, the proposed active inductor contributes to implement a cost-effective high-Q notch filter for frequencies up to quasi-millimeter-wave frequencies.

This paper proposes a low power and high speed track and hold circuit (T/H circuit) based on the two-stage structure. The proposed circuit consists of two internal T/H circuits connected in cascade. The first T/H circuit converts an input signal into a step voltage and it is applied to the following second T/H circuit which drives large load capacitors and consumes large power. Applying the step voltage to the second T/H circuit prevents the second T/H circuit from charging and discharging its load capacitor during an identical track phase and enables low power operation. Thanks to the two-stage structure the proposed T/H circuit can save 29% of the power consumption compared with the conventional one. An optimum design procedure of the proposed two stage T/H circuit is explained and its validity is confirmed by HSPICE simulations.

WOS: 000255999900002, A novel current controllable floating or grounded inductor simulator circuit with minimum elements is proposed. The circuit uses two dual output- second generation current controlled conveyors (DO-CCCIIs) with parasitic resistance at terminal X and one grounded capacitor externally connected. Proposed circuit is suitable for fully integrated circuit design. Analysis and simulation results are included.

A pulsed operating mode of a piezoelectric plate is considered in different variants of connection of RL circuits. Water serves as an acoustic load. Calculations are performed taking into account the internal impedance of an electric generator. The optimal values of the parameters that ensure the minimum pulse duration are determined.

In this paper, a linearized small-signal model for a six-pulse HVDC system is presented. In this paper, the effects of on and off states resistances, forward voltage drop, and snubber circuits of the thyristors and filter circuits are taken into account. RL series circuits are used for modeling of the converter transformer and ac system. To validate the model developed in this paper, a comparison is made with the PSCAD/EMTDC time-domain simulation program.

A power-efficient Dickson-based charge pump circuit is proposed and verified in this paper. Using a PMOS transfer switch in the new circuit solves the problem of the output voltage loss and its body control switch can suppress the parasitic bipolar action. Comparing this new one with the conventional circuit, the new circuit generates output voltage as high as 2.9VDD while the conventional one only 2VDD. For their efficiency values, the new circuit has better efficiency than the conventional one by as much as 14.5% with the area overhead of 12.2% using 3.5-μm and 40-V CMOS high-voltage process.

Generic and process-independent equivalent circuit model for simulating the performance of spiral inductor used in monolithic microwave integrated circuit design on gallium-arsenide substrate is presented. New formulas for the series inductor and feedback capacitor are presented. The experimental verification shows the proposed scalable model can be used as the prediction and optimization of spiral inductor performance.

Distributed circuit parameter extraction from field result of non-uniform transmission line provides circuit designers an efficient way to predict the effect of non-uniform structures. The motivation of this paper is to study the efficiency and applicability of the extracted distributed circuit parameters. These parameters are extracted from the FDTD results in this paper and are used to construct an equivalent circuit. Exciting the circuit with Gaussian pulse and using the equivalent circuit method, the transmitted and reflected pulse waveforms on the circuit can be obtained. By comparing these waveforms and the corresponding frequency domain S parameters with those obtained directly from FDTD, the applicable scope of the extracted circuit parameters can be studied.

A new wide input range square-rooting circuit is presented. The proposed circuit consists of a dual translinear loop, an absolute value circuit, and current mirrors. A current-mode technique is used to provide wide input range with simple circuitry. The output signal of the proposed circuit is the current which is proportional to the square root of input current. The proposed square-rooting circuit was confirmed by using PSpice simulator program. The simulation results demonstrate that the proposed circuit provides the excellent temperature stability with wide input current range.

An effective technique for determination of the circuit parameters in the air core inductor lightning impulse test is presented. The air core inductor is a specific test object affecting the test waveform of which the time to half is often shorter than the standard requirement. To increase the time to half, Glaninger's circuit was introduced by connecting the additional circuit parameters, i.e. the additional inductor and resistor. In order to select the additional circuit parameters and obtain the lightning impulse voltage waveform according to the standard requirement, it is necessary to precisely determine the other test circuit parameters, i.e. the front time resistance, the tail time resistance, parasitic series inductance, and load impedance composing of load resistance, load capacitance, and load inductance. In this paper, the matrix pencil method is employed to determine the circuit parameters by using the recorded waveform from the preliminary experiment. With the known circuit parameters, the additional circuit parameters can be searched to obtain the standard lightning impulse voltage waveform. The proposed method has been verified by some simulation and experimental cases successfully. The proposed technique is very useful in the lightning impulse voltage test of an air core inductor and helps test engineers in design appropriate circuit impedance without a trial and error approach.

