The modulation bandwidth of quantum well nanoLED and nanolaser devices is calculated from the laser rate equations using a detailed model for the Purcell enhanced spontaneous emission. It is found that the Purcell enhancement saturates when the cavity quality-factor is increased, which limits the maximum achievable spontaneous recombination rate. The modulation bandwidth is thereby limited to a...

In this paper, a printed hexagonal wide slot antenna, fed by a microstrip line with fork like tuning stub for bandwidth enhancement is proposed and experimentally investigated. The impedance, radiation and gain characteristics of this antenna are studied. Simulation and experimental results indicate that a 1.5:1 VSWR bandwidth, of about 1 GHz and 2:1 VSWR bandwidth of 1.34 GHz is achieved at op...

In present wireless communication devices are getting smaller in size but the operation is held by such devices are needed much greater bandwidth. Microstrip antennas are smaller in size but having drawback of low bandwidth and low efficiency. Literature shows that the leading work on MSA is focused on designing compact sized broadband MSA. Last few years many miniaturization and bandwidth enha...

Since the birth of multi–spectral imaging techniques, there has been a tendency to consider and process this new type of data as a set of parallel gray–scale images, instead of an ensemble of an n–D realization. Although, even now, some researchers make the same assumption, it is proved that using vector geometries leads to better results. In this paper, first a method is prop...

 A step-by-step algorithm for enhancement of periodic signals that are highly corrupted by additive uncorrelated white gausian noise is proposed. In each adaptation step a new parallel second-order section is added to the previous filters. Every section has only one adjustable parameter, i.e., the center frequency of the self-tuning filter. The bandwidth and the convergence factor of each secti...

Introduction Dynamic contrast enhanced (DCE-MRI) of the breast should ideally be performed at high temporal and high spatial resolution to evaluate both enhancement dynamics and lesion spatialarchitectural features (1,2). There is, however, an inherent tradeoff between the maximum achievable temporal and spatial resolution (3). In this work, a formalism is presented that considers the dual band...

An investigation for the enhancement strategy of bandwidth performance and analysis of different types of losses associated with reflectarray antennas is presented in this paper. Studies are carried out using different commercially available dielectric materials with dielectric permittivity ( r) values ranging from 2.08 to 13 and loss tangent (tan ) ranging from 0.0003 to 0.025. The performance...

Abstract: New types of wideband circularly polarised (CP) squareand rectangular-loop antennas are developed and discussed. It is shown that the bandwidth for circular polarisation of a loop antenna can be significantly increased by adding a parasitic loop inside the original loop. The addition of the parasitic element can create one more minimum axial ratio (AR) point, which can appropriately c...

A probe feed, slotted hexagonal patch antenna has been proposed. Bandwidth enhancement has been improved by suitably cutting slots into hexagonal patch. Proposed antenna is suitable for various telecoms, LAN, WiFi applications in ISM-band. It is demonstrated that the proposed antenna exhibits resonance in ISM-Band and a peak gain of 6dBi.The antenna structure is described and simulated results ...

By optically injecting a quantum dash laser and simultaneously producing a significant lowering of the device threshold, a large enhancement in the differential gain is realized. This effect is observed by way of a dramatic reduction in the linewidth enhancement factor and a large increase in the 3-dB modulation bandwidth, especially as the injection wavelength is blue-shifted. Compared to its ...