As today’s communication devices are becoming smaller in size, they need antennas also of small size which are capable of providing higher performance. Modern telecommunication systems need antennas with wider bandwidth, multiband support, low cost and conventionally smaller design dimensions for commercial as well as military applications. This ever increasing demand of small, multiband antenn...

We consider the problem of periodic nonuniform sampling of a multiband signal and its reconstruction from the samples. We derive the conditions for exact reconstruction and find an explicit reconstruction formula. Key features of this method are that the sampling rate can be made arbitrarily close to the minimum (Landau) rate and that it can handle classes of multiband signals that are not pack...

This work presents a new planar multiband antenna based on fractal geometry. This structure is optimized and validated into simulation by using CST-MW Studio. To feed this antenna we have used a CPW line which makes it easy to be incorporated with integrated circuits. The simulation results presents a good matching input impedance and radiation pattern in the GSM band at 900 MHz and ISM band at...

In this paper, we propose a new approach to improve the performance of speech enhancement technique based on multi-band spectral subtraction for white Gaussian noise. First, the original power spectral subtraction and multiband spectral subtraction methods are surveyed and implemented. Next, the generalization is applied on multiband spectral subtraction. Finally, the flattened noise spectrum w...

In this paper, a new antenna is presented which has an application in cellular telecommunication systems. The designed antenna works at the frequency range of 1900-2600 MHz which is able to cover 2G, 3G and 4G (LTE) services of the cellular telecommunication. In this paper, the micro-strip structure has been used to design the antenna. The shape of the patches is triangular where a peripheral r...

A new molecular conducting material, [BDTA][Ni(dmit)2]2, with a novel multiband electronic structure has been prepared by simple mixing of precursor salts of the components.

This communication defines a figure of merit for multiband antennas that gives an objective quantification of the similarities between radiation patterns at the different antenna operating bands.

In this paper we proposed anovel multiband delay line which consists of two types of split-ring resonators: the broadiside coupled and the single split-ring resonator. Proposeddelay line exhibits two left-handed bands that can be shifted by twisting the split rings for certain angle or by changing their lengths. This delay line is suitable for design of multiband frequency scanning antennas sin...

Multi-stream and multi-band methods can improve the accuracy of speech recognition systems without overly increasing the complexity. However, they cannot be applied blindly. In this paper, we review our experience applying multi-stream and multiband methods to the Broadcast News corpus. We found that multi-stream systems using different acoustic front-ends provide a significant improvement over...