The output voltage of small wind driven generator presented non-cyclical fluctuation affected by wind speed, which then leads to unstable accumulator charging voltage. In order to improve charging efficiency and prolong accumulator's service life, this paper designed a steady voltage circuit based on UC3842. It is mainly composed by rectifier filter circuit, Buck chopper circuit and post-processing circuit. With wind power variation, the duty ratio of PWM wave outputted by UC3842 is changing accordingly. Then, the circuit will output steady voltage to charge accumulators. This design is characterized by simple circuit, relatively low cost and convenient maintenance etc.

In this study, the system was designed for monitoring the voltage condition of each battery’s cell. The method used in this study is by using passive shunt resistor balancing method. An electronic circuit was designed in order to balance the value of the able voltage at the battery cells using resistors and then to remove the excess voltage. The result showed that the electrical circuit was capable to balance the voltage of each cell. Based on experiment with several values of load, it is can concluded that 0.1C rate of discharge has the best performance, because it does not affect battery voltage characteristic significantly which leads to better sensor reads.

This paper introduces a novel current-mode biquadratic circuit using plus type differential voltage current conveyors (DVCCs) and grounded passive components. The circuit is constructed with two plus type dual current output DVCCs (DO-DVCCs), two grounded capacitors and two resistors. The circuit can realize multiple circuit transfer functions by choosing the appropriate input and output terminals. Additionally, the circuit parameters Q and ω 0 can be set orthogonally by adjusting the passive components. The biquadratic circuit enjoys very low sensitivities to the circuit components. An example is given together with simulated results by PSPICE.

A compact active inductor circuit is proposed. The circuit is based on the gyrator-C approach with both transconductance stages realized by MOS transistors in common-source configuration. The circuit has minimal number of transistors, is suitable for low voltage operation, offers a wide inductive band, high quality factor and low power dissipation. Simulation results are provided for a 0.13 μm CMOS process with 1.2 V supply voltage.

A new methodology for the representation of a transformer winding or any set of magnetically coupled coils by means of an equivalent circuit is presented in this paper. This circuit is suitable for the representation of the frequency-behavior of a system of coils at high frequencies and it consists of RL coupled circuit elements. The frequency-behavior representation of the actual impedances is accomplished by means of additional RL loops. Therefore, the circuit synthesis theory takes a step beyond the RL Foster or Cauer equivalent circuits, which were developed to represent only a single inductive element. Starting from the proposed equivalent circuit, the matrix equation of the system of coupled inductive branches is derived and their equivalence with the characteristic equations of the real system is proved. Finally, the method is applied to the modeling of transformer windings.

Electromagnetic launch systems consist of pulsed power, rectification, and launch components. The finite-element (FE) code EMAP3D is used to compute the fields diffusing into sliding electrical contact launch components using quasi-static field equations. FE analysis of the entire launch system, though not impossible, would be a time-consuming process not worth the effort. Circuit theory based on lumped parameters is better suited for the analysis of some of the electrical components such as the generator, rectifier, power conditioning, and delivery components. Circuit theory becomes almost inevitable when one seeks to maximize the power delivered to launch components through impedance tuning techniques. Hence, one is inclined to look at ways of analyzing entire launch systems applying circuit theory to some components and FE analysis to others where detailed fields are required. An algorithm to couple an external circuit with an applied potential difference and prescribed resistances and inductances with a simple railgun is presented in this paper. The railgun is analyzed using EMAP3D. The external circuit is treated using circuit theory. Continuity of current and potentials is maintained through iterative calculations matching the currents and potentials between the circuit and the railgun. The advantages of this algorithm are that it treats the components using circuit theory and field theory separately and shows rapid convergence

