15686

14019

كارشناسي ارشد

مخابرات (ميدان و موج)

اصفهان : دانشگاه صنعتي اصفهان

1399

سيزده، 110ص. : مصور، جدول، نمودار

ابوالقاسم زيدآبادي‌نژاد

احمد بخت‌افروز

محسن مداح علي، مسعود عمومي

1399/05/13

كتابنامه

برق

مهندسي برق و كامپيوتر

1399/05/13

2625377

Analysis Design Simulation and Construction of a Microwave Metamaterial Inspired Small Antenna Javad Ghasemi Vincheh j ghasemi@ec iut ac ir July 20 2020 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Assoc Prof Abolghasem Zeidaabadi Nezhad zeidabad@cc iut ac ir AbstractDue to the increasing use of wireless communication devices such as cell phones and newer applications such as the Internetof Things IOT and smart cars efforts to reduce the size and weight of electrical circuits which lead to shrinkage of theentire system are unavoidable thus it is essential to pay attention to proper antenna design as a key part of all wirelesscommunication systems Since the desired characteristics of the antenna such as bandwidth and radiation efficiency aredirectly related to its dimensions and as the dimensions get smaller the antenna performance may be lost therefore there arefundamental limitations in antenna miniaturization which is a major challenge in antenna design and forces the designer toestablish a trade off between design parameters In this thesis using structure called metamaterial inspired which consistof a single metamaterial unit cell an electrically small antenna in 2 4 GHz WiFi band has been designed simulated andfabricated The measurement results are in good agreement with theory The structure of this antenna consists of a planardipole antenna printed on the FR 4 substrate which is approximately one third the length of a half wave dipole By placinga specially designed parasitic element in the nearfield region of the dipole that is on the other side of the substrate thewhole structure acts as a resonant RLC circuit Therefore the impedance matching between the antenna and the source isdone without an external matching circuit Matching is also done between the antenna and the free space i e the desiredradiation efficiency is achieved For this antenna the fractional bandwidth is about 4 the radiation efficiency is 86 andthe maximum gain is about 1 2 dBi The radiation pattern of this antenna is monopole like and has linear polarization Also the ka parameter which is a measure of the electrically small size of the antenna is equal to 0 74 and because ka 1 it indicates that the antenna is small Antenna with such features is suitable for various IoT applications but with slightchanges in some parameters the desired frequency range for the intended application is obtained easily Key Words Electrically Small Antenna Metamaterial Metamaterial Inspired Nearfield ResonantParasitic Element

ابوالقاسم زيدآبادي‌نژاد

احمد بخت‌افروز

محسن مداح علي، مسعود عمومي