Evolution and Move toward Fifth-Generation Antenna

With the introduction of various antennas in the field of antenna technology, most of the constraints related to the transmission and receiving of the signals at different intervals have been resolved. By the rapid growth in industry and consequently high demands in the communication arena, the conventional antennas are unable to respond to these extended requirements. However, those initial antennas were suitably used in the field of technology. In the recent decades, by introducing new antenna technologies such as metamaterial structures, substrate integrated waveguide (SIW) structures and microstrip antennas with various feeding networks could meet the demands of the current systems. As stated before, in the frequency ranges of below 30 GHz, antenna size and bandwidth are of the important issues, so that novel antennas can be created in low frequencies, which are able to achieve reliable radiation properties when combined with new multiband antennas. Generally, transmission lines are practical in low frequencies and short distances, while higher frequencies are mainly used due to bandwidth goals. This chapter is organized into three subsections related to the 5G wireless communication systems: antennas below 15 GHz or accordingly antennas with wavelength less than 1/20; antennas operating between 15 and 30 GHz; higher frequency antennas or millimeter-wave antennas, which are desired for above 40 GHz

Low-Loss and Dual-Band Filter Inspired by Glide Symmetry Principle Over Millimeter-Wave Spectrum for 5G Cellular Networks

This paper focuses on designing a dual-band, bandpass filter configuration inspired by glide-symmetric structures in a single plane. Geometry configuration of elliptical slots on both sides of single substrate generally affects electromagnetic fields as well as rejection bands. Easy fabrication with misalignment avoidance during assembly procedure unlike conventional structures based on gap waveguide technology, make them appropriate to use in electromagnetic devices. Parametric study on dispersion characteristics is carried out in this article to find out how rejection-bands are offered through breaking the symmetry. A method for producing symmetry is also suggested, which may be helpful for reconfigurable devices. Moreover, equivalent circuit model is demonstrated to get insight of the mechanism of the presented glide symmetry scheme. The transmission frequency ranges of two passbands with center frequencies of 19.74 GHz and 28.233 GHz are shown by the measured and calculated S- parameters of five unit-cell structures

Effectiveness of Emotional Intelligence Training in Addiction Potential among Students

Objective: The present study was carried out to investigate the effectiveness of emotional intelligence training in addiction potential among male students of Shahid Chamran University of Ahwaz. Method: This study was conducted as a quasi-experimental one with pre-test and post-test and a control group. The statistical population of the study consisted of undergraduate male students of Shahid Chamran University of Ahwaz in 2012-2013. From the number of 600 students in the initial sample, 30 students qualified with the inclusion criteria for entering the study were selected via criterion sampling and, then, were randomly assigned to two groups. Having received eight 90-minute training sessions (twice a week), the experimental group completed the post-test. The control group also completed the post-test while they received no intervention. Zargar’s addiction potential scale (2006) was used as the measurement instrument of this study. Results: The results of the study showed the effectiveness of emotional intelligence training in reducing students’ addiction potential. Conclusion: Emotional intelligence training is effective in reducing students’ addiction potential

Laparoscopic Adjustable Gastric Banding Connecting Tube Causing Small Bowel Obstruction and Perforation

Background. Laparoscopic adjustable gastric banding (LAGB) is an effective method of reducing excess weight in obese patients. We report a patient who developed a bowel obstruction caused by the connecting tube between the gastric band and the injection port. Case Presentation. The patient was a 42-year-old Caucasian female who had undergone LAGB 19 months earlier. She presented with dehydration, low-grade fever, tachycardia, and mild abdominal tenderness. Laparotomy revealed that the connecting tube was looped around the mesentery, and a loop of small bowel was incarcerated between the tube and the mesentery. The incarcerated small bowel loop was perforated in two places. Conclusion. Surgeons should be aware of the possibility of obstruction caused by the connecting tube in patients who have undergone LAGB

Low-loss and dual-band filter inspired by glide symmetry principle over millimeter-wave spectrum for 5G cellular networks

Summary: This paper focuses on designing a dual-band, bandpass filter configuration inspired by glide-symmetric structures in a single plane. Geometry configuration of elliptical slots on both sides of single substrate generally affects electromagnetic fields as well as rejection bands. Easy fabrication with misalignment avoidance during assembly procedure unlike conventional structures based on gap waveguide technology, make them appropriate to use in electromagnetic devices. Parametric study on dispersion characteristics is carried out in this article to find out how rejection-bands are offered through breaking the symmetry. A method for producing symmetry is also suggested, which may be helpful for reconfigurable devices. Moreover, equivalent circuit model is demonstrated to get insight of the mechanism of the presented glide symmetry scheme. The transmission frequency ranges of two passbands with center frequencies of 19.74 GHz and 28.233 GHz are shown by the measured and calculated S- parameters of five unit-cell structures

Reconfigurable intelligent surfaces as the key-enabling technology for smart electromagnetic environments

Future wireless systems integrating communication and sensing will require handling an enormous amount of data with extremely low latency. Intense video streaming data traffic, pervasive-augmented and virtual reality services, advanced haptic-tactile interaction and holography-type communications, in fact, reveal a trend towards experience-based networks and multi-sense media, which require seamless connectivity and ultra-high capacity. Using current 5G technologies to take mentioned challenges, might not represent the desired solution and a completely new paradigm is needed. Recently, to support this change, scientists have been focusing on the concept of Smart Electromagnetic Environments (SEE), based on deploying a number of smart nodes, whose electromagnetic response needs to be finely adapted to the changing operative conditions. In this framework, a pivotal role is played by reconfigurable intelligent metasurfaces, allowing the implementation of smart skins, reflecting intelligent surfaces, smart repeaters, and intelligent antennas. This paper aims at offering an insightful review of the role of intelligent metasurfaces in advancing the concept of SEE. Different application domains will be illustrated: advanced signal processing at the physical layer, a new generation of smart antennas whose intelligence is enabled by the physical layer, and practical implementation of reflecting intelligent surfaces. With an in-depth analysis of these areas, this review sheds light on how intelligent metasurfaces drive innovation in wireless communication shaping the future of SEEs