RLC Equivalent Circuit Research Articles

Rectangular spiral coil analysis for inductively coupled RFID systems based on Partial Element Equivalent Circuit method

In order to achieve maximum power efficiency with inductively coupled RFID tags, the impedances of the spiral coil and the integrated circuit must be matched to each other. In this paper, we present a numeric approximation of the impedance of a rectangular spiral coil by means of a coupled electromagnetic and circuit analysis called Partial Element Equivalent Circuit method and verify our simulation with measurement results. We include the effective permittivity in our 3D capacitance extraction method and fit the simulated impedance to a simple RLC equivalent circuit model which is also used by our measurement device and compare the resulting element values. Our Matlab-based simulator shows good agreement over the frequency band of interest and allows for optimization for various design goals.

Resonant RF network antennas for large-area and large-volume inductively coupled plasma sources

Large-area and large-volume radio frequency (RF) plasmas are produced by different arrangements of an elementary electrical mesh consisting of two conductors interconnected by a capacitor at each end. The obtained cylindrical and planar RF networks are resonant and generate very high RF currents. The input impedance of such RF networks shows the behaviour of an RLC parallel resonance equivalent circuit. The real impedance at the resonance frequency is of great advantage for power matching compared with conventional inductive devices. Changes in the RLC equivalent circuit during the observed E–H transition will allow future interpretation of the plasma–antenna coupling. Furthermore, high power transfer efficiencies are found during inductively coupled plasma (ICP) operation. For the planar RF antenna network it is shown that the E–H transition occurs simultaneously over the entire antenna. The underlying physics of these discharges induced by the resonant RF network antenna is found to be identical to that of the conventional ICP devices described in the literature. The resonant RF network antenna is a new versatile plasma source, which can be adapted to applications in industry and research.

(Invited) Equivalent Circuit Representation of Resonant Accelerometer

The equivalent RLC circuit for the resonant accelerometer isdescribed in detail, which shows that equivalent circuit containstwo variable capacitances and two variable resistances due to theacceleration and amplitude. Using the electromechanical couplingfactor presented here and the mode function of the transversedeflection vibration of the double clamped beam, the equivalent circuit parameters related to the size of the accelerometer and thedrive voltage are derived. In short, the mechanical and electrical parameters of the resonant accelerometer can be calculated andanalyzed accurately by the formulae derived in this paper.

EQUIVALENT LUMPED-ELEMENT CIRCUIT OF APERTURE AND MUTUALLY COUPLED CYLINDRICAL DIELECTRIC RESONATOR ANTENNA ARRAY

This paper presents an electrical model of aperture and mutually coupled three-elements cylindrical dielectric resonator antenna (CDRA) array designed for 802.11a system applications. In electrical model, each antenna component is represented by its equivalent RLC circuit. The advanced design system (ADS) software is used to build the electrical model and predict the behavior of return loss, while the antenna structure is simulated using CST microwave studio before fabrication. The flrst and last radiating elements of the proposed array are excited through the aperture slots while the middle element is excited through the mutual coupling of its neighboring elements. The slot length and inter-slot distance efiects on bandwidth are comprehensively analyzed and presented. The maximum gain of the proposed array for 5.0GHz band is about 10.8dBi, and the achieved simulated (CST, ADS) and measured impedance bandwidths are 1.076GHz, 1.0GHz, and 1.2GHz respectively. The proposed CDRA array antenna exhibits an enhancement of the gain (7.4%) and bandwidth (93.3%) as compared to a literature work with aperture slots. In this study, it is also observed that by using the mutual coupling instead of third slot to excite the middle CDRA, side lobe levels are also reduced signiflcantly over the entire 5.0GHz band.

The Behavior of MFIE and EFIE at Interior Resonances and Its Impact in MOT Late Time Stability

In the vicinity of a certain interior frequency, the current density on the surface of a perfect electric conducting scatterer, when illuminated by an incident field, is divided into two parts: an induced surface current caused by the incident field and a resonance surface current associated with the interior resonance mode. Equivalent RLC circuit models are proposed respectively for PEC scatterers associated with the electric field integral equation (EFIE) and the magnetic field integral equation (MFIE). Using the circuit models, together with the power conservation law, the different behavior of the resonance surface currents associated with EFIE and MFIE is analyzed and checked with numerical examples in two-dimensional space. It is shown that the interior resonance behavior has significant influence on the late time stability associated with time domain EFIE and MFIE.

