The transfer of graphene onto dielectric substrates to form an antenna needs to be performed with... more The transfer of graphene onto dielectric substrates to form an antenna needs to be performed with care, as tears and cracks may appear on the samples transferred improperly. This paper studies a detailed method in estimating the performance of a millimeter-wave (MMW) antenna built using commercially-available graphene layers. In contrast to the widely studied monolayer graphene, the proposed antenna is produced based on the chemical vapor deposition (CVD) technique, which is to be secured onto the antenna substrate via adhesive material without removal of the transition metal substrate from the graphene layer sample. The antenna performance modeled using this technique indicated quite similar results to a model using ideal monolayer graphene in terms of gain, radiated power and radiation efficiency. Its performance benchmarked against a copper antenna operating at the same MMW frequency also indicated similar performance improvements as with another antenna designed using monolayer ...
The improvement of Terahertz (THz) antenna requires efficient (nano)materials to operate within t... more The improvement of Terahertz (THz) antenna requires efficient (nano)materials to operate within the millimeter wave and THz spectrum. In this paper, doped graphene is used to improve the performance of two types of patch antennas, a rectangular and an elliptical antenna. The surface conductivity of conventional (non-doped) graphene is first modeled prior to the design and simulation of the two graphene based antennas in an electromagnetic solver. Next, different graphene models and their corresponding surface conductivities are computed based on different bias voltages or chemical doping. These configurations are then benchmarked against a similar antenna based on conventional metallic (copper) conductor to quantify their levels of performance improvement. The graphene based antennas showed significant improvements for most parameters of antenna than that of the conventional antenna. Besides that, the higher chemical potentials resulting from higher biasing voltages also resulted in this trend. Finally, the elliptical patch graphene antenna indicated better reflection performance, radiation efficiency and gain than a rectangular patch operating at the same resonant frequency.
International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, 2021
In the applications of millimeter and sub‐millimeter wave, the conductivity of metal parts in ele... more In the applications of millimeter and sub‐millimeter wave, the conductivity of metal parts in electronic devices can easily degrade when conventional metals like copper are employed. Furthermore, oxidation may arise when such devices are utilized in severe environmental conditions. To avoid this, conventional conductors such as copper can be coated with other non‐active materials to inhibit this problem. Monolayer graphene is used in this study as a coating layers for copper in millimeter‐wave antennas. Two types of graphene coatings are investigated: non‐doped and doped monolayer graphene. These coatings can either be used as the patch, ground or both conducting layers of a microstrip patch antenna. Results showed that coating using doped graphene improves the performance of antenna in terms of gain, radiated power and radiation efficiency by 11.81%, 8.48%, and 11.48%, respectively, compared to antennas made using copper and coated using gold and non‐doped graphene at millimeter‐wa...
Hydro Power 97 3. Hydro power system classification A different countries have different criteria... more Hydro Power 97 3. Hydro power system classification A different countries have different criteria to classify hydro power plants, a general classification of hydro power plants is as follows in table 1 :
International Journal of Power Electronics and Drive Systems, Feb 1, 2023
In this paper, an efficient early termination (ET) mechanism for systematic turbo-polar code (STP... more In this paper, an efficient early termination (ET) mechanism for systematic turbo-polar code (STPC) based on optimal estimation of scaling factor (SF) is proposed. The gradient of the regression line which best fits the distance between a priori and extrinsic information is used to estimate the SF. The multiplication of the extrinsic information by the proposed SF presents effectiveness in resolving the correlation issue between intrinsic and extrinsic reliability information traded between the two typical parallel concatenated soft-cancellation (SCAN) decoders. It is shown that the SF has improved the conventional STPC by about 0.3 dB with an interleaver length of 64 bits, and about 1 dB over the systematic polar code (SPC) at a bit error rate (BER) of 10 −5. A new scheme is proposed as a stopping criterion, which is mainly based on the estimated value of SF at the second component decoder and the decoded frozen bits for each decoding iteration. It is shown that the proposed ET results in halving the average number of iterations (ANI) without adding considerable complexity. Moreover, the modified codes present comparable results in terms of BER to the codes that utilize fix number of iterations.
Bulletin of Electrical Engineering and Informatics, Jun 1, 2022
This paper proposed an experimental device that emulates and facilitates teaching the theoretical... more This paper proposed an experimental device that emulates and facilitates teaching the theoretical concepts of error-control coding (ECC) techniques. Two prototypes laboratory boards were designed and implemented. The first board simulates the transmitter side of a typical digital communication system. It mainly contains a data source, (7,4) Hamming encoder, cyclic redundancy check encoder (CRC), and Gaussian noise generator. The second board has two types of Hamming decoders, a syndrome decoder, and a maximum likelihood (ML) decoder that accepts the received soft signals at the channel output. Each board has several control switches so that the trainee can change the code variables, noise power, user ID, in addition to display tools such as light-emitting diodes (LEDs), and test points for the oscilloscope that help the user to observe the results. Moreover, results and setting variables can also be displayed on a PC's screen connected through a USB port and organic light emitting diodes (OLED) display that is attached to the receiver board. The pipelining architecture of the field programmable gate array (FPGA) device was exploited in this proposed system to reduce the processing delay and hence increase the data throughput. Furthermore, we proved that both theoretical and experimental tests are identical.
The transfer of graphene onto dielectric substrates to form an antenna needs to be performed with... more The transfer of graphene onto dielectric substrates to form an antenna needs to be performed with care, as tears and cracks may appear on the samples transferred improperly. This paper studies a detailed method in estimating the performance of a millimeter-wave (MMW) antenna built using commercially-available graphene layers. In contrast to the widely studied monolayer graphene, the proposed antenna is produced based on the chemical vapor deposition (CVD) technique, which is to be secured onto the antenna substrate via adhesive material without removal of the transition metal substrate from the graphene layer sample. The antenna performance modeled using this technique indicated quite similar results to a model using ideal monolayer graphene in terms of gain, radiated power and radiation efficiency. Its performance benchmarked against a copper antenna operating at the same MMW frequency also indicated similar performance improvements as with another antenna designed using monolayer ...
The improvement of Terahertz (THz) antenna requires efficient (nano)materials to operate within t... more The improvement of Terahertz (THz) antenna requires efficient (nano)materials to operate within the millimeter wave and THz spectrum. In this paper, doped graphene is used to improve the performance of two types of patch antennas, a rectangular and an elliptical antenna. The surface conductivity of conventional (non-doped) graphene is first modeled prior to the design and simulation of the two graphene based antennas in an electromagnetic solver. Next, different graphene models and their corresponding surface conductivities are computed based on different bias voltages or chemical doping. These configurations are then benchmarked against a similar antenna based on conventional metallic (copper) conductor to quantify their levels of performance improvement. The graphene based antennas showed significant improvements for most parameters of antenna than that of the conventional antenna. Besides that, the higher chemical potentials resulting from higher biasing voltages also resulted in this trend. Finally, the elliptical patch graphene antenna indicated better reflection performance, radiation efficiency and gain than a rectangular patch operating at the same resonant frequency.
International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, 2021
In the applications of millimeter and sub‐millimeter wave, the conductivity of metal parts in ele... more In the applications of millimeter and sub‐millimeter wave, the conductivity of metal parts in electronic devices can easily degrade when conventional metals like copper are employed. Furthermore, oxidation may arise when such devices are utilized in severe environmental conditions. To avoid this, conventional conductors such as copper can be coated with other non‐active materials to inhibit this problem. Monolayer graphene is used in this study as a coating layers for copper in millimeter‐wave antennas. Two types of graphene coatings are investigated: non‐doped and doped monolayer graphene. These coatings can either be used as the patch, ground or both conducting layers of a microstrip patch antenna. Results showed that coating using doped graphene improves the performance of antenna in terms of gain, radiated power and radiation efficiency by 11.81%, 8.48%, and 11.48%, respectively, compared to antennas made using copper and coated using gold and non‐doped graphene at millimeter‐wa...
Hydro Power 97 3. Hydro power system classification A different countries have different criteria... more Hydro Power 97 3. Hydro power system classification A different countries have different criteria to classify hydro power plants, a general classification of hydro power plants is as follows in table 1 :
International Journal of Power Electronics and Drive Systems, Feb 1, 2023
In this paper, an efficient early termination (ET) mechanism for systematic turbo-polar code (STP... more In this paper, an efficient early termination (ET) mechanism for systematic turbo-polar code (STPC) based on optimal estimation of scaling factor (SF) is proposed. The gradient of the regression line which best fits the distance between a priori and extrinsic information is used to estimate the SF. The multiplication of the extrinsic information by the proposed SF presents effectiveness in resolving the correlation issue between intrinsic and extrinsic reliability information traded between the two typical parallel concatenated soft-cancellation (SCAN) decoders. It is shown that the SF has improved the conventional STPC by about 0.3 dB with an interleaver length of 64 bits, and about 1 dB over the systematic polar code (SPC) at a bit error rate (BER) of 10 −5. A new scheme is proposed as a stopping criterion, which is mainly based on the estimated value of SF at the second component decoder and the decoded frozen bits for each decoding iteration. It is shown that the proposed ET results in halving the average number of iterations (ANI) without adding considerable complexity. Moreover, the modified codes present comparable results in terms of BER to the codes that utilize fix number of iterations.
Bulletin of Electrical Engineering and Informatics, Jun 1, 2022
This paper proposed an experimental device that emulates and facilitates teaching the theoretical... more This paper proposed an experimental device that emulates and facilitates teaching the theoretical concepts of error-control coding (ECC) techniques. Two prototypes laboratory boards were designed and implemented. The first board simulates the transmitter side of a typical digital communication system. It mainly contains a data source, (7,4) Hamming encoder, cyclic redundancy check encoder (CRC), and Gaussian noise generator. The second board has two types of Hamming decoders, a syndrome decoder, and a maximum likelihood (ML) decoder that accepts the received soft signals at the channel output. Each board has several control switches so that the trainee can change the code variables, noise power, user ID, in addition to display tools such as light-emitting diodes (LEDs), and test points for the oscilloscope that help the user to observe the results. Moreover, results and setting variables can also be displayed on a PC's screen connected through a USB port and organic light emitting diodes (OLED) display that is attached to the receiver board. The pipelining architecture of the field programmable gate array (FPGA) device was exploited in this proposed system to reduce the processing delay and hence increase the data throughput. Furthermore, we proved that both theoretical and experimental tests are identical.
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