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"Experimental study on fiber power-splitter using a grating is described. Special attention is paid to the splitting ratio. Experiments were performed with a simple grating confirming the theoretical prediction Double passing of the grating results in a selectable splitting ratio of 5:7. Grating is made by photographic technique. Parameter b (width of slit) and d (period) of grating are designed with computer simulation."

"Transmission grating spectroscopes look like simple filters and are designed to screw into place on the eyepiece of a telescope for visual use, or into the camera adapter for digicam or CCD imaging. Using the most popular commercially made filter gratings. Rainbow Optics (US) and Star Analyzer (UK), as examples, this book provides the reader with information on how to set up and use the grating one needs to obtain stellar spectrograms. It also discusses several methods on analyzing the results. This book is written in an easy to read style, perfect for getting started on the first night using the spectroscope, and specifically showing how the simple transmission filter is used on the camera or telescope. No heavy mathematics or formulas are involved, and there are many practical hints and tips, something that is almost essential to success when starting out. This book helps readers to achieve quick results, and by following the worked examples, they can successfully carry out basic analysis of the spectra."

"ABSTRAKIn this paper a new way of derivation of an evolution equation for short pulses in a dielectric waveguide including one model of a metamaterial waveguide is shown. This derivation model relies upon projecting to an orthogonal basis. In our case such orthogonal basis for cylindrical waveguides is chosen as Bessel functions. "

"A design of novel optical power divider with tapered coupled wave-guide structure is proposed. The structure of optical power divider is directional coupler, which consists of parallel tapered wave-guide. The device was designed and its feature was simulated by the beam propagation method (BPM). Unique power coupling characteristics are demonstrated. A special case of a 1 x 3 Optical Power Divider has been designed. Simulation of the output power distribution at a wavelength of 1.31 μm shows the discretionary splitting ratio 0.32: 0.33: 0.35 for interaction length longer than 3 mm."

"Fiber Bragg grating (FBG) merupakan divais optoelektronika yang bekerja dengan cara menyaring panjang gelombang yang melaluinya. Nilai panjang gelombang tersebut ditentukan oleh indeks bias efektif struktur FBG. Sebagai sensor yang sensitif terhadap tekanan dan temperatur, FBG memiliki potensi pengaplikasian yang luas. Pada penelitian ini dilakukan deteksi tekanan hidrostatik rendah sebagai dasar pengembangan FBG single-mode berstruktur uniform sebagai sensor tekanan dalam air serta pengamatan pengaruh temperatur optical interrogator terhadap hasil pengukuran yang diperoleh. Pada tahap awal, dilakukan karakterisasi FBG untuk berbagai tekanan yang diwakili oleh berbagai beban dalam rentang 0 gram hingga 500 gram dengan kenaikan 50 gram. Berdasarkan hasil tersebut, selanjutnya dilakukan eksperimen pengukuran tekanan hidrostatik sedang dari arah 180° untuk melihat pengaruh arah tekanan pada FBG. Eksperimen tersebut dilakukan dengan rentang 0 liter hingga 20 liter dengan kenaikan volume air 2,5 liter dan menghasilkan hubungan linier dengan gradien negatif saat diberikan tekanan dari arah bawah FBG. Selanjutnya dilakukan juga  eksperimen pengukuran tekanan hidrostatik rendah arah vertikal tegak lurus FBG dengan rentang 0 ml hingga 10 ml dengan kenaikan volume air 0,25 ml. Hasil penelitian menunjukkan bahwa terdapat hubungan yang linier antara tekanan hidrostatik rendah dengan panjang gelombang Bragg dengan sensitivitas sebesar 0,0004142 nm/(Pa°C).

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Fiber Bragg grating (FBG) is an optoelectronic device that operates by filtering the wavelength passing through it. The wavelength value is determined by the effective refractive index of the FBG structure. As a sensor that is sensitive to both pressure and temperature, FBG has wide-ranging potential applications. In this study, the detection of low hydrostatic pressure was performed as the basis for developing a uniform structured single-mode FBG as an underwater pressure sensor. Initially, FBG characterization was conducted for various pressures represented by different loads ranging from 0 grams to 500 grams with a 50-gram increment. Based on these results, subsequent experiments were carried out to measure moderate hydrostatic pressure from the 180° direction to observe the effect of pressure direction on FBG. The experiment was performed with a range of 0 liters to 20 liters, with a 2.5-liter increment in water volume, and yielded a linear relationship with a negative gradient when pressure was applied from below the FBG. Furthermore, experiments were conducted to measure low vertical hydrostatic pressure with a range of 0 ml to 10 ml, using a 0.25 ml increment in water volume. The research findings indicate a linear relationship between low hydrostatic pressure and Bragg wavelength, with a sensitivity of 0,0004142 nm/(Pa°C)."

