Electrical characteristics of dynamic loudspeakers

The chief electrical characteristic of a dynamic loudspeaker's driver is its electrical impedance as a function of frequency. It can be visualized by plotting it as a graph, called the impedance curve. Explanation The most common driver type is an electro-mechanical transducer using a voice coil rigidly connected to a diaphragm (generally a cone). Other types have similar connections, though differing in detail, between their acoustical environment and their electrical properties. The voice coil in moving coil drivers is suspended in a magnetic field provided by the loudspeaker magnet structure. As electric current flows through the voice coil (from an electronic amplifier), the magnetic field created by the coil reacts against the magnet's fixed field and moves the voice coil (and so the cone). Alternating current will move the cone back and forth. Resonance The moving system of the loudspeaker—consisting of the cone, cone suspension, spider, and voice coil—ca

Analysis of Quantized Electrical Characteristics of Microscale TiO2 Ink-Jet Printed Memristor

Heinrich Hofmann, Marijana Mionic Ebersold, Goran Stojanovic

We demonstrate the ink-jet printed fabrication technique for TiO2-based memristor, followed by detailed analysis of electrical characteristics and development of a new model that considers observed phenomena of quantized conductance steps. The existence of pinched hysteretic current-voltage characteristics is evidence of memristive behavior, provided by the reversible atomic rearrangement taking place in the functional layer. For the first time, performed electrical measurement on the micrometer thickness devices based on TiO2 active layer has captured the plateaux steps of the conductance at integer multiples of elementary quantum conductance. This behavior is consistent with the assumption that transport from electrode to electrode emerges through confined paths of conductive filaments with radius in the nanometer size range. Moreover, we introduce a novel model, based on the diffusion equation for ballistic transport in memristive devices, which considers the conductance plateaux steps.

Institute of Electrical and Electronics Engineers2015

Properties and Printability of Inkjet and Screen-Printed Silver Patterns for RFID Antennas

Danick Briand, Nico de Rooij, Francisco Molina Lopez, Jinyu Jason Ruan

We report the modeling, and geometrical and electrical characterization, of inkjet and screen-printed patterns on different polymeric substrates for use as antennas in radio-frequency identification (RFID) applications. We compared the physical and electrical characteristics of two silver nanoparticle-based commercial inkjet-printable inks and one screen-printable silver paste, when deposited on polyimide (PI), polyethylene terephthalate (PET), and polyetherimide (PEI) substrates. First, the thickness of the inkjet-printed patterns was predicted by use of an analytical model based on printing conditions and ink composition. The predicted thickness was confirmed experimentally, and geometrical characterization of the lines was completed by measuring the root-mean-square roughness of the patterns. Second, direct-current electrical characterization was performed to identify the printing conditions yielding the lowest resistivity and sheet resistance. The minimum resistivity for the inkjet-printing method was 8.6 +/- A 0.8 mu I (c) cm, obtained by printing four stacked layers of one of the commercial inks on PEI, whereas minimum resistivity of 44 +/- A 7 mu I (c) cm and 39 +/- A 4 mu I (c) cm were obtained for a single layer of screen-printed ink on polyimide (PI) with 140 threads/cm mesh and 90 threads/cm mesh, respectively. In every case, these minimum values of resistivity were obtained for the largest tested thickness. Coplanar waveguide transmission lines were then designed and characterized to analyze the radio-frequency (RF) performance of the printed patterns; minimum transmission losses of 0.0022 +/- A 0.0012 dB/mm and 0.0016 +/- A 0.0012 dB/mm measured at 13.56 MHz, in the high-frequency (HF) band, were achieved by inkjet printing on PEI and screen printing on PI, respectively. At 868 MHz, in the ultra-high-frequency band, the minimum values of transmission loss were 0.0130 +/- A 0.0014 dB/mm for inkjet printing on PEI and 0.0100 +/- A 0.0014 dB/mm for screen printing on PI. Although the resistivity achieved is lower for inkjet printing than for screen printing, RF losses for inkjetted patterns were larger than for screen-printed patterns, because thicker layers were obtained by screen printing. Finally, several coil inductors for the HF band were also fabricated by use of both printing techniques, and were used as antennas for semi-passive smart RFID tags on plastic foil capable of measuring temperature and humidity.

Springer Verlag2014

Effect of metal buffer layer and thermal annealing on HfOx-based ReRAMs

Behnoush Attarimashalkoubeh, Igor Krawczuk, Yusuf Leblebici, Jury Sandrini, Elmira Shahrabi

In this paper, we investigate different methods and approaches in order to improve the electrical characteristics of Pt/HfOx/TiN ReRAM devices. We discuss the improvement of the ReRAM electrical characteristics after the insertion of a Hf and Ti buffer layer. As a result, the resistance window increases more that 10 times, and the set and reset voltages decrease both in absolute value and variability. Furthermore, we show the influence of an annealing step at different temperatures on the Pt/HfOx/Hf/TiN memory devices on forming voltage and HRS. Considering the importance of achieving high density memory, we demonstrated the possibility of multi-level resistance state in the fabricated devices bu controlling the enforced compliance current. In addition, we show the endurance characteristic of the fabricated memories and their error rate. Finally, we report the transient behavior of the memory devices, investigating the device speed and switching mechanism.

Ieee2016

Properties and Printability of Inkjet and Screen-Printed Silver Patterns for RFID Antennas

Danick Briand, Nico de Rooij, Francisco Molina Lopez, Jinyu Jason Ruan

Springer Verlag2014