The Study of Equivalent Circuit for Vibrating-Beam-Type Resonant Accelerometer

Based on the equivalent simplified model of the vibrating beam, the equivalent RLC circuit of vibrating-beam-type resonant accelerometer is described in detail, which shows that equivalent circuit contains a variable capacitances and a variable resistances due to the acceleration. Using the electromechanical coupling factor presented here and the mode function of the transverse deflection vibration of the double clamped beam, the equivalent parameters of the accelerometer with the size of the beam and comb are derived. These results are the bases of designing the drive /sense circuit of the vibrating-beam-type accelerometer.

Design of compact low‐pass filter with large reject band using open circuit stubs and two‐cascaded DGS quasitriangular resonators

AbstractThis article investigates a quasitriangular of defected ground structure (DGS) for low‐pass filters (LPFs) application. An equivalent RLC circuit model is presented and its corresponding parameters are as well extracted using the parametric relationships. The LPFs using the proposed DGS pattern combined with open stubs are designed and fabricated. The proposed LPF presents the advantages of small size, low insertion loss and ultrawide stopband with 20 dB attenuation from 4 GHz to >20 GHz. The simulated results obtained by equivalent circuit model and full‐wave electromagnet show good agreement with the measured ones. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:122–127, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27260

Tunable High-Q N-Path Band-Pass Filters: Modeling and Verification

A differential single-port switched-RC N-path filter with band-pass characteristic is proposed. The switching frequency defines the center frequency, while the RC-time and duty cycle of the clock define the bandwidth. This allows for high-Q highly tunable filters which can for instance be useful for cognitive radio. Using a linear periodically time-variant (LPTV) model, exact expressions for the filter transfer function are derived. The behavior of the circuit including non-idealities such as maximum rejection, spectral aliasing, noise and effects due to mismatch in the paths is modeled and verified via measurements. A simple RLC equivalent circuit is provided, modeling bandwidth, quality factor and insertion loss of the filter. A 4-path architecture is realized in 65 nm CMOS. An off-chip transformer acts as a balun, improves filter-Q and realizes impedance matching. The differential architecture reduces clock-leakage and suppresses selectivity around even harmonics of the clock. The filter has a constant <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$-$</tex></formula> 3 dB bandwidth of 35 MHz and can be tuned from 100 MHz up to 1 GHz. Over the whole band, IIP3 is better than 14 dBm, <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm P}_{\rm 1dB}=2\ $</tex></formula> dBm and the noise figure is 3–5 dB, while the power dissipation increases from 2 mW to 16 mW (only clocking power).

On the origin of the high-Q high-frequency oscillations of magnetars

A model for the high-frequency (20–2400 Hz) quasi-periodic oscillations (QPOs) of magnetars based on the representation of coronal magnetic loops as equivalent electric RLC circuits is proposed. The observed periods of the QPOs and their high Q-factor (Q ≈ 104–105) are explained. It follows from the model that the QPOs can be excited not only in the tail of a flare but also before the main pulse. The parameters of the QPO source at the “ringing tail” stage of the flare from SGR 1806–20 on December 27, 2004, have been estimated: electric current I ≈ 3 × 1019 A, minimum magnetic field strength Bmin ≈ 1013 G, and electron density n ≈ 2 × 1016 cm−3.

Dual Passband Filter Using Hybrid Microstrip Split Ring Resonators and Coplanar Waveguide Quarter Wavelength Resonators

A novel dual passband filter using hybrid microstrip split ring resonators and coplanar wavelength (CPW) quarter wavelength resonators is presented. An equivalent RLC circuit model is presented, and its corresponding parameters are also extracted from the theoretical analysis. The proposed dual passband filter has two passbands with the center frequencies of 2.44 GHz and 3.5 GHz. Good agreement among equivalent circuit (EC), electromagnetic (EM) simulated and measured results is demonstrated.

Band-Notched UWB Printed Monopole Antenna With a Novel Segmented Circular Patch

A band-notched ultrawideband monopole antenna with a novel segmented radiating patch is presented. Band-notched characteristic in the 5.7-GHz WLAN band is obtained by segmenting a circular monopole patch into three parts. The measured results are in good agreement with the simulated ones. Moreover, the surface current and electric field distributions are analyzed and an equivalent parallel RLC circuit concept is applied to explain the band-notched function. On the basis of the equivalent parallel RLC circuit analysis, the notch frequency and bandwidth of the notched band can be widely adjusted by optimizing the key parameters.

