Mutual Capacitive Coupling Research Articles

Modeling and Signal Integrity Analysis of RRAM-Based Neuromorphic Chip Crossbar Array Using Partial Equivalent Element Circuit (PEEC) Method

This paper provides a comprehensive study of signal integrity issues in RRAM-based neuromorphic chip crossbar arrays due to interconnect parasitic. First, the parasitic parameters of the crossbar array are calculated by the partial equivalent element circuit (PEEC) method with an efficient unit-cell approach. Numerical experiments show that for a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$50\times 50$ </tex-math></inline-formula> array scale, this method consumes only 1.5% of the calculation time of the commercial software based 3D model, which translates to a calculation speed up of 72 times. Moreover, the PEEC circuit simulation results match well with those of the 3D model. Then, we investigate the effects of parasitic parameters such as capacitance and inductance, as well as the feature size of the crossbar array on signal integrity. All of them will lead to corresponding changes in parasitic effects, which in turn result in the most common signal integrity issues such as crosstalk, time delay and mutual capacitive coupling induced sneak path problem. Different from other studies, the excitation used in this paper is the neural spike signal generated by the Izhikevich neuron model, which is both rich in dynamic characteristics and high in computational efficiency. Finally, based on the study we propose a simple but effective design scheme for reduction of signal distortion, which can provide valuable design guidance for neuromorphic systems to achieve high performance and high computational accuracy.

Tunable interdot coupling in few-electron bilayer graphene double quantum dots

We present a highly controllable double quantum dot device based on bilayer graphene. Using a device architecture of interdigitated gate fingers, we can control the interdot tunnel coupling between 1 and 4 GHz and the mutual capacitive coupling between 0.2 and 0.6 meV, independent of the charge occupation of the quantum dots. The charging energy and, hence, the dot size remain nearly unchanged. The tuning range of the tunnel coupling covers the operating regime of typical silicon and GaAs spin qubit devices.

Interplay between mutual capacitive coupling and tunneling in silicon single electron transistor coupled to dopant atom

Interplay between mutual capacitive coupling and tunneling in silicon single electron transistor coupled to dopant atom

Capacitive Coupling in EMI Filters Containing T-Shaped Joint: Mechanism, Effects, and Mitigation

The attenuation performance of an electromagnetic interference filter can be significantly degraded by coupling, parasitics, and frequency-dependent nonlinearity, especially in high frequency (HF) range. This article reveals and investigates a mutual capacitive coupling effect in the popular filter structures with T-shaped joint. The mechanism is explained and the impact on filter attenuation is analyzed, which show this coupling is the dominant cause of performance degradation of T-shaped filters and a major cause for other T-shape-related filters. The effect patterns for both common-mode (CM) and differential-mode (DM) filters are analytically derived and further examined in multistage filter structures. Mitigation solutions using PCB slits and grounded shielding are proposed to improve filter transfer gain up to 30 dB in the HF range. A topological strategy is also presented, further enhancing filter attenuation. In addition, the impact of relative positions of the inductors on the coupling capacitance is discussed, and five positions are experimentally studied and compared. Experimental results obtained from three-phase LCL and LCLC filters verify the significance of this coupling and the effectiveness of the mitigation methods.

Calculation of a capacitively-coupled floating gate array toward quantum annealing machine

Quantum annealing machines based on superconducting qubits, which have the potential to solve optimization problems faster than digital computers, are of great interest not only to researchers but also to the general public. In this paper, we propose a quantum annealing machine based on a semiconductor floating gate (FG) array. The purpose of using the architecture of nand flash memories is to reuse a mature technology to create large arrays of silicon qubits. Current high-density nand flash memories use sufficiently small FG cells to make the number of electrons stored in each cell small and countable. The high packing density of these cells creates mutual capacitive couplings that can be used to generate cell-to-cell interactions. We explore these characteristics to derive an Ising Hamiltonian for the FG system in the single-electron regime. Considering the size of a cell (10 nm), the ideal operation temperature of a quantum annealer based on FG cells is estimated to be approximately that of liquid nitrogen. Assuming the parameters of a commercial 64 Gbit nand, we estimate that it is possible to create 2-megabyte (MB) qubit systems solely using conventional fabrication processes. Our proposal demonstrates that a large qubit system can be obtained as a natural extension of the miniaturization of commercial-grade electronics, although more effort will likely be required to achieve high-quality qubits.