A sub-1-V nanopower full CMOS voltage reference circuit was proposed in TSMC 0.18μm CMOS process in this paper. The circuit consists of a self-regulating technique circuit, a proportional to absolute temperature (PTAT) current circuit and active load circuit. In order to reduce power consumption and save area of the chip, the proposed circuit contains only MOSFETs, avoiding the use of resistors. Cadence Spectre simulation results show that the temperature coefficient of the output voltage was 66.9 ppm/°C in a range from −40 to 120 °C, and the line sensitivity was 197.5 ppm/V in a supply voltage range of 1–3 V Meanwhile, the power supply rejection ratio (PSRR) of the voltage reference achieved −93.22 dB@DC and −15.45 dB@10MHz, and the proposed circuit merely consumed 0.23 μW of power at room temperature. Our proposed circuit would be suitable for use in subthreshold-operated and power-sensitive large scale integrated circuit.

A new type of Class DE inverter is proposed. The proposed circuit consists of two switches, a parallel resonant circuit, and a capacitor connected in series with the parallel resonant circuit. The proposed circuit shows two features mainly. First, the voltage stress of the switching devices is low. Second, the switch voltage and its derivative are zero at the switch turning on, therefore, the proposed circuit reduces switching losses. In the circuit experiments of the proposed circuit, the measured efficiency of the dc/ac power conversion was 93.2 % at the loaded quality factor Q = 5, the switching frequency 500 kHz, and the output power 0.336 W. The experimental results show good agreement with the theoretical performance.

The dc-dc converters which are suitable for the fuel cell need high boost ability, low input current ripple, and small size. As one of the dc-dc converters having the three characteristics, interleaved soft-switching multilevel boost converter is proposed. This circuit is composed of two multilevel boost converter parts and an auxiliary inductor. By the auxiliary inductor, the switches can achieve low voltage switching. However, this circuit has a disadvantage of employing many circuit component. This paper proposes interleaved soft-switching multilevel boost converter with coupled inductor. The proposed circuit reduces the number of circuit components by coupling the two inductors in interleaved soft-switching multilevel boost converter. Additionally, since the leakage inductance takes a role as the auxiliary inductor of the conventional circuit, the proposed circuit realizes the smaller size and the lower cost. Furthermore, the proposed circuit achieves half the input current ripple of the conventional circuit. The operational principle of the proposed circuit has been confirmed by analysis and reduced scale circuit experiment in steady-state.

The standard method for controlling an IGBT inverter (or any VSC inverter for that matter) is by vector current control. This control system consists of two cascaded control loops. One possible realisation of the outer controller is to control the DC bus voltage such that no more power is taken off the DC bus than is available. This creates a current reference, which is fed into the inner current controller. The inner current controller then regulates the current passing through the IGBT such that the desired power is dispatched onto the grid. Whilst most research treats the grid connection as a simple RL circuit, there is little consistency on the method by which the gains of the inner current controller are selected. Internal model control, modulus optimum and root locus methods are just a few of the methods used to find the gains. However, it is not clear which of these methods yields the best performance of the inner current controller. This work suggests that tuning on phase margin or manually tuning may not achieve the best results.

For the capacitance signal of capacitive sensor output is tiny, a capacitive sensor detection circuit is designed to solve the problem of hard measuring. Its sensitivity is 1V/pF. The design of noise suppression circuit is added, making the output DC voltage signal more stable. The detection circuit includes a sine wave generator circuit, a differential amplifier circuit, a band-pass filter circuit, a peak detector circuit and a low-pass filter circuit. The frequency of sine wave excitation signal is 20 kHz, peak to peak 20 V. Experimental results show that the measurement accuracy of the detection circuit is high, and the output is stable. It can meet the requirements of capacitive sensor.

In this paper, we design a dynamic voltage balancing circuit between the super capacitor module which is suitable for electric vehicle charging station. The voltage balancing circuit using the energy transfer for the purpose of the voltage balance. Through the 'peak load shifting' way, achieve all the super capacitor unit voltage relative equilibrium. This equalization circuit compared with the existing voltage balancing strategy, each super capacitor unit can implement automatic equalizing, simplify the circuit. Power conversion device in the circuit realize zero current switching, reduce the circuit loss. At the same time through the voltage balancing circuit calculation analysis, get the main factors influencing the performance of circuit, in order to carry out the parameter design for the circuit. Simulation and experimental results show that the equalization circuit has good balancing effect.

