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PENURUNAN NOISE FIGURE PERFORMANCE (FN) PADA HBT SI / SI 1-X GEX BERDASARKAN PENGATURAN STRIPE EMITER AREA (AE) DAN FRACTION MOLE (X).

Poli-Teknologi Vol 9, No 2 (2010)
Publisher : Politeknik Negeri Jakarta

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Abstract

Paper ini membahas pengaruh perubahan stripe emiter area (Ae) dan fraction mole (x) terhadap unjuk kerja HBT SiGe antara lain Resistensi parasitis RB dan RC, fT, fmaks, current gain (β) serta noise figure (Fn,), model dikembangkan dari HBT SiGe IBM generasi kedua dengan Ae 0,1810 m2. Saat Ae diturunkan menjadi Ae 0,1210 m2 dan Ae 0,0910 m2 dan fraction mole (x) dinaikkan menjadi dua kali (2) maka parameter RB, dan β mempunyai relasi positif sedangkan RC , fT, fmaks negatif terhadap perubahan tersebut. Model HBT SiGe dengan x: 0.1 dan Ae:0,1810 m2 mempunyai nilai Fn minimum terendah dibanding dengan Ae 0,1210 m2 dan 0.0910 m2 yaitu 0.57 dB , 0.64 dB, 0.69 dB. Jika nilai fraction mole (x) diturunkan 50% , menyebabkan kenaikkan Fn yang tidak linier yaitu 77%, 79% dan 89% dari nilai semula. Relasi noise figure (Fn) dengan stripe emiter area (Ae) dan fraction mole (x) diekspresikan dengan relasi berikut ; F k A x n e. 0  , jadi noise figure (Fn) dapat diperkecil dengan memperarea stripe emiter area (Ae) dan menaikkan fraction mole (x). Kata kunci : Noise Figure (Fn), stripe emiter area (Ae), fraction mole (x), SiGe HBT ABSTRAK Paper ini membahas pengaruh perubahan stripe emiter area (Ae) dan fraction mole (x) terhadap unjuk kerja HBT SiGe antara lain Resistensi parasitis RB dan RC, fT, fmaks, current gain (β) serta noise figure (Fn,), model dikembangkan dari HBT SiGe IBM generasi kedua dengan Ae 0,1810 m2. Saat Ae diturunkan menjadi Ae 0,1210 m2 dan Ae 0,0910 m2 dan fraction mole (x) dinaikkan menjadi dua kali (2) maka parameter RB, dan β mempunyai relasi positif sedangkan RC , fT, fmaks negatif terhadap perubahan tersebut. Model HBT SiGe dengan x: 0.1 dan Ae:0,1810 m2 mempunyai nilai Fn minimum terendah dibanding dengan Ae 0,1210 m2 dan 0.0910 m2 yaitu 0.57 dB , 0.64 dB, 0.69 dB. Jika nilai fraction mole (x) diturunkan 50% , menyebabkan kenaikkan Fn yang tidak linier yaitu 77%, 79% dan 89% dari nilai semula. Relasi noise figure (Fn) dengan stripe emiter area (Ae) dan fraction mole (x) diekspresikan dengan relasi berikut ; F k A x n e. 0  , jadi noise figure (Fn) dapat diperkecil dengan memperarea stripe emiter area (Ae) dan menaikkan fraction mole (x). Kata kunci : Noise Figure (Fn), stripe emiter area (Ae), fraction mole (x), SiGe HBT

Measurement and Simulation Techniques For Piezoresistive Microcantilever Biosensor Applications

TELKOMNIKA Indonesian Journal of Electrical Engineering Vol 10, No 6: October 2012
Publisher : Institute of Advanced Engineering and Science