Coplanar waveguides loaded with symmetric and asymmetric pairs of slotted stepped impedance resonators: Modeling, applications, and comparison to SIR‐loaded CPWS

ABSTRACTThis article is focused on the analysis and modeling of coplanar waveguide (CPW) transmission lines loaded with pairs of slotted stepped impedance resonators (S‐SIRs), etched in the ground planes. These structures may be described by a pair of parallel‐connected transmission lines, each one loaded with a series‐connected parallel resonator, and with mutual capacitive coupling between such resonators. If the structures are symmetric, the transmission coefficient exhibits a single transmission zero, related to the fundamental resonance of the SIRs, though perturbed by the effects of mutual coupling. However, if symmetry is disrupted, two notches appear, separated a distance that depends on the level of asymmetry, coupling, and CPW length. Therefore, these structures may be useful for the implementation of differential sensors and comparators. It is shown that if the S‐SIR‐loaded CPWs are electrically small, the structures can be modeled by a lumped element equivalent circuit. Using this model, the resonance frequencies are obtained analytically. The proposed lumped element model is validated through electromagnetic simulation and experiment, and a prototype comparator loaded with dielectric samples is fabricated and measured. Finally, the circuit model of the structure is compared to that of SIR‐loaded CPW transmission lines. Despite the fact that the lumped element equivalent circuits of these structures are completely different, the equations providing the transmission zeros are formally identical.© 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2741–2745, 2016

Electroinductive waves role in left-handed stacked complementary split rings resonators

In this letter it is presented a Left-Handed Metamaterial design route based upon stacked arrays of screens made of complementary split rings resonators under normal incidence in the microwave regime. Computation of the dispersion diagram highlights the possibility to obtain backward waves provided the longitudinal lattice is small enough. The experimental results are in good agreement with the computed ones. The physics underlying the Left-Handed behavior is found to rely on electroinductive waves, playing the mutual capacitive coupling the major role to explain the phenomenon. Our route to Left-Handed metamaterial introduced in this paper based on stacking CSRRs screens can be scaled to millimeter and terahertz for future applications.

Renormalization group study of capacitively coupled double quantum dots

The numerical renormalization group (NRG) is employed to study a double quantum dot(DQD) system consisting of two equivalent single-level dots, each coupled to its ownlead and with a mutual capacitive coupling embodied in an interdot interactionU′, in addition to the intradot Coulomb interactionU. Wefocus on the regime with two electrons on the DQD, and the evolution of the system on increasingU′/U. The spin-Kondoeffect arising for U′ = 0 (SU(2) × SU(2)) is found to persist robustly with increasingU′/U, before a rapid but continuous crossover to (a) theSU(4) point U′ = U where charge and spin degrees of freedom are entangled and the Kondo scale is stronglyenhanced; and then (b) a charge-Kondo state, in which a charge-pseudospin is quenchedon coupling to the leads/conduction channels. A quantum phase transition ofKosterlitz–Thouless type then occurs from this Fermi liquid, strong coupling (SC) phase, toa broken symmetry, non-Fermi liquid charge ordered (CO) phase at a criticalUc′. Our emphasis in this paper is on the structure, stability and flows betweenthe underlying RG fixed points; on the overall phase diagram in the(U,U′)-plane and evolution of the characteristic low-energy Kondo scale inherent to the SCphase; and on static physical properties such as spin- and charge-susceptibilities(staggered and uniform), including universality and scaling behaviour in the stronglycorrelated regime. Some exact results for associated Wilson ratios are also obtained.

Dipole Mode Response of a Multiconductor Cable Above a Ground Plane in a Transient Electromagnetic Field

This paper describes an analytical technique that may be used to obtain the worst case dipole mode currents on individual wires of a multiconductor cable as a result of a transient electromagnetic radiation field. The dipole mode response is due to the E field parallel to the length of the cable. To obtain the solution, the conductors and their image in the ground plane are considered as forming a loop, and the resultant loop is solved as a transmission mode loop. The solution is given in matrix form as an upper bound of the true current including both mutual inductive and mutual capacitive coupling. The mathematical results are presented in the time domain and are uniquely applicable to experimental results obtained in EMP simulation with narrow pulse driving fields.