Indonesian journal of electrical engineering and computer science, Apr 1, 2024
This paper introduces the design of a multiple-input-multiple-output (MIMO) antenna optimized for... more This paper introduces the design of a multiple-input-multiple-output (MIMO) antenna optimized for low-profile applications supporting sub-6 GHz fifth-generation (5G) wireless applications. We have started the design from a single antenna with a square patch shape, each antenna array is composed from 4-element radiators fed by using power dividers and quarter microstrip lines. Mounted on a single Rogers RT5880 substrate, the MIMO antenna functions at 3.5 GHz. In order to miniature and to decrease the mutual coupling between the both antennas array we have optimised a magnetic wall based on periodic structures permitting to decrease the mutual coupling between the both antenna array. The unit element from the wall was optimised, studied and validated in order to absorb the surface current and to enhance the isolation between the different radiating elements. The dimensions of the proposed MIMO antenna are 154×220×0.578 mm³. The MIMO antenna final circuit achieves a peak gain of 9 dBi and an isolation around-30 dB. The introduction of the magnetic wall permits to enhance the isolation between the antenna array from-20 dB to-30 dB at 3.5 GHz band. This advancement contributes to the overall performance improvement of the MIMO antenna system.
Indonesian Journal of Electrical Engineering and Computer Science, Mar 1, 2023
In this work, we design a microstrip patch antenna having a dimension of 3.279×4.232 mm 2 and con... more In this work, we design a microstrip patch antenna having a dimension of 3.279×4.232 mm 2 and consisting of a Foam-like substrate, of a relative dielectric permittivity of 1 and with a width of 0.5 mm, placed between two identical Rogers RT5880 substrates, having a value of 2.2 as relative dielectric permittivity, a loss tangent of 0.0009 and a height of 0.508 mm. The designed antenna resonates at 28 GHz, featuring a maximum gain of 9.77 dBi and a wide frequency bandwidth of 2.9 GHz. Compared to the conventional antenna, this proposed structure achieved an important enhancement of the directivity, with a value around 38.8°. The CST Microwave Studio software was used for all designs and analysis.
In this paper, a symmetrical monolayer metamaterial superstrate is placed on a microstrip patch a... more In this paper, a symmetrical monolayer metamaterial superstrate is placed on a microstrip patch antenna resonant at 3.5 GHz. MTM metamaterial based CSRR Complementary Split Ring Resonators, constituting two rectangular rings is opposite splits on both ends, which are printed on Rogers RT 5880 type substrate with relative permittivity of 2.2, tangential loss of 0.0009, and a thickness of 0.508mm. This resonator is capable of exhibiting an ε-negative permittivity. Moving an MTM superstrate loaded with a 2 × 3 grating on a single radiating element, provides a gain increase from 4.66 dBi to 5.67 dBi was found at its operating frequency, and the radiation pattern was directional and stable over the entire frequency band. For a 4×1 antenna array loaded with MTM, the gain reaches about 9.84 dBi. the proposed antenna is suitable for 5G mobile applications.
This work presents and describes the design of a novel multilayer antenna structure based on meta... more This work presents and describes the design of a novel multilayer antenna structure based on metasurfaces for 5G mobile applications. The suggested antenna has good matching input impedance around 28 GHz, a bandwidth of 2.2 GHz, and an enhancement of gain in comparison with standard patch antenna. This antenna is mounted on two substrates; the first one is the foam, and the second is Roger’s substrate suitable for 5G mobile applications. The whole dimensions of the final circuit are 3.28x4.23mm2. The proposed antenna structure has a high gain, good matching of input impedance and an aperture angle of 57 ° which is more directive compared to the rectangular antenna element.
An innovative design of a circular polarization antenna for wireless power transmission is descri... more An innovative design of a circular polarization antenna for wireless power transmission is described. The suggested antenna is simply constructed, which consists of a square radiating patch having a slotted center with feeding via a probe and an L-shaped ground plane. The application of this L-shaped ground allows a short connection of the probe power supply to the square patch while retaining a certain elevation from the ground plane to the square patch while using an air layer substrate, thereby allows a proper adaptation of the impedance and an improvement of the bandwidth. The purpose of utilizing the slot in the center of the square patch is to create a circular polarization with an axial ratio value of under 3dB. By means of a through-hole through the vertical L-shaped ground plane, the patch radiating can be readily excited with a probe feed pointing into the same plane as the patch. This approach allows to further improve the bandwidth of the circular polarization. In this w...
We report here a method for determining the thickness of semiconductor and dielectric thin fihns ... more We report here a method for determining the thickness of semiconductor and dielectric thin fihns based on the optical transmission turning points. An analytical treatment of the transmittance taking into account the shrinkage of the interference fringes caused by thickness inhomogeneities and the bandwidth of the incoming radiation is used. The computation algorithm is original, simple and straightforward. The accuracy of the method is studied, and the effects of the experimental noise, the uncertainty in the value of the substrate refractive index and of the number of available fringes on the spectra are considered. The precision of the thickness is estimated to be around 0.4% (or less) for films whose optical thicknesses (product of the refractive index and the thickness) are in the range 0.5-10 b~m. The method is applied to obtain large-area thickness profiles by computing the thickness from spectra taken over different positions of the film surface. In this case, a special mechanical mounting is needed for the acquisition of the transmission data. This procedure presents the advantage of local analysis of the films, allowing the non-flatness of the substrate to be ignored. This last is the major inconvenience in the use of a surface profile measurement system. Results are given for films up to 7 cm large (there is no difficulty in increasing this value even further) and with different thickness profiles.
In this work a method for the determination of the thickness and optical properties of low optica... more In this work a method for the determination of the thickness and optical properties of low optical thickness films D-600 nm , Ž. Ž. from the experimental transmittance T and back reflectance RЈ measurements, is proposed. An original analytical formulation without any kind of approximation is employed for the computations. The computing algorithm is presented in detail and an error study is given. The method is applied for the characterization of sputtered CdTe and a-Si thin films of optical thickness in the range of 250 nm.
Thin films of CuA1Te 2 have been deposited on molybdenum using rf sputtering. The electrical prop... more Thin films of CuA1Te 2 have been deposited on molybdenum using rf sputtering. The electrical properties of Mo/CuAITe2/Mo have been investigated analysing the currentvoltage characteristics of these structures. The behaviour of these characteristics as a function of the annealing temperature has been explained.
CuAITe 2 films have been grown by RF sputtering on both unheated and heated glass substrates. The... more CuAITe 2 films have been grown by RF sputtering on both unheated and heated glass substrates. The X-ray diffraction spectra exhibit one diffraction line at 24.60 ° corresponding to the (112) direction which is the preferred orientation in the chalcopyrite phase. When deposited onto 1500C heated substrates, the formation of binary compounds is favoured. The resistivity variations versus the temperature show a peak around T = 140°C. In order to study the electrical properties of p-type CuAITe 2 samples, ohmic contacts were prepared by RF sputtering of Mo onto these films.
TELKOMNIKA (Telecommunication Computing Electronics and Control)
The requirement for applications operating at a variety of frequencies in a unified wireless devi... more The requirement for applications operating at a variety of frequencies in a unified wireless device has greatly enhanced in recent years. For this purpose, multi-functional wireless components are essential. This paper presents a new design of a wideband circularly-polarized microstrip antenna array with defected ground structure (DGS). A previous design was introduced which cover the C-band at 5.8 GHz and operates in the industrial scientific medical (ISM) band for wireless communication applications. The proposed antenna has excellent performances which include good input impedance matching with a fed of the circular polarization at 5.8 GHz. The proposed design is validated and optimized by adding a new design of defected ground structure. This aperture geometry enables the antenna to operate in a wideband. The obtained results show that the modified antenna has a good performance in terms of return loss, bandwidth, gain and radiation pattern and demonstrate that the proposed antenna offers a good solution for multi-standard wireless communication applications.
