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All Journal JURNAL Al-AZHAR INDONESIA SERI SAINS DAN TEKNOLOGI Exhibition and Seminar on Science and Creative Technology – Al Azhar Proceeding
Hamid, Sofian
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Biochemistry, Genetics & Molecular Biology Computer Science & IT Decision Sciences, Operations Research & Management Electrical & Electronics Engineering Industrial & Manufacturing Engineering Public Health

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Design of Multiband Miniaturized Antenna using Metamaterial Concept for WLAN/WiMAX Application Sofian Hamid
JURNAL Al-AZHAR INDONESIA SERI SAINS DAN TEKNOLOGI Vol 1, No 1 (2011)
Publisher : Universitas Al Azhar Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36722/sst.v1i1.11

Abstract

Design of low cost multiband antenna is presented. The antenna works in WLAN/WMAX band and has a very compact dimension of 2 cm x 2 cm, making it suitable for handheld devices. This small dimension is achieved since the antenna is loaded with the metamateria element. To miniaturize the antenna dimension further, modification on the left side of ground-plane is introduced, which is inspired by the self complementary antenna concept. Resonance at lower frequency is given by the single cell metamaterial loading on 2.36 – 2.45 frequency; at the middle frequency is given by the thin slot on 3.26 – 3.49 frequency; and at higher frequency is given by the main radiator on 5.3 – 6 GHz frequency. The antenna has omnidirectional pattern and moderate directivity of 2-3 dBi on those frequencies.
Design of Novel Yagi Aperture Antennas for Indoor TV Reception using Low Cost Materials Sofian Hamid
JURNAL Al-AZHAR INDONESIA SERI SAINS DAN TEKNOLOGI Vol 1, No 3 (2012)
Publisher : Universitas Al Azhar Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36722/sst.v1i3.45

Abstract

Most commercial Yagi antennas for TV reception are built based on wires. These Yagi wire-antennas are commonly used as outdoor antennas due to their size and weight properties. In this paper, novel light weight Yagi aperture antennas are introduced. Two prototypes had been built by using low cost materials such as aluminum (insects) screen, cylinder can, aluminum foil, and styrofoam. The antennas worked at the TV band and have gains around 9.7 – 13.5 dBi comparable to the outdoor Yagi wire antennas. Due to their lightweight and smaller dimension nature, they were suitable for used as indoor TV antennas. The antennas had also unique property due to the use of Styrofoam. They were portable, easy to construct and deconstruct.
Light-Based Positioning System Using Arduino Assidqi, Nurul Imam; Astharini, Dwi; Hamid, Sofian; Hermawan, Denny; Aribowo, Budi
EXSACT-A Vol 1, No 1 (2023)
Publisher : Universitas Al Azhar Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36722/exc.v1i1.2286

Abstract

The Light Positioning System (LPS) represents an innovative technology employed for precise object localization by utilizing light as a positional reference. This method encompasses the utilization of light sources, such as LED lights or other visible light emitters, which can be strategically positioned at various orientations and angles. This research centers on the practical implementation of the LPS paradigm through the application of Arduino. Additionally, the study involves the integration of the Kalman filter algorithm within the Arduino framework to enhance the accuracy of sensor data estimations. The LPS implementation employs distinct sensors, namely the Photoresistor LM393, Photodiode LM393, and TF-Luna Lidar. The programming is accomplished using the Arduino Integrated Development Environment (IDE), while the hardware framework is based on the Arduino Mega 2560 microcontroller. In this research, the ESP32 module plays a pivotal role as it establishes a seamless connection between the sensor data and the Blynk platform. This integration empowers effective and comprehensive data monitoring and analysis, facilitating real-time tracking and evaluation of the LPS system's performance. The photoresistor exhibits better reading accuracy compared to the photodiode, as evident from the obtained RMSE values. The KF PR with 16 LEDs has the smallest RMSE value, which is 0,03. The TF-Luna LiDAR sensor readings are more accurate and effective under well-lit conditions as opposed to low-light conditions. The RMSE value at lux 160 is 1,28 , while the RMSE value at lux 2 is 3,32
FPGA Implementation of Kalman Filter for Visible Light Wahyudi, Imam; Astharini, Dwi; Gandana, Danny M; Hamid, Sofian; Hermawan, Denny; Aribowo, Budi
EXSACT-A Vol 1, No 1 (2023)
Publisher : Universitas Al Azhar Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36722/exc.v1i1.2280

Abstract

Visible Light (VL) has received significant attention due to its benefits in energy efficiency, wide bandwidth availability, and resistance to electromagnetic interference. This final project discusses VL utilizing the Kalman Filter (KF) to predict and estimate the position of related data. The development of the VL method is carried out using Xilinx FPGA Arty A7 hardware, and the KF implementation is carried out in a two-dimensional framework with the Linear KF approach. The main objective of this Final Project is to implement VL using Photodetectors (Photodiode and Photoresistor LM393) on FPGA. The use of Xilinx FPGA Arty A7 hardware and Xilinx SDK software provides the flexibility and reliability required for system implementation. The results indicate that the implementation of Xilinx FPGA Arty A7-35T with KF and the use of 16 LED and 8 LED configurations yield relatively accurate estimations. While the Photodiode LM393 (PD LM393) sensor does not exhibit superior results compared to the Photoresistor LM393 (PR LM393) sensor, this research effectively optimizes light measurements by utilizing the sensor and KF algorithm. The Root Mean Squared Error (RMSE) results show that for the system with 16 LEDs, KF with PR LM393 has an RMSE of approximately ). This RMSE value indicates that KF with PR LM393 can provide relatively more accurate estimations. Similarly, for the system with 8 LEDs, KF with PR LM393 has an RMSE of around ). In this case, KF with PR LM393 again provides relatively more accurate estimations. Meanwhile, the RMSE result for 2D KF in this system is approximately ), indicating that the KF estimation has a relatively small error value compared to the actual measurement value. This demonstrates that KF effectively reduces noise and measurement data fluctuations in the LM393 Photodetector system with 16 LEDs.
Zero-Waste Thinking in Digital Signal Processing: Reducing Computational, Data, and Energy Waste Amjat Al Baihaqi; Ibrohim Hasan; Damar Royyan Saputra; Sofian Hamid; Dwi Astharini
EXSACT-A Vol 3, No 1 (2025)
Publisher : Universitas Al Azhar Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36722/exc.v3i1.4587

Abstract

In the modern digital era, the concept of waste extends beyond the physical realm and into the digital domain, manifesting as redundant data, excessive computation, and continuous processing of unnecessary signals. This study introduces the application of zero-waste thinking to Digital Signal Processing (DSP), with a focus on minimizing computational, data, and energy waste in always-on audio systems. A lightweight, energy-aware Voice Activity Detection (VAD) method is proposed, utilizing signal energy and zero-crossing rate (ZCR) features to intelligently activate or suppress processing based on speech presence. MATLAB-based simulations were conducted to evaluate system performance under various noise conditions, measuring computational load, activation efficiency, and detection accuracy. The results show that the proposed approach significantly reduces unnecessary processing while maintaining reliable speech detection. This work offers a practical framework for sustainable and efficient DSP, contributing to the emerging paradigm of digital zero-waste systems.
Co-Authors Amjat Al Baihaqi Assidqi, Nurul Imam Budi Aribowo Damar Royyan Saputra Denny Hermawan Dwi Astharini Gandana, Danny M Ibrohim Hasan Imam Wahyudi Indrawan, Imam Wahyudi