Passive Circuit Elements Research Articles

Microwave transmission characteristics of ZnO nanowire

Electrical characteristics of single ZnO nanowire with various diameters at the high-frequency range are presented. Transmission characteristics were measured as S-parameter and RLC circuit simulation to deduce passive circuit elements. The result showed that the contact parameters were dominant as frequency increases. This study discovered the parasitic effects supposed to be minimised, contribute significantly to major signal transmission of ZnO nanowire and are crucial in developing such nano-electronic devices.

Ultra-Compact WiMAX Bandpass Filter Embedded Into a Printed Circuit Board With a ${\rm SrTiO}_{3}$ Composite Layer

An ultra-compact bandpass filter has been developed for 2.3-2.7 GHz worldwide interoperability used for microwave access applications. The proposed filter was fully embedded into a multilayered printed circuit board (PCB) with a high dielectric strontium titanate (SrTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) composite film layer. In order to reduce the size of the filter and to avoid unwanted 3-D electromagnetic coupling between the embedded passive filter circuit elements, the proposed filter was designed using J-inverter transformation technology. Two grounding via inductors and a single grounding capacitor were also utilized to generate three independent finite transmission zeros to enhance the rejection characteristics at the proper frequency bands. Since the J-inverter transformed filter circuit elements could be designed with relatively small inductance and large capacitance values, the high dielectric composite film was highly effective in reducing the size and improving the performance of the filter. The high dielectric film exhibited a dielectric constant of 17, a tangent loss of 0.01, and a capacitance density of 12.2 pF/mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at 1 GHz. The measured maximum insertion loss in the passband ranged from 2.3 to 2.7 GHz was better than 1.8 dB, with a minimum value of 1.58 dB at 2.6 GHz. The return loss was higher than 15 dB in the passband. The transmission zeros occurred at 1.71 and 5.1 GHz, and provided suppressions of 45 dB at 1.71 GHz, and 54 dB at 5.1 GHz, respectively. The measured group delay was less than 0.8 ns in the passband. The embedded bandpass filter had a volume of 2.6 × 2.6 × 0.55 (H) mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , which is the smallest one found, compared to previously reported devices, the filter, embedded into the eight-layered packaging substrate with the high dielectric composite layer, dramatically reduced the size up to 56%, and its performance was also much improved in comparison to the one embedded into a conventional six- layered PCB.

A Chaotic Attractor in Delayed Memristive System

Over the last three decades, theoretical design and circuitry implementation of various chaotic generators by simple electronic circuits have been a key subject of nonlinear science. In 2008, the successful development of memristor brings new activity for this research. Memristor is a new nanometre‐scale passive circuit element, which possesses memory and nonlinear characteristics. This makes it have a unique charm to attract many researchers’ interests. In this paper, memristor, for the first time, is introduced in a delayed system to design a signal generator to produce chaotic behaviour. By replacing the nonlinear function with memristors in parallel, the memristor oscillator exhibits a chaotic attractor. The simulated results demonstrate that the performance is well predicted by the mathematical analysis and supports the viability of the design.

Alternative reading

Researchers at Hewlett Packard Laboratories in California have developed a low power technique for reading memristor crossbar arrays. Their method drastically reduces power consumption and can sense a single memristor state without disturbing adjacent elements.The memristor is the fourth class of two-terminal passive circuit element after the resistor, the capacitor and the inductor. It was proposed by Leon Chua in 1971, but a practical solid-state realisation did not appear until 2008 when a team at Hewlett Packard developed a switching memristor based on titanium dioxide thin films. Since then, research into memristor technology has increased as new challenges have presented themselves, including the control of power leakage and consumption.

A Low Voltage Active Circuit for Realizing Floating Inductance, Capacitance, Frequency Dependent Negative Resistances and Admittance Converter

A low voltage design of an active circuit for realizing a floating inductance, capacitance, frequency dependent negative resistance (FDNR) and admittance converter, depending on the selection of passive circuit elements, is described. The circuit employs only two differential voltage second-generation current conveyors (DVCCIIs) at low voltage levels (±0.75 V) and does not require passive element matching. The circuit has a grounded capacitor for simulating the floating inductance. The frequency performance of the circuit is tested using PSpice simulations. The application of the circuit for realizing a band pass and notch filter configuration is also described.

