Browsing by Author "Sarker, Nayan"

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Design of multiband centimetre wave antennas for an OFDM based RFID system
(Institute of Information and Communication Technology, 2018-07-21) Sarker, Nayan; Mondal, Dr. Md. Rubaiyat Hossain
In the era of object marking, radio frequency identification (RFID) has attracted wide attention. RFID is suitable not only for indoor but also for outdoor environment providing long distance object identification facilities. The major components of an RFID system are the RFID reader and the tag with the antenna for wireless data transfer between them. Little research has been done so far to analyze the fading effect for outdoor applications in the context of RFID. This research focuses on the development of an RFID reader antenna for outdoor scenarios. Two multiband patch antennas and an array antenna operating at centimetre band are proposed for an orthogonal frequency division multiplexing (OFDM) based radio-frequency identification (RFID) reader. The first one is a dual band antenna with centre frequencies of 7.30 GHz and 9.50 GHz, while the second one is a triple band antenna centred at 7.75 GHz, 9.70 GHz and 11.90 GHz. Both the patch antennas are designed with equal-width horizontal arms as radiating elements and a microstrip feeding line as the feeder. The simulated radiation efficiency of the multiband patch antennas is above 80% at each resonance frequency. The antennas are moderately small sized with dimensions of 40.30 mm by 35.10 mm. The designed double E-shaped array antenna provides resonance at frequencies of 7.23 GHz, 10 GHz, and, 11.748 GHz with dimensions of 86.584 mm by 35.117 mm. The spacing between the array elements of the proposed array antenna is 12 mm that minimizes grating lobe and mutual coupling between the array elements. The simulated antenna performance metrics such as (gain and directivity) of the designed array antenna at these three different frequencies are (9.81 dB and 10.13 dBi), (8.01 dB and 8.308 dBi) and (8.12 dB and 8.681 dBi) respectively. Simulations with Computer Simulation Technology (CST) Microwave Studio tool indicate that competitive values of different antenna parameters are achieved when compared with centimetre band antennas described in the literature. With the use of MATLAB tool, the bit error rate (BER) performance of the multiband antennas are simulated for outdoor Rayleigh and Rician fading channels. Simulation results for the proposed antennas indicate that for a given number of OFDM subcarriers, the larger the bandwidth of the signals received by the RFID reader, larger the BER degradation.
Dual Band Antenna Design and Prediction of Resonance Frequency Using Machine Learning Approaches
(Scopus, 22-10-18) Haque, Md. Ashraful; Sarker, Nayan; Singh, Narinderjit Singh Sawaran; Rahman, Md Afzalur; Hasan, Md. Nahid; Islam, Mirajul; Zakariya, Mohd Azman; Paul, Liton Chandra; Sharker, Adiba Haque; Abro, Ghulam E. Mustafa; Hannan, Md; Pk, Ripon
An inset fed-microstrip patch antenna (MPA) with a partial ground structure is constructed and evaluated in this paper. This article covers how to evaluate the performance of the designed antenna by using a combination of simulation, measurement, creation of the RLC equivalent circuit model, and the implementation of machine learning approaches. The MPA’s measured frequency range is 7.9–14.6 GHz, while its simulated frequency range is 8.35–14.25 GHz in CST microwave studio (CST MWS) 2018. The measured and simulated bandwidths are 6.7 GHz and 5.9 GHz, respectively. The antenna substrate is composed of FR-4 Epoxy, which has a dielectric constant of 4.4 and a loss tangent of 0.02. The equivalent model of the proposed MPA is developed by using an advanced design system (ADS) to compare the resonance frequencies obtained by using CST. In addition, the measured return loss of the prototype is compared with the simulated return loss observed by using CST and ADS. At the end, 86 data samples are gathered through the simulation by using CST MWS, and seven machine learning (ML) approaches, such as convolutional neural network (CNN), linear regression (LR), random forest regression (RFR), decision tree regression (DTR), lasso regression, ridge regression, and extreme gradient boosting (XGB) regression, are applied to estimate the resonant frequency of the patch antenna. The performance of the seven ML models is evaluated based on mean square error (MSE), mean absolute error (MAE), root mean square error (RMSE), and variance score. Among the seven ML models, the prediction result of DