Nasr Gad - Academia.edu (original) (raw)

Papers by Nasr Gad

Scientific reports, Jun 12, 2024

SN Applied Sciences, Nov 14, 2023

Scientific Reports, Sep 14, 2023

This study employs characteristic mode analysis to investigate a defected ground antenna for mult... more This study employs characteristic mode analysis to investigate a defected ground antenna for multiband applications. The antenna structure incorporates three U-shaped slots in the ground plane, forming a defected ground structure. The microstrip line is exclusively present on the front side plane. The antenna is printed on a substrate made of a ceramic-filled PTFE composite with a size of 20 mm × 21 mm × 0.76 mm and a dielectric constant of 3. The proposed antenna is analyzed using the characteristic mode analysis based on the method of moment and simulated by an electromagnetic simulator based on the finite element method. A multiband antenna is fabricated and tested to validate the proposed antenna performance. The simulation and measurement results reveal that the antenna exhibits good input impedance bandwidths of S 11 ≤ − 10 dB that extend from 2 to 12 GHz with three bands around the operating frequencies (2.96, 6.06, and 8.03) GHz.

Egyptian Journal of Pure and Applied Science

Lead-based Perovskite materials and solar cells attracted attention in the last decade, however, ... more Lead-based Perovskite materials and solar cells attracted attention in the last decade, however, lead toxicity hinders the way to commercialization; therefore, partial, or total replacement of lead by environmentally friendly materials is suggested. In this work, wxAMPS software is employed to study the electrical characteristics of MAPbI 3 , MAPbZnI 3 , and MAPbCoI 3 as active layers in the cell configuration (FTO/ TiO 2 /perovskite /Spiro-MeOTAD/Ag). The thickness of the different active layers is optimized from 200 nm-800 nm for the best electrical performance. For MAPbI 3 , the best electrical parameters of (24.54%, 23.41 mA/cm 2) is achieved at 550 nm thickness, while for MAPb 0.9 Zn 0.1 I 3 (23.96%, , 23,17 mA/cm 2) is obtained at 500 nm. MAPb 0.9 Co 0.1 I 3 achieves the highest PCE of 24.97% at 700 nm. With increasing the active layer thickness, PCE and shortcircuit current increase; however, at the same time the fill factor and opencircuit voltage decrease. The quantum efficiency (QE) is also simulated at different thicknesses for the three active layers. QE of the cells with different active layers increases with the thickness. The QE in the wavelengths ranges from 600-800 nm increases from 71% at 200 nm to 89% at thicknesses 550, 500, and 700 nm for MAPbI 3 , MAPbZnI 3 , and MAPbCoI 3 , respectively. The PCE is not only affected by the active layer thickness, but also by its defect density. The optimum defect density for the best PCE is obtained at 1x10 14 cm-3. This simulation study confirms that MAPb 0.9 Zn 0.1 I 3 , and MAPb 0.9 Co 0.1 I 3 , are promising materials for high-efficiency perovskite solar cells.

Smart Materials for Opto-Electronic Applications

Egyptian Journal of Pure and Applied Science

A new Plus-shaped Dielectric Resonator Antenna (DRA) with parasitic rectangular elements (P-DRA) ... more A new Plus-shaped Dielectric Resonator Antenna (DRA) with parasitic rectangular elements (P-DRA) is proposed for multi-band applications. The antenna is made up of a plus-shaped dielectric resonator and four parasitic rectangular elements that create a rectangular antenna with four L-slots. The P-DRA has a relative permittivity of 15 and is mounted on a 50-ohm microstrip feeding line with a partial and defective ground structure. The proposed R-DRA is designed with the dimensions (15 x 12 x 6.4) mm 3. The impedance bandwidth, radiation pattern, return loss, and antenna gain are obtained using an electromagnetic simulator that employs the finite element method. Furthermore, the obtained results are validated by another 3D simulator using the finite integration technique solver. The P-DRA is designed for multiband applications such as sub-7 GHz (4-8 GHz), wireless local area network (WLAN), X-band (9-10) GHz, and (11-12) GHz, and Kuband (13-16) GHz. The parasitic elements not only contribute to the excitation of additional frequency bands but also enhance the bandwidth of the operating frequencies, providing two broad bands of (4-8) GHz and (13-16) GHz with integrated resonant frequencies.

Egyptian Journal of Pure and Applied Science

Inrtoduction Currently, Machine learning techniques have received a great deal of attention, espe... more Inrtoduction Currently, Machine learning techniques have received a great deal of attention, especially, its promising subset deep learning. Deep learning has been used extensively in a variety of scientific and engineering fields, including device design [1,3] , an inspection of electronic chips in semiconductor production lines [4] , computer vision [5] , and natural language processing and cognitive sciences [6]. There has also been a tremendous effort to use deep learning in the field of photonic devices, particularly in analyzing and predicting waveguide characteristics as in [7,10] .

Menoufia Journal of Electronic Engineering Research

The electrical performance of photovoltaic (PV) cells or arrays is greatly influenced by the ambi... more The electrical performance of photovoltaic (PV) cells or arrays is greatly influenced by the ambient temperature and the solar radiation intensity (irradiation) as well. The effect of temperature and solar irradiance on the main characteristics of solar panels and photovoltaic modules is investigated in this paper. The primary parameters are identified and extracted using the capacitive load approach. These parameters are Short Circuit Current (Isc), Maximum Power Point Current (Impp), Open Circuit Voltage (Voc), Maximum Power Point Voltage (Vmpp), Maximum Power Point (Pmax), Fill factor (FF) and Efficiency (η). The PV cell used in this study is poly-crystal silicon. Its commercial name is Kyocera solar KC130GT. MATLAB Simulink is used to assess the capacitive load method in the investigation of I-V and P-V curves. These two curves are derived based on the effects of varying temperatures (30, 35, 40, and 45 o C) at a constant irradiance (1000 W/m 2) on the PV cell performance and the effect of varying irradiance (250, 500, 750, and 1000 W/m 2) at constant temperature (25 o C) as well. It is concluded that by increasing the irradiance at constant temperature, Isc and Voc are increasing. As a result, η increases from 13.9% at 250 W/m 2 to reach 14.7% at 1000 W/m 2. In the case of increasing temperature at constant irradiance, η decreases from 13.5% at 30 o C to reach 12.8% at 45 o C. This is due to the large drop in Voc compared to the small increment in Isc.

The Applied Computational Electromagnetics Society Journal (ACES)

In this article, a novel design of a quad-band parasitic hat microstrip antenna is proposed for m... more In this article, a novel design of a quad-band parasitic hat microstrip antenna is proposed for multiband applications. The proposed antenna consists of a rectangular patch of dimensions 30 mm×11 mm cut with four L-shaped slots connected with a rectangular slot in the middle of the front side of the antenna to form a parasitic hat based upon defected microstrip structure. On the other side of the antenna, a defected ground structure is integrated as five rectangular slots embedded in the ground plane with the same width but with various lengths. The suggested antenna is designed and fabricated on a substrate material with an area of 45 × 40 mm2 with a thickness of 1.52 mm to generate four frequency bands. The proposed antenna is fed by a microstrip transmission line. The simulated radiation patterns, return losses, maximum gains, and efficiencies of the antenna are carried out by using electromagnetic simulation software based on the finite element method. The measured return loss r...

2022 Photonics North (PN)

The main objective of this thesis is to design, fabricate, analyze, and investigate planar printe... more The main objective of this thesis is to design, fabricate, analyze, and investigate planar printed slot antennas based on defected ground structures for multiband applications. In the first part, a novel wideband printed square spiral slot antenna consists of two phase-shifted square spiral slot elements inductively coupled to coplanar waveguide is designed. In the second part, a novel design of a microstrip-fed planar printed slot antenna using defected ground structures for multiband applications is presented.Glavni namen disertacije je načrtovanje, izdelava, analizirane in proučevanje ravninskih tiskanih režastih anten osnovanih na necelih ravninah mase za večpasovno uporabo. V prvem delu je zasnovana nova širokopasovna tiskana kvadratna spiralna režasta antena, ki je sestavljena iz dveh fazno premaknjenih kvadratnih spiralnih režastih anten, ki sta induktivno sklopljeni na koplanarni vod. V drugem delu je predstavljena nova vrsta ravninske režaste antene z mikrotrakastim napajan...

2020 International Conference on Innovative Trends in Communication and Computer Engineering (ITCE), 2020

This paper presents a new design of a slotted rectangular microstrip antenna for radar and 5G app... more This paper presents a new design of a slotted rectangular microstrip antenna for radar and 5G applications. The proposed antenna consists of a rectangular patch fed with a microstrip line in the front side and the ground in the back side. The proposed antenna is designed and simulated by using the finite integration technique (FIT). In this study, four narrow rectangular slots are etched around the edges and a wide rectangular slot in the center to generate dual frequency bands. Further, two corners are truncated to enhance the gain. The optimum design is simulated by using a double-sided substrate that has 0.79mm thickness with an area of 21.756 × 21.756 mm2. The simulation results show that the proposed design has good input-impedance bandwidths (S11≤ -10dB) at frequencies 17.07 and 26.82 GHz with 7.65 and 5.64dB gain, respectively. The performance of the reported design is suitable for dual band applications.

2021 International Conference on Electronic Engineering (ICEEM), 2021

A design of multiband hybrid-shape dielectric resonator antenna (DRA) is presented. In this desig... more A design of multiband hybrid-shape dielectric resonator antenna (DRA) is presented. In this design the dielectric resonator material (DR) is fed by 50Ω rectangular microstrip line arranged on top of a substrate. The antenna uses the defected ground structure (DGS) technique. Results are obtained using electromagnetic simulator to study the impedance bandwidth, radiation pattern, return loss and antenna gain. This proposed antenna is simulated obtaining four bands (4.04-8.016), (9.7-10.6), (11.48-12.48) and (14.16-15.16) GHz for S11 ≤ -10 dB, with resonated frequencies (4.6, 7.4, 10.2, 12.2, and 14.48) GHz and provides impedance bandwidth of (55.6%, 8.6%, 8.1%, and 6.9%) which can be employed in multiband applications, like WLAN, sub-6 GHz, X-band, and Ku-band.

2021 38th National Radio Science Conference (NRSC), 2021

In this article, a suggested design of mirror stairs microstrip antenna that has a planar geometr... more In this article, a suggested design of mirror stairs microstrip antenna that has a planar geometry with defected structures is presented for multiband applications. The suggested antenna generates six resonance frequencies to cover 3.965 GHz (WiMAX), 7GHz, 9.188GHz (ultra-wideband, satellite)11.664GHz (space program application), 12.956GHz (indoor high-data-rate application) and 13.861 (land mobile satellite, radio navigation application) that cover the range from 2 to 17 GHz. The suggested antenna contains five rectangular slots based upon the defected ground structure (DGS) under the transmission line feed. The middle rectangular slot works as a mirror that reflects the image of the second rectangular slot. The third slot and all the rectangular slots have the same width, whereas the top side of the suggested antenna contains three rectangular strips as patch antennas based on defected microstrip structure (DMS). The suggested antenna is designed by a simulator that depends on the finite element method (FEM). The suggested antenna is printed and fabricated on double-sided substrate material that is 1.524 mm thick with an area of 45 × 40 mm2. The simulation and measurement results prove that the suggested antenna has good input impedance bandwidths as S11 ≤ −10 dB at six operating frequencies. The measurement results display good agreements with simulation results. For study purposes, we analyze the suggested antenna and simulated results compared on bandwidth, gain, efficiency, and return loss. The resultant antenna with mirror stairs shape based on DGS and DMS has improved in parameter performance mostly enhancement in bandwidth.

