design of adaptive matching circuit for intelligent quadrifilar helical antenna using the genetic algorithm
نویسندگان
چکیده
in some mobile systems, intelligent antennas are used to increase efficiency in a wide frequency band and different environmental and electromagnetic conditions. environmental factors, such as position of nearby objects, antenna mobility and even user type, can vary the antenna input impedance appreciably. therefore, it is necessary to incorporate an adaptive impedance matching circuit between the antenna array elements and the transceiver to maximize the antenna radiation power. in this research note, the design of adaptive matching circuit for intelligent quadrifilar helical antenna in the uhf band (for gsm) is presented. the ga algorithm is used to optimize the results. the designed circuit can decrease the vswr from 20 to less than 2 at any frequency within the gsm bandwidth.
منابع مشابه
A Small Printed Quadrifilar Helical Antenna for BGAN/GPS Applications
This paper presents an element of a 2×2-element array antenna for Inmarsat BGAN/GPS applications. The element is an axial mode printed quadrifilar helical antenna that has been integrated with a compact feed network to provide sequential phase rotation for circular polarization (CP) radiation. The novel integrated lumped-element feed network is designed to provide a balanced RF power to the fou...
متن کاملfault location in power distribution networks using matching algorithm
چکیده رساله/پایان نامه : تاکنون روشهای متعددی در ارتباط با مکان یابی خطا در شبکه انتقال ارائه شده است. استفاده مستقیم از این روشها در شبکه توزیع به دلایلی همچون وجود انشعابهای متعدد، غیر یکنواختی فیدرها (خطوط کابلی، خطوط هوایی، سطح مقطع متفاوت انشعاب ها و تنه اصلی فیدر)، نامتعادلی (عدم جابجا شدگی خطوط، بارهای تکفاز و سه فاز)، ثابت نبودن بار و اندازه گیری مقادیر ولتاژ و جریان فقط در ابتدای...
the use of appropriate madm model for ranking the vendors of mci equipments using fuzzy approach
abstract nowadays, the science of decision making has been paid to more attention due to the complexity of the problems of suppliers selection. as known, one of the efficient tools in economic and human resources development is the extension of communication networks in developing countries. so, the proper selection of suppliers of tc equipments is of concern very much. in this study, a ...
15 صفحه اولAn Efficient Adaptive Boundary Matching Algorithm for Video Error Concealment
Sending compressed video data in error-prone environments (like the Internet and wireless networks) might cause data degradation. Error concealment techniques try to conceal the received data in the decoder side. In this paper, an adaptive boundary matching algorithm is presented for recovering the damaged motion vectors (MVs). This algorithm uses an outer boundary matching or directional tempo...
متن کاملinvestigating the feasibility of a proposed model for geometric design of deployable arch structures
deployable scissor type structures are composed of the so-called scissor-like elements (sles), which are connected to each other at an intermediate point through a pivotal connection and allow them to be folded into a compact bundle for storage or transport. several sles are connected to each other in order to form units with regular polygonal plan views. the sides and radii of the polygons are...
simulation and design of electronic processing circuit for restaurants e-procurement system
the poor orientation of the restaurants toward the information technology has yet many unsolved issues in regards to the customers. one of these problems which lead the appeal list of later, and have a negative impact on the prestige of the restaurant is the case when the later does not respond on time to the customers’ needs, and which causes their dissatisfaction. this issue is really sensiti...
15 صفحه اولمنابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
the modares journal of electrical engineeringناشر: tarbiat modares university
ISSN 2228-527 X
دوره 7
شماره 1 2008
میزبانی شده توسط پلتفرم ابری doprax.com
copyright © 2015-2023