九州大学 研究者情報
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基本情報 研究活動
BARAKAT ADEL TAWFIK MOHAMED MOHAMED(ばらかつと あでいる たわふいつく もはまつど もはまつど) データ更新日:2021.06.21



主な研究テーマ
次世代の生物医学インプラントのためのワイヤレス電力伝送
キーワード:ワイヤレス電力伝送 (WPT), バンドパスフィルター (BPF), 亡命グラウンド構造 (DGS)
2016.04.
フィルター・チップ上のミリ波帯で
キーワード:バンドパスフィルター(BPF), 亡命接地構造(DGS)
2015.02~2017.02.
60 GHz オンチップ統合型アンテナ
キーワード:アンテナ、60 GHz帯、オン・チップ
2010.02~2015.02.
研究業績
主要原著論文
1. Barakat, Adel; Yoshitomi, Kuniaki; Pokharel, Ramesh K., Design Approach for Efficient Wireless Power Transfer Systems During Lateral Misalignment, IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, 10.1109/TMTT.2018.2852661, 66, 9, 4170-4177, 2018.09.
2. Elsaidy, Elsayed; Barakat, Adel; Abdel-Rahman, Adel B.; Allam, Ahmed; Pokharel, Ramesh K., Ultracompact CMOS 60-GHz Tapped-Line Combline BPF With Two Transmission Zeros Using Defected Ground Structures, IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY, 10.1109/TCPMT.2018.2861411, 8, 9, 1642-1649, 2018.09.
3. Nusrat Jahan, Siti Amalina Enche Ab Rahim, Hamed Mosalam, Adel Barakat, Takana Kaho, Ramesh K. Pokharel,, 22-GHz-Band Oscillator Using Integrated H-Shape Defected Ground Structure Resonator in 0.18-mu m CMOS Technology, IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS, 10.1109/LMWC.2018.2801031, 28, 3, 233-235, 2018.03, A novel 22-GHz-band oscillator using an integrated defected ground structure (DGS) resonator is presented for quasimillimeter waveband applications. The DGS is etched on the first metal layer (M1) below a 50-Ω microstrip line on the top metal layer (M6) of 0.18-μm one-poly six-metal (1P6M) complementary metal-oxide-semiconductor (CMOS) technology. The proposed oscillator is fabricated using 0.18-μm CMOS technology, and the measured carrier frequency and phase noise are 22.88 GHz and -129.21 dBc/Hz (-108.05 dBc/Hz) at 10-MHz (1 MHz) offset frequency, respectively. The power dissipation is 6 mW that results in a figure of merit to be -188.8 dB. As the DGS resonator could be designed at any high frequency, it may give an alternative design approach of high performance voltage controlled oscillator and frequency synthesizers at K-band and beyond, thus alleviates the problem of self-resonance that a spiral inductor usually encounters at higher frequency..
4. Fairus Tahar, Adel Barakat, Redzuan Saad, Kuniaki Yoshitomi, Ramesh K. Pokharel, Dual-Band Defected Ground Structures Wireless Power Transfer System With Independent External and Inter-Resonator Coupling, IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS, 10.1109/TCSII.2017.2740401, 64, 12, 1372-1376, 2017.12, This brief proposes a design methodology based on the admittance (J-) inverters for a dual-band wireless power transfer (WPT) system that employs two cascaded circulars defected ground structure (DGS) resonators with different capacitive loading to guarantee distinct resonances. A single microstrip line excites the two DGSs, and when two DGS resonators are coupled back to back, it transforms to a dual band pass filter leading to WPT at both bands. Each of the DGS resonators has independent coupling. Thus, the realized J-Inverters are designed independently. Also, we employ a single stub for the matching. This stub appears with a different length according to the operating frequency; hence, an independent external coupling is achieved at both frequencies. A compact size of 30 mm × 15 mm is fabricated achieving a WPT efficiency of more than 71% at a power transfer distance of 16 mm for both bands (0.3 and 0.7 GHz)..
5. Fairus Tahar, Redzuan Saad, Adel Barakat, Ramesh Kumar Pokharel, 1.06 FoM and Compact Wireless Power Transfer System Using Rectangular Defected Ground Structure Resonators, IEEE Microwave and Wireless Components Letters, 10.1109/LMWC.2017.2750032, 27, 11, 1025-1025, 2017.11, This letter proposes a wireless power transfer (WPT) system using coplanar waveguide fed rectangular defected ground structure (DGS) resonators. One of the advantages of rectangular DGS resonator is that it has higher quality (Q-) and coupling (K-) factor compared to the H-shape or semi-H-shape DGS resonators. When two DGS resonators are coupled back-to-back, it transforms to a bandpass filter with tight coupling, resulting in the transfer of power wirelessly. The fabricated WPT system of size 35.8 mm×20 mm achieves, for the first time, a figure of merit of more than one at a WPT distance from 40 to 44 mm..
6. Anwer S. Abd El-Hameed, Adel Barakat, Adel B. Abdel-Rahman, Ahmed Allam, Ramesh Kumar Pokharel, Ultracompact 60-GHz CMOS BPF Employing Broadside-Coupled Open-Loop Resonators, IEEE Microwave and Wireless Components Letters, 27, 9, 818-820, 2017.09, This letter presents a 60-GHz ultracompact on-chip bandpass filter (BPF). The designed filter is based on a unique structure, which consists of two overlapped broadside-coupled open-loop resonators, achieving a high level of miniaturization. Moreover, each resonator is loaded by a metal-insulator-metal capacitor to get further miniaturization. Defected ground structure pattern is constructed under the filter structure to enhance the insertion loss (IL). This BPF is designed and fabricated using a standard 0.18-μm complementary metal-oxide-semiconductor technology for millimeter-wave applications. The fabricated BPF chip size is 240 × 225 μm2 including pads. The measured results agree well with the simulation ones and show that the BPF has an IL of 3.3 dB at 59.5-GHz center frequency, and a bandwidth of 12.9 GHz..
7. Nusrat Jahan, Siti Amalina Enche Ab Rahim, Adel Barakat, Takana Kaho, Ramesh Kumar Pokharel, Design and Application of Virtual Inductance of Square-Shaped Defected Ground Structure in 0.18- μm CMOS Technology, IEEE Journal of the Electron Devices Society, 10.1109/JEDS.2017.2728686, 5, 5, 2168-6734, 2017.07, This paper investigates a possibility of application of a virtual inductor realized by an integrated defected ground structure (DGS) to design a front-end circuit in CMOS technology. Two types of DGS are analyzed and found that the inductance realized by a square-shaped DGS achieves smaller size and higher quality factor than an H-shaped DGS. Then, a 15-GHz low phase noise voltage-controlled oscillator (VCO) employing the proposed square-shaped DGS in 0.18-μm 1P6M CMOS technology is designed. The fabricated VCO operates from 15.2 to 16.12 GHz and consumes 5-mW power. The measured phase noise is -132.08 dBc/Hz at 10-MHz offset frequency, and this results in the figure of merit (FoM) and FoM taking account of the area to be 189.1 and 199.9 dB, respectively..
8. Adel Barakat, Ahmed Allam, Hala Elsadek, Adel B. Abdel-Rahman, Ramesh Kumar Pokharel, Americ Bisognin, Cyril Luxey, 60 GHz CMOS Circular Patch Antenna on Chip, Microwave Journal, 60, 2, 90-100, 2017.02.
9. Sherif Hekal, Adel B. Abdel-Rahman, Hongting Jia, Ahmed Allam, Adel Barakat, Ramesh Kumar Pokharel, A Novel Technique for Compact Size Wireless Power Transfer Applications Using Defected Ground Structures, IEEE Transactions on Microwave Theory and Techniques, http://dx.doi.org/10.1109/TMTT.2016.2618919, 65, 1, 591-599, 2017.02, This paper presents a novel technique for high efficiency and compact size wireless power transfer (WPT) systems. These systems are based on coupled defected ground structure (DGS) resonators. Two types of DGSs (H-shape and semi-H-shape) are proposed. The semi-H-shaped DGS realizes larger inductance value, and this results in higher WPT efficiency. Instead of using an inductive-fed resonant coupling, we propose capacitive-fed resonant coupling, which reduces the design complexity and enhances the efficiency further. The DGS resonator of both the systems is loaded by chip capacitors for miniaturization. An equivalent circuit using approximate quasi-static modeling is extracted. An analytical design procedure is developed to calculate the optimum design parameters for the proposed WPT systems. The optimized structures are fabricated and measured. The simulation and measurement results are in good agreement. The proposed semi-H-shaped DGS WPT system has a peak efficiency of 73% at a transmission distance of 25 mm. In turn, the figure of merit becomes the highest among the WPT systems proposed so far..