In this paper, the design of a wideband printed slot antenna for multiband applications is presen... more In this paper, the design of a wideband printed slot antenna for multiband applications is presented. The proposed antenna consists of two square spiral slot elements with 180 out of phase excitation and external feeding by a coplanar wave guide (CPW). The antenna is designed on a single-sided low cost FR4 substrate. Spiral antenna and its feeding circuit are compact in size with overall dimensions 40 mm × 65 mm × 1.6 mm. The antenna was simulated and measured in frequency range from 2-17 GHz and it exhibits multiple wide band operation within this range. The antenna was firstly simulated using electromagnetic simulation software based on method of moments (MoM) and later on fabricated and measured. The measured return loss and radiation pattern results are in good agreement with the simulated results. The proposed antenna can be embedded in wireless systems and integrated with microwave circuits to lower the manufacturing cost. The obtained results for return loss and gain show th...

─ This paper presents the design of a microstrip-fed, planar-printed, slot antenna using defected... more ─ This paper presents the design of a microstrip-fed, planar-printed, slot antenna using defected ground structures (DGSs) for multiband applications. The antenna structure consists of two groups of five straight slot elements. The slot elements in each group are of the same width but different lengths on the ground plane and separated by a small strip and a slot cut on both sides of the strip to interconnect the group of slots with each other. The microstrip line is designed on the front side of the PCB with a right angle for all the slots to make it easy to mount the slots and the microstrip with a monolithic microwave integrated circuit (MMIC). The proposed antenna is designed and simulated using an electromagnetic simulator based on the method of moment (MoM). For the validation the antenna was fabricated on a double-sided substrate material that was 0.79 mm thick with an area of 45 × 40 mm. The simulation and measurement results show that the antenna has good input-impedance ba...

The main objective of this thesis is to design, fabricate, analyze, and investigate planar printe... more The main objective of this thesis is to design, fabricate, analyze, and investigate planar printed slot antennas based on defected ground structures for multiband applications. In the first part, a novel wideband printed square spiral slot antenna consists of two phase-shifted square spiral slot elements inductively coupled to coplanar waveguide is designed. In the second part, a novel design of a microstrip-fed planar printed slot antenna using defected ground structures for multiband applications is presented.

European Journal of Science and Technology, 2021

Scientific reports, Jun 12, 2024

SN Applied Sciences, Nov 14, 2023

Scientific Reports, Sep 14, 2023

This study employs characteristic mode analysis to investigate a defected ground antenna for mult... more This study employs characteristic mode analysis to investigate a defected ground antenna for multiband applications. The antenna structure incorporates three U-shaped slots in the ground plane, forming a defected ground structure. The microstrip line is exclusively present on the front side plane. The antenna is printed on a substrate made of a ceramic-filled PTFE composite with a size of 20 mm × 21 mm × 0.76 mm and a dielectric constant of 3. The proposed antenna is analyzed using the characteristic mode analysis based on the method of moment and simulated by an electromagnetic simulator based on the finite element method. A multiband antenna is fabricated and tested to validate the proposed antenna performance. The simulation and measurement results reveal that the antenna exhibits good input impedance bandwidths of S 11 ≤ − 10 dB that extend from 2 to 12 GHz with three bands around the operating frequencies (2.96, 6.06, and 8.03) GHz.