Instrumentation amplifier implements second-order active low-pass filter with high gain factor

A single-ended second-order active low-pass filter can simultaneously provide high gain factor and dc voltage subtraction. This makes it possible to reduce the number of components and signal processing stages needed in an application where small voltage changes are measured on the top of large dc voltage masked by a large amplitude oscillating carrier. The filter described in this paper is constructed from a conventional 3-op-amp instrumentation amplifier and five passive circuit elements.

Spintronic Memristor: Compact Model and Statistical Analysis

The fourth fundamental passive circuit element - memristor, has received the increased attentions after a real device was demonstrated by HP Lab in 2008. The distinctive characteristic of a memristor to record the historical profile of the voltage/current through itself creates great potentials in highly integrated circuit and system design. Among all the proposed memristor structures, magnetic-based spintronic memristor becomes a promising technology for its simple structure and the compatibility to the traditional CMOS process. In this paper, we depict a compact model of the spintronic memristor based on the magnetic-domain-wall motion mechanism. Our model takes into account the variations of material parameters and fabrication process, which significantly affect the actual electrical characteristics of a memristor in nano-scale technologies. Furthermore, we present the applications of the compact model, analyze the effect of process variations on memristor electrical properties, and discuss the corresponding circuit design considerations. Our proposed compact model can be easily implemented in Verilog-A language, compatible to SPICE-based simulation, and beneficial to minimize the design margin of memristor-based circuit implementations.

Adaptive Properties of Stochastic Memristor Networks: A Computational Study

A ‘memristor’ is a passive two-terminal circuit element the electric resistance of which depends on the history of the charge that has passed through it. We implemented a platform to simulate adaptive properties of stochastic memristor networks. We showed that such networks follow a stable behavior that diverges from its initial state depending on the history of stimulation. Additionally, we observed that the connectivity patterns of the networks influence their adaptive properties. These results confirm the adaptive properties of statistical memristor networks and suggest that they can be potentially used as complex and self-assembled ‘learning machines’.

Teaching Memristors to EE Undergraduate Students [Class Notes

Generations of electrical engineers have learned that there are three fundamental passive two-terminal circuit elements: resistor, capacitor, and inductor. Nevertheless, this apparently immovable situation changed in 2008 when Nature published an article on the memristor, which was proved to be the fourth fundamental circuit element. Since then, researchers have devoted time and effort to find how this device may possibly change the future of electronics. It is time then to introduce the memristor in EE undergraduate courses, but how? The great majority of works on memristor published so far have been aimed at experienced researchers and not at young students. The goal of this paper is providing an original point of view on this issue and describing a simple approach to memristor which is suitable to be used in EE undergraduate courses.

Memristor as an archetype of dynamic data-driven systems and applications to sensor networks

Since its introduction a decade ago, DDDAS has been applied to a wide range of science and technology fields, with specific focus of areas requiring fast and reliable processing of massive data streams from diverse resources. It is crucial to explore architectures and systems which are naturally suited to the DDDAS framework. In this paper, we show that the memristor – the fourth fundamental two-terminal passive circuit element alongside the well-known resistor, capacitor, and inductor – affords the efficient implementation of the working principles of DDDAS. Hence memristors can be considered as an archetype of DDDAS nanoscale hardware embodiment, being the smallest and most basic dynamic data driven application system. Memristors are electrical components with inherent memory processes; they have been predicted about four decade ago and have been physically implemented recently. We discuss the role that DDDAS may play in the development of computing platforms and sensor networks based on memristors in the next few years.

