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III-Nitride Metal-Oxide-Semiconductor Heterojunction (MOSH) structure consists of a thin dielectric layer deposited on top of a semiconductor heterostructure with a 2D electron gas at the heterojunction interface. MOSH structures are the key components for high-power low-loss, fast RF switches. The paper discusses two types of high-power switches using III-Nitride MOSH structures. The first type uses the MOSH structure as the gate region of an AlGaN/GaN HFET. The second type uses MOSH structure as a switching capacitor. In the 2GHz - 10 GHz frequency range, switching powers from 20 to 60 W/mm have been achieved with the insertion loss below 1 dB.

Carbon-based nanoelectromechanical devices are approaching applications in electronics. Switches based on individual carbon nanotubes deliver record low off-state leakage currents. Arrays of vertically aligned carbon nanotubes or nanofibers can be fabricated to constitute varactors. Very porous, low density arrays of quasi-vertically aligned arrays of carbon nanotubes behave mechanically as a single unit with very unusual material properties.

We propose a new design to achieve optical waveguide switch. We construct a photonic crystal waveguide with one yttrium iron garnet (YIG) rod array on the two sides of the waveguide. Through the mode analysis, we find in special frequency range a few YIG rods under magnetic field can form the magnetic reflectance wall that blocks the light flow. Removing the magnetic field will delete the reflection wall and let the blocked light to be switched on.

We consider a discrete model that describes a linear chain of particles coupled to two defects. This model can be regarded as a linear generalization of the familiar Fano–Anderson model. The analytical result for the plane wave transmission coefficient is obtained. Comparing the transmission coefficient of Gaussian wave with that of plane wave, we can draw a conclusion that arising perfect reflection due to destructive interference depends on the input waveform of incident particle and a necessary switching condition of Fano resonance is the input plane wave. This interesting feature may play a guiding role in devising various particle switches in theory and experiment.

Conventional circuit breakers suffer from two main deficiencies: they are slow to operate and develop an electrical arc. These may be overcome by using solid-state switches which in turn introduce other problems, most significantly power dissipated while in the on-state. Nevertheless, a number of solid-state devices are candidates for implementation as low-voltage circuit breakers and there are several options based on the semiconductor material that may function as high-power switches. This paper presents a unique, extensive and systematic evaluation of these options. Voltage-controlled devices are selected due to the simplicity of the controlling circuit and their resilience to $dv$/$dt$-induced switching. Properties of fully solid-state circuit breakers are established and systematic comparisons are made among switches built of silicon and other wide bandgap (WBG) devices such as SiC MOS and GaN HEMT transistors. Using SPICE simulation it is shown that solid-state circuit breakers (SSCBs) based on WBG devices exhibit superior characteristics compared with silicon devices, with faster switching and higher voltage and current ratings. Hybrid circuit breakers, combining both conventional and solid-state switches, are discussed too and a new design circuit is simulated and compared to both conventional and fully solid-state designs.

In traditional phased-array T/R modules, front-end modules such as limiter, low-noise amplifier (LNA) and RF switch are generally implemented by independent devices, with low integration and high cost. This paper realizes the integration of all receiver functional modules in the 0.13$\mu$m CMOS SOI process, including RF switch, LNA with limiter, 6-bit digital controlled attenuator and phase shifter, and drive amplifier. The LNA integrates a limiting function, which can suffer 2W continuous wave. Fast charge–discharge circuit is applied to the low insertion loss RF switch, which greatly reduces the switching time. The phase shifter adopts a double balanced switch used for 180^∘ phase shift, which significantly reduces the phase error. The measured channel gain is about 28dB with an NF about 2.3dB and an IP1 dB above $-$14dBm. The state error of attenuator is less than $+∕-0.6$dB with step error less than $+∕-0.3$dB. The RMS phase error of phase shifter is less than 1.8 degrees. The fully integrated transceiver IC occupies an area of $5\times 5.6$mm². This receiver draws only 128mA with a 3.3V power supply.