Indonesian journal of electrical engineering and computer science, Apr 1, 2024
This paper introduces the design of a multiple-input-multiple-output (MIMO) antenna optimized for... more This paper introduces the design of a multiple-input-multiple-output (MIMO) antenna optimized for low-profile applications supporting sub-6 GHz fifth-generation (5G) wireless applications. We have started the design from a single antenna with a square patch shape, each antenna array is composed from 4-element radiators fed by using power dividers and quarter microstrip lines. Mounted on a single Rogers RT5880 substrate, the MIMO antenna functions at 3.5 GHz. In order to miniature and to decrease the mutual coupling between the both antennas array we have optimised a magnetic wall based on periodic structures permitting to decrease the mutual coupling between the both antenna array. The unit element from the wall was optimised, studied and validated in order to absorb the surface current and to enhance the isolation between the different radiating elements. The dimensions of the proposed MIMO antenna are 154×220×0.578 mm³. The MIMO antenna final circuit achieves a peak gain of 9 dBi and an isolation around-30 dB. The introduction of the magnetic wall permits to enhance the isolation between the antenna array from-20 dB to-30 dB at 3.5 GHz band. This advancement contributes to the overall performance improvement of the MIMO antenna system.
Indonesian Journal of Electrical Engineering and Computer Science, Mar 1, 2023
In this work, we design a microstrip patch antenna having a dimension of 3.279×4.232 mm 2 and con... more In this work, we design a microstrip patch antenna having a dimension of 3.279×4.232 mm 2 and consisting of a Foam-like substrate, of a relative dielectric permittivity of 1 and with a width of 0.5 mm, placed between two identical Rogers RT5880 substrates, having a value of 2.2 as relative dielectric permittivity, a loss tangent of 0.0009 and a height of 0.508 mm. The designed antenna resonates at 28 GHz, featuring a maximum gain of 9.77 dBi and a wide frequency bandwidth of 2.9 GHz. Compared to the conventional antenna, this proposed structure achieved an important enhancement of the directivity, with a value around 38.8°. The CST Microwave Studio software was used for all designs and analysis.
In this paper, a symmetrical monolayer metamaterial superstrate is placed on a microstrip patch a... more In this paper, a symmetrical monolayer metamaterial superstrate is placed on a microstrip patch antenna resonant at 3.5 GHz. MTM metamaterial based CSRR Complementary Split Ring Resonators, constituting two rectangular rings is opposite splits on both ends, which are printed on Rogers RT 5880 type substrate with relative permittivity of 2.2, tangential loss of 0.0009, and a thickness of 0.508mm. This resonator is capable of exhibiting an ε-negative permittivity. Moving an MTM superstrate loaded with a 2 × 3 grating on a single radiating element, provides a gain increase from 4.66 dBi to 5.67 dBi was found at its operating frequency, and the radiation pattern was directional and stable over the entire frequency band. For a 4×1 antenna array loaded with MTM, the gain reaches about 9.84 dBi. the proposed antenna is suitable for 5G mobile applications.
This work presents and describes the design of a novel multilayer antenna structure based on meta... more This work presents and describes the design of a novel multilayer antenna structure based on metasurfaces for 5G mobile applications. The suggested antenna has good matching input impedance around 28 GHz, a bandwidth of 2.2 GHz, and an enhancement of gain in comparison with standard patch antenna. This antenna is mounted on two substrates; the first one is the foam, and the second is Roger’s substrate suitable for 5G mobile applications. The whole dimensions of the final circuit are 3.28x4.23mm2. The proposed antenna structure has a high gain, good matching of input impedance and an aperture angle of 57 ° which is more directive compared to the rectangular antenna element.
