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A printed elliptic UWB reconfigurable dual band-rejected antenna operating from 0.75 to over 6GHz was designed and performed for multi-standard telecommunication systems such as GSM 850, GSM 900, LTE, ISM 868, WiFi, WLAN, WiMAX… The main antenna consists of a very high selective UMTS (2.1 GHz) band-rejection micro-strip fed monopole. The reconfigurable discarded bands were obtained by printing two...
The hardware simulator facilitates the test and validation cycles by replicating channel artifacts in a controllable and repeatable laboratory environment. After a description of the MIMO channel models and the hardware simulator architecture, this paper presents new implementation algorithm of its digital block. The proposed algorithm allows the selection of specific environments and various scenarios,...
Improvement of THz waveguides with reduced losses has seen a rapid progress in the recent years. Among designs with the low loss, Planar Goubau Line have been designed and fabricated on high resistivity silicon substrate. In this contribution, we discuss two kinds of Planar Goubau lines: rectangular cross section line for low loss transmission and corrugated line in order to slow down and confine...
This paper presents a new scheme of Pure Sinwave Inverters using Pic-18F4620 microcontroller to eliminate the most amount of current harmonics that flows through the whole circuit, and to obtain pure sinwave current at the output load side. The proposed inverter, with lossless harmonic power, gives pure sinusoidal output voltage and current. It is aimed to be used with AC machines, sensitive appliances...
This paper investigates the decoding of rate 1/2 Non-Binary LDPC codes using a non-iterative approach based on the Maximum-Likelihood (ML) principle. The iterative decoding approach based on the well known Extended-Min-Sum (EMS) algorithm, considered as the most efficient decoding algorithm to decode NB-LDPC codes, executes the decoding process iteratively. The main operations of this algorithm are...
In this paper, the propagation of electromagnetic waves through an infinite slab of biaxial chiral medium is analytically formulated for an arbitrary incidence using the 4×4 transition matrix method. In this powerful method, a state vector differential equation is extracted whose solution is given in terms of a transition matrix relating the tangential field components at the input and output planes...
A hepta-band dielectric loaded Minkowski Fractal Slot Antenna is presented in this article. Fractal geometry is utilized to generate multiple frequency bands conforming to various wireless standards. The idea behind placement of the dielectric resonator is to increase the impedance bandwidth at the upper frequency band. The proposed antenna exhibits a hepta-band performance over the frequency range...
Low frequency (LF) noise and especially trap assisted GR noise in semiconductor devices does not affect only the performances of radio frequency (RF) and microwave transmitters (oscillators) but also that of receivers (local oscillators, mixers). Measurement and simulation characterization tools of semiconductor devices become crucial in order to optimize their characteristics and circuit performances...
A simple planar ultra-wideband (UWB) microstrip-fed antenna with defected ground structure and two parasitic patches is presented. Two symmetrical quarter-circle shaped segments are cut both on the each of lower edges of the radiating patch and on the each of upper edges of the ground plane. These segments provide a wider bandwidth than the ordinary rectangular antenna especially in the middle frequencies...
Ageing of organic solar cells is still a problem to resolve before these devices can reach the market. This question can be addressed using different strategies including encapsulating materials, device design and buffer layers, with the latter being addressed in this paper. The shelf life of un-encapsulated small-molecule organic solar cells, (ITO/PEDOT-PSS/CuPC/C60/buffer layer/Al), have been studied...
In this work, we are interested in the evaluation of the capacity of the ultra wideband (UWB) channel in an underground mine. Using optimal power spectrum allocation (OPSA) at the transmitter side, we have computed this capacity by taking into account the fading characteristics of the channel. The results show the pertinence of the optimal power spectrum allocation for this type of channel. An improvement...
A high efficient GaN HEMT power amplifier with a new topology is presented for to be used at 3.4-3.7 GHz band. Short sections of the Microstrip-lines are used as harmonic traps at the load network in order to improve the efficiency. The fabricated GaN HEMT amplifier delivers 37.5 dBm saturated output power and the maximum power-added efficiency of 80% and a maximum drain efficiency of 83% are obtained...
In this paper, microstrip transmission lines and antennas realized on Molded Interconnect Devices (MIDs) are presented. Measurements of two transmission lines realized by LDS on LCP vectra E820i substrate and inkjet printing on ABS PC substrates allowed the extraction of LCP vectra E820i and ABS PC permittivities. Measurement results show that lower losses are obtained with the LDS fabrication technique,...
We describe a contactless technique for dielectric permittivity characterization using a resonant near-field scanning microwave microscope. By measuring the shift in the system's resonant frequency as we scan over an insulating sample, we obtain quantitative images of dielectric variations. This system is composed of a probe coupled to a dielectric resonator.
This paper presents the design of quarter-wave retarders for the C and the L bands using two perpendicular reflective metals coated with a single layer thin film. The overall reflection of 81% is achieved for the quarter-wave retarder.
Dirac equation is one of the fundamental equations of quantum mechanics, but the interpretation of its solutions in terms of spinors is very abstract. It is proposed in this paper to show that some electromagnetic solutions exist in terms of standing waves. We shall exhibit explicit solutions as standing modes of a rectangular electromagnetic cavity. We conclude by proposing a physical interpretation...
Reconfigurable RF filter in Software Defined Radio (SDR) receivers is a promising solution to reduce analog circuit size especially in case of multi-standard radio context. In this paper, a new approach to design tunable RF filters using dual behavior resonators (DBR) topology is proposed. This design methodology is performed to design an electrical tunable filter able to switch between UMTS, WiFi...
Dual-mode resonators are particularly attractive because they offer size-reduction as well as the ability to achieve tunable filters. Tuning the bandwidth of the filter by adjusting dimensions of its perturbation element is commonly used. It is shown in this paper that different shapes of cuts, which are used as perturbation element, have different effects on stability of the filter center frequency...
The impact of human body on the wireless communication systems is very required recently in indoor environments. The prediction of accurate and efficient coverage is more and more needed in the presence of various obstacles. This paper will present electromagnetic indoor propagation modeling with integration of human body, taking into account the nature of materials existing in the environment, based...
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