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All Journal International Journal of Electrical and Computer Engineering Bulletin of Electrical Engineering and Informatics Jurnal Ilmiah Teknik Elektro Komputer dan Informatika (JITEKI) Jurnal Penelitian Pendidikan IPA (JPPIPA) Makara Journal of Technology
Retno Wigajatri Purnamaningsih
Universitas Indonesia
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Education Electrical & Electronics Engineering Engineering Materials Science & Nanotechnology Mechanical Engineering Physics

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III-Nitride Semiconductors based Optical Power Splitter Device Design for underwater Application Retno Wigajatri Purnamaningsih; Nyi Raden Poespawati; Elhadj Dogheche
International Journal of Electrical and Computer Engineering (IJECE) Vol 8, No 5: October 2018
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (644.467 KB) | DOI: 10.11591/ijece.v8i5.pp3866-3874

Abstract

In this paper, we introduce III-nitrides based 1× 4 optical power splitter for underwater optical communication applications. To the best of our knowledge, this is a first study for the design of multimode interference (MMI) and four-branch taper waveguide based on GaN/sapphire. The microstructure of GaN semiconductor grown by Metalorganic Chemical Vapor Deposition (MOCVD) on (0001) sapphire reported. The numerical experimental is conducted using the 3D FD-BPM method. The results showed that the optical power splitter has an excess loss of 0.013 dB and imbalance of 0.17 dB. The results open the opportunity for the future device using this technology for the underwater application.
Optimization of triple-junction hydrogenated silicon solar cell nc-Si:H/a-Si:H/a-SiGe:H using step graded Si1‑xGex layer Nji Raden Poespawati; Rizqy Pratama Rahman; Junivan Sulistianto; Retno Wigajatri Purnamaningsih; Tomy Abuzairi
Bulletin of Electrical Engineering and Informatics Vol 10, No 2: April 2021
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/eei.v10i2.2765

Abstract

This paper shows the attempt to increase the performance of triple-junction hydrogenated silicon solar cells with structure nc-Si:H/a-Si:H/a-SiGe:H. The wxAMPS software was used to simulate and optimize the design. In an attempt to increase the performance, an a-SiC:H layer on the p-layer was replaced with an a-Si:H layer and an a-SiGe layer was replaced with a step graded Si1-xGex layer. Then, to achieve the best performing device, we optimized the concentration of germanium and thickness of the step graded Si1-xGex layer. The result shows that the optimum concentration of germanium in the p-i upper layer and i-n lower layer are 0.86 and 0.90, respectively and the optimum thicknesses are 10 nm and 230 nm, respectively. The optimized device performed with an efficiency of 19.08%, adding 3 more percent of efficiency from the original design. Moreover, there is a significant possibility of increasing the efficiency of a triple-junction solar cell by modifying it into a step graded Si1-xGex layer.
Design of a 1x4 Optical Power Divider Based on Y-Branch Using III-Nitride Semiconductor Nauval Franata; Retno Wigajatri Purnamaningsih
Jurnal Ilmiah Teknik Elektro Komputer dan Informatika Vol 8, No 1 (2022): March
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/jiteki.v8i1.23646

Abstract

Optical communications are identified as a technology that is able to meet future demands. As a passive component of optical communication, optical power dividers play an essential role. We propose a novel 1x4 optical power divider design, which is a combination of an optical power divider design using a Y-branch and an optical power divider using rectangular waveguides utilizing mode coupling phenomena from our previous researched designs. The 1x4 optical power divider design using three Y-branches and utilizing mode coupling phenomena is described in this work. The design consists of three sections: an input Y-branch, rectangular waveguides, and two output Y-branches. By utilizing mode coupling phenomena with 3 rectangular waveguides, the optical power was transferred from one waveguide to its adjacent, so we obtained a wider splitting angle at the input Y-branch. The design was optimized using the beam propagation method (BPM) at a wavelength for optical communication of λ = 1.55 µm. We optimized various parameters such as the width and thickness of the waveguide, splitting angles, coupling gaps, and coupling lengths by doing numerous experiments. The result shows that the proposed design was successfully split into four outputs with 0.14 dB power imbalance at four output ports and 0.12 dB excess loss through the design. The excess loss and power imbalance at varied wavelengths were also observed. The distribution of excess loss and power imbalance is almost stable through the C-band range (1530-1565 nm). The proposed design shows the possibility of a new wide-angle optical power divider design and demonstrates the development possibilities of optical interconnections at wavelengths of 1530-1565 nm.
Indonesia Dini Marhaeni Elecevani; Retno Wigajatri Purnamaningsih
Jurnal Penelitian Pendidikan IPA Vol. 8 No. 2 (2022): April
Publisher : Postgraduate, University of Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jppipa.v8i2.1426

