Yono Hadi Pramono

Ultra wide-band antenna with low cost for radar application

In this paper, design of ultra wide-band antenna for radar application has been proposed. The antenna consists of circular patch and partial ground plane on the adjacent side. The proposed antenna is designed in FR-4 substrate which has 1.6 mm thick and 4.6 relative permittivity value. The dimension of the substrate is 42 mm × 50 mm × 1.6 mm. Ground plane shapes also had an impact on the outcome. Antenna radiation pattern is bi-directional which is also influenced by the current density flowing on the surface.

Design and fabrication of low-cost reconfigurable microstrip antenna using photodiode as optical switching

Design, fabrication, and characterization prototype of reconfigurable dipole microstrip antenna using photodiode as optical switching have been conducted in the Laboratory for Optical and Microwave Physics Department Faculty of ITS. This paper presents a new reconfigurable antenna design using photodiode as optical switching. In order to be optical switching, photodiode must be illuminated by optical source. The optical source used is Infrared with power 8 mW. Antenna is fabricated in FR-4 substrate which has 1.6 mm thick and 4.8 relative permittivity value. The dimension of the substrate is 131 mm × 21.5 mm × 1.6 mm. The structure of antenna is Coplanar Stripline (CPS) dipole. Measurement is conducted in two state. First state is photodiodes unilluminated Infrared and the second state is illuminated. The measurement result indicate that if condition is not illuminated by Infrared (OFF-state) antenna has resonance frequency of 2010 MHz and 2120 MHz. At frequency 2010 MHz, S11 value −35.7 dB and bandwidth ...

Design and fabrication of tunable microstrip antenna using photodiode as optical switching controlled by Infrared

In this paper, design, fabrication, and characterization new tunable microstrip antenna using photodiode as optical switching has been proposed. The proposed antenna is fabricated in FR-4 substrate 4.8 relative permittivity value. The dimension of the substrate is 47 mm × 75 mm × 1.6 mm. The measurement result indicates that, if photodiode unilluminated by Infrared (OFF state) the proposed antenna works at frequency 4400 MHz with S11 value -16 dB. Meanwhile, if photodiode is illuminated by Infrared (ON state), antenna works at a frequency of 4500 MHz with S11 value - 15 dB. There was a shift of 100 MHz of resonant frequency and -1 dB in S11 value. The proposed antenna are more easily fabricated and the switching methods more simple than other techniques. Also, the cost is relatively cheaper than the other techniques of optical switching.

Effect of calcination temperature on the photocatalytic activity of TiO2 powders prepared by co-precipitation of TiCl3

The adsorption of basic dye methylene blue (MB) onto titanium dioxide (titania) powder that were prepared by coprecipitation method of TiCl3 and NH4OH as iniatial material with different calcination temperature was studied to examine the photocatalytic activity. Synthesis process carried out by the solution pH was adjusted to be 8. Effect of calcination temperature on the titania powder were characterized with Differential Scanning Calorimetry/Thermogravimetry (DSC/TG), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM). The result of TG and XRD showed that the NH4Cl decomposed between 235-372°C. The XRD result showed that the anatase TiO2 only contained a single phase when the calcination temperature of the precursor at 800°C, and over which it began to grow rutile phase. The influence of synthesis condition on the photocatalytic activity of TiO2 powder was determined by the photodegradation of MB dye under UV light.

Design and optimization high-performance bi-circular loop antenna with plane reflector and coaxial feed line at 2.45 GHz frequency

The aim of this study is to find the best design for high-performance medium range antenna by simulating bi-circular loop antenna with plane reflector. The coaxial feed line at 2.45 GHz frequency Finite Different Time-Domain (FD-TD) method was employed in simulation. The simulation results showed that the best parameters value are 14.95 mm of loops radius, 1.15 mm of links radius, and 15.57 mm of reflector gap. In these parameters, the antenna had a characteristic value of return loss −36.65 dB, bandwidth 354 MHz, gain 9.04 dB, VSWR 1.001, and the characteristic impedance of 49.97 Ω. Moreover, it was also used as IoT or other medium range communication applications.