We prove that the two conditions from the definition of a biquandle by Fenn, Jordan-Santana, Kauffman [1] are equivalent and thus answer a question posed in the paper. We also construct a weak biquandle, which is not a biquandle.

It is known that the number of biquandle colorings of a long virtual knot diagram, with a fixed color of the initial arc, is a knot invariant. In this paper, we construct a more subtle invariant: a family of biquandle endomorphisms obtained from the set of colorings and longitudinal information.

This paper presents a protocol to support hard real-time traffic of end-to-end communication over non real-time LAN technology. The network is set up with nodes and switches, and real-time communication is handled by software (protocol) added between the Ethernet protocols and the TCP/IP suite. The proposed protocol establishes a virtual circuit based on admission control and manages hard real-time traffic to bypass the TCP/IP stack. This makes considerably reduce the dwell time in the nodes, and increase the achievable data frame rate. After the bypassing, traffic schedule is performed according to dynamic-priority EDF algorithm. The work does not need any modifications in the Ethernet hardware and coexists with TCP/IP suites, and then the LAN with the protocol can be connected to any existing Ethernet networks. It can be adopted in industrial hard real-time applications such as embedded systems, distributed control systems, parallel signal processing and robotics. We have performed some experiments to evaluate the protocol. Compared to some conventional hard real-time network protocols, the proposed one has better real-time performances and meets the requirements of reliability for hard real-time systems.

We analyze and propose an all-optical switch working over the C-band of the International Telecommunication Union (ITU), which is based on nonlinear switching cells made of photonic crystal (PhC). Indeed, the nonlinear switching cells are directional couplers (DCs) embedded in PhC, which can work over the C-band of the ITU (wavelength from 1530 to 1565 nm). The nonlinear switching method uses a relatively low-power external command signal for obtaining nonlinear effects. This external command signal is inserted in the central coupling region of the DC, which acts as another waveguide. The switching process is based on the change from the cross state to the bar state owing to the external command signal. In our simulations we used the plane-wave expansion (PWE), finite-difference time-domain (FDTD), and our own binary propagation method (BiPM).

In addition to controlling the structure of multi-chromophoric arrays, monitoring the spatial orientation of the chromophores in artificial light harvesting devices is a challenge of growing interest. We report in this article our recent advances in this field. It is expected that a better understanding of the physicochemical properties of rigid cofacial porphyrinic tweezers and an identification of the factors governing them will be crucial for the design and the elaboration of new nano-molecules endowed with original properties. Extended multi-porphyrinic architectures, polypeptides bearing pendant porphyrins have been synthesized as linear devices, and a star-like pentaporphyrin as an arborescent array. The structure and the original conformation of the latter confer to this system an unusual duality in its physicochemical properties.

A pyridyl side arm porphyrin incorporating C${}_{10}$ alkyl chains at the periphery of the porphyrin suitable for surface immobilisation on HOPG has been synthesised and tested for two state switching in solution. Temperature switching, involving reversible complexation of a covalently appended pyridyl side arm to the Zn(II) porphyrin, was comprehensively characterised by using variable temperature ¹H NMR (-30 to +100${}^{\circ }$C) and UV-vis (10 to 90${}^{\circ }$C) in toluene. Molecular modelling assisted in understanding strain within the complex.

A gas trigatron type gap for a 36-channel ring switch of a five-cascade water-insulated double step forming line with output impedance of 2.9 Ohm “Gamma-1” high-current electron accelerator is described in this paper. At discharge operating voltage of 1 MV its overall dimensions are: height ~ 160 mm, diameter ~ 240 mm. When operated with a mixture of insulating gas and nitrogen in proportion 40%SF₆+60%N₂ at 17 MPa pressure, the trigger delay is (16 ± 2) ns, with a self-break safety margin of not less than 1.5. The gap electrode surfaces are made of tungsten alloy. When operating as a part of the double step forming line switch, the average energy, switched through a single gap, is 3.3 kJ, and the current is 95 kA.

