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Design, Fabrication, and Experimental Evaluation of a 435 MHz Helical Antenna for 433 MHz IoT Modules Rusfa Rusfa; Rozeff Pramana; Bavitra Bavitra; Ferly Oktavia; M. Hasbi Sidqi Alajuri; Andreas M Simannulang
Jurnal Elektronika dan Telekomunikasi Vol. 25 No. 2 (2025)
Publisher : National Research and Innovation Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/jet.813

Abstract

The rapid growth of wireless communication demands within Internet of Things (IoT) applications requires antennas that exhibit high efficiency, compact dimensions, and reliable performance in the UHF band. This study aims to design, simulate, fabricate, and evaluate the performance of a helical antenna operating at 435 MHz, with its results compared against a slot antenna. The design process was conducted using CST Studio Suite with parameter optimization to achieve an optimal configuration. The prototype was fabricated using copper wire as the radiating element and an aluminum ground plane. Experimental testing was carried out with a UHF Antenna Demonstrator, followed by validation through a 433 MHz RF module integrated with Arduino. The simulation results indicated that the optimized helical antenna achieved aVoltage Standing Wave Ratio (VSWR) of 1.8 and a gain of 11.5 dBi. In contrast, the measurement results demonstrated improved performance, with a VSWR of 1.05, a return loss of −32.4 dB, and a bandwidth of 41 MHz. Comparative analysis revealed that the helical antenna outperformed the slot antenna in terms of efficiency, directional radiation pattern, and transmission distance, reaching up to 25 m compared to 15 m for the slot antenna. These findings confirm that the helical antenna is a more suitable and effective solution for UHF IoT communication systems, providing reliable performance for modern wireless applications.
Detecting Shallow Water Submarine Cables with Single Beam Echosounder in Tidung Island M Hasbi Sidqi Alajuri; Henry M. Manik; Muhammad Zainuddin Lubis; RozeffPramana; Basyaruddin Islmail Harahap; Doli Bonardo; Marisha Pertiwi; Suhengki
Journal of Applied Geospatial Information Vol. 10 No. 1 (2026): Journal of Applied Geospatial Information (JAGI)
Publisher : Politeknik Negeri Batam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30871/jagi.v10i1.12118

Abstract

Detecting submarine cables in tropical shallow waters remains challenging due to environmental complexity and the similarity of backscatter signatures to other seafloor objects. This study characterizes the acoustic backscatter response of two types of submarine cables concrete-armored and non-armored in the waters of Tidung Island using a SIMRAD EK-15 and a Furuno FCV-628 echosounder operating at 200 kHz. Data processing was conducted to derive Volume Backscattering Strength (SVc) and Surface Scattering Strength (SS). Measurements of the concrete-armored cable using the Furuno system produced SVc values of −6.701 dB and −5.055 dB, and SS values of −11.855 dB and −9.510 dB, indicating high reflectivity due to the impedance contrast between concrete and seawater. In contrast, measurements of the non-armored cable using the SIMRAD system yielded SVc values of −11.547 dB and −12.600 dB and SS values of −14.612 dB and −15.665 dB, reflecting weaker and more variable returns caused by direct exposure of the cable structure to sediments and hydrodynamic forces. The consistent differences between the two cable types demonstrate that each structure exhibits a distinctive acoustic signature that can be used as a discriminating parameter for mapping. This study provides important empirical evidence by presenting direct acoustic backscatter characterization of submarine cables in Indonesia and demonstrates that commercial echosounders can reliably support infrastructure inspection in shallow-water environments.
Implementation of IoT-based water quality monitoring instruments in cantang grouper cultivation ponds Hollanda Arief Kusuma; M Hasbi sidqi Alajuri; Anggarudin Anggarudin; Dwi Eny Djoko Setyono; Henky Irawan
Computer Science and Information Technologies Vol 6, No 3: November 2025
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/csit.v6i3.p235-244

