11042

10173

كارشناسي ارشد

مخابرات (ميدان)

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1394

چهارده، 92ص.: مصور

ابوالقاسم زيدآبادي نژاد

محسن مداح علي

ذاكر حسين فيروزه، رضا صفيان

1394/12/01

مهندسي برق و كامپيوتر

ID10173

Design and Simulation of a Reflectarray Antenna in X band for Cosecant Squared Radiation Pattern Shabnam Rouzbahani s rouzbahani@ec iut ac ir January 12 2016 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Persian Supervisor Assoc Prof Abolghasem Zeidaabadi Nezhad zeidabad@cc iut ac ir Abstract Cosecant squared radiation pattern is one of the specific radiation patterns which is used for search and surveillanceradars A feature that distinguishes this radiation pattern from others is that the received power from a target with a range independent radar cross section flying at constant height is range independent The important of using of this radiationpattern is in elevation that has wide beam and is suitable for search radar Different ways to form cosecant squared radiation pattern are provided The first method is to form the reflector surface The second method is to use an array antenna in front of the parabolic reflector so that the amplitude and phase of eacharray element is determined The third method is the use of stacked beams and the parabolic reflector so that each feedproduce a specific beam and finally the beams in a microwave circuit with different weights are combined and cosecantsquared pattern is resulted In this thesis a reflectarray antenna with an open ended waveguide feed in X band to produce cosecant squared radiationpattern is designed and simulated The design is based on the distribution of non linear phase of each reflectarray antennaelement Two reflectarrays with two different unit cells as single layer and two layer are designed and simulated the resultsare satisfactory Key Words Cosecant squared Radiation Pattern Reflectarray Shaped Parabolic Reflector

ابوالقاسم زيدآبادي نژاد

محسن مداح علي

ذاكر حسين فيروزه، رضا صفيان