A Class of Pseudo-Differential Operators Associated with Bessel Operators

AbstractA class of pseudo-differential operators (p.d.o.), generalizing Bessel differential operator d2/dx2 + (1 − 4μ2)/(4x2), is defined. Symbol classes Hm and Hm0 are introduced. It is shown that p.d.o.′s associated with symbols belonging to these classes are continuous linear mappings of the Zemanian space Hμ into itself. An integral representation of p.d.o.′s is obtained. Using Haimo′s theory of the Hankel convolution it is shown that p.d.o.′s satisfy a certain L1 - norm inequality

ELECTROMAGNETIC ELECTRON-CYCLOTRON WAVES WITH AC FIELD IN THE MAGNETOSPHERE

In this paper the effect of externally injected beam of cold electrons on electromagnetic electron-cyclotron (EMEC) waves in the magnetosphere has been discussed. The investigation is conducted using the methodology of characteristic solution and considering kappa distribution function in the presence of AC field.  The objective of present study is to examine the variation in growth rate of EMEC waves when temperature anisotropy, magnitude of AC field and number density of energetic particles varies. It is inferred that EMEC waves grow more significantly when propagating oblique to magnetic field direction rather than parallel to magnetic field direction. Also that as the temperature anisotropy and number density of background plasma increases, growth rate of EMEC waves increases

COLD BEAM INJECTION IN RELATIVISTIC EMEC WAVE FOR KAPPA DISTRIBUTION FUNCTION WITH AC FIELD FOR MAGNETO-PLASMA

The effect of cold electron beam on electromagnetic electron cyclotron (EMEC) wave has been studied by using the unperturbed Lorentzian (Kappa) distribution in the magnetosphere for relativistic plasma. The dispersion relation is obtained by using the method of characteristic solutions and kinetic approach. An expression for the growth rate of a system has been calculated. It is inferred that in addition to the relativistic plasma obliquity and effect of cold electron beam modifies the growth rate and it also shifts the wave band significantly. The relativistic electrons by increasing the growth rate and widening the bandwidth may explain a wide frequency range of EMEC wave emissions in the magnetosphere

Dimensions Selection Criteria of Stair shaped Slot for Obtaining the Wideband Response of CPDRA

The analysis of a circularly polarised (CP) dielectric resonator antenna (DRA) with the aperture coupled feeding technique is presented in this paper. Until now, the random techniques have been developed for obtaining the CP response in DRA. It is glaringly required to develop a fixed mathematical criterion for the selection of dimensions of the antenna structure. The criterion for selection of the stair-shaped slot dimensions, which is utilised for obtaining the CP response, is defined in this paper. The ranges of slot length ratios are investigated so that a wide CP bandwidth can be obtained. The antenna offers the 10-dB impedance of 58.62% (4.1 GHz - 7.5 GHz) and 3-dB axial ratio bandwidth of 40.86 per cent (4.26GHz - 6.385 GHz)

Small Signal Parameter Extraction of III-V Heterojunction Surrounding Gate Tunnel Field Effect Transistor

This work presents simulation study and analysis of nanoscale III-V Heterojunction Gate All Around Tunnel Field Effect Transistor, along with the extraction of small signal parameters of the device. Transfer characteristics and output characteristics of the device were observed. The device is simulated for extraction of small signal parameters such as transconductance, gate-source capacitance, gate-drain capacitance, by varying doping concentration of drain region and channel length. Cut-off frequency of the device is also obtained. The results reported agree well with the data available in literature

Two Dimensional Modeling of III-V Heterojunction Gate All Around Tunnel Field Effect Transistor

Tunnel Field Effect Transistor is one of the extensively researched semiconductor devices, which has captured attention over the conventional Metal Oxide Semiconductor Field Effect Transistor. This device, due to its varied advantages, is considered in applications where devices are scaled down to deep submicron level. Like MOSFETs, many geometries of TFETs have been studied and analyzed in the past few years. This work, presents a two dimensional analytical model for a III-V Heterojunction Surrounding Gate Tunneling Field Effect Transistor. 2-D Poisson’s equation in cylindrical coordinates has been solved to derive the expression of Surface Potential and threshold voltage of the device. A broken gap GaSb/InAs heterostructure has been considered in this work. Variation of potential profiles are shown with different gate and drain biases, by varying radius of the transistor,and different gate metals. Also, variation of threshold voltage is shown with respect to channel length and radius of the nanowire

Investigation of Single Boron Acceptors at the Cleaved Si:B (111) Surface

The cleaved and (2 x 1) reconstructed (111) surface of p-type Si is investigated by scanning tunneling microscopy (STM). Single B acceptors are identified due to their characteristic voltage-dependent contrast which is explained by a local energetic shift of the electronic density of states caused by the Coulomb potential of the negatively charged acceptor. In addition, detailed analysis of the STM images shows that apparently one orbital is missing at the B site at sample voltages of 0.4 - 0.6 V, corresponding to the absence of a localized dangling-bond state. Scanning tunneling spectroscopy confirms a strongly altered density of states at the B atom due to the different electronic structure of B compared to Si.Comment: 6 pages, 7 figure