Abstract

Grouper fish farming in Indonesia has great potential, but water quality management remains a challenge. Manual monitoring at hatchery D-Marine aquaculture struggles to detect sudden changes, risking mass mortality. This study developed an IoT-based water quality monitoring system using an ESP32 microcontroller, DS18B20 temperature sensors, pH sensors, dissolved oxygen (DO) sensors, a micro-SD card, an organic light emitting diode (OLED) display, and the Ubidots platform. The methodology involved device design, sensor calibration, and field testing. Calibration showed sensor accuracy above 90%. Field tests recorded water temperatures of 26.84 °C (tank 1) and 27.74 °C (tank 2), with pH values of 6.73 and 6.87, which did not meet Indonesian national standard (SNI) standards. Data transmission to Ubidots had a 95% packet delivery ratio (PDR) for device 1 and 97% for device 2. The system successfully provided real-time water quality data, supporting effective farm management. However, improvements to the dissolved oxygen sensor and an automatic control system are needed for better stability and efficiency.
Improving the Quality of X-Ray Images of the Lungs of COVID-19 and Healthy Patients Using the Contrast Limited Adaptive Histogram Equalization (CLAHE) Method in Batam Marisha Pertiwi; Fortia Magfira; Dwi Rahmaisyah; M. Hasbi Sidqi Alajuri
JEECS (Journal of Electrical Engineering and Computer Sciences) Vol. 10 No. 1 (2025): June
Publisher : Fakultas Teknik Universitas Bhayangkara

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.54732/jeecs.v10i1.3

Abstract

X-ray imaging is a widely used technique for observing lung patients conditions. Compared to other radiographic methods, X-ray is more accessible, cost-effective, and commonly available in healthcare facilities. However, digital X-ray images often suffer from low quality, particularly in terms of image contrast, which complicates the process of identifying lung abnormalities accurately. In Embung Fatimah Hospital in Batam, X-ray imaging is routinely used to screen COVID-19 and healthy patients. To address the issue of poor image contrast, this study applies the Contrast Limited Adaptive Histogram Equalization (CLAHE) technique, aiming to enhance image clarity and support more effective analysis. The research involved 20 lung X-ray images, consisting of 10 from COVID-19 and 10 from healthy patients, retrieved from the hospital’s radiology department system. The images underwent digital processing using Matlab software. The workflow included converting the images to grayscale before applying contrast enhancement with the CLAHE method, using three different distribution types: Uniform, Rayleigh, and Exponential. Following enhancement, Peak Signal to Noise Ratio and Mean Square Error metrics were calculated for each distribution type to evaluate image quality improvement. The result shown that all three CLAHE methods effectively enhanced the visual contrast of the lung images. The average MSE values for COVID-19 images were 26.27, 25.25, and 25.62, while for healthy images they were 28.27, 27.35, and 27.44. Meanwhile, the average PSNR values for COVID-19 images reached 155.63, 196.58, and 180.58, with healthy images scoring 98.27, 122.22, and 118.97. Overall, the process achieved an accuracy of 100%.
Analisis Perbandingan Output Daya Panel Surya Monokristalin dengan dan tanpa Reflektor Cermin Harahap, Basyaruddin Ismail; wanatirta, Bimbi Adytia; alajuri, M. Hasbi Sidqi; Bonardo, Doli; Bavitra, Bavitra
Jurnal Ilmiah Teknik Mesin, Elektro dan Komputer Vol. 5 No. 2 (2025): Juli: Jurnal Ilmiah Teknik Mesin, Elektro dan Komputer
Publisher : Lembaga Pengembangan Kinerja Dosen

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.51903/juritek.v5i2.4332

Abstract

This research aims to analyze the comparison of the power output of monocrystalline solar panels with and without the use of mirror reflectors. The utilization of solar energy continues to grow, but the efficiency of solar panels highly depends on light intensity. The use of mirror reflectors is proposed as a method to increase the irradiation received by the panels. A quantitative experimental method was used, involving two identical configurations of monocrystalline solar panels: one without a reflector (control) and one with a mirror reflector. Voltage, current, temperature, and power data were collected every minute from 08:00 to 14:00 WIB using a microcontroller-based data acquisition system. The average results show an increase in the output power of the panel with a reflector (1.75W) compared to without a reflector (1.58W), although the temperature of the panel with a reflector is slightly higher. Analysis of variance (ANOVA) shows that the F-value (15206.12) far exceeds the F-table (2.012305) with a p-value approaching zero (0). These results statistically prove the existence of a significant difference in power output between the two configurations. Thus, it can be concluded that the use of mirror reflectors substantially increases the power output of monocrystalline solar panels, making it an effective strategy for optimizing the performance of photovoltaic systems.