A circuit topology for a bi-directional isolated DC-DC converter and its operation are proposed and evaluation results are discussed. This converter is based on a voltage-source primary circuit and a current-source secondary circuit with an active clamp circuit. To decrease the lower limit of the input voltage for a large voltage range, the proposed topology uses a “small boost circuit” consisting of only a boosting capacitor and a switch on the secondary side. Only when the input voltage is decreased, the switch is kept in the on-state and the secondary voltage is boosted by using transformer series inductance. A 2-kW prototype converter, which has a previously proposed control and the new small boost circuit of the proposed topology, decreased the input voltage lower limit from 289 to 267 V under maximum output conditions.

We investigate the effect of piezoelectric (PZT) material on the flutter speed, vibration mode and frequency, and energy harvesting power and efficiency of a flexible flag in various fluids. We develop a fully coupled fluid-solid-electric model by combining the inviscid vortex sheet model with a linear electro-mechanical coupling model. A resistance only circuit and a resonant resistance-inductance (RL) circuit are considered. For a purely resistive circuit, an increased electro-mechanical coupling factor results in an increased flutter speed, vibration frequency, averaged electric power and efficiency. A consistent optimal resistance is found that maximizes the flutter speed and the energy harvesting power. For a resonant RL circuit, by tuning the inductance to match the circuit frequency to the flag's vibration frequency, the flutter speed can be greatly decreased, and a larger averaged power and efficiency are obtained. We also consider a model scale set-up with several commonly used commercial materials for operating in air and water. Typical ranges of dimensionless parameters are obtained for four types of material that span a wide range of solid density and rigidity values. We find that the resistance only circuit is more effective when the flag is placed in a lighter fluid (e.g. air), while the RL circuit is able to reduce the flutter speed when the flag is placed in a heavier fluid (e.g. water).

From the viewpoint of electric circuit theory, the three fundamental two-terminal passive circuit elements, resistor R , capacitor C, and inductor L, are defined in terms of a relationship between two of the four basic circuit variables, charge q, current i, voltage v, and magnetic flux φ. From a symmetry concern, there should be a fourth fundamental element defined from the relationship between charge q and magnetic flux φ. Here we present both theoretical analysis and experimental evidences to demonstrate that a two-terminal passive device employing the magnetoelectric (ME) effects can exhibit a direct relationship between charge q and magnetic flux φ, and thus is able to act as the fourth fundamental circuit element. The ME effects refer to the induction of electric polarization by a magnetic field or magnetization by an electric field, and have attracted enormous interests due to their promise in many applications. However, no one has linked the ME effects with fundamental circuit theory. Both the linear and nonlinear-memory devices, termed transtor and memtranstor, respectively, have been experimentally realized using multiferroic materials showing strong ME effects. Based on our work, a full map of fundamental two-terminal circuit elements is constructed, which consists of four linear and four nonlinear-memory elements. This full map provides an invaluable guide to developing novel circuit functionalities in the future.

The traditional AC-DC power switching supplies often use the diode rectifier, due to the presence of the large filter capacitor and the switching devices, the power factor of the circuit is usually low, and the harmonic pollution in the grid side is serious. To solve the problem, a method that cascades a PFC (power factor correction) circuit is generally used, however, this increases the circuit stages, which not only reduces the circuit efficiency, but also causes the circuit structure and the control strategy more complex. In this paper, we study a kind of LLC resonant AC-DC converter circuit with PFC function based on a double inductor structure circuit, which can realize the single-stage power conversion and improve the power transmission efficiency. The characteristics of the circuit can achieve the conventional LLC resonant conversion, which ensures the switching devices working in soft-switching mode. And the double inductor structure PFC circuit, using interleaving methods, can better overcome the harmonic distortion problem in the input current in the traditional single-stage PFC AC-DC circuit. In this paper, the theoretical analysis and simulation of the circuit topology are given out, and the experimental results verify the correctness of the theoretical analysis, it also proves that the circuit can both have a good PFC and a AC-DC transform function.

