The Effect of Feeding Technique on the Parameter Analysis of 5G ‎Applications Dual Bands Microstrip Patch Antenna

أدى التطور السريع لتقنيات المحمول مثل G4 و G5  والشبكات اللاسلكية إلى مزيد من البحث لتوظيف نطاق جديد من الترددات ، إلى جانب ضرورة تقليل الحجم واستهلاك الطاقة ، علاوة على ذلك ، فإنه يركز على الهوائيات المرنة التي يمكن استخدامها في مجموعة واسعة من التطبيقات. يبحث هذا البحث في تصميم الهوائي بثلاث طرق تغذية (تغذية خط ميكروستريب ، تغذية متقاربة متقاربة ، تغذية مقترنة بفتحة عدسة) ويكتشف أفضل طريقة تغذية. في التصميم المقترح، تم استخدام Rogers RT / duroid ™ 5880 كركيزة ، وتمت محاكاة جميع التصميمات المقترحة عبر محاكاة برامج تقنية محاكاة الكمبيوتر. (CST) من المفترض أن يعمل الهوائي بترددات 6 و 28 جيجاهرتز. كعنصر إشعاعي ، يتم استخدام رقعة نحاسية مستطيلة ، والأرض مصنوعة من النحاس. تم فحص المعلمات الرئيسية للهوائي مثل الكسب والاتجاهية وكفاءة الإشعاع و VSWR.The rapid development of mobile technologies such as 4G and 5G and wireless networks lead to more research to employ a new range of frequencies, along with the necessity of reducing size and power consumption, moreover, it focuses on flexible antennas that can be used in a wide range of applications. This research investigates antenna design with three feeding methods (microstrip line feed, proximity coupled feed, and aperture coupled feed) and finds out the best feeding method. In the proposed design, a Rogers RT/duroid™ 5880 is used as a substrate, and all of the proposed designs were simulated via computer simulation technology (CST) software simulations. The antenna is supposed to operate at frequencies of 6 and 28 GHz. As a radiative element, a rectangular copper patch is used, and the ground is made of copper. The antenna main parameters like gain, directivity, radiation efficiency and VSWR were investigated

Efficient systematic turbo polar decoding based on optimized scaling factor and early termination mechanism

In this paper, an efficient early termination (ET) mechanism for systematic turbo-polar code (STPC) based on optimal estimation of scaling factor (SF) is proposed. The gradient of the regression line which best fits the distance between a priori and extrinsic information is used to estimate the SF. The multiplication of the extrinsic information by the proposed SF presents effectiveness in resolving the correlation issue between intrinsic and extrinsic reliability information traded between the two typical parallel concatenated soft-cancellation (SCAN) decoders. It is shown that the SF has improved the conventional STPC by about 0.3 dB with an interleaver length of 64 bits, and about 1 dB over the systematic polar code (SPC) at a bit error rate (BER) of . A new scheme is proposed as a stopping criterion, which is mainly based on the estimated value of SF at the second component decoder and the decoded frozen bits for each decoding iteration. It is shown that the proposed ET results in halving the average number of iterations (ANI) without adding considerable complexity. Moreover, the modified codes present comparable results in terms of BER to the codes that utilize fix number of iterations

Modeling and performance evaluation of antennas coated using monolayer graphene in the millimeter and sub-millimeter wave bands

Abstract In the applications of millimeter and sub-millimeter wave, the conductivity of metal parts in electronic devices can easily degrade when conventional metals like copper are employed. Furthermore, oxidation may arise when such devices are utilized in severe environmental conditions. To avoid this, conventional conductors such as copper can be coated with other non-active materials to inhibit this problem. Monolayer graphene is used in this study as a coating layers for copper in millimeter-wave antennas. Two types of graphene coatings are investigated: non-doped and doped monolayer graphene. These coatings can either be used as the patch, ground or both conducting layers of a microstrip patch antenna. Results showed that coating using doped graphene improves the performance of antenna in terms of gain, radiated power and radiation efficiency by 11.81%, 8.48%, and 11.48%, respectively, compared to antennas made using copper and coated using gold and non-doped graphene at millimeter-wave frequencies. Meanwhile, at sub-millimeter wave frequencies, the metal (copper and gold)-based antenna showed worse performance compared to millimeter waves. Furthermore, coating of the conducting elements for the sub-millimeter wave antenna using doped and non-doped graphene improved gain, radiated power and radiation efficiency by 33.94%, 32.73%, and 32.01%, respectively, for the coating with doped graphene, and about 14.87%, 16.56%, and 15.72% for the coating with non-doped graphene. This indicates the suitability of graphene-based antennas in both frequency bands and the expected levels of improvements for different parameters when these antenna elements are coated with doped and non-doped graphene