10. Sherif Hekal, Adel B. Abdel-Rahman, Ahemd Allam, Hongting Jia, Adel Barakat, Ramesh Kumar Pokharel, Asymmetric Wireless Power Transfer Systems Using Coupled DGS Resonators, IEICE Electronics Express, http://doi.org/10.1587/elex.13.20160591, 13, 21, 20160591, 2016.11, his paper presents a new design for wireless power transfer (WPT) systems using asymmetric structures for the transmitter (TX) and the receiver (RX), and the TX/RX are constructed using spiral-strips defected ground structure (DGS) resonators. The proposed spiral-strips DGS resonator overcome the problem of low self-inductance that encountered by H-shape DGS resonator in [1, 2], so that the proposed WPT system that employs the proposed spiral-strips DGS resonators has better efficiency and higher power transmission distance. Design methodology of the proposed WPT system are formulated and fabricated. The measurement results show a WPT efficiency of 78% at a transmission distance of 40 mm with the TX and RX areas of 50 x 50 mm2 and 30 x 30 mm2, respectively..
11. Sherif Hekal, Adel B. Abdel-Rahman, Hongting Jia, Ahmed Allam, Adel Barakat, Takano Kaho, Ramesh Kumar Pokharel, Compact Wireless Power Transfer System Using Defected Ground Bandstop Filters, IEEE Microwave and Wireless Components Letters, 10.1109/LMWC.2016.2601300, 26, 10, 2016.10, This letter presents a new design for wireless power transfer (WPT) applications using two coupled bandstop filters (BSF). The stopband is created by etching a defected structure on the ground plane, and the power is transferred through electromagnetic (EM) resonant coupling when the two BSFs are coupled back to back. An equivalent circuit model of the proposed WPT system is extracted. Verification of the proposed design is performed through a good agreement between the EM simulation, circuit simulation, and measurement results. The proposed system achieves a measured WPT efficiency of 68.5% at a transmission distance of 50 mm using a compact size (40 x 40mm²). This results in a figure of merit of the proposed system to be 0.856 and the ratio of transmission distance/lateral size is 1.25 that is the highest among the WPT systems proposed so far using planar structures..
12. Nessim Mahmoud, Adel Barakat, Adel B. Abdel-Rahman, Ahmed Allam, Ramesh Kumar Pokharel, Compact Size On-Chip 60 GHz H-Shaped Resonator BPF, IEEE Microwave and Wireless Components Letters, 10.1109/LMWC.2016.2597219, 26, 9, 681-683, 2016.09, In this letter, we propose a compact size, small insertion loss 60 GHz on-chip H-shaped resonator bandpass filter (BPF) using 0.18 μm standard CMOS technology. The BPF Size is miniaturized by loading the H-shaped resonator with metal-insulator-metal capacitors at its ends. Besides, two defected ground structure cells are etched under the coupled lines to improve the filter insertion loss. Furthermore, selectivity is enhanced by loading the center of the H-shaped resonator with two unsymmetrical meander line stubs generating two transmission zeroes at 50 and 70 GHz. The fabricated BPF chip size is 240×650 μm2. The measured insertion loss and fractional bandwidth are 2.5 dB at 60 GHz and 21%, respectively..
13. Adel Barakat, Muhammad Hanif, Ramesh Kumar Pokharel, Miniaturized Low loss 60GHz CMOS Mixed Coupled BPF with Patterned Ground shield, Microwave and Optical Technology letters, 10.1002/mop.29650, 58, 3, 697-699, 2016.03, This letter presents a miniaturized low loss mixed coupled on-chip band-pass filter using overlapped open loop ring resonators and using patterned ground shields. The fabricated prototype shows an insertion loss of 3.7 dB, a return loss > 20 dB, a bandwidth of 13 GHz, and a chip size of 700 μm × 450 μm.
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14. Adel Barakat, Ramesh Kumar Pokharel, Takana Kaho, 60 GHz on-chip mixed coupled BPF with H-shaped defected ground structures, Electronics Letters, 10.1049/el.2015.4465, 2016.03, This letter presents a 60 GHz miniaturized, low loss on-chip bandpass filter (BPF) based on open-loop resonators (OLR). Overlapping of the BPF’s resonators leads to miniaturization and introduces a mixed coupling configuration. Moreover, its resonators are folded to minimize the size and the insertion loss. H-shaped defected ground structures are also used to reduce insertion loss and to improve the out of band rejection. The measured insertion loss, return loss, centre frequency, and bandwidth are 2.85 dB, 18 dB, 59 GHz and 15.5 GHz with a chip size of 368 × 262 um2 including pads..
15. Adel Barakat, Ahmed Allam, Hala Elsadek, Adel Abdelrahman, Ramesh Kumar Pokharel, Takana Kaho, Improved gain 60 GHz CMOS antenna with N-well grid, IEICE Electronics Express, 10.1587/elex.13.20151115, 13, 5, 2016.03, This paper presents a novel technique to enhance Antenna-on-Chip (AoC) gain by introducing a high resistivity layer below it. Instead of using the costly ion implantation method to increase resistivity, the N-well that is available in the standard CMOS process is used. A distributed grid structure of N-well on P-type substrate is designed such that the P and N-type semiconductors are fully depleted forming a layer with high resistivity. By an electromagnetic simulation, the using depletion layers enhance the antenna gain and radiation efficiency without increasing the occupied area. The simulated and measured |S11| are in fair agreement. The measured gain is –1.5 dBi at 66 GHz..
主要学会発表等
1. ADEL Barakat, POKHAREL RAMESH KUMAR, Sherif Hekal, Simple design approach for asymmetric resonant inductive coupled WPT systems using J-inverters, 2016 Asia Pacific Microwave Conference (APMC), 2016.12, This paper presents a simple and precise design method for asymmetric resonant inductive coupled wireless power transfer (WPT) systems without the involvement of circuit or electromagnetic (EM) simulators. The design method is based on the generalized second-order band-pass filter (BPF). First, the values of the BPF's J-inverters are computed based on the mutual coupling between the transmitter (TX) and the receiver (RX). Then, the required components are extracted from the J-inverters values. We achieved good agreements between the analytical design procedure, the circuit and the EM simulations, and the measurements. The measured efficiency is 75% at a transmission distance of 38 mm, and the sizes of the TX and RX are 50×50 mm2 and 30×30 mm2, respectively..
2. Anwer S. Abd El-Hameed, Nessim Mahmoud, ADEL Barakat, Adel B. Abdel-Rahman, Ahmed Allam, POKHAREL RAMESH KUMAR, A 60-GHz on-chip tapered slot Vivaldi antenna with improved radiation characteristics, 2016 10th European Conference on Antennas and Propagation (EuCAP), 2016.04, This paper presents a design of 60-GHz exponential tapered slot Vivaldi antenna-on-chip (AOC). The antenna is designed using standard 0.18μm six metal-layers CMOS technology. A double-Y balun feeding structure is used to make transition from coplanar waveguide to slot-line. Two techniques are investigated for improving antenna radiation properties. The first technique incorporates equal corrugations on the edges of exponential flaring section and other on the backed-edge of antenna to enhance the antenna gain. Second, a planar arc reflector is constructed using metal vias between M6 and M1 to inhibit the back lobe, contributing to the enhancement of gain and efficiency. The overall antenna size is compact and equal to 785μm × 930μm. The influence of the antenna position on the radiation properties is also studied. The proposed antenna offers endfire radiation pattern with a simulated peak gain and a radiation efficiency of -0.4 dBi and 32%, respectively..
3. Sherif hekal, Adel B. Abdel-Rahman, Ahmed Allam, ADEL Barakat, JIA HONGTING, POKHAREL RAMESH KUMAR, Asymmetric strongly coupled printed resonators for wireless charging applications, 2016 IEEE 17th AnnualWireless and Microwave Technology Conference (WAMICON), 2016.04, This paper presents a simple compact design for wireless charging applications using asymmetric strongly coupled printed resonators (SCPR). The proposed resonators are further loaded by surface mounted (SMD) capacitors for miniaturization. The system consists of two substrates. The first transmitting substrate contains a driving loop on the top layer and the high Q-resonator on the bottom layer. Similarly, the second substrate contains the high Q-resonator as the receiver and a loop as the load. An equivalent circuit model is extracted. An analytic design method is proposed to get a high wireless power transfer (WPT) efficiency. Good agreement between electromagnetic simulations, circuit simulations, and measurements was achieved. The proposed system achieves a measured WPT efficiency of 60% at 100 MHz using a receiving resonator of size 20 mm × 20 mm away for a transmission distance of 35 mm from the transmitting resonator of size 30 mm × 30 mm..