In this paper, we present a novel method to develop wideband scalable inductor models that are accurate over a large dimensional space. We use a modified double-π topology for the inductor equivalent circuit model. The circuit element values are computed using empirical functions which are formulated using inductor geometries and numerical coefficients. Values of the coefficients are extracted from electromagnetic simulation data over a large inductor geometrical space. A neural network model is trained to learn the relationship between the geometrical dimensions and coefficients. The model has been developed and tested in integrated circuit process technology. Result shows that the model is very accurate over a large geometrical space and frequency range. The technique is general and is applicable to other passive components model development.

Power system operates close to its operational limit to achieve a higher level of utilization of the grid infrastructure. As a result, its transient behavior is of great importance to prevent violation of the operation limits. This paper proposes an internal model control (IMC)-based approach for voltage-sourced converters (VSC) to improve their dynamic behavior. This IMC controller is designed based on a detailed model of the VSC. The proposed control approach has superior performance, i.e., faster step response and less overshoot, and higher axes decoupling than the conventional dq-current control method. The proposed IMC-based controller has a straightforward design procedure, and can be implemented using simple PI and PID controllers. Several case studies are presented to evaluate and compare the transient performance of the IMC-based controller with conventional dq current control subsequent to step changes in the set points of direct and quadrature axes current, single-phase fault, and three-phase fault.

Circuit model for TSV-based solenoid inductors is presented and investigated. Based on the measurement, the related lumped circuit elements can be extracted, and they are independent of the operating frequency by virtue of the RL ladder. Hence, the circuit model is compatible with the SPICE simulators. Based on the circuit model, the impacts of design parameters on the quality factor and inductance are studied. Finally, the frequency-thermal analysis of TSV-based solenoid inductors is carried out.

A circuit architecture modelling rate-independent hysteretic phenomena is presented and discussed. The core of the circuit is a ladder structure with longitudinal nonlinear resistors and transverse linear capacitors. In a separate loop, a linear combination of input and capacitor voltages provides the driving voltage for a resistor with monotonic, piecewise-linear driving-point characteristic. The resistor current represents the output variable. The circuit parameters can be found from experimental data through a standard quadratic programming optimization procedure. The model fitting features are tested by using two experimental data sets. One is the B(H) function of a magnetic material; the other is the deformation of a piezoelectric actuator as a function of the applied voltage. In this last case, an accurate comparison with the predictions of the well-known Preisach model evidences that the circuit model achieves the same accuracy with a much smaller number of parameters. All the circuit simulations are performed by using PSPICE.

A new four-quadrant multiplier circuit is presented in this paper. Compared to the corresponding already published works, the accuracy of the circuit as well as the linearity performance is significantly improved. DC transfer characteristic of the circuit shows the nonlinearity error of 1.1% over a considerable range of the inputs. The performance of the circuit, in terms of the conceivable mismatch in trans-conductance parameter and threshold voltage are thoroughly analyzed. The circuit is simulated using HSPICE with TSMC level 49 (BSIM3v3) parameters for 0.18 μm CMOS technology, where under supply voltage of 1.8 V the −3 dB bandwidth of the proposed circuit is 1.45 GHz and the total harmonic distortion at 1 MHz, remains as low as 0.4 %.

A graphical/numerical technique is presented for the extraction of roots (poles and zeros) of RC and RL circuits, where the roots lay on the real axis in the s-plane. The method constructs a corresponding LC circuit for the RC or RL circuit, and as demonstrated, all real axis roots are shifted to the jω axis, where the swiping-frequency signals exit. The process takes place in two steps: in the first step the roots in the real axis RHP (RRHP), if any, are mirrored to the real axis LHP (RLHP), and in the second step the roots on the RLHP are moved to the jω axis. It is also shown that the magnitude of the corresponding roots in the two circuits, RC (or RL) and the corresponding LC, relate by a scaling factor log(ω C ) = log(ω R )/2.

A planar transformer circuit derived from a unified CPW mode is presented. The elements of the model are calculated directly from the equations for CPWs and the transformer geometries. The substrate eddy current losses and coupling with the transformer lines are modeled by RL network structures and mutual inductances. One turn planar transformers have been designed and fabricated on various resistivity substrates. A good agreement is obtained between the measurement and the equivalent circuit. This work demonstrates the application of the unified model for transformers.

