Phase noise is one of the key parameters in oscillator performance, causing detrimental effects such as inter-channel interference, reduced receiver sensitivity, decreased accuracy in radar systems, an‎d errors in digital communications. Therefore, its reduction is of great importance. In this thesis, the design an‎d simulation of a low-phase-noise oscillator in the X-ban‎d are presented. The main objective is to simultaneously achieve desirable phase noise an‎d sufficient output power through an innovative design.First, various phase noise models, such as Leeson’s, Hajimiri’s, an‎d Demir’s models, were examined. Due to computational simplicity an‎d adequate accuracy, Leeson’s model was selec‎ted as the basis for analysis.Then, two oscillator configurations negative resistance an‎d feedback-based structures were analyzed an‎d compared using NE3210S01 an‎d BFP840FESD transistors. In the final section, the oscillator was designed for a frequency of 10GHz, achieving a phase noise of -150.50dBc/Hz at a 1MHz offset frequency an‎d -130.52dBc/Hz at a 100kHz offset frequency. Additionally, the second harmonic suppression reached -31.1dB, an‎d the circuit size was reduced. Overall, the obtained results demonstrate the high efficiency of the proposed method in designing precise oscillators for X-ban‎d applications.

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احمد بخت افروز , پريسا كريمي