Egyptian Journal of Pure and Applied Science

Lead-based Perovskite materials and solar cells attracted attention in the last decade, however, ... more Lead-based Perovskite materials and solar cells attracted attention in the last decade, however, lead toxicity hinders the way to commercialization; therefore, partial, or total replacement of lead by environmentally friendly materials is suggested. In this work, wxAMPS software is employed to study the electrical characteristics of MAPbI 3 , MAPbZnI 3 , and MAPbCoI 3 as active layers in the cell configuration (FTO/ TiO 2 /perovskite /Spiro-MeOTAD/Ag). The thickness of the different active layers is optimized from 200 nm-800 nm for the best electrical performance. For MAPbI 3 , the best electrical parameters of (24.54%, 23.41 mA/cm 2) is achieved at 550 nm thickness, while for MAPb 0.9 Zn 0.1 I 3 (23.96%, , 23,17 mA/cm 2) is obtained at 500 nm. MAPb 0.9 Co 0.1 I 3 achieves the highest PCE of 24.97% at 700 nm. With increasing the active layer thickness, PCE and shortcircuit current increase; however, at the same time the fill factor and opencircuit voltage decrease. The quantum efficiency (QE) is also simulated at different thicknesses for the three active layers. QE of the cells with different active layers increases with the thickness. The QE in the wavelengths ranges from 600-800 nm increases from 71% at 200 nm to 89% at thicknesses 550, 500, and 700 nm for MAPbI 3 , MAPbZnI 3 , and MAPbCoI 3 , respectively. The PCE is not only affected by the active layer thickness, but also by its defect density. The optimum defect density for the best PCE is obtained at 1x10 14 cm-3. This simulation study confirms that MAPb 0.9 Zn 0.1 I 3 , and MAPb 0.9 Co 0.1 I 3 , are promising materials for high-efficiency perovskite solar cells.

Smart Materials for Opto-Electronic Applications

Egyptian Journal of Pure and Applied Science

A new Plus-shaped Dielectric Resonator Antenna (DRA) with parasitic rectangular elements (P-DRA) ... more A new Plus-shaped Dielectric Resonator Antenna (DRA) with parasitic rectangular elements (P-DRA) is proposed for multi-band applications. The antenna is made up of a plus-shaped dielectric resonator and four parasitic rectangular elements that create a rectangular antenna with four L-slots. The P-DRA has a relative permittivity of 15 and is mounted on a 50-ohm microstrip feeding line with a partial and defective ground structure. The proposed R-DRA is designed with the dimensions (15 x 12 x 6.4) mm 3. The impedance bandwidth, radiation pattern, return loss, and antenna gain are obtained using an electromagnetic simulator that employs the finite element method. Furthermore, the obtained results are validated by another 3D simulator using the finite integration technique solver. The P-DRA is designed for multiband applications such as sub-7 GHz (4-8 GHz), wireless local area network (WLAN), X-band (9-10) GHz, and (11-12) GHz, and Kuband (13-16) GHz. The parasitic elements not only contribute to the excitation of additional frequency bands but also enhance the bandwidth of the operating frequencies, providing two broad bands of (4-8) GHz and (13-16) GHz with integrated resonant frequencies.

Egyptian Journal of Pure and Applied Science

Inrtoduction Currently, Machine learning techniques have received a great deal of attention, espe... more Inrtoduction Currently, Machine learning techniques have received a great deal of attention, especially, its promising subset deep learning. Deep learning has been used extensively in a variety of scientific and engineering fields, including device design [1,3] , an inspection of electronic chips in semiconductor production lines [4] , computer vision [5] , and natural language processing and cognitive sciences [6]. There has also been a tremendous effort to use deep learning in the field of photonic devices, particularly in analyzing and predicting waveguide characteristics as in [7,10] .

Menoufia Journal of Electronic Engineering Research

The electrical performance of photovoltaic (PV) cells or arrays is greatly influenced by the ambi... more The electrical performance of photovoltaic (PV) cells or arrays is greatly influenced by the ambient temperature and the solar radiation intensity (irradiation) as well. The effect of temperature and solar irradiance on the main characteristics of solar panels and photovoltaic modules is investigated in this paper. The primary parameters are identified and extracted using the capacitive load approach. These parameters are Short Circuit Current (Isc), Maximum Power Point Current (Impp), Open Circuit Voltage (Voc), Maximum Power Point Voltage (Vmpp), Maximum Power Point (Pmax), Fill factor (FF) and Efficiency (η). The PV cell used in this study is poly-crystal silicon. Its commercial name is Kyocera solar KC130GT. MATLAB Simulink is used to assess the capacitive load method in the investigation of I-V and P-V curves. These two curves are derived based on the effects of varying temperatures (30, 35, 40, and 45 o C) at a constant irradiance (1000 W/m 2) on the PV cell performance and the effect of varying irradiance (250, 500, 750, and 1000 W/m 2) at constant temperature (25 o C) as well. It is concluded that by increasing the irradiance at constant temperature, Isc and Voc are increasing. As a result, η increases from 13.9% at 250 W/m 2 to reach 14.7% at 1000 W/m 2. In the case of increasing temperature at constant irradiance, η decreases from 13.5% at 30 o C to reach 12.8% at 45 o C. This is due to the large drop in Voc compared to the small increment in Isc.