All-optical logic gates in directional coupler waveguide consisting of nonlinear material

All-optical logic gate devices on directional coupler waveguides containing nonlinear materials are proposed. The proposed waveguides consist of three straight waveguides with constant parameters, which the waveguides will be coupled each other. The waveguides contain optical nonlinear material assumed as Kerr-type material, which is SnO2 as film material of waveguides. In this paper, SnO2 material was used due to having higher nonlinearity value than other nonlinear materials such as LiNbO3. The principle utilized to produce logic gate function was coupling mode between waveguides and refractive index changes depending on input power intensity due to the characteristics of the nonlinear material which was used. The waveguides were numerically analyzed using the Finite Difference Beam Propagation Method (FDBPM). The proposed waveguide can be applied to varied of optical logic function at certain input power, such as AND, OR and XNOR gates at certain input power.

Modeling of well drilling heating on crude oil using microwave

As the world’s oil reserves are dwindling, some researchers have been prompted to make a breakthrough to further improve the efficiency of exploration and production. One of the technologies used is heating the crude oil. This paper presents the modeling results of heat treatment on crude oil using microwave energy. Modeling is conducted by assuming that the diameter of the well is 11,16 cm, the heat source is applied on the surface of the well, and the cut-off frequency in the air and on crude oil are 1,56 GHz. and 0.91 GHz, respectively. The energy generated by the microwave radiation is converted into heat energy which is absorbed by the crude oil. Consequently, this energy increases the temperature of crude oil through a heat transfer mechanism. The results obtained showed that the temperature of crude oil is about 200°C at a depth of 62.5cm, and at a distance of 3 cm from the center of the well. Temperature along the well follows an exponential function, which is from the center of the well in the direction radially outward from the cylinder axis. It has been observed that the temperature decreases as measured from the well surface along the cylinder.As the world’s oil reserves are dwindling, some researchers have been prompted to make a breakthrough to further improve the efficiency of exploration and production. One of the technologies used is heating the crude oil. This paper presents the modeling results of heat treatment on crude oil using microwave energy. Modeling is conducted by assuming that the diameter of the well is 11,16 cm, the heat source is applied on the surface of the well, and the cut-off frequency in the air and on crude oil are 1,56 GHz. and 0.91 GHz, respectively. The energy generated by the microwave radiation is converted into heat energy which is absorbed by the crude oil. Consequently, this energy increases the temperature of crude oil through a heat transfer mechanism. The results obtained showed that the temperature of crude oil is about 200°C at a depth of 62.5cm, and at a distance of 3 cm from the center of the well. Temperature along the well follows an exponential function, which is from the center of the well in the di...

Fabrication slab waveguide based polymethyl methacrylate (PMMA) with spin coating method

Fabrication and characterization slab waveguide based polymethyl methacrylate (PMMA) has been carried out. Slab waveguide fabrication done by the spin coating method. Slab waveguide fabrication process carried out by the rotational speed of 1000, 2000, and 3000 rpm respectively played for 10 seconds. Then the slab waveguides heated using a hot plate. Heating process starting from room temperature then increased 5°C to 70°C with a 5 minute warm-up time interval. From the results of characterization fabricated slab waveguides to determine the film thickness is made. Then made observations on the waveguide by passing the light beam He-Ne laser on the thin layer through a single mode optical fiber. From the results of characterization is known that the fabrication of a slab waveguide with a layer thickness of 166 μm. From this research it is known that polymethyl methacrylate (PMMA) can be used as a waveguide with a spin coating method.

Influence of pH on the formulation of TiO2 powder prepared by co-precipitation of TiCl3 and photocatalytic activity

Titanium dioxide (titania) nanoparticle were synthesized by coprecipitation process of titanium trichloride (TiCl3) in aqueous medium, with NH4OH as pH regulator. The pH solution was varied during the synthesis process between pH 3-8.4, and all samples were calcined temperature at 400°C for 3 hours. Characteristics and properties of the TiO2 powder were investigated using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM). XRD results show that the single-phase rutile formed when the pH is less than 5, anatase single phase formed began pH 8, and the pH of the solution between 5-8 formed mixed phase rutile-anatase-brookite, rutile-brookite or anatase-brookite. Methylene Blue (MB) photodegradation test were performed in order to evaluate photocatalytic activity. Nanoparticles TiO2 rutile, anatase phase, and mixed phase rutile-brookite, anatase-brookite used to test the photocatalytic activity by measuring the absorbance spectrum photodegradation using UV-Vis spectrometer. The test results showed th...