A new ultawideband circular fractal antenna with notched-band characteristics is presented. A notched-band characteristic is achieved by employing a U-shape slot in 50 Ω feed lines. The ultra-wideband impedance matching and compact size have been obtained by using CPW-feed technique and the fractal concept. The measured result of proposed fractal antenna exhibits the ultra wideband characterist...

In this paper, properties of reflection phase in one-dimensional quaternary photonic crystals combining dispersive meta-materials and positive index materials are investigated by transfer matrix method. Two omnidirectional band gaps are located in the band structure of considered structure. However, we limit our studies to the frequency range of the second wide band gap. We observe that the val...

Preparation of nanomaterials with various morphologies and exploiting their novel physical properties are of vital importance in nanoscientific field. Similarly to the III-N compound semiconductors, Si3N4 nanostructures also could be potentially used for making optoelectronic devices. In this paper, we report on an improved Fe-catalyzed chemical vapour deposition method for synthesizing ultra-l...

This paper investigates the Multi-bandOFDM (MB-OFDM) based Ultra-Wideband for working group on short-range high data-rate Ultra-wide-Band (UWB) communications. An overview of the MB-OFDM PHYlayer architecture with its various parameters is presented and the optimal choice of critical parameters is discussed. Next, we derive the theoretical un coded bit error rate (BER) of MB-OFDM over the fadin...

A planar band pass filter topology is built using broadside coupled structure. The design is aimed at achieving pass band that covers the frequency range from 3.1GHz to 10.6 GHz. as required by modern Ultra Wide Band (UWB) indoor and outdoor communication systems . Multiple unlicensed users could share spectrum previously allocated to the users, including licensed users, on a non-interference b...

A novel ultra-wideband (UWB) bandpass filter (BPF) with notched band based on microstrip/slotline ring resonators is presented in this paper. The UWB BPF is fabricated with two microstrip ring resonators on the top copper layer and a slotline ring resonator on the bottom ground layer. Thus, an ultra-wide passband can be achieved owing to the coupling effects and microstrip/slotline transitions ...

UWB (Ultra Wide Band) technology is a reliable transmission scheme for wireless communication with high data rates. UWB is defined as signals with fractional band width more than 20% of its central frequency or as signals with bandwidth more than 500MHZ. UWB can be characterized with ultra-short duration pulses called monopulses which has excellent immunity in interference from sensitivity or m...