Material properties analysis of graphene base transistor (GBT) for VLSI analog circuits design

Graphene base transistor’s (GBT) analysis has been reviewed in this paper. This study has been focused on work carried out by other authors for GBT physics. Here prominence has been given to material properties and their effects on GBT for VLSI analog circuit design to operate in high frequency range of THz. Various papers in literature have been reported for the implementation of designs with different emitter and collector materials. Materials properties are the controlling parameters to decide cut-off frequency (f­T), trans-conductance, gain and off current (Ioff) in GBT. The implemented results of literatures signify that the electron affinity and work function of emitter and collector are the dominant factors for flow of charges from emitter to collector. Dependency of these two parameters on dielectric constant and thickness of emitter-base insulator (EBI) and base collector insulator (BCI) that are tantalum pentoxide (Ta2O5), carbon-doped silicon oxide (SiCOH) and SiO2 has been studied. Effects of collector and BCI thickness have been investigated in detail to scrutinize base leakage current by the virtue of back scattering in collector-BCI interface. Small signal equivalent circuit model for GBT have also been studied by including parasitic capacitance behaviour between graphene Dirac-point potential with respect to graphene fermi level, emitter, EBI, BCI and collector fermi level potential

Observation of elastic bound modes in the continuum in architected beams

We report the experimental observation of an elastic bound mode in the continuum (BIC) in a compact region of an architected beam. We consider a long slender beam with rigid masses attached at periodic intervals, with a compact segment bounded by four protruding side beams. The key idea is to seek a mode where the side beams move out-of-phase with the compact region, thereby nullifying the forces and moments outside this region and resulting in a bound mode. The structure is modeled using Euler-Bernoulli beam theory and the side beams are designed by imposing equilibrium constraints required for a BIC. Multiple BICs are found in the compact region, and for each BIC, we find a one-parameter family of BIC supporting side beam designs. The predictions are verified by three-dimensional finite element simulations, followed by their experimental observation using laser Doppler vibrometry in a macro-scale structure. Our approach allows to achieve BICs in an arbitrary sized compact region of the architected beam. Our findings may open avenues for confining elastic wave energy in compact regions for applications in sensors and resonators

Bound modes in the continuum based phononic waveguides

We analytically predict and numerically demonstrate the existence of a family of bound modes in the continuum (BICs) in bi-layered spring mass chains. A coupled array of such chains is then used to illustrate transversely bound waves propagating along a channel in a lattice. We start by considering the compact region formed by coupling two spring mass chains with defects and predict bound modes arising due to reflection symmetries in this region. Dispersion analysis of a waveguide consisting of an array of appropriately coupled bi-layered chains reveals the presence of a branch having bound modes in the passband. Finally, detailed numerical analyses verify the existence of a BIC and its propagation through the waveguide at passband frequencies without energy leakage. The framework allows to achieve BICs and their propagation, for any arbitrary size and location of the compact region. Such BICs open avenues for novel classes of resonators with extremely high $Q$ factors due to zero energy leakage and allow for guiding confined waves in structures without requiring bandgaps

Automated safety and online healthcare system

This paper aims at designing and development of an Automated Safety & Online Healthcare System in which we are focusing on the intelligent integration of various technologies to come out with a single integrated system for Accident detection, notification and aftermath practices. Our proposed system presents completely an innovative idea for detection of an automobile accident and post detection measures.We have customized our research in mainly five modules: Crash detection module, GSM interface module, PRF module, Universal Database Module and, the last and most important Web module