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Abstract

Applications of microcantilevers as biosensors have been explored by many researchers for the applications in medicine, biological, chemistry, and environmental monitoring. This research discusses a design of measurement method and simuations for piezoresistive microcantilever as a biosensor, which consist of designing Wheatstone bridge circuit as object detector, simulation of resonance frequency shift based on Euler Bernoulli Beam equation, and microcantilever vibration simulation using COMSOL Multiphysics 3.5. The piezoresistive microcantilever used here is Seiko Instrument Technology (Japan) product with length of 110 μm, width of 50 μm, and thickness of 1 μm. Microcantilever mass is 12.815 ng, including the mass receptor. The sample object in this research is bacteria EColi. One bacteria mass is assumed to 0.3 pg. Simulation results show that the mass of one bacterium will cause the deflection of 0,03053 nm and resonance frequency value of 118,90 kHz. Moreover, four bacterium will cause the deflection of 0,03054 nm and resonance frequency value of 118,68 kHz. These datas indicate that the increasing of the bacteria mass increases the deflection value and reduces the value of resonance frequency

Pore Structure and Morphology Characterizations of Mesoporous ZSM-5 Synthesized at Various Aging Time

Jurnal ILMU DASAR Vol 12, No 1 (2011)
Publisher : Fakultas MIPA Universitas Jember

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Abstract

Mesoporous ZSM-5 has been successfully synthesized at various aging time of 6, 12 and 24 h. Mesoporous ZSM-5 was synthesized using cetyltrimethylammonium bromide (CTABr) as a template. Synthesis was carried out hydrothermally with aging and crystallization temperature at 60oC and 150oC. XRD patterns of the resulted material showed diffraction lines at 2θ = 23o and at small angle (2θ < 5o) which is characteristic of the structure of ZSM-5 and the existing of the mesoporous material. It was found that crystallinity of the sample increased at longer aging time. The result of nitrogen gas sorption analysis showed that all samples have pore size about 3,8 nm. The porosity of ZSM-5 decreased with shorter of aging time. ZSM-5 synthesized at 6 h aging time has the highest porosity of 72.57%. Aging time also affected the particle size, the longer the aging time, the smaller the particle size. The particle size was ranging 1.25 – 1.0 μm. Keywords: Pore structure, morphology, mesoporous ZSM-5, aging time

Observation of Tunneling Effects in Lateral Nanowire pn Junctions

Makara Journal of Technology Vol 18, No 2 (2014)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

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Abstract

As electronic device dimensions are continuously reduced, applied bias conditions significantly change and the transport mechanisms must be reconsidered. Tunneling devices are promising for scaled-down electronics because of expected high-speed operation and relatively low bias. In this work, we investigated the tunneling features in silicon-oninsulator lateral nanowire pn junction and pin junction devices. By controlling the substrate voltage, tunneling features can be observed in the electrical characteristics. We found that the minimum substrate voltage required for tunneling to occur in pn junctions is higher as compared with pin junctions. The main cause of these effects relies in the difference between the doping profiles, since the pn junctions contain a co-doped region, while the pin junctions contain an i-layer.

Fiber Optic Ring Resonator Sensor Detection Technique Based on Spectral Intensity Integration

Makara Journal of Technology Vol 19, No 1 (2015)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

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Abstract

Resonant field phenomenon in optical ring resonator has been a major theme for various studies and can be used for various sensor applications. The spectral response shape changes are subjects to be discussed and analyzed for detection in optical sensor system. The spectral response changes are caused by various factors ranging from refractive index of the surrounding medium, medium loss due to absorption and scattering, and coupling variation between waveguides. These optical phenomena are mostly used for bio-sensor applications, since it is free from electromagnetic interference (EMI) and non-physically destructive. In this paper, we discuss our current research in developing optical bio-sensor in the form of a fiber optic ring resonator with monochromatic laser source based on spectral integration detection method, which is sufficiently sensitive and accurate.

Design of Generating Dual Frequency Operation for Triangular Microstrip Antenna Using Electromagnetic Coupling

Makara Journal of Technology Vol 9, No 2 (2005)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

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Abstract

A new design is proposed in this paper by applying a pair of slits using a microstrip feed line. Therefore the microstrip line feeding system is electromagnetically coupled to the patch. The antenna works at two different frequencies in the range from 2 GHz to 4 GHz (S band frequency). The results of the simulation shows that the dual frequency operation can be created when the slit width is 1 mm and the height of the slits ranges from 10 mm to 14 mm with inter slit distance of 3 mm, 5 mm and 7 mm as well.