An innovative design of a circular polarization antenna for wireless power transmission is descri... more An innovative design of a circular polarization antenna for wireless power transmission is described. The suggested antenna is simply constructed, which consists of a square radiating patch having a slotted center with feeding via a probe and an L-shaped ground plane. The application of this L-shaped ground allows a short connection of the probe power supply to the square patch while retaining a certain elevation from the ground plane to the square patch while using an air layer substrate, thereby allows a proper adaptation of the impedance and an improvement of the bandwidth. The purpose of utilizing the slot in the center of the square patch is to create a circular polarization with an axial ratio value of under 3dB. By means of a through-hole through the vertical L-shaped ground plane, the patch radiating can be readily excited with a probe feed pointing into the same plane as the patch. This approach allows to further improve the bandwidth of the circular polarization. In this w...
We report here a method for determining the thickness of semiconductor and dielectric thin fihns ... more We report here a method for determining the thickness of semiconductor and dielectric thin fihns based on the optical transmission turning points. An analytical treatment of the transmittance taking into account the shrinkage of the interference fringes caused by thickness inhomogeneities and the bandwidth of the incoming radiation is used. The computation algorithm is original, simple and straightforward. The accuracy of the method is studied, and the effects of the experimental noise, the uncertainty in the value of the substrate refractive index and of the number of available fringes on the spectra are considered. The precision of the thickness is estimated to be around 0.4% (or less) for films whose optical thicknesses (product of the refractive index and the thickness) are in the range 0.5-10 b~m. The method is applied to obtain large-area thickness profiles by computing the thickness from spectra taken over different positions of the film surface. In this case, a special mechanical mounting is needed for the acquisition of the transmission data. This procedure presents the advantage of local analysis of the films, allowing the non-flatness of the substrate to be ignored. This last is the major inconvenience in the use of a surface profile measurement system. Results are given for films up to 7 cm large (there is no difficulty in increasing this value even further) and with different thickness profiles.
In this work a method for the determination of the thickness and optical properties of low optica... more In this work a method for the determination of the thickness and optical properties of low optical thickness films D-600 nm , Ž. Ž. from the experimental transmittance T and back reflectance RЈ measurements, is proposed. An original analytical formulation without any kind of approximation is employed for the computations. The computing algorithm is presented in detail and an error study is given. The method is applied for the characterization of sputtered CdTe and a-Si thin films of optical thickness in the range of 250 nm.
Thin films of CuA1Te 2 have been deposited on molybdenum using rf sputtering. The electrical prop... more Thin films of CuA1Te 2 have been deposited on molybdenum using rf sputtering. The electrical properties of Mo/CuAITe2/Mo have been investigated analysing the currentvoltage characteristics of these structures. The behaviour of these characteristics as a function of the annealing temperature has been explained.
CuAITe 2 films have been grown by RF sputtering on both unheated and heated glass substrates. The... more CuAITe 2 films have been grown by RF sputtering on both unheated and heated glass substrates. The X-ray diffraction spectra exhibit one diffraction line at 24.60 ° corresponding to the (112) direction which is the preferred orientation in the chalcopyrite phase. When deposited onto 1500C heated substrates, the formation of binary compounds is favoured. The resistivity variations versus the temperature show a peak around T = 140°C. In order to study the electrical properties of p-type CuAITe 2 samples, ohmic contacts were prepared by RF sputtering of Mo onto these films.
TELKOMNIKA (Telecommunication Computing Electronics and Control)
The requirement for applications operating at a variety of frequencies in a unified wireless devi... more The requirement for applications operating at a variety of frequencies in a unified wireless device has greatly enhanced in recent years. For this purpose, multi-functional wireless components are essential. This paper presents a new design of a wideband circularly-polarized microstrip antenna array with defected ground structure (DGS). A previous design was introduced which cover the C-band at 5.8 GHz and operates in the industrial scientific medical (ISM) band for wireless communication applications. The proposed antenna has excellent performances which include good input impedance matching with a fed of the circular polarization at 5.8 GHz. The proposed design is validated and optimized by adding a new design of defected ground structure. This aperture geometry enables the antenna to operate in a wideband. The obtained results show that the modified antenna has a good performance in terms of return loss, bandwidth, gain and radiation pattern and demonstrate that the proposed antenna offers a good solution for multi-standard wireless communication applications.
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