DESIGN AND IMPLEMENTATION OF RAT-RACE COUPLER IN TRACKING RADAR FMCW S-BAND

• Main Author: Karunia Ramadhan - NIM 18113012 , Dina
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/26672
• Institution: Institut Teknologi Bandung

<p align="justify">Monopulse tracking system of FMCW tracking radar is a tracking technique that compare the magnitude of the two or more receiver antennas. This system requires a component to produce &#931; (sum) and &#916; (difference) channels to compare two the received signals so the target’s position can be defined. In this final project, rat-race coupler is designed to be applied in monopulse tracking system of FMCW tracking radar. This component has function as &#931; and &#916; channels producer. Center fequency of this coupler is following the center frequency of the radar, S-band 2.95 GHz. Rat-race coupler is designed in microstrip form. The design and implementation process of rat-race coupler begins with design the simulation using a software. During the simulation process, optimization of size parameters to obtain the best result. Then the final design is proceed to fabrication process. Then the fabricated rat-race coupler is measured to know some parameters such as return loss and phase of each port. The result gives minimum return loss in frequency 2.73 GHz. Phase difference between port 4 and port 1 when input is coming from port 3 is 1.9o (close to 0o). When the input is coming from port 2 the phase difference between them is 180.629o (close to 180o). Application of rat-race coupler in monopulse tracking system has function as producer of &#931; channel and &#916; channel from two receiver identic antennas. Then this information is used to monopulse tracking system by using power detector and Arduino Uno that will compare the &#916; voltage from two diffence angles. So position of the target can be found. <p align="justify"> <br />