Current Issue : July - September Volume : 2013 Issue Number : 3 Articles : 6 Articles
The limitation of the electromagnetic interferences (EMIs) caused by UWB radiating sources into WLAN/WiMAX communication systems operating in the frequency band located around 5.5?GHz requires the adoption of appropriate design features. To this purpose, a notch filter integrated into an UWB antenna, which is able to ensure a better electrical insulation between the two mentioned communication systems with respect to that already presented by the authors Moeikham et al. (2011), is proposed in this paper. The proposed filter, consisting in a rectangular slot including a quarter-wavelength strip integrated on the lower inner edge of the UWB radiating patch, is capable of reducing the energy emission in the frequency range between 5.1 and 5.75?GHz resulting in lower EMIs with sensible electronic equipments working in this frequency band. The antenna structure has no need to be tuned after inserting the rectangle slot with a quarter-wavelength strip. The proposed antenna has potential to minimize the EMIs at a frequency range from 5.1 to 5.75?GHz. The radiation patterns are given nearly omnidirectional in xy plane and likely bidirectional in yz plane at all frequencies by the proposed antenna. Therefore, this antenna is suitable to apply for various UWB applications....
?is paper deals with a new through-the-wall (TTW) radar demonstrator for the detection and the localisation of people in a\r\nroom (in a noncooperative way) with the radar situated outside but in the vicinity of the ??rst wall. A?er modelling the propagation\r\nthrough various walls and quantifying the backscattering by the human body, an analysis of the technical considerations which\r\naims at de??ning the radar design is presented. ??inally, an ultrawideband (UWB) frequency modulated continuous wave (??MCW)\r\nradar is proposed, designed, and implemented. Some representative trials show that this radar is able to localise and track moving\r\npeople behind a wall in real time....
Ingestible wireless capsule endoscopy (WCE) is the one and only painless, effective, novel, diagnostic technology for inspecting the\r\nentire gastrointestinal (GI) tract for various diseases, such as obscure gastrointestinal bleeding (OGIB), tumors, cancer, Crohn�s\r\ndisease, and celiac disease. Since the development of this technology, several companies have made remarkable improvements in\r\ntheir clinical products, but there are still some limitations that relate to the use of conventional wired endoscopy. Some of the\r\nmajor limitations that currently impede its wider application include its inability to repeat the view of critical areas, working time\r\nconstraints, and poor image resolution. Many research groups currently are working on ways to solve these limitations. Presently,\r\ndeveloping the ability to control the movement of the capsule, increasing its image transmission speed, and obtaining high-quality\r\nimages are the main issues in the research area. A complex capsule with some therapeutic tools for the treatment of diseases of the\r\nGI tract also is at the beginning of development for the next generation of an active medical robot. In this paper, we report the\r\nstatus of several activities related to WCE, including improvement of capsule technology, research progress, technical challenges,\r\nand key indicators concerning the next-generation, active, medical robot....
?is paper analyzes the end-to-end outage performance of high-speed-railway train-to-train communication model in highspeed\r\nrailway over independent identical and nonidentical Nakagami-m channels. ?e train-to-train communication is intertrain\r\ncommunication without an aid of infrastructure (for base station). Source train uses trains on other rail tracks as relays\r\nto transmit signals to destination train on the same track. ?e mechanism of such communication among trains can be divided\r\ninto three cases based on occurrence of possible-occurrence relay trains. ??e ??rst present a new closed form for the sum of squared\r\nindependent Nakagami-m variates and then derive an expression for the outage probability of the identical and non-identical\r\nNakagami-m channels in three cases. In particular, the problem is improved by the proposed formulation that statistic for sum of\r\nsquared Nakagami-m variates with identical m tends to be in??nite. Numerical analysis indicates that the derived analytic results\r\nare reasonable and the outage performance is better over Nakagami-m channel in high-speed railway scenarios....
The modeling, simulation, and analysis of target characteristics are essential to a synthetic aperture radar (SAR) image-based autotarget recognition (ATR) system. The coupling effect between targets and rough surface is also important to the electromagnetic scattering and remote sensing. In this work, the simulations to SAR images of targets above a finite rough surface have been investigated. The effect of rough surface on the target characteristics, or the coupling between the rough surface and targets, is analyzed in details by observing changes of locations and intensities of scattering centers in the SAR images. The SAR images are obtained by taking two-dimensional inverse fast Fourier transforms (FFTs) of the scattered fields, which are computed by the combined high-frequency method of shooting and bouncing ray (SBR) and truncated-wedge incremental-length diffraction coefficients (TW-ILDCs). Simulated results of SAR images for complicated targets above a rough surface are given under the 0.25 Ã?â?? 0.25?m2 resolution at the X band, in which the coupling effect between targets and rough surface has been studied in details....
A design technique for wire antennas, based on the Structure-Based Evolutionary Programming, is used to design a broadband antenna with an end-fire radiation pattern and a very simple geometry, operating in the 3ââ?¬â??16?GHz frequency band, namely, from the S band to the Ku band. The antenna has been analyzed with NEC-2 during the evolutionary process, looking for high gain, good input match, and robustness with respect to realization tolerances. The outcome of our design procedure shows a very good performance....
Loading....