The Applied Computational Electromagnetics Society Journal (ACES)

In this article, a novel design of a quad-band parasitic hat microstrip antenna is proposed for m... more In this article, a novel design of a quad-band parasitic hat microstrip antenna is proposed for multiband applications. The proposed antenna consists of a rectangular patch of dimensions 30 mm×11 mm cut with four L-shaped slots connected with a rectangular slot in the middle of the front side of the antenna to form a parasitic hat based upon defected microstrip structure. On the other side of the antenna, a defected ground structure is integrated as five rectangular slots embedded in the ground plane with the same width but with various lengths. The suggested antenna is designed and fabricated on a substrate material with an area of 45 × 40 mm2 with a thickness of 1.52 mm to generate four frequency bands. The proposed antenna is fed by a microstrip transmission line. The simulated radiation patterns, return losses, maximum gains, and efficiencies of the antenna are carried out by using electromagnetic simulation software based on the finite element method. The measured return loss r...

2022 Photonics North (PN)

The main objective of this thesis is to design, fabricate, analyze, and investigate planar printe... more The main objective of this thesis is to design, fabricate, analyze, and investigate planar printed slot antennas based on defected ground structures for multiband applications. In the first part, a novel wideband printed square spiral slot antenna consists of two phase-shifted square spiral slot elements inductively coupled to coplanar waveguide is designed. In the second part, a novel design of a microstrip-fed planar printed slot antenna using defected ground structures for multiband applications is presented.Glavni namen disertacije je načrtovanje, izdelava, analizirane in proučevanje ravninskih tiskanih režastih anten osnovanih na necelih ravninah mase za večpasovno uporabo. V prvem delu je zasnovana nova širokopasovna tiskana kvadratna spiralna režasta antena, ki je sestavljena iz dveh fazno premaknjenih kvadratnih spiralnih režastih anten, ki sta induktivno sklopljeni na koplanarni vod. V drugem delu je predstavljena nova vrsta ravninske režaste antene z mikrotrakastim napajan...

2020 International Conference on Innovative Trends in Communication and Computer Engineering (ITCE), 2020

This paper presents a new design of a slotted rectangular microstrip antenna for radar and 5G app... more This paper presents a new design of a slotted rectangular microstrip antenna for radar and 5G applications. The proposed antenna consists of a rectangular patch fed with a microstrip line in the front side and the ground in the back side. The proposed antenna is designed and simulated by using the finite integration technique (FIT). In this study, four narrow rectangular slots are etched around the edges and a wide rectangular slot in the center to generate dual frequency bands. Further, two corners are truncated to enhance the gain. The optimum design is simulated by using a double-sided substrate that has 0.79mm thickness with an area of 21.756 × 21.756 mm2. The simulation results show that the proposed design has good input-impedance bandwidths (S11≤ -10dB) at frequencies 17.07 and 26.82 GHz with 7.65 and 5.64dB gain, respectively. The performance of the reported design is suitable for dual band applications.

2021 International Conference on Electronic Engineering (ICEEM), 2021

A design of multiband hybrid-shape dielectric resonator antenna (DRA) is presented. In this desig... more A design of multiband hybrid-shape dielectric resonator antenna (DRA) is presented. In this design the dielectric resonator material (DR) is fed by 50Ω rectangular microstrip line arranged on top of a substrate. The antenna uses the defected ground structure (DGS) technique. Results are obtained using electromagnetic simulator to study the impedance bandwidth, radiation pattern, return loss and antenna gain. This proposed antenna is simulated obtaining four bands (4.04-8.016), (9.7-10.6), (11.48-12.48) and (14.16-15.16) GHz for S11 ≤ -10 dB, with resonated frequencies (4.6, 7.4, 10.2, 12.2, and 14.48) GHz and provides impedance bandwidth of (55.6%, 8.6%, 8.1%, and 6.9%) which can be employed in multiband applications, like WLAN, sub-6 GHz, X-band, and Ku-band.

