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A broad generalization of memristors--a recently postulated circuit element--to an interesting class of nonlinear dynamical systems called memristive systems is introduced. These systems are unconventional in the sense that while they behave like resistive devices, they can be endowed with a rather exotic variety of dynamic characteristics. While possessing memory and exhibiting small-signal inductive or capacitive effects, they are incapable of energy discharge and they introduce no phase shift between the input and output waveforms. This zero-crossing property gives rise to a Lissajous figure which always passes through the origin. Memristive systems are hysteretic in the sense that their Lissajous figures vary with the excitation frequency. At very low frequencies, memristive systems are indistinguishable from nonlinear resistors while at extremely high frequencies, they reduce to linear resistors. These anomalous properties have misled and prevented the identification of many memristive devices and systems-including the thermistor, the Hodgkin-Huxley membrane circuit model, and the discharge tubes. Generic properties of memristive systems are derived and a canonic dynamical system model is presented along with an explicit algorithm for identifying the model parameters and functions.
Radiofrequency switches are critical components in wireless communication systems and consumer electronics. Emerging devices include switches based on microelectromechanical systems and phase-change materials. However, these devices suffer from disadvantages such as large physical dimensions and high actuation voltages. Here we propose and demonstrate a nanoscale radiofrequency switch based on a memristive device. The device can be programmed with a voltage as low as 0.4 V and has an ON/OFF conductance ratio up to 10(12) with long state retention. We measure the radiofrequency performance of the switch up to 110 GHz and demonstrate low insertion loss (0.3 dB at 40 GHz), high isolation (30 dB at 40 GHz), an average cutoff frequency of 35 THz and competitive linearity and power-handling capability. Our results suggest that, in addition to their application in memory and computing, memristive devices are also a leading contender for radiofrequency switch applications.
Memory circuit elements, namely memristive, memcapacitive and meminductive
systems, are gaining considerable attention due to their ubiquity and use in
diverse areas of science and technology. Their modeling within the most widely
used environment, SPICE, is thus critical to make substantial progress in the
design and analysis of complex circuits. Here, we present a collection of
models of different memory circuit elements and provide a methodology for their
accurate and reliable modeling in the SPICE environment. We also provide codes
of these models written in the most popular SPICE versions (PSpice, LTspice,
HSPICE) for the benefit of the reader. We expect this to be of great value to
the growing community of scientists interested in the wide range of
applications of memory circuit elements.
This paper presents a novel fully passive and reversible RF switch based on resistive switching effect observed in CBRAM memory. To maintain the on state or the off state no power is required, since as for a mechanical bi-stable switch, the on state is characterized by a real metallic bridge while the off state is related to the absence of this bridge. To switch on, a positive voltage up to 10V is necessary during few second to create the conductive filament, while a negative voltage is necessary to break it. To validate this new concept, a DC characterization has been conducted to determine the best way to switch between the two states. The transition has been characterized up to 0.15 GHz and an isolation of −20 dB with a insertion loss of −1.6 dB has been observed at 0.15GHz with a very simple design. To go further, a design of a switch able to operate up to 10GHz is presented.
This paper reports the development and characterization of a novel switching device for use in microwave systems. The device utilizes a switching mechanism based on nanoionics, in which mobile ions within a solid electrolyte undergo an electrochemical process to form and remove a conductive metallic ldquobridgerdquo to define the change of state. The nanoionics-based switch has demonstrated an insertion loss of ~0.5 dB, isolation of >0 dB, low voltage operation (1 V), low power (~muW) and low energy (~nJ) consumption, and excellent linearity up to 6 GHz. The switch requires fewer bias operations (due to non-volatile nature) and has a simple planar geometry allowing for novel device structures and easy integration into microwave power distribution circuits.