DEVELOPMENT OF FULL DUPLEX ANTENNA USING 3D PRINTING TECHNOLOGY AT 2.4 GHZ FOR WIRELESS COMMUNICATION APPLICATIONS

• Main Author: Fairuz Faadhilah, Avelia
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/87641
• Institution: Institut Teknologi Bandung

Wireless communication has become an important part of modern technology, allowing data exchange via electromagnetic waves between devices. In this system, the antenna plays an important role as the main component for transmitting and receiving signal waves. One of the frequencies widely used in wireless communication is 2.4 GHz because of its global availability and license-free status in many countries. Full duplex communication system is a communication system where transmitting and receiving signals can be done at the same frequency and time so that spectral efficiency can increase up to 2 times. However, this communication system requires high isolation to overcome self-interference that occurs due to transmit signals leaking to the receive port (Rx). In addition to high isolation, light weight is also an essential parameter in the antenna realization to ensure that the device remains efficient and easy to integrate into the wireless communication system. In this case, 3D printing technology emerges as a solution because it allows the manufacture of antenna structures with lighter weight. Therefore, this study aims to develop full duplex antenna with high isolation and lightweight using 3D printing technology at a frequency of 2.4 GHz for wireless communication applications. This research method involves several stages, such as design, optimization, realization, measurement, and analysis of the antenna results. Simulations are carried out using electromagnetic software to design the optimal antenna. There are two isolation techniques used in the design, namely polarization diversity and phase diversity using a hybrid ring coupler where a three-port microstrip antenna with a 180° hybrid coupler is used to improve isolation between ports. The antenna realization uses Acrylonitrile Butadiene Styrene (ABS) material printed with 3D printing technology as a substrate. This material was chosen because it has a light density (1.0–1.05 g/cm³) compared to conventional materials such as FR-4, which has a 1.7–1.9 g/cm³ density. Manual painting techniques using copper ink with an assumed thickness of 0.1 mm are applied to the surface of the patch and antenna ground. The main parameters measured to validate the design results include reflection coefficients (S11, S22, S33), isolation coefficients (S21, S13, S23), bandwidth, and antenna gain. The results of the study indicate that the realized full duplex microstrip antenna has good performance where the S-parameter value for the three ports has reached a iv value below -10 dB. The isolation between the transmit and receive ports measured is -46 dB, which meets the isolation criteria for a full-duplex system. However, there are some differences in the results between the simulation and realization due to the deformation of the shape of the antenna due to the use of thin materials. This deformation affects the effective length of the antenna, which then impacts the shift in the resonance frequency. In addition, variations in the conductivity of the paint from manual painting also affect the depth of the measured antenna. Further optimization is being carried out to improve the performance of the designed antenna so that it can work better at the expected working frequency. However, the reported results indicate that the developed antenna can be used for wireless communication systems.