2021 38th National Radio Science Conference (NRSC), 2021

In this article, a suggested design of mirror stairs microstrip antenna that has a planar geometr... more In this article, a suggested design of mirror stairs microstrip antenna that has a planar geometry with defected structures is presented for multiband applications. The suggested antenna generates six resonance frequencies to cover 3.965 GHz (WiMAX), 7GHz, 9.188GHz (ultra-wideband, satellite)11.664GHz (space program application), 12.956GHz (indoor high-data-rate application) and 13.861 (land mobile satellite, radio navigation application) that cover the range from 2 to 17 GHz. The suggested antenna contains five rectangular slots based upon the defected ground structure (DGS) under the transmission line feed. The middle rectangular slot works as a mirror that reflects the image of the second rectangular slot. The third slot and all the rectangular slots have the same width, whereas the top side of the suggested antenna contains three rectangular strips as patch antennas based on defected microstrip structure (DMS). The suggested antenna is designed by a simulator that depends on the finite element method (FEM). The suggested antenna is printed and fabricated on double-sided substrate material that is 1.524 mm thick with an area of 45 × 40 mm2. The simulation and measurement results prove that the suggested antenna has good input impedance bandwidths as S11 ≤ −10 dB at six operating frequencies. The measurement results display good agreements with simulation results. For study purposes, we analyze the suggested antenna and simulated results compared on bandwidth, gain, efficiency, and return loss. The resultant antenna with mirror stairs shape based on DGS and DMS has improved in parameter performance mostly enhancement in bandwidth.

In this paper, the design of a wideband printed slot antenna for multiband applications is presen... more In this paper, the design of a wideband printed slot antenna for multiband applications is presented. The proposed antenna consists of two square spiral slot elements with 180 out of phase excitation and external feeding by a coplanar wave guide (CPW). The antenna is designed on a single-sided low cost FR4 substrate. Spiral antenna and its feeding circuit are compact in size with overall dimensions 40 mm × 65 mm × 1.6 mm. The antenna was simulated and measured in frequency range from 2-17 GHz and it exhibits multiple wide band operation within this range. The antenna was firstly simulated using electromagnetic simulation software based on method of moments (MoM) and later on fabricated and measured. The measured return loss and radiation pattern results are in good agreement with the simulated results. The proposed antenna can be embedded in wireless systems and integrated with microwave circuits to lower the manufacturing cost. The obtained results for return loss and gain show th...

─ This paper presents the design of a microstrip-fed, planar-printed, slot antenna using defected... more ─ This paper presents the design of a microstrip-fed, planar-printed, slot antenna using defected ground structures (DGSs) for multiband applications. The antenna structure consists of two groups of five straight slot elements. The slot elements in each group are of the same width but different lengths on the ground plane and separated by a small strip and a slot cut on both sides of the strip to interconnect the group of slots with each other. The microstrip line is designed on the front side of the PCB with a right angle for all the slots to make it easy to mount the slots and the microstrip with a monolithic microwave integrated circuit (MMIC). The proposed antenna is designed and simulated using an electromagnetic simulator based on the method of moment (MoM). For the validation the antenna was fabricated on a double-sided substrate material that was 0.79 mm thick with an area of 45 × 40 mm. The simulation and measurement results show that the antenna has good input-impedance ba...

The main objective of this thesis is to design, fabricate, analyze, and investigate planar printe... more The main objective of this thesis is to design, fabricate, analyze, and investigate planar printed slot antennas based on defected ground structures for multiband applications. In the first part, a novel wideband printed square spiral slot antenna consists of two phase-shifted square spiral slot elements inductively coupled to coplanar waveguide is designed. In the second part, a novel design of a microstrip-fed planar printed slot antenna using defected ground structures for multiband applications is presented.

European Journal of Science and Technology, 2021