NMR is one of the important analytic tools which is used to obtain certain information such as metabolic concentrations in neural or muscular tissues. In some other important applications such as proton decoupling, it is necessary to design NMR transmitters/receivers capable of operating at multiple frequencies, while maintaining a good performance at each frequency. In this work, a new nuclear magnetic resonance (NMR) receiver microcoil based on MEMS technology is proposed. The designed structure uses MEMS microswitches with low contact resistance and NMR-based actuation mechanism. The proposed device can detect carbon (13C), proton (1H), and phosphorus (31p) nucleus with larmor frequencies of 96.36MHz, 383MHz, and 155.11MHz at 9 T magnetic field, respectively. The designed microcoil achieves three important goals:

• (1)Getting high SNR, high Q and high filling factor which are key parameters in NMR performance, by changing number of turns.
• (2)Turning into the array of microcoils to obtain better SNR.
• (3)Turning into two or three microcoils inside of each other for simultaneous detection.

The MEMS microswitch in this paper uses static magnetic field of the NMR for its operation ($B_0=9$T) which simplifies the switch mechanism. This switch is small (150$\mu$m$\times$50$\mu$m$\times$6$\mu$m), scattering parameters of 43.2db isolation and 0.0059 insertion loss and maximum displacement of 2.03$\mu$m due to the magnetostatic actuation. In this work, the models and investigations are conducted using finite element simulations in COMSOL Multiphysics. The switch scattering parameters are obtained by HFSS 12.0.

This chapter introduces the principle of shape memory function in polymers and classifies shape memory polymers according to their molecular structures, trigger patterns and applications based on a literature review. One of the novel functional shape memory polymers with substrate bonding antibacterial activity is detailed and a new design of supramolecular shape memory polymers is discussed. Finally, shape memory fibres are introduced in comparison with other existing man-made fibres to clarify the uniqueness of such smart textile materials.

III-Nitride Metal-Oxide-Semiconductor Heterojunction (MOSH) structure consists of a thin dielectric layer deposited on top of a semiconductor heterostructure with a 2D electron gas at the heterojunction interface. MOSH structures are the key components for high-power low-loss, fast RF switches. The paper discusses two types of high-power switches using III-Nitride MOSH structures. The first type uses the MOSH structure as the gate region of an AlGaN/GaN HFET. The second type uses MOSH structure as a switching capacitor. In the 2GHz - 10 GHz frequency range, switching powers from 20 to 60 W/mm have been achieved with the insertion loss below 1 dB.

Networking has become an integral part in day to day life. Basic knowledge of network components plays a significant vital role in understanding any network either wired or wireless. This paper mainly focuses on description and working of basic components required to setup a network and also a discussion on few network issues like how to assign IP addresses etc and a sample design of wired and wireless network.

Carbon-based nanoelectromechanical devices are approaching applications in electronics. Switches based on individual carbon nanotubes deliver record low off-state leakage currents. Arrays of vertically aligned carbon nanotubes or nanofibers can be fabricated to constitute varactors. Very porous, low density arrays of quasi-vertically aligned arrays of carbon nanotubes behave mechanically as a single unit with very unusual material properties.

Transient electromagnetic interference (EMI) generated during the switching of dis-connector and circuit breakers in 500 kV substations may cause malfunction or damage to electronic equipment positioned nearby if appropriate immunity measures are not taken. After analyzing the results and waveform characteristics of EMI, the experimental result shows that the EMI in secondary circuit is mainly caused by switch and breaker operations, their waveform characteristic is damped oscillatory, and the intensity of wave should not be neglected. The results also show that the EMI due to switch operations is caused by the electric discharge in primary circuit, and the EMI due to breaker operations is caused by the inductor, contactor oscillate and electric discharge. The impact of the electric discharge of the breakers in primary circuit into the secondary circuit is negligible.