DIFFERENTIALLY FED RING PRINTED ANTENNA ARRAY FOR LBAND SAR APPLICATION

• Main Author: Sahlendar Asthan - NIM: 23216101 , Rheyuniarto
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/30394
• Institution: Institut Teknologi Bandung

In this research, a differentially fed ring printed antenna array configured by a circular ring-shaped is designed, simulated, and realized. The antenna is designed to work at frequency of 1,275 GHz for L-band synthetic aperture radar (SAR) application. Differentially fed at the opposite edge sides is adopted to have symmetrical radiation pattern. The proposed antenna is deployed on FR-4 Epoxy dielectric substrate with the thickness of 1,6 mm. The antenna design consists of single and array element of rings. For single antenna, a half-ring element is added inside the main ring and compared to single antenna without half-ring. Different feeding methods and number of input ports are also configured and analyzed. Meanwhile, antenna array is arranged by using 1 5 and 4 5 elements. Single antennas with and without half-ring using microstrip line with two input ports have wide impedance bandwidth of 450 MHz (fBW of 35,29%). A symmetrical radiation pattern is obtained in E-plane by using proximity coupling yet has narrow impedance bandwidth of 30 MHz (fBW of 2,35%). The realized antenna is ring printed antenna array which consists of 5 elements. The characterization result shows a good agreement between the simulation and measurement. It is noticed that the proposed antenna can work properly at the desired frequency of 1,275 GHz with good performance in S11 and VSWR of 25,56 dB and 1,11, respectively. The antenna has impedance bandwidth of 30 MHz from 1,26 GHz to 1,29 GHz and gain of 15,83 dBi at frequency of 1,275 GHz. The measured 3-dB beamwidth in E-plane with azimuth ( ) of 0o and 90o are 103o and 52o, respectively, while in H-plane with elevation ( ) of 90o is 96o. The optimized ring printed antenna array 1 5 has dimension of 61,4 mm 173 mm.