4. Elsayed Elsaidy, ADEL Barakat, Adel B. Abdel-Rahman, Ahmed Allam, POKHAREL RAMESH KUMAR, Radiation performance enhancement of a 60 GHz CMOS Quasi-Yagi antenna, 2016 IEEE 17th Annual Wireless and Microwave Technology Conference (WAMICON), 2016.04, This paper presents a study on 60 GHz CMOS Quasi-Yagi antenna for radiation performance enhancement. The driven element is meandered for size compactness and is fed by a coplanar waveguide to coplanar stripline transition. Moreover, the ground plan was corrugated to serve as the reflecting element. Furthermore, the director was designed from multi-element which led to gain and efficiency enhancement. Finally, the effect of the antenna location on the radiation characteristics was studied. The simulated gain and efficiency are -0.746 dBi and 21.4%, respectively at 60 GHz, and The design has an area of 1 × 0.87 mm2..
5. Nessim Mahmoud, Anwer S. Abd El-Hameed, ADEL Barakat, Adel B. Abdel-Rahman, Ahmed Allam, POKHAREL RAMESH KUMAR, Performance enhancement of 0.18µm CMOS on chip bandpass filters using H-shaped parasitic element, 2015 27th International Conference on Microelectronics (ICM), 2015.12, A design of an improved open loop resonator on-chip bandpass filter for 60 GHz millimeter-wave applications using 0.18 μm CMOS technology is presented. The proposed on-chip BPF employs H-shaped parasitic structure inserted between two open loop coupled resonator. The adoption of a two open loop coupled resonators BPF and the utilization of two transmissions zero located at 48 and 80 GHz permit a compact size and high selectivity of the BPF. In addition, the parasitic H-shaped structure increases the capacitance between the two resonators, which enables a further reduction of the physical length of the filter and enhances the coupling between the resonators which improve the filter insertion loss. The proposed BPF has a center frequency of 60 GHz, an insertion loss of -2 dB, a 3dB band width of 13 GHz, and a core size 160×480 μm2 with total chip size 680×280 μm2 (including bonding pads)..
6. Nessim Mahmoud, Adel Barakat, Anwer S. Abd El-Hameed, Adel B. Abdel-Rahman, Ahmed Allam, Ramesh Kumar Pokharel, Study of SiO2 thickness effect on insertion loss of CMOS 60 GHz band pass filter, 2015 IEEE International Conference on Electronics, Circuits, and Systems (ICECS), 2015.12, This paper presents a study of the effect of the SiO2 substrate thickness on the insertion loss performance of half wavelength open loop resonator bandpass filter. It has been observed that the main reason for insertion loss degradation is the small thickness of SiO2. An insertion loss of -1.49dB is achieved with a SiO2 thickness of 24μm. Furthermore, an equivalent lumped circuit model of the filter is proposed to verify this observation. The S-parameters of lumped element circuit model are obtained using the ADS simulator and compared with the results obtained from the EM simulator showing good agreement..
7. Anwer S. Abd El-Hameed, ADEL Barakat, Adel B. Abdel-Rahman, Ahmed Allam, POKHAREL RAMESH KUMAR, A60-GHz double-Y balun-fed on-chip Vivaldi antenna with improved gain, 2015 27th International Conference on Microelectronics (ICM), 2015.12, A60-GHz double-Y balun-fed exponential tapered slot Vivaldi antenna-on-chip (AOC) is designed using standard 0.18μm six metal-layer CMOS technology. A double-Y balun feeding structure is used to make transition from coplanar to slot line. Three methods are developed for improving antenna radiation properties. First, an impeding longitudinal rectangular slits on the backed edge of the Vivaldi antenna are used to enhance the gain. Second, loading circular metal-strips are used as additional director into the slot area of Vivaldi antenna on M6. Finally, a planar arc reflector is used to inhibit the back lobe, contributing to the enhancement of gain and efficiency. The overall antenna size is very compact and equal to 700um×940μm. The influence of the antenna position on the radiation properties is also studied. The proposed antenna offers a simulated peak gain and a radiation efficiency of -1.9 dBi and 24%, respectively..
