Purpose: This study focuses on the design and evaluation of dipole antennas for Unmanned Aerial Vehicles (UAVs) operating at a frequency of 433 MHz. The aim is to develop small and lightweight antennas that do not compromise the aerodynamic characteristics of UAVs, ensuring effective communication between the UAV and the Ground Control Station (GCS). Methodology: The research employed CST software to design and simulate dipole antennas using various materials, including copper, gold, silver, aluminum, and iron. The simulation parameters were analyzed in terms of Voltage Standing Wave Ratio (VSWR) values and return loss. Results: The simulation results revealed that the silver antenna material exhibited the best performance, with a VSWR value of 1.3191 and a return loss of -17.222 dB. However, during the fabrication stage, copper was chosen for the antennas, which yielded a VSWR measurement result of 1.427 and a return loss value of -15.09 dB. Subsequent testing of the dipole antenna's communication distance, when placed on a UAV, resulted in a Received Signal Strength Indicator (RSSI) value of -70.68 dBm. This indicated that the antenna maintained a signal quality of 96% at a distance of 2.5 km. Limitation: One limitation of this study is that it primarily focuses on simulations and testing at a specific frequency (433 MHz) and material selection (copper for fabrication). The results may not be directly applicable to different frequencies or materials used in UAV antennas. Additionally, real-world conditions, such as environmental interference, could affect the performance of the antennas. Contribution:This research contributes to the development of efficient and lightweight dipole antennas for UAVs, ensuring reliable communication with GCS. The findings, particularly the choice of copper for fabrication, provide valuable insights for improving UAV communication systems without compromising flight performance.

Purpose: This research focuses on the design and analysis of a helix antenna operating at 433 MHz with a 4 MHz bandwidth. The study aims to investigate the antenna's performance and functionality, with a focus on reception capabilities. Methodology: The initial design of the helix antenna was conducted through simulation. Subsequently, the fabricated antenna was tested using a 6000 A vector network analyzer. The research evaluated various antenna parameters, including return loss (-19.8866 dB), Voltage Standing Wave Ratio (VSWR) (1.22547), and impedance (46.5695 Ohms). The helix antenna's radiation pattern was found to be directional, with a simulated gain of 9.231 dB. A 1000 mW radio telemetry module served as the signal source during testing. Results: The research findings demonstrate that the helix antenna, designed to operate at 433 MHz, is functional as a receiver. The test results revealed a maximum transmission distance of 2.6 kilometers, with signal strength measurements presented in Received Signal Strength Indicator (RSSI) values (%). However, it is important to note that the obtained data during testing were suboptimal. This suboptimal performance can be attributed to less-than-ideal outdoor line-of-sight conditions due to various obstacles affecting signal reception. Limitation: A limitation of this study is that the outdoor line-of-sight conditions during testing were not optimal, which impacted the signal strength received by the antenna. Additionally, the study primarily focuses on reception capabilities, and further research may be needed to explore other aspects of the helix antenna's performance. Contribution: This research contributes to the understanding of the functionality of a helix antenna operating at 433 MHz as a receiver. Despite suboptimal testing conditions, the study confirms the antenna's usability for reception purposes and provides valuable insights into its performance characteristics.