A COMPACT LOW-PASS FILTER WITH SHARP CUTOFF AND LOW INSERTION LOSS CHARACTERISTIC USING NOVEL DEFECTED GROUND STRUCTURE

In this paper, a compact stepped-impedance hairpin resonator (SIHR) low-pass fllter (LPF) with an improved split-ring resonator defected ground structure (ISRR DGS) and two elliptical DGSs is presented. The proposed LPF exhibits the advantages of low insertion loss, sharp cutofi characteristic, wide stopband over the ordinary LPFs. The introduced DGSs are presented to improve the in- band and out-band characteristic. An equivalent RLC circuit model of the two kinds of DGSs is presented and analyzed. Combining with these two structures, a new SIHR LPF having 3dB cutofi frequency of 2.5GHz is fabricated and measured. Measured results show that the selectivity of the proposed LPF is more than 100dB/GHz and the insertion loss is less than 0.5dB in the passband. A wide stop-band bandwidth with 20dB attenuation from 2.58 up to 7.5GHz is achieved. Moreover, the occupied area is only 20 £ 25mm 2 .

Modeling, Analysis, and Design of Graphene Nano-Ribbon Interconnects

Graphene nanoribbons (GNRs) are considered as a prospective interconnect material. A comprehensive conductance and delay analysis of GNR interconnects is presented in this paper. Using a simple tight-binding model and the linear response Landauer formula, the conductance model of GNR is derived. Several GNR structures are examined, and the conductance among them and other interconnect materials [e.g., copper (Cu), tungsten (W), and carbon nanotubes (CNTs)] is compared. The impact of different model parameters (i.e., bandgap, mean free path, Fermi level, and edge specularity) on the conductance is discussed. Both global and local GNR interconnect delays are analyzed using an RLC equivalent circuit model. Intercalation doping for multilayer GNRs is proposed, and it is shown that in order to match (or better) the performance of Cu or CNT bundles at either the global or local level, multiple zigzag-edged GNR layers along with proper intercalation doping must be used and near-specular nanoribbon edge should be achieved. However, intercalation-doped multilayer zigzag GNRs can have better performance than that of W, implying possible application as local interconnects in some cases. Thus, this paper identifies the on-chip interconnect domains where GNRs can be employed and provides valuable insights into the process technology development for GNR interconnects.

Resonant properties of the Sierpinski‐based fractal resonator and its application on low‐loss miniaturized dual‐mode bandpass filter

AbstractIn this article, resonant characteristics of novel microstrip resonators based on the Sierpinski carpet fractal geometries are proposed in detail. With increasing the iteration order of the Sierpinski‐based fractal resonators, the resonant frequency is decreased but the unloaded quality factor is slightly enhanced. The resonant properties are discussed using the RLC equivalent circuit. Additional, the design guide for bandpass filter using the nth order resonator is also developed. Using these fractal resonators, several dual‐mode bandpass filters using different order resonators can be designed and fabricated to verify the advantages of the size and insertion loss reduction. It is also found good agreement between the simulation and measurement is achieved. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1358–1361, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24321

Compact low pass filter using novel elliptic shape DGS

AbstractA novel elliptic shape defected ground structure (DGS) is investigated for low pass filter (LPF) applications. An equivalent RLC circuit model is presented and its corresponding parameters are also extracted from the measured S‐parameters. The filter presents the advantages of compact size, high selectivity, low insertion loss and high out‐band suppression more than 32 dB from 5.15 to 10 GHz. Good agreements with response of equivalent circuit, electromagnetic simulation, and measurement is demonstrated. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1088–1091, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24263

A NOVEL LOW PASS FILTER USING ELLIPTIC SHAPE DEFECTED GROUND SSTRUCTURE

This paper presents a novel elliptic shape defected ground structure (DGS) for low pass filter (LPF) applications. An equivalent RLC circuit model is presented and its corresponding parameters are also extracted from the measured S-parameters. The filter presents the advantages of compact size, high selectivity; low insertion loss and high out-band suppression from 5.15 GHz to 10 GHz below −31 dB. Good agreement with response of equivalent circuit, electromagnetic simulation, and measurement is demonstrated