Plasma-Profile Control Using External Circuit in a Capacitively Coupled Plasma Reactor

Very high frequency (VHF) capacitively coupled plasma (CCP) sources offer several benefits, including low plasma potential, high electron density, and controllable dissociation. However, standing electromagnetic waves can make the spatial structure of VHF plasmas a sensitive function of operating conditions and reactor geometry. This paper discusses how the profile of VHF CCPs can be controlled using an external circuit that modifies the electrical boundary conditions. A 2-D plasma model with external circuit has been used for this study, where networks of passive circuit elements can be connected to different electrodes in the reactor. Plasma simulations have been performed for several combinations of capacitors and inductors. It is found that the external circuit can be used to change the radio-frequency current return path, thereby modifying the plasma profile. In general, the plasma is pulled toward the electrode with an inductive impedance and pushed away from the electrode with a capacitive impedance. These changes in plasma profile are related to the relative voltage and their phase on different electrodes.

Memristive switching of single-component metallic nanowires

Memristors have recently generated significant interest due to their potential use innanoscale logic and memory devices. Of the four passive circuit elements, the memristor (atwo-terminal hysteretic switch) has so far proved hard to fabricate out of a singlematerial. Here we employ electromigration to create a reversible passive electricalswitch, a memristive device, from a single-component metallic nanowire. To achieveresistive switching in a single-component structure we introduce a new class ofmemristors, devices in which the state variable of resistance is the system’s physicalgeometry. By exploiting electromigration to reversibly alter the geometry, werepeatedly switch the resistance of single-component metallic nanowires betweenlow and high states over many cycles. The reversible electromigration causes thenanowire to be cyclically narrowed to approximately 10 nm in width, resultingin a change in resistance by a factor of two. As a result, this work represents apotential route to the creation of nanoscale circuits from a single metallic element.

What is memristor?

The well-known three basic passive circuit elements - resistor (R), capacitor (C), and inductor (L), defines the three mathematical relations connecting the pairings of four fundamental circuit variables: electric current (i), voltage (v), electrical charge (q) and magnetic flux (phi) as: dV = R * di (resistance) dq = C * dv (capacitance) d(phi) = L * di (inductance)

Mechanical dissociation of retinal neurons with vibration

AbstractNeuromorphic devices that implement the functions of biological neural circuits by means of VLSI technology have been attracting great attention in engineering fields in the last decade. Concurrently, progress in neuroscience research has demonstrated nonlinear computations at the single neuron level, suggesting that individual neurons are not merely passive circuit elements but computational units. Thus, elucidating the properties of neuronal signal processing is an essential step in developing the next generation of neuromorphic devices. In this study, we developed a method of dissociating single neurons from specific sublayers of mammalian retinas without using proteolytic enzymes, instead combining tissue incubation in a low‐Ca2+ medium with a vibrodissociation technique previously developed for slices of brain and spinal cord. Our method takes less time and requires less manual skill than in the conventional enzymatic method, but yields a sufficient number of cells usable for acute electrophysiological experiments. Single retinal neurons dissociated by our method are useful for measuring nonlinear membrane conductances as well as spike firing properties in the perforated‐patch whole‐cell configuration. These neurons also enable us to investigate the effects of proteolytic enzymes on membrane excitability in such cells. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(9): 43–52, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10062

Phase-transition driven memristive system

Memristors are passive circuit elements which behave as resistors with memory. The recent experimental realization of a memristor has triggered interest in this concept and its possible applications. Here, we demonstrate memristive response in a thin film of vanadium dioxide. This behavior is driven by the insulator-to-metal phase transition typical of this oxide. We discuss details of this form of phase-change memristance and potential applications of our device. Most importantly, our results demonstrate the potential for a realization of memristive systems based on phase-transition phenomena.