8. M. Hanif, POKHAREL RAMESH KUMAR, 吉富邦明, ADEL Barakat, Hala Elsadek, A gain enhanced 60 GHz CMOS antenna-on-chip using off-chip Mu near zero metamaterial lens, 2015 IEEE 4th Asia-Pacific Conference on Antennas and Propagation (APCAP), 2015.07, This paper presents a Mu Near Zero Metamaterial (MNZ-MM) lens to enhance the gain of a 60 GHz Antenna-on-Chip (AoC). First, a MNZ-MM unit cell is designed to ensure the near zero characteristics at the 60 GHz band. Furthermore, a 3 by 3 matrix of the MNZ-MM is placed in the desired direction of radiation such that the radiated waves are coupled and the gain is enhanced and the AoC's |S11| is negligibly affected. The simulated gain and efficiency of the AoC with MNZ-MM lens are 2.8dBi and 35%, respectively..
9. Adel Barakat, Ahmed Allam, Hala Elsadek, Adel B. Abdel-Rahman, S. Muhammad Hanif, Ramesh K. Pokharel, Miniaturized 60 GHz triangular CMOS Antenna-on-Chip using asymmetric artificial magnetic conductor, 2015 IEEE 15th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems (SiRF), 2015.01, This paper presents a miniaturized triangular Antenna-on-Chip (AoC) designed and fabricated on a 0.18 μm CMOS process using asymmetric rectangular artificial magnetic conductor (R-AMC). An AMC acts as a shield plane between the AoC and the lossy CMOS substrate. AoC using asymmetric R-AMC presents a smaller overall area than that of the previous reported AoC with symmetric AMCs. The triangular AoC area including the asymmetric AMC cells is only 0.81mm2 with a simulated gain of -0.2 dBi at 60 GHz. Measurements confirm the wide impedance bandwidth of the AoC..
10. Adel Barakat, Ahmed Allam, Hala Elsadek, Haruichi Kanaya, Ramesh K. Pokharel, Small size 60 GHz CMOS Antenna-on-Chip: Gain and efficiency enhancement using asymmetric Artificial Magnetic Conductor, 2014 44th European Microwave Conference (EuMC), 2014.10, This paper presents a small size 60 GHz Antenna-on-Chip (AoC) designed and fabricated using 0.18 um TSMC Complementary Metal Oxide Semiconductor (CMOS) process. AoC performance is enhanced using asymmetric Artificial Magnetic Conductor (AMC). The AoC area including the AMC is 1715 um by 710 um. As AMC shields AoC from the lossy CMOS substrate, simulated gain of -0.25 dBi is achieved at 60 GHz for design rule compatible circular AoC with 12.8 dB front-to-back ratio (FBR) due to removal of AMC cells below the AoC. Measurements agree well with simulation results and confirm operation at the 60 GHz band with a peak measured gain of -3 dBi at 64 GHz..
11. Adel Barakat, Ahmed Allam, Hala Elsadek, Haruichi Kanaya, Hongting Jia, Kuniaki Yoshitomi, Ramesh Pokharel, Back radiation reduction of 60 GHz CMOS slot Antenna-on-Chip (AoC) using Artificial Dielectric Layer (ADL) for Area Reuse, 2014 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), 2014.07, Antenna-on-Chip (AoC) integration with other radio frequency and digital circuits is a prime target for complete System-on-Chip (SoC). However, CMOS AoC integration suffers from two main disadvantages. First, AoC suffers from losses due to low resistivity CMOS substrate (σ=10S/m) which leads to reduction of the AoC efficiency (A. Barakat, et al, IEEE IMS, June2013). Second, AoC occupies a large area that cannot be reused because of the strong field below the AoC..
12. Adel Barakat, Ahmed Allam, Ramesh K. Pokharel, Hala Elsadek, Mohammed Ragab, Keji Yoshida, Compact size high gain AoC using rectangular AMC in CMOS for 60 GHz millimeter wave applications, 2013 IEEE MTT-S International Microwave Symposium Digest (IMS), 2013.06, This paper presents a compact size, high gain triangular Antenna-on-Chip (AoC), designed and fabricated using a 0.18 μm CMOS process and optimized over different cells' configurations of rectangular artificial magnetic conductor (R-AMC). An AMC acts as a shield plane between the AoC and the lossy CMOS substrate. R-AMC shows better shielding characteristics than previously reported AMCs. Measurement results confirm the wide impedance bandwidth of the AoC..
13. Adel Barakat, Ahmed Allam, Ramesh K. Pokharel, Hala Elsadek, Mohammed Ragab, Keji Yoshida, 60 GHz triangular monopole Antenna-on-Chip over an Artificial Magnetic Conductor, 2012 6th European Conference on Antennas and Propagation (EUCAP), 2012.03, A high-gain and small-area triangular monopole Antenna-on-Chip (AOC), designed using a standard CMOS process and optimized over a modified rectangular Artificial Magnetic Conductor (AMC). The rectangular AMC acts as a shield between the AOC and the lossy CMOS substrate. Using this configuration, a Frequency Selective Surface (FSS) is realized by the shield providing high wave impedance around 60 GHz. The AOC dimensions including the AMC are 0.86 mm by 1.76mm. The antenna gain is 0.3 to 1 dBi from 57 to 64 GHz..
14. Adel Barakat, Ahmed Allam, Ramesh K. Pokharel, Hala Elsadek, Mohammed Ragab, Keji Yoshida, Performance optimization of a 60 GHz Antenna-on-Chip over an Artificial Magnetic Conductor, 2012 Japan-Egypt Conference on Electronics, Communications and Computers (JEC-ECC), 2012.03, This paper presents an optimization methodology for a 60 GHz triangular monopole Antenna-on-Chip (AOC), designed using a standard 0.18 μm CMOS process and optimized over a Jerusalem Cross Artificial Magnetic Conductor (JC-AMC). The JC-AMC acts as a shield between the AOC and the lossy CMOS substrate. Different configurations of JC-AMC cells are tested to acquire best AOC performance. It has been found that increasing the number of JC-AMC cells in the feeding direction and decreasing its number of cells in the direction perpendicular to the feed can improve the antenna characteristics in terms of gain, efficiency, front-to-back ratio, and small area..
15. Adel Barakat, Mostafa ElKhamy, Bandwidth extension of UWB planar antenna with band-notched characteristics, 2010.10, In this paper, an ultra-wideband (UWB) antenna with a band notched filter is proposed. The transmission range of this antenna covers the FCC unlicensed band from 3.1 to 10.6 GHz with a notch filter from 4.9 to 6.3 GHz to avoid interference with IEEE802.11a system. The notch filter is implemented using a U-shaped slot. To extend the impedance bandwidth of the antenna, an electroband-gap (EBG) structure is used. EBG lattice holes surrounding the radiating patch enhances the impedance bandwidth to be from 3 GHz to 12 GHz with a return loss (S11 <; -10 dB). The return loss (S11) for the designed antenna is simulated using HFSS® software package. The antenna design is also fabricated on Rogers RO3006 substrate and measured using Vector Network Analyzer (HP8719ES). The measurement results also confirm that the proposed technique is effective in extending the impedance bandwidth to 12 GHz..
学会活動
所属学会名
EuMA
IEEE
受賞
EuMW 2014 Student Grant , European Microwave Association , 2014.10.
Nine month special research student at EJUST center, Kyushu University, Egyptian Ministry of Higher Education, 2013.07.
PHD initiative sponsorship, IEEE MTT society, 2013.06.
Best student paper award , 2012 Japan-Egypt Conference on electronics, communications and computers, 2012.03.
Japan Study Program (JSP) , Government of Japan , 2012.03.
Short-Term travel to Japan, Center for Japan-Egypt Cooperation in Science and Technology (EJUST Center) at Kyushu University, 2011.06.
1st paper by EJUST student , Egypt-Japan University of Science and Technology, 2010.08.
Five years scholarship to obtain MSc. and Ph.D. degrees , Egyptain Ministry of Higher Education, 2010.02.

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