CIRCULARLY POLARIZED ARRAY ANTENNA WITH DOLPH TSCHEBYCHEFF POWER DISTRIBUTION

• Main Author: ZASKIA PRATIWI (NIM : 23215059), CITRA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/21533
• Institution: Institut Teknologi Bandung

Array antenna is an antenna that consists of some elements and used to obtain a certain radiation pattern and increase gain. Side lobe in array antenna is desired as low as possible. The way to reduce the side lobe is to use non uniform power distribution. The distribution that can be used are binomial and Dolph Tchebyscheff. In Dolph Tschebycheff distribution, Tchebyscheff polynomial is used to obtain an optimum array for a certain side lobe level. Side lobe level is the ratio of amplitude between main lobe and side lobe. In this research, the design and realization of microstrip array antenna 1x5 use square patch. This array antenna uses multiple slots to achieve wider bandwidth. The slots are located diagonally over the patch to produce circular polarization. The antenna is designed to work at C-band frequency with a center frequency around 5.3 GHz. Antenna is fed by proximity coupling and connected to 50Ω SMA connector. In the proximity coupling method, the feedline is located between two substrates and the patch is located over upper substrate. Both substrates has the thickness of 0.8 mm and are implemented using FR4 Epoxy with a relative permittivity (εr) of 4.3. Array antenna has the total dimension of 119 mm × 44.1 mm. Bandwidth based on the simulation result for Dolph Tschebycheff distribution of 760 MHz whereas bandwidth that obtained by uniform distribution is 740 MHz. Side lobe level for Dolph Tschebycheff distribution is 14.99 dB and for uniform distribution is 9.1 dB so that there is the side lobe suppresion of 5.89 dB.