Professor Dr. Salah I. Yahya, working in the Department of Software Engineering at Koya University, published 10 articles in 2023.
Dr. Salah I. Yahya is a consulting engineer and senior member of the American Institute of Electrical and Electronics Engineers. He is currently editor of Aro the Scientific Journal of Koya University and a member of the editorial board of three other academic journals He is the Technical Director of the National Ranking of Kurdistan Regional Universities (NUR) website and a member of the Bologna High Committees of the Ministry of Higher Education and Scientific Research of the Kurdistan Regional Government and the Central Government.
About the author:
Name: Salah I. Yahya
Qualification: Ph.D.
Academic rank: Professor
Affiliation: Department of Software Engineering, Faculty of Engineering, Koya University
TAP: https://sites.google.com/koyauniversity.org/salah-ismaeel/
Google Scholar account: https://scholar.google.com/citations?user=jXO8SZkAAAAJ&hl=en
ORCID account: https://orcid.org/0000-0002-2724-5118
Here are the articles:
1thTitle: Design and analysis of a compact microstrip lowpass–bandpass diplexer with good performance for wireless applications
Abstract: This paper presents the design of a novel lowpass–bandpass diplexer with compact size and good performance using microstrip cells. For this purpose, two microstrip lowpass and bandpass filters are separately designed and mathematically analyzed. The proposed microstrip diplexer has a novel and simple structure. It occupies a compact area of 0.037 λg2 (722 mm2), and its insertion loss and S11 at both channels are low. The insertion loss at the lower and upper channels is only 0.047 and 0.16 dB, respectively. Meanwhile, both channels are flat with the maximum group delay of 1.68 ns which is the lowest compared to the previously reported diplexers mentioned in this paper. To design the proposed diplexer, first, a lowpass diplexer with good performance is designed which has low losses and a good figure of merit. It has a flat passband with a sharp roll-off. Then, to achieve the proposed diplexer, a bandpass resonator is added to the lowpass filter without any extra matching circuit, which saves the overall size. The proposed diplexer is designed, simulated, and fabricated, where the simulation and measurement results are close.
2thTitle: Design and Fabrication of a Compact Branch-Line Hybrid Coupler with a Balanced Phase Using a New Microstrip Structure for GSM Applications
Abstract: A novel microstrip quadrature hybrid coupler is mathematically designed, optimized and fabricated in this work. The physical structure of the proposed coupler is new and it occupies a very small area of 0.01 λg2. The novel stubs embedded inside the conventional rectangle are connected parallel lines. The ends of these stubs are connected to a solid rectangle, which make the overall structure different from the previous works. Our branch-line coupler is designed to work at 1.8 GHz for GSM applications. The phase imbalance between S21 and S31 is only 0.01°, which is very small compared to the previous works. Another advantage of the presented coupler is its high isolation, which is about 40 dB. Meanwhile, other parameters such as common port return loss and coupling factors are desired. To design this coupler, two low-loss lowpass filters (LPFs) are designed and embedded in the main structure. A mathematical design method is presented to decrease the losses, where a 0.002 dB insertion loss for the LPF is achieved. We measured the presented structure. The measurement results verifies the simulations with high accuracy. Therefore, due to having a novel structure, very small size, the lowest phase shift, good isolation and good return loss the proposed coupler can be easily used in RF communication systems.
Link of the paper: https://www.sciencedirect.com/science/article/abs/pii/S1434841123000031
3thTitle: A Comprehensive Review on Microstrip Couplers: Structure, Design Method, and Performance
Abstract: In this work, several types of microstrip couplers are investigated in terms of structure, performance and design methods. These planar 4-ports passive devices transmit a signal through two different channels. Designers' competition has always been in miniaturizing and improving performance of couplers. Some couplers have been offered with a novel structure, which is a special feature. A high-performance coupler should have high isolation and low losses at both channels. The channels are usually overlapped so that the common port return loss in these channels should be low. Among the couplers, those with balanced amplitude and phase are more popular. The popular mathematical analysis methods are even/odd mode analysis, extracting the information from the ABCD matrix and analyzing the equivalent LC circuit of a simple resonator. According to the phase shift value, couplers are classified as 90º and correct multiples of 90º, where a microstrip 0º coupler can be used as a power divider. Some couplers have filtering and harmonic elimination features that are superior to other couplers. However, few designers paid attention to suppressing the harmonics. If the operating frequency is set in according to the type of application, the coupler becomes particularly valuable.ABCD Matrix
Link of the paper: https://aro.koyauniversity.org/index.php/aro/article/view/1108
4thTitle: Multiplierless low-cost implementation of Hindmarsh–Rose neuron model in case of large-scale realization
Abstract: Implementation of neural networks in case of hardware helps us to understand the different parts of the human brain operation, using artificial intelligence (AI). This paper presents a new model of the Hindmarsh–Rose (HR) Neuron that is based on basic polynomial functions called Nyquist-look up table-Hindmarsh–Rose (N-LUT-HR) based on an accurate sampling of the original model. The proposed approach is investigated in terms of its digital realization feasibility. According to high matching between the original and proposed terms, it is showed that the new modified model can follow all spiking patterns of primary model with low-error computations. In hardware case, the proposed and original models are implemented on Xilinx FPGA XC2VP30 chip to validate different aspects of the simulation results. Hardware results demonstrate that our model regenerates the desired patterns in low-cost and high-frequency (speed-up) in comparison with the other similar works. Overall saving in FPGA resources show that this new model is capable of being used in large-scale networks in case of minimum required resources (FPGA costs). In addition, the analysis of hardware indicates that the new circuits can work in a maximum frequency of 123 MHz with 98.25% saving in FPGA costs (resources utilization of FPGA).
Link of the paper: https://onlinelibrary.wiley.com/doi/abs/10.1002/cta.3570
5thTitle: Design of a Compact Quad-Channel Microstrip Diplexer for L and S Band Applications.
Abstract: In this paper, two novel dual-band bandpass filters (BPFs) and a compact quad-channel diplexer working at 1.7/3.3 GHz and 1.9/3.6 GHz are proposed. In the proposed diplexer design, triangular loop resonators and rectangular loop resonators are used together to reduce the circuit size and improve diplexer performances. Insertion loss (IL) and return loss (RL) of the proposed diplexer are better than 0.8 dB and 21 dB, respectively, at these four operating frequencies. Output ports isolation parameter is better than 30 dB. With the achieved specifications, the proposed diplexer can be used in L and S band applications.
Link of the paper: https://www.mdpi.com/2072-666X/14/3/553
6thTitle: A Dynamic Recurrent Neural Network for Predicting Higher Heating Value of Biomass.
Abstract: The higher heating value (HHV) is the main property showing the energy amount of biomass samples. Several linear correlations based on either the proximate or the ultimate analysis have already been proposed for predicting biomass HHV. Since the HHV relationship with the proximate and ultimate analyses is not linear, nonlinear models might be a better alternative. Accordingly, this study employed the Elman recurrent neural network (ENN) to anticipate the HHV of different biomass samples from both the ultimate and proximate compositional analyses as the model inputs. The number of hidden neurons and the training algorithm were determined in such a way that the ENN model showed the highest prediction and generalization accuracy. The single hidden layer ENN with only four nodes, trained by the Levenberg–Marquardt algorithm, was identified as the most accurate model. The proposed ENN exhibited reliable prediction and generalization performance for estimating 532 experimental HHVs with a low mean absolute error of 0.67 and a mean square error of 0.96. In addition, the proposed ENN model provides a ground to clearly understand the dependency of the HHV on the fixed carbon, volatile matter, ash, carbon, hydrogen, nitrogen, oxygen, and sulfur content of biomass feedstocks.
Link of the paper: https://www.mdpi.com/1422-0067/24/6/5780
7thTitle: A High-Efficiency Diplexer for Sustainable 5G-Enabled IoT in Metaverse Transportation System and Smart Grids
Abstract: Symmetry is essential in the design of complex systems like the Metaverse Transportation Sys-tem (MTS) and helps ensure that all components work together effectively. In the development of a microstrip diplexer for 5G-enabled IoT and MTS, maintaining symmetry is crucial to achieving flat responses with low group delays. By integrating transportation technology and the Metaverse, the Metaverse Transportation System (MTS) can greatly improve the effectiveness and intellect of transportation systems in reality. To establish a dependable network, it is essential to include 5G-enabled Internet of Things (IoT) and sensor networks with a sustainable design that focuses on efficiency and energy conservation. A three-channel microstrip lowpass-bandpass diplexer has been developed for 5G-enabled IoT and MTS implementation. Multi-channel designs are rare due to the complex design process, but this diplexer is very compact at only 0.004 λg2. All channels have flat responses with group delays of 0.34 ns, 1.7 ns, and 0.34 ns at the lower, middle, and upper passbands, respectively. The lowpass channel has a cut-off frequency of 1.22 GHz, suitable for mid-band 5G applications. Compared to previous work, this diplexer achieves the smallest size, lowest group delay, and insertion and return losses at the lower channel. It consists of a lowpass-bandpass section connected to a band-pass filter analyzed mathematically, and its performance has been verified through simulation and measurement with good accuracy.
Link of the paper: https://www.mdpi.com/2073-8994/15/4/821
8thTitle: A Super-Efficient GSM Triplexer for 5G-Enabled IoT in Sustainable Smart Grid Edge Computing and the Metaverse
Abstract: Global concerns regarding environmental preservation and energy sustainability have emerged due to the various impacts of constantly increasing energy demands and climate changes. With advancements in smart grid, edge computing, and Metaverse-based technologies, it has become apparent that conventional private power networks are insufficient to meet the demanding requirements of industrial applications. The unique capabilities of 5G, such as numerous connections, high reliability, low latency, and large bandwidth, make it an excellent choice for smart grid services. The 5G network industry will heavily rely on the Internet of Things (IoT) to progress, which will act as a catalyst for the development of the future smart grid. This comprehensive platform will not only include communication infrastructure for smart grid edge computing, but also Metaverse platforms. Therefore, optimizing the IoT is crucial to achieve a sustainable edge computing network. This paper presents the design, fabrication, and evaluation of a super-efficient GSM triplexer for 5G-enabled IoT in sustainable smart grid edge computing and the Metaverse. This component is intended to operate at 0.815/1.58/2.65 GHz for 5G applications. The physical layout of our triplexer is new, and it is presented for the first time in this work. The overall size of our triplexer is only 0.007 λg2, which is the smallest compared to the previous works. The proposed triplexer has very low insertion losses of 0.12 dB, 0.09 dB, and 0.42 dB at the first, second, and third channels, respectively. We achieved the minimum insertion losses compared to previous triplexers. Additionally, the common port return losses (RLs) were better than 26 dB at all channels.
Link of the paper: https://www.mdpi.com/1424-8220/23/7/3775
9thTitle: A Novel Configuration of Microstrip Coupler with Low Loss and Suppressed Harmonics
Abstract: This work presents a novel structure to design a microstrip coupler. The best values of S21 and S31 are 0.65 dB and 0.83 dB, respectively, in the passband of the proposed coupler. Another significant advantage of this coupler is its filtering frequency response, where it can suppress the harmonics below the passband from DC and above the passband, from 1st up to 7th harmonics. The phase difference between S21 and S31 is 90°±0.1°, which indicates a high phase balance. Beside these features, a compact size of 0.01 λg2 is achieved using the proposed novel configuration of the microstrip coupler. A perfect mathematical design method is introduced to show how the insertion loss (IL) can be reduced. Two BPFs are designed, analyzed and placed in the coupler structure. Finally, the designed coupler is fabricated and measured to verify the simulation results, where the experimental results are close to the simulated results.
Link of the paper: https://www.sciencedirect.com/science/article/abs/pii/S1434841123001279?via%3Dihub
10thTitle: A high-performance microstrip bandpass filtering coupler with low-loss and compact size
Abstract: In this letter, novel spiral-coupled transmission lines are used to obtain a high-performance microstrip coupler. The advantages of the proposed microstrip coupler are novel structure, filtering frequency response, suppressed harmonics up to second harmonics, transmission poles, low losses, compact size, and good phase balance. The proposed structure is novel and different from the previous coupler designs such as rate-races, rings, and branch-lines types. It is presented for the first time in this work with a very small size and good performance. The size of this coupler is only 82.6 mm2 (0.004 λg2). The common port return loss is 33 dB and the insertion losses at port 2 and port 3 are 2.2 and 2.7 dB, respectively. To prove the accuracy of the design method and simulation results, the proposed coupler is fabricated and measured where the measurement results confirm the simulation results and the proposed design method.
Link of the paper: https://onlinelibrary.wiley.com/doi/abs/10.1002/mop.33732