"ABSTRAKHybrid coupler merupakan salah satu bentuk rangkaian yang sangat diperlukan dalam bidang teknologi rangkaian terpadu gelombang mikro. Teknologi hybrid coupler telah mengalami perubahan yang besar dalam beberapa dekade terakhir, hal ini disebabkan oleh perubahan yang sangat pesat dalam aplikasi MIC pada bidang telekomunikasi maupun elektronika. Dalam tugas tesis ini, dibuat suatu rancang bangun rangkaian hybrid couplers dengan menggunakan saluran transmisi coplanar waveguide, karena saluran ini memberikan kemudahan dalam memperluas rangkaian pada bidang substrat bagian alas sehingga sangat cocok digunakan pada rangkaian microwve.Perancangan ini dilakukan dengan menggunakan perangkat lunak dan perangkat keras berupa mesin quick circuit dan pengukuran dilakukan pada semua gerbang dengan frekuensi kerja 1.8 GHz.

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ABSTRACT

Hybrid couplers form an indispensable circuit in modem microwave integrated-circuit technology. Hybrid couplers technology has undergone a substantial change over the past decade, due to the rapidly growing applications of MICs in the telecommunications and electronic. In this thesis, hybrid coupler is designed and made circuit by using transmission line of coplanar waveguide and then this transmission line necessary only on the surface side of the substrate, allowing planar circuit on the top side to be extended and then thus making it compatible with microwave.

Hybrid coupler was design by using quick cam circuit and measured at all port with frequency operation 1,8 GHz."

"Antena aktif yang merupakan integrasi antara antena gelombang mikro dengan perangkat aktif seperti amplifier telah mendapat perhatian yang luas pada beberapa tahun belakangan ini. Pada umumnya, penempatan elemen aktif yaitu transistor microwave dalam rangkaian terintegrasi microwave (Microwave Integrated Circuit, MIC) dibuat pada saluran transmisi microstrip. Pada tesis ini dibahas mengenai rancangan microwave power amplifier sebagai elemen aktif dari antena yang dibuat dengan memakai rangkaian penyesuai saluran transmisi coplanar waveguide. Keuntungan utama yang diharapkan dapat diperoleh dengan pemakaian coplanar waveguide antara lain; interkoneksi komponen pada rangkaian lebih mudah karena hanya bagian permukaan dari struktumya yang diperlukan, memberikan kemudahan dalam memperluas rangkaian pada bidang atas substrat sehingga sangat sesuai digunakan pada rangkaian terintegrasi microwave.Transistor microwave yang dipakai pada rancangan amplifier ini adalah GaAs MeSFET tipe NE 76084 yang memiliki potensi tidak stabil (potentially unstable) pada frekuensi 5 GHz, dan kondisi ini umumnya dihindari dalam rancangan microwave amplifier. Sekalipun transistor tersebut berpotensi tidak stabil, pada tesis ini diperlihatkan realisasi rancangan microwave amplifier dengan membuatnya menjadi stabil melalui pemilihan koefisien refleksi beban yang sesuai.Perancangan dilakukan dengan bantuan perangkat lunak CAD untuk amplifier, AutoCAD dan perangkat keras mesin cetak quick circuit. Pengukuran terhadap beberapa parameter seperti power gain, bandwith, return loss dan VSWR dilakukan pada rancangan akhir amplifier dengan frekuensi operasi 5 GHz.

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Active antennas which are integration between microwave antenna and an active device such as amplifier have found wide interest in the past few years. Mostly, the placement of active element (i.e. microwave transistor) in microwave integrated circuit (MIC) made on microstrip transmission line. This paper describes the design of microwave power amplifier as an active part of active antenna implemented on coplanar waveguide. With the design proposed here, the main advantage which may be expected from the proposed coplanar waveguide compared to microstrip line is based on the fact, that network interconnection is easily obtained. It structure's necessary only on the surface side of the substrate, allowing planar circuits on the top side to be extended and thus making it compatible with microwave integrated-circuit.

The amplifier investigated in this paper utilized GaAs MeSFET (NE 76084) which is potentially unstable can be realized by the proper selection of the load reflection coefficient. This condition must, therefore, be avoided for the design of microwave amplifier.

The amplifier was designed using several tools such as CAD for amplifier and Auto CAD software, and Quick-circuit machine. Measured result of power gain, VSWR and bandwidth of the amplifier operating in 5 GHz are given."

"Cbaracterization of tbe properties of microwave device proves to be an .. senlial complemenl 10 Ibetbeoretical or simulaUon works. Tbus, Ibe .. tablishment of tool used for tbe cbaraclerization Is one of Ibeimportant steps in tbe experimeDtal sludy. In this paper, a test-fixture to cbaracterize tbe reflectivity aDdtraDsmissivity of microwave device is reported wbereby tbe refleelion and traDsmission properties caD beobtained under normal incidence using a specially designed paraUel plate waveguide (PPW) simulator.Tbis Is possible siDce tbis type of simulator is potentially \