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Pengembangan Antena Mikrostrip Susun untuk Radar Pengawas Pantai Zulkiflia, Fitri Yuli; Wahyu, Yuyu; -, Basari; Raharjo, Eko Tjipto
Jurnal Elektronika dan Telekomunikasi Vol 13, No 2 (2013)
Publisher : Indonesian Institute of Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (921.641 KB) | DOI: 10.14203/jet.v13.55-59

Abstract

Makalah ini membahas pengembangan antena mikrostrip yang disusun secara linier sebanyak empat elemen untuk aplikasi radar pengawas pantai. Teknik pencatuan yang digunakan untuk mencatu antena susun ini adalah proximity coupled. Desain antena menggunakan software CST microwave studio dan dirancang untuk bekerja di frekuensi 9,4 GHz. Hasil simulasi memperlihatkan impedance bandwidth antena pada return loss ≤ -9,54 dB adalah 760 MHz dari  9,34-10,1 GHz dan dari  hasil ukur  adalah 860 MHz dari frekuensi  9,35-10,21 GHz. Di samping itu, hasil simulasi menunjukkan half power beamwidth (HPBW) pada phi=0 sebesar 23,7o dengan sidelobe level (SLL) sebesar -12,03 dB, sementara pada phi=90 diperoleh  HPBW sebesar 77,2o dengan SLL tertekan sampai -19,78 dB. Sebagai tambahan, gain dari antena diperoleh sebesar 11,33 dB.  Adapun  hasil pengukuran menunjukkan hasil HPBW pada phi=0 sebesar 20o dengan SLL  sebesar -18,9 dB dan pada phi=90 diperoleh HPBW sebesar 65o dengan SLL -15,51 dB.
Development of Proximity-Based COVID-19 Contact Tracing System Devices for Locally Virus Spread Prevention Ainul Fitriyah Lubis; Basari Basari
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.v8i1.23697

Abstract

COVID-19 contact tracing is a preventive solution to slow the spread of the virus. Several countries have implemented manual contact tracing as well as digital tracking using smartphone applications. A proximity-based COVID-19 contact tracing system device using BLE (Bluetooth Low Energy) technology focuses on tracking and controlling the spread of the virus in local communities. The devices consist of a signal sending device (tag) and a signal receiving device (scanner). Suppose a system device is implemented in a factory. The tag will be used by employees by placing it in the front pocket of the factory employee's clothes or hooked on the shirt. The tag will continuously send a signal that will be read by the scanner. This received signal with the received signal strength indicator (RSSI) format will be used to calculate the distance between the scanner and the tag. Then the distance will be used to determine the coordinate point of the tag, with calculations using the trilateration algorithm. Therefore, the distance between tags can be obtained, while with signal fluctuation, the actual coordinate point cannot be obtained, yet proximity information can still be obtained by filtering distance data at a specified time interval that is less than the threshold value of the distance, 2 meters, then comparing the data with the overall data, resulting in a percentage value. A high percentage, above 80%, indicates the closeness between tags.
Electrochemical Detection and Spectrophotometry of Dopamine using Commercial Screen-Printed Electrodes Eunike Thirza Hanita Christian; Basari Basari; Siti Fauziyah Rahman; Yudan Whulanza
Journal of Biomedical Science and Bioengineering Vol 2, No 1 (2022)
Publisher : Center for Biomechanics, Biomaterials, Biomechantronics and Biosignal Processing (CBOIM3S)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jbiomes.2022.v2i1.7-13

Abstract

Lab-on-chip is miniaturized devices integrated into a chip which can run one or several analyses which are usually done in laboratory settings, such as biochemical detection. Dopamine is an important neurotransmitter which regulates hormones, control of movement, emotion, attention, and motivation. Excess, lack, and dysregulation of dopamine could cause numbers of diseases and disorders. The technique used to measure and evaluate dopamine usually are expensive to run, require longer time to run, require some technical qualification to run, require expensive equipments, and some are invasive to do. These are the reasons why a lab-on-chip system is needed to make the detection of dopamine concentration faster, easier, and more portable. This paper studied the accuracy of using electrochemical detection to measure the concentration of liquid specimens of dopamine compared to uv/vis spectrophotometry. Electrochemical detection method named cyclic voltammetry was chosen for this study. The hypothesis for this study is that both peak current (ip) and absorbance positively correlate to concentration, therefore both could be used with minimal error margin. For this study, the peak current (ip) and absorbance of different concentrations of liquid specimen of dopamine are measured, and its regression were observed. It was shown that the concentration of liquid specimens of dopamine is linear to both anodic peak current (ipa) and absorbance. Due to the high R2 values of 0.9883, electrochemical detection could be used and implemented to detect dopamine concentration for application of lab-on-chip, as it is more portable and requires less volume of sample compared to spectrophotometry.
Dual-Band Singly-Fed Proximity-Coupled Tip-Truncated Triangular Patch Array for Land Vehicle Mobile System Basari, Basari; Sumantyo, Josaphat Tetuko Sri
Makara Journal of Technology Vol. 19, No. 3
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

This paper proposes a dual-band left-handed circularly polarized triangular-patch array that is developed for land vehicle mobile system aimed at mobile satellite communications. The array consists of six tip-truncated triangular patches, which the first three patches are used for reception and the second three patches are used for transmission purpose. Each of three-patches has a beam pattern that can be switched in three different 120°-coverage beam in azimuth-cut plane at a minimum targeted gain at a desired elevation angle. The targeted minimum gain of the array is 5 dBic, in order for data communications with a large geostationary satellite can be achieved. The array is able to operate in two different frequency bands i.e. 2.50 GHz band for reception (down-link) and 2.65 GHz band for transmission (uplink). The array is simulated using the Method of Moments-based software (Ansoft Maxwell), fabricated and measured to confirm the simulated results. The measurement results show that the 5dBic-gain and the 3dB-axial ratio of the reception elements cover all of 360° azimuth direction. In the case of transmission elements, 4.3dBic-gain and the 3dBaxial ratio can be obtained.
Coax-Fed Dipole-Type Applicator for Hepatic Cancer RF Ablation Basari, Basari; Rakhmadi, Aditya; Saito, Kazuyuki
Makara Journal of Technology Vol. 22, No. 1
Publisher : UI Scholars Hub

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Abstract

Cancer is the third leading cause of mortality in the world and is one of the most difficult diseases to detect and cure. This fact motivates us to investigate a treatment method by using radiofrequency (RF) ablation. RF ablation therapy kills cancer cells by electromagnetically heating them up. The treatment uses an applicator that is inserted into the body to heat the cells. The cancer cells are exposed to a temperature of more than 60 °C in short duration (a few seconds to a few minutes), thereby causing cell destruction locally. To ensure effective treatment, a minimally invasive method is selected so that good local temperature distribution inside the cancer cells can be achieved. In this paper, a coax-fed dipole-type applicator is proposed for interstitial irradiation technique in hepatic cell treatment. The applicator design is conducted by simulation in CST Microwave Studio to obtain an appropriate size at operating frequency of 2.45 GHz. We also consider localizing the ablation area by designing the tip of the applicator such that the main electromagnetic radiation locally exists around it. The proposed applicator is inserted into a simple phantom model of an adult human body with normal and cancerous liver cells. Both simulation and measured results show that the proposed applicator is able to operate at center frequency of 2.45 GHz in a blood droplet-type ablation zone. A temperature of 60 °C around the cancer cell can be achieved by simulation. Moreover, a square four-array applicator is analyzed to increase the ablation zone for a larger tumor cell. The simulation results show that a reasonably wider local ablation area can be achieved.