Magnetorheological Valve for Hybrid Electrohydrostatic Actuation

There is an increasing demand for compact actuators capable of producing large deflections, large forces, and broad frequency bandwidths. Due to their solid state nature, smart materials can enable novel actuator solutions that compete favorably with established technologies based on electric, hydraulic, or pneumatic motors. However, in all existing active materials, large force and broadband responses are obtained at small displacements and methods for transmitting very short transducer element motion to large deformations need to be developed. We present a new hybrid actuator which operates on the principle of rectification of magnetostrictive vibrations by means of magnetorheological (MR) flow control. Experiments and theoretical calculations are aimed at substantiating the feasibility of the hybrid actuator and establishing design criteria for the development of an effective MR valve. The experiments presented here demonstrate the ability of the valve to completely block the flow due to the combined action of a pressure differential and MR fluid activation. For characterization purposes, two variations of the main valve concept are considered, one with moving coils and the other with fixed coils. Actuation measurements conducted on the complete actuator show deflections of 6.5 in. in response to fluid inputs produced with a hydraulic piston in combination with an applied quasistatic voltage of amplitude 5 V. A system-level model is presented which is developed by treating the system as an RLC equivalent electrical circuit with operation across electrical, mechanical, and fluid domains. Attributes and shortcomings of the model are discussed through comparison of model results with experimental data.

Modeling Crosstalk Effects in CNT Bus Architectures

Carbon nanotubes (CNTs) have been widely proposed as interconnect fabric for nano and very deep submicron (silicon-based) technologies due to their robustness to electromigration. In this paper, issues associated with crosstalk among bus lines implemented by CNTs are investigated in detail. CNT-based interconnects are modeled and the effects of crosstalk on performance and correct operation are evaluated by simulation. Existing models are modified to account for geometries in bus architectures made of parallel single-walled nanotubes and a single multiwalled nanotube. New RLC equivalent circuits are proposed for these bus architectures. A novel bus architecture with low crosstalk features is also proposed. This bus architecture is made of dual-walled nanotubes arranged in parallel. In this architecture, the crosstalk-induced delay and corresponding uncertainty (as well as crosstalk-induced peak voltage) are significantly reduced; a modest area penalty is incurred. Reductions up to 59% for the crosstalk-induced delay and up to 81% for the crosstalk-induced peak voltage are reported. These results confirm that the proposed bus arrangement noticeably improves performance and provides reliable operation

편파 다이버시티를 위한 바람개비 형태의 루프 안테나 설계

본 논문에서는 편파 다이버시티를 구현하기 위한 바람개비 형태의 루프 안테나를 제안하였다. 제안된 루프 안테나의 원주는 일반적인 소형 루프 안테나의 길이(<TEX>${\lambda}$</TEX>)보다 10배가 크나, 소형 루프 안테나와 같이 수평면에서 무지향성 패턴을 얻을 수 있다. 기생 루프 안테나의 사용을 통해 안테나의 임피던스 정합 문제를 해결하고, 등가 회로를 제시하여 제안된 안테나의 설계 의도가 수식적으로 설명될 수 있음을 보였다. 제안된 안테나는 2.6 GHz에서 설계, 제작되었으며 정재파비 2:1 이하를 기준으로 6 %의 대역폭, 편파 분리도 15 dB, 이득 1.5 dBi의 시뮬레이션 결과를 나타내었고, 시뮬레이션 결과와 측정 결과가 잘 일치하였다. A windmill-shaped loop antenna is designed for polarization diversity. Its circumference is almost 10 times that of a conventional small loop antenna whose circumference is less than <TEX>${\lambda}/10$</TEX> but its the radiation pattern is omni-directional. An identical parasitic element is placed over the radiator to match the antenna input impedance. An equivalent transmission line and RLC circuit models are shown to fully describe for the windmill-shaped loop antenna. The proposed antenna has a bandwidth of 6 % with input VSWR less than 2:1 and a polarization purity of 15 dB at 2.6 GHz, and the gain of 1.5 dBi. The simulated and measured results show fairly good agreement.

유전알고리듬을 이용한 차동신호선의 등가회로 모델링

회로 전송선 배선 시 신호선은 직선의 형태와 방향을 바꾸기 위한 구부러지는 형태를 가진다. 차동 신호선의 정확한 등가회로는 이러한 전송선 구조의 시?공간 영역에서의 신호적 특성과 인접 신호선들 간의 영향을 평가할 수 있게 해준다. 이를 위해 기존의 몇 몇 CAD Tool들이 등가 회로 모델과 그 파라미터 값들을 추출 해주기도 하지만, 이는 큰 연산량과 시간을 요구한다. 본 논문에서는 구부러진 차동 신호선의 등가회로를 모델링하기 위해 기본적 모델인 RLC-모델의 파라미터 값을 유전 알고리듬을 이용하여 추출하는 방법을 제시한다. 본 방법에 의해 더욱 빠르게 물리적 구조를 갖는 차동 신호선의 등가회로를 모델링 할 수 있다.