Experimental demonstration of associative memory with memristive neural networks

AbstractWhen someone mentions the name of a known person we immediately recall her face and possibly many other traits. This is because we possess the so-called associative memory - the ability to correlate different memories to the same fact or event. Associative memory is such a fundamental and encompassing human ability (and not just human) that the network of neurons in our brain must perform it quite easily. The question is then whether electronic neural networks - electronic schemes that act somewhat similarly to human brains - can be built to perform this type of function. Although the field of neural networks has developed for many years, a key element, namely the synapses between adjacent neurons, has been lacking a satisfactory electronic representation. The reason for this is that a passive circuit element able to reproduce the synapse behaviour needs to remember its past dynamical history, store a continuous set of states, and be &amp;quot;plastic&amp;quot; according to the pre-synaptic and post-synaptic neuronal activity. Here we show that all this can be accomplished by a memory-resistor (memristor for short). In particular, by using simple and inexpensive off-the-shelf components we have built a memristor emulator which realizes all required synaptic properties. Most importantly, we have demonstrated experimentally the formation of associative memory in a simple neural network consisting of three electronic neurons connected by two memristor-emulator synapses. This experimental demonstration opens up new possibilities in the understanding of neural processes using memory devices, an important step forward to reproduce complex learning, adaptive and spontaneous behaviour with electronic neural networks.

Nanoparticle Assemblies as Memristors

Recently a memristor ( Chua, L. O. IEEE Trans. Circuit Theory 1971 , 18 , 507 ), the fourth fundamental passive circuit element, has been demonstrated as thin film device operations ( Strukov, D. B.; Snider, G. S.; Stewart, D. R.; Williams, R. S. Nature (London) 2008 , 453 , 80 ; Yang, J. J.; Pickett. M. D.; Li, X.; Ohlberg, D. A. A.; Stewart, D. R.; Williams, R. S. Nat. Nanotechnol. 2008 , 3 , 429 ). A new addition to the memristor family can be nanoparticle assemblies consisting of an infinite number of monodispersed, crystalline magnetite (Fe(3)O(4)) particles. Assembly of nanoparticles that have sizes below 10 nm, exhibits at room temperature a voltage-current hysteresis with an abrupt and large bipolar resistance switching (R(OFF)/R(ON) approximately 20). Interestingly, observed behavior could be interpreted by adopting an extended memristor model that combines both a time-dependent resistance and a time-dependent capacitance. We also observed that such behavior is not restricted to magnetites; it is a general property of nanoparticle assemblies as it was consistently observed in different types of spinel structured nanoparticles with different sizes and compositions. Further investigation into this new nanoassembly system will be of importance to the realization of the next generation nanodevices with potential advantages of simpler and inexpensive device fabrications.

An Equivalent Circuit Modeling of an Equispaced Metallic Nanoparticles (MNPs) Plasmon Wire

Based on the electric dipole moment (EDM) model of free oscillating electrons inside a single metallic nanoparticle (MNP), a comprehensive methodology is presented in the paper for calculating the equivalent circuit elements associated with an MNP. To find out the passive circuit elements for the MNP, the electromagnetic (EM) power flows are calculated by deriving the relaxation damping, radiation outflow, host matrix EM coupling, and applied signal interaction. The law of conservation of energy is then used to compute the extended oscillatory equation motion of a spherical MNP. The resonant behavior of a single MNP is represented by a lumped resonant circuit model, where the circuit parameters <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RLC</i> are derived from the equation of motion of the EDM and EM near-field energy outside the MNP. Finally, equivalent circuit of a linearly equispaced MNPs plasmon wire is modeled as a voltage-controlled voltage source by using the nearest surface plasmon interactions.

Coupled Ionic and Electronic Transport Model of Thin‐Film Semiconductor Memristive Behavior

The memristor, the fourth passive circuit element, was predicted theoretically nearly 40 years ago, but we just recently demonstrated both an intentional material system and an analytical model that exhibited the properties of such a device. Here we provide a more physical model based on numerical solutions of coupled drift-diffusion equations for electrons and ions with appropriate boundary conditions. We simulate the dynamics of a two-terminal memristive device based on a semiconductor thin film with mobile dopants that are partially compensated by a small amount of immobile acceptors. We examine the mobile ion distributions, zero-bias potentials, and current-voltage characteristics of the model for both steady-state bias conditions and for dynamical switching to obtain physical insight into the transport processes responsible for memristive behavior in semiconductor films.

The speed of dissemination of information about the realization of the fourth passive electronic circuit element measured by Google hits

This paper aims to demonstrate briefly that major scientific achievements spread through the Internet according to an exponential expression until a saturation point.