SIMPLE: System Automatic Essay Assessment for Indonesian Language Subject Examination

Makara Journal of Technology Vol 11, No 1 (2007)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

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Abstract

Evaluation of study of a student is a very important aspect of an educational process. Evaluation is aimed at measuring the level of student understanding of the given lecture materials. Measuring student understanding of the course material, using essay-type exam, is generally used as the evaluation tool. In this essay-type exam, the student has to answer questions using sentences, whereby choices of possible answers are not indicated. The student has to answer the questions with his/her sentences. The answers may vary, since it reflects the students  thoughts of the materials. One of the weaknesses of essay-type exam is the difficulty to grade the answers and it tends to be time consuming. Currently, automatic grading systems that may speed up the grading process, are being developed in many research institutions.The method used to grade, varies zorm one system to another, and one of the popular system is he Latent Semantic Analysis (LSA). LSA is a method of grading essay by extracting words and representing the sentence in the form of mathematical or statistical formulation, from a text with a relatively large number of words. The grade of the essay is determined, by matching the important words to a group of words prepared by the human rater. This paper describes an effort to developed LSA, enhanced with word weighting, word order and the word synonym to improve the accuracy of grading. This system is called SIMPLE. SIMPLE is used to grade answers using bahasa Indonesia. The exam is carried out on-line through the Web. From the experiments conducted, for small classes, the conformity of grade compared to the grade of human rater lies between 69.80 % - 94.64 %, and for medium size classes the conformity lies between 77.18 % - 98.42 % with the human rater. These results are roughly proportional with the result of LSA system, which grade essay given in English.

Two Element Microstrip Antenna Array with Defected Ground Structure

Makara Journal of Technology Vol 12, No 2 (2008)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

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Abstract

This paper presents a two element microstrip antenna array using trapezium shape defected ground structure (DGS). The DGS is inserted in the ground plane between two elements of antenna array. Insertion of the DGS is intended to suppress the mutual coupling effect produced by antenna array. Simulation and measurement results were taken and compared between antenna array with and without DGS. Measurement results show that the antenna with DGS compared to antenna without DGS can suppress mutual coupling effect to 7.9 dB, improve the return loss to 33.29% from -30.188 dB to -40.24 dB and axial ratio bandwidth enhancement to 10 MHz. This bandwidth enhancement is achieved from frequency 2.63 GHz – 2.67 GHz for antenna without DGS and from frequency 2.63 GHz – 2.68 GHz for antenna with DGS. In addition, the DGS antenna also improved the antenna gain to 0.6 dB. The results show that the implementation of the trapezium DGS can improve the radiation properties of the antenna without DGS.

Analysis of Hole Lifetime in SOI MOSFET Single-Photon Detector

Makara Journal of Technology Vol 17, No 1 (2013)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

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Abstract

Hole lifetime in the silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistor (MOSFET) singlephoton detector was evaluated by the analysis of drain current histograms for different light intensities and substrate voltages. It was found that the peaks in the histogram corresponding to the larger number of stored holes grew as the gate bias decreased. This was attributed not to the increased light absorption efficiency or collection efficiency of the photo-generated holes, but to the prolonged hole lifetime presumably caused by the higher transverse electric field inside the body of SOI MOSFET.

Pore Structure and Morphology Characterizations of Mesoporous ZSM-5 Synthesized at Various Aging Time

Jurnal ILMU DASAR Vol 12 No 1 (2011)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

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Abstract

Mesoporous ZSM-5 has been successfully synthesized at various aging time of 6, 12 and 24 h. Mesoporous ZSM-5 was synthesized using cetyltrimethylammonium bromide (CTABr) as a template. Synthesis was carried out hydrothermally with aging and crystallization temperature at 60oC and 150oC. XRD patterns of the resulted material showed diffraction lines at 2θ = 23o and at small angle (2θ < 5o) which is characteristic of the structure of ZSM-5 and the existing of the mesoporous material. It was found that crystallinity of the sample increased at longer aging time. The result of nitrogen gas sorption analysis showed that all samples have pore size about 3,8 nm. The porosity of ZSM-5 decreased with shorter of aging time. ZSM-5 synthesized at 6 h aging time has the highest porosity of 72.57%. Aging time also affected the particle size, the longer the aging time, the smaller the particle size. The particle size was ranging 1.25 – 1.0 μm.