7649

7121

كارشناسي ارشد

مخابرات

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1391

نه،96ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

رضا صفيان

ابوالقاسم زيدآبادي

26/1/92

مهندسي برق و كامپيوتر

ID7121

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Wideband Microwave Couplers Shirin nejat s nejat@ec iut ac ir Date of Submission 2012 12 1 Department Of Electrical And Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisore Reza Safian rsafian@cc iut ac ir Abstract Researche experience and scientific advances in the field of high frequency show that wave guiding structures play a effective role in the evolution and innovation of the microwave circuits The necessity of design and construction of communication subsystems and devices used in microwave frequencies increases the importance of correct understanding and accurate analysis and synthesis of subsystems One of the most widely used devices of microwave elements is coupler low cost and simple construction has its own importance Therefore the type of coupler should be choosen appropriately according to the manufacturing facilities Couplers are used to split and combine microwave signals and sampling The general structure for a coupler is including two transmision line With a mechanism for coupling between them Therefore design and construction of these instruments has its own particular importance In this thesis a novel wideband microstrip 90 3dB branch line coupler is proposed The design process is carried out using coupler theory Then a hybrid coupler 3dB 90 is designed and simulated at 4GHz Simulated result of the coupler indicate low insertion loss and the coupling remains almost constant and appropriate isolation over the coupler bandwidth Also larger bandwidth can be achieved Finally the coupler is fabricated and measured to provide and experimental demonstration of its actual branchline coupler performances Good agreements between the measurement and simulation result are achieved and demonstrated Keyword Directional coupler Branchline coupler Microwave circuits Wideband Microstrip line

رضا صفيان

ابوالقاسم زيدآبادي