Analisa Teknik Dua Polinomial untuk Penekanan Sidelobe

Lubis, Andi Yahya (2018) Analisa Teknik Dua Polinomial untuk Penekanan Sidelobe. Undergraduate thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Dalam radar, antena array sangat umum digunakan karena memiliki nilai gain yang besar dan semakin banyaknya elemen yang digunakan nilai puncak sidelobe yang dihasilkan semakin rendah. Namun jumlah sidelobe akan semakin banyak dan sistem akan semakin kompleks. Untuk membatasi jumlah elemen, diperlukan metode yang menghasilkan nilai puncak sidelobe yang rendah. Metode sidelobe suppression (SLS) dengan teknik dua polinomial merupakan metode penekanan nilai sidelobe dengan cara mengalikan dua faktor array. Dengan jumlah elemen dan null yang ditentukan, pola radiasi yang didapat pada polinomial pertama digunakan untuk mencari posisi null kanan dan kiri yang berdekatan dengan mainlobe. Daerah diluar null tersebut dimanfaatkan untuk wilayah sidelobe serta digunakan untuk mencari weight dari polinomial kedua yang ditujukan untuk penekanan sidelobe. Dalam penelitian ini, metode dua polinomial dibuat berdasarkan rumus dan masukan data yang diberikan pada literatur penelitian Zafar-Ullah, Aqdas dan Fahad yang berjudul “Efficient Sidelobe Suppression by Matching Beam in Two Polynomial Technique”. Hasil simulasi kemudian dibandingkan dengan pola radiasi antena array uniform linier dengan 9 elemen dan jarak antar elemennya sebesar λ /2. Berdasarkan hasil simulasi, puncak sidelobe level (PSLL) yang dihasilkan pada antena array dengan metode dua polinomial sebesar -21,07 dB dan lebih rendah dibandingkan dengan PSLL pada antena array tanpa metode yaitu sebesar -11,92 dB. ====================================================================================================== On RADAR, an antenna array is usually used because it has high gain and it’s sidelobe level getting lower as the more elements were used. But it also will increase the number of sidelobes and the system will be more complex. To limit the number of sidelobes, a method is needed to achieve lower of peak sidelobe level. Sidelobe suppression method with two polynomial technique is a method to suppress sidelobe by multiply two array factor. With the desired number of element and null, the radiation pattern which is got from the first polynomial is used for searching the position of right and left null, which is close to the main lobe. The region outside that null is called sidelobe region and used to search the weight of the second polynomial and that weight is used for sidelobe suppression. The result of this research is the analysis of two polynomial methods on suppressing sidelobe. On this research, this two polynomial technique was made based on the formulation and data input which was given on the Zafar-Ullah, Aqdas and Fahad research literature by title “Efficient Sidelobe Suppression by Matching Beam in Two Polynomial Technique”. The result of the simulation then being compared to the radiation pattern of the antenna array with 9 elements and space between element is λ /2. Based on the simulation, the result of peak sidelobe level (PSLL) of the antenna array with two polynomial technique is -21,07 dB and that is lower than PSLL of antenna array without that technique is -11,92 dB.

Item Type: Thesis (Undergraduate)
Uncontrolled Keywords: Sidelobe suppression, array factor, null steering, adaptive beamforming, uniform linear array.
Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK5101 Telecommunication
Divisions: Faculty of Industrial Technology > Electrical Engineering > (S1) Undergraduate Theses
Depositing User: Lubis Andi Yahya
Date Deposited: 07 Mar 2018 06:36
Last Modified: 07 Mar 2018 06:36
URI: http://repository.its.ac.id/id/eprint/49644

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