In this paper, an ultra-low-noise amplifier with frequency band switching capability is designed, simulated and fabricated. The two frequency ranges of this amplifier consist of the 2.4 to 2.5 GHz and 3.1 GHz to 3.15 GHz frequency bands. The designed amplifier has a noise figure of less than 1dB, a minimum gain of 23 dB and a VSWR of less than 2 in the whole frequency band. The design process s...

A new multi-layer substrate integrated waveguide (SIW) structure is developed to design dual-band evanescent-mode band-pass filters (BPFs). Two independent series LC circuits are implemented by incorporating metallic irises in the different layers of the structure. The combination of the metallic irises with capacitive-plates is embedded inside the SIW to independently excite two evane...

Band-notch characteristic has been of great interest recently to overcome the electromagnetic interference of Ultra-wideband systems (UWB) with other existing ones. In this paper, we present a novel microstrip-fed antenna with band rejection property appropriate for UWB applications. Band-notch characteristic has been achieved by adding a rectangular resonant element to the ground section. A pr...

In this work, we present a dual-band band-pass filter with fixed low-band resonant frequency and tunable high-band resonant frequency. The proposed filter consists of two split-ring resonators (SRRs) with a stub and microfluidic channels. The lower resonant frequency is determined by the length of the SRR alone, whereas the higher resonant frequency is determined by the lengths of the SRR and t...

objectives: to evaluate different signal-processing algorithms for tactile identification of environmental sounds in a monitoring aid for the deafblind. two men and three women, sensorineurally deaf or profoundly hearing impaired with experience of vibratory experiments, age 22-36 years. methods: a closed set of 45 representative environmental sounds were processed using two transposing (trha, ...

brain-computer interfaces (bci) record brain signals, analyze and translate them into control commands which are relayed to output devices that carry out desired actions. these systems do not use normal neuromuscular output pathways. actually, the principal goal of bci systems is to provide better life style for physically-challenged people which are suffered from cerebral palsy, amyotrophic la...

in this article, the effect of cells' radius on the behavior of wavelength switching optical filter andthe effect of the radius of the optical filters' key characteristics such as wavelength resonance onan optical filter based on photonic crystals, have been investigated. currently, the most commonapplied mechanism for designing optical filter based on photonic crystals is using twomechanisms s...

in this paper energy bands and berry curvature of graphene was studied. desired hamiltonian regarding the next-nearest neighbors obtained by tight binding model. by using the second quantization approach, the transformation matrix is calculated and the hamiltonian of system is diagonalized. with this hamiltonian, the band structure and wave function can be calculated. by using calculated wave f...

sol-gel derived sulfur modified and pure zno nanorod were prepared using zinc chloride and thiocarbamide as raw materials. prepared nanorods were characterized by means of x-ray diffraction (xrd), thermogravimetry- differential scanning calorimetry (tg–dsc), uv- vis absorption spectroscopy, brunauer emmett teller (bet) specific surface area and barrett joyner halenda (bjh) pore size distributio...

in this study, the effect of cold rolling process on the microstructure and texture evolution in 1wt. % si non-orientedelectrical steel was investigated. for this purpose, all samples were processed through single-stage hot rolling at1100 ° c and two-stage cold rolling (cross rolling and unidirectional rolling) with intermediate annealing at 650 °cfor 35 seconds. finally, all of them were fully...