Abstract

Electrosurgery Unit (ESU) is a medical surgical device that uses high frequency and high voltage with the aim that the patient does not experience excessive bleeding during the operation process. The development of electrosurgery unit technology evolves over time from monopolar to bipolar. However, in the development of the use of the tool, monopolar technology is always the most widely used in tissue surgery techniques. For this reason, this research was determined to use only the Monopolar principle. In Electrosurgery, the actual unit only uses one frequency selection, by changing (increasing or decreasing) the power value. With cases like this sometimes the user or equipment users will always change the power value during operation to determine the right power value. In this case, the author tries to make a prototype of an electrosurgery device with a frequency that can be selected (300, 350, 400, 450, 500, 550, 600 and 650 KHz) with a fixed power. By examining the results of the effectiveness of cutting (CUT) on tissue samples. It is hoped that it will be known which one is faster and more effective which can be used in cutting techniques (CUT) in surgery
Penjaminan Kualitas Pengukuran Tegangan dari Multifunction Calibrator sebagai Standar Pengukuran di Badan Standardisasi Nasional (SNSU-BSN) Nibras Yayienda; Retno Wigajatri Purnamaningsih
Jurnal Penelitian Pendidikan IPA Vol. 8 No. 3 (2022): July
Publisher : Postgraduate, University of Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jppipa.v8i3.1467

Abstract

Based on ISO 17025: 2017 clause 7.7, SNSU BSN as the peak of traceability must have quality assurance for measurement results, this is in line with the peer review result of Electrical Laboratory in 2017 and 2019 that suggest doing an intermediate check to support the quality of the measurement results issued by the Electrical Laboratory of SNSU – BSN. The method used method in this research is intermediate check including establishing the control line from the initial data and examining it every month over the year. The out-of-control measurement result will be analyzed more deeply using F-test and T-Test. The result of this test will be the basis of control line updating. The measurement points used are 100 mV, 1 V, 10 V, 100 V, and 1000 V. Over the year, there is no updating in the control line for 100 mV, 1 V, and 10 V because there is no out-of-control measurement result. Besides, there are 2 times control line updating for each 100 V and 1000 V because of artifact movement and drift. Even though it has been updated repeatedly, the last formed control line and the distribution of all data are still in the control line formed by the manufacturer's specifications.
Improved Optical Probe for Measuring Phytoplankton Suspension Concentrations Based on Optical Fluoresensce and Absorption Purnamaningsih, Retno Wigajatri; Prihantini, Nining Betawati
Makara Journal of Technology Vol. 16, No. 2
Publisher : UI Scholars Hub

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Abstract

This paper discusses the results of improved optical probe that works according to optical fluorescence and absorption phenomena for measuring the phytoplankton suspension concentrations. Measurements are made on the Scenedesmus sp. culture. The laboratory test has shown that range of concentration from 104 up to around 1 x 106 cells/mL; fluorescence intensity at λ = 685 nm; and logarithmic of transmission intensity at λ = 405 nm are proportional to the cell concentration linear with proportional constant γ = 4 × 10-5 and β = –2 × 10-7 mL/cell respectively.
Design of GaN-Based Low-Loss Y-Branch Power Splitter Purnamaningsih, Retno Wigajatri; Saraswati, Irma; Poespawati, Nji Raden; Dogheche, Elhadj
Makara Journal of Technology Vol. 18, No. 3
Publisher : UI Scholars Hub

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Abstract

We present a Y-branch power splitter design with a multimode section using GaN on Sapphire at telecommunication wavelength. The GaN sample optical properties were also investigated, resulting in a refractive index for the GaN layers nTE=2.289±0.001 and nTM=2.324±0.00. Optimization of the structure parameters for this structure was conducted accurately using BPM methods. The results demonstrated the possibility of realizing a GaN-based Y-branch power splitter for various applications.
Co-Authors Andrianto Handojo Dimitris Pavlidis, Dimitris Dini Andiani Dini Andiani, Dini Dini Marhaeni Elecevani Elhadj Dogeche, Elhadj Elhadj Dogheche Elhadj Dogheche Hendrik Kurniawan Irma Saraswati Junivan Sulistianto Luh Putu Ratna Sundari Nauval Franata NB Prihantini Nibras Yayienda Nji Raden Poespawati Nyi Raden Poespawati Nyi Raden Poespawati, Nyi Prihantini, Nining Betawati Rizqy Pratama Rahman Tomy Abuzairi