Comparative Performance Evaluation of LoRa RFM-95W and RA-01H Modules at 921.4 MHz Range and Signal Quality Analysis with Rubber Duck and Spring Antennas

This study investigates the impact of antenna selection on the performance of 921.4 MHz Long Range Radio (LoRa) communication, focusing on the relationship between distance, Received Signal Strength Indicator (RSSI), and Signal-to-Noise Ratio (SNR). The RFM-95W and RA-01H LoRa modules were tested with two antenna types, rubber duck and spring antennas, over distances ranging from 50 to 1400 meters. Results show that the rubber duck antenna consistently outperformed the spring antenna, achieving a maximum range of 1400 meters with an average RSSI of -115.8 dBm and an average SNR of -9.6 dB when paired with the RFM-95W module. In contrast, the spring antenna performed better at shorter distances, such as 50 meters, with an average RSSI of -69.4 dBm and an average SNR of 6.1 dB on the same module. The RA-01H module performed best with the rubber duck antenna, achieving a maximum range of 400 meters, with an average RSSI of -120 dBm and an average SNR of -5.4 dB. Environmental factors and antenna characteristics played critical roles, with the rubber duck antenna proving more effective for longer-range communication due to its larger size, higher gain, and greater maximum power input. These findings provide valuable insights for optimizing LoRa systems at 921.4 MHz in Indonesia, aligning with regional regulatory constraints and environmental challenges. The results guide antenna selection based on specific distance and application requirements, offering practical recommendations for deploying LoRa systems in various real-world scenarios where reliable long-range communication is crucial.