This paper presents a newly proposed T-model of spiral inductors in 90nm radio frequency (RF) CMOS technology. Inductor modeling is one of the most difficult problems facing silicon-based RF integrated circuit designers, and the inclusion of many parameters of the inductor equivalent circuit consumes a lot of time during circuit simulation. In this paper, two models of spiral inductors were simulated to compare their agreement with the measured data from 100MHz to 10GHz. The proposed T-model had less parameters than the conventional double-π model, and also showed good agreement in the RF performance of the spiral inductors, such as quality factor (Q-factor) and inductance (L). In addition, the proposed T-model had an error rate of less than 5% with the S-parameter of measured data, similar to the double-π model.

A piezoelectric plate with a series or parallel correcting RL circuit connected to the input is considered. The transducer is excited by a half-sinusoidal electric voltage pulse at the eigenfrequency of the plate. The calculated possibility of reducing the duration of an acoustic pulse is compared for each type of correcting-circuit connection to a probe radiating into a liquid or a solid. In each case, the optimal (in view of the shortest radiated pulses) parameters that characterize this radiating system are determined and the durations and amplitudes of the radiated acoustic pulses are estimated.

We demonstrated high-speed data transmission from a superconducting front-end circuit to a semiconductor back-end circuit for an analog-to-digital converter. In this study, the front-end circuit consisted of a 1–4 demultiplexer and four-channel stacked-type amplifiers. The back-end circuit consisted of low noise amplifiers and decision circuits. In the front-end circuit, data distribution at a frequency of 10 GHz and amplification of four-channel data signals at 2.5 GHz were performed and an output voltage of 4.2 mV was obtained. In the back-end circuit, data decision at 2.5 GHz was successfully performed at an error rate below 10−6. These results enable us to operate the whole A/D converter at sampling frequency of 10 GHz and evaluate its performance, including the bit accuracy.

Piezoelectric elements connected to shunt circuits and bonded to a mechanical structure form a dissipation device that can be designed to add damping to the mechanical system. Due to the piezoelectric effect, part of the vibration energy is transformed into electrical energy that can be conveniently dissipated. Therefore, by using appropriate electrical circuits, it is possible to dissipate strain energy and, as a consequence, vibration is suppressed through the added passive damping. From the electrical point of view, the piezoelectric element behaves like a capacitor in series with a controlled voltage source and the shunt circuit, commonly formed by an RL network, is tuned to dissipate the electrical energy, more efficiently in a given frequency band. It is important to know that large inductances are frequently required, leading to the necessity of using synthetic inductors (obtained from operational amplifiers). From the mechanical point of view, the vibration energy can be attenuated in a single mode, or in multiple modes, according to the design of the damping device and the frequency band of interest. This work is devoted to the study of passive damping systems for single modes or multiple modes, based on piezoelectric patches and resonant shunt circuits. The present contribution discusses the modeling of piezoelectric patches coupled to shunt circuits, where the basics of resonant shunt circuits (series and parallel topologies) are presented. Following, the devices used in passive control (piezoelectric patch and synthetic inductors) are analyzed from the electrical and experimental viewpoints. The modeling of multi-degree-of-freedom mechanical systems, including the effects of the passive damping devices is revisited, and, then a design methodology for the multi-modal case is defined. Also, it is briefly reviewed the optimization method used for design purposes, namely the LifeCycle Model. Finally, experimental results are reported, illustrating the success of using the methodology presented in passive damping applications applied to mechanical and mechatronic systems.

While piezoelectric actuators have been widely used in vibration suppression and high precision controls, their intrinsic nonlinearity such as hysteresis, if not considered in control design, may deteriorate the system performance. In this research, a new methodology is proposed for the high-precision and robust control using piezoelectric actuator with hysteresis compensation. This methodology is featured by the introduction of a resistance/inductance circuit connected to the piezoelectric actuator to form an actuator network and a new integral continuous sliding mode control (ICSMC) algorithm. In addition to the well-known increased passive damping and active control authority, the main advantage of the actuator network in this particular study is that the charge and/or current in the piezoelectric actuator now become independent state variables that can be directly measured and fed back. Not only can this actuator network configuration improve the hysteresis characterization, the control design can also be greatly simplified. With the introduction of the RL shunt circuit, two dynamic subsystems (the mechanical structure and the electrical circuit) are formed. With these two coupled dynamic subsystems as basis, we then develop an ICSMC scheme which combines the advantages of conventional continuous sliding mode control and integral variable structure control. Different from the inverse cancellation of hysteresis behavior which might not be reliable due to the measurement noise, a direct piezoelectric hysteresis compensation is achieved using this control strategy. Detailed analysis and case studies demonstrate that this new methodology can lead to improved precision for both tracking control and vibration attenuation, enhanced control robustness, and smoother control action.

Based on the field-circuit equivalence concept, the equivalent circuit to analyze the voltage distribution of a 500-kV dc transmission-line voltage divider under impulse voltages has been developed. The hybrid finite-element analytical approach is applied to extract the capacitance and inductance parameters of the equivalent circuit, and the Milne method is used to solve this complicated circuit. The voltage distribution along the resistor coils of the divider under impulse voltages is calculated and its nonuniformity is discussed. The analysis results are in good agreement with the measurement results. The selection of capacitors parallel with the resistor turns to improve the voltage distribution along the resistor coils is studied, and the optimal selection of these capacitors is suggested.

This letter proposes a voltage drop by current (IR drop) and threshold voltage compensation pixel circuit, in which the power line is eliminated. The proposed circuit provides a larger fill factor than the conventional one because the circuit does not use a VDD line but instead utilizes the scan line as a power line. The proposed pixel circuit was verified using both circuit analysis and circuit simulations. The proposed circuit could increase the aperture ratio and compensate for the IR drop and threshold voltage variations in active matrix organic light-emitting diode devices, where I and R are current and resistance of the supply power lines. Using the proposed pixel circuit, a large fill factor with both IR drop and threshold voltage compensation was achieved.

To realize the tap coefficient of a finite impulse response(FIR) filter or the twiddle factor of a fast Fourier transform(FFT) using a current-mode analog circuit, a high accurate current-attenuator circuit is needed This paper introduces an accuracy enhancement technique in the current-mode signal processing. First of all, the DC of set-current error in a conventional current-attenuator using a gate-ratioed orient mirror circuit is analyzed and then, the current-attenuator circuit with a negligibly small DC offset-current error is introduced. The circuit consists of N-output current mirrors connected in parallel with me another. The output current of the circuit is attenuated to 1/N of the input current. On the basis of the Kirchhoff current law, the current scale ratio is determined simply by the number of the current mirrors in the N-current mirrors connected in parallel. In the proposed current-attenuator circuit the scale accuracy is limited by the ac gain error of the current mirror. Considering that a current mirror has a negligibly small ac gain error, the attainable maximum scale accuracy is theoretically -80[dB] to the input current.

Two a-Si thin-film transistors (TFTs) demultiplexer circuits, resistive load (RL) and complementary-like logic (CLL), are proposed and compared with the conventional pass transistor logic (PTL) demultiplexer circuit. Analytical and experimental results indicate that the proposed RL and CLL demultiplexers outperform the PTL circuit by providing larger output voltage swings (OVSs), faster dynamic responses, and less OVS sensitivities to the device instability. The pulse-bias stress experiments, simulating the normal condition of operation, are conducted both on individual a-Si TFTs and a-Si TFT demultiplexer circuits, and the variations in device/circuit electrical characteristics are measured during 12 h. The measurement results indicate that the OVS degradation of proposed circuits can be limited to 7 mV/h, suggesting a long circuit lifetime.

Here we present our studies of first- and second-order superconducting low-pass sigma-delta modulators with the filtering function realized using an RL-circuit. These modulators have been simulated for different circuit parameters using device level simulations. A linear discrete time model of the first-order modulator has been done. Simulations of the first-order sigma-delta modulator operating at an oversampling ratio of 128 and a bandwidth of 60 MHz give a maximum SNR of 70 dB using a resistance of only 1 m/spl Omega/. The SNR dependence on the parameters of the RL-filter is well predicted by the linear model. Some circuit parameters give however rise to harmonic distortions which can not be predicted by the simple linear model. Under the same conditions, the performance of second-order sigma-delta modulators was found to have a maximum SNR of only 82 dB. We conclude that the estimated upper bound on SNR for superconducting RL-filtered low-pass sigma-delta modulators, is for physical realizable circuits not high enough to give an advantage over other techniques.