Submitted in partial fulfillment of the requirements for master in electric engineering

مقطع كارشناسي ارشد/ رشته مهندسي مخابرات/ دانشگاه رازي دانشكده مهندسي برق
عنوان پايان نامه:Submitted in partial fulfillment of the requirements for master in electric engineering
نگارش: علي جمال الدين/ استاد راهنما: دكتر قاسم عظيمي

چکیده

Abstract
Filter networks are essential building elements in many areas of RF/microwave engineering, such networks are used to select /reject or separate/combine signals at different frequencies [1].
In this project, a compact microstrip lowpass filter with ultra wide stopband and sharp roll-off is presented. To achieve a sharp roll-off a ring resonator is used, also to achieve an ultra wide stopband response, rectangular and tapered shape suppressing cell are used. The proposed filter is fabricated, simulated and measured. Moreover, a microstrip lowpass filter with compact size, wide stopband and low transition band using couple radial stubs are designed. To have wide stopband, bended transmission lines with stepped impedance suppressing cells are employed.
Keywords: couple radial stub resonator; low insertion loss; lowpass filter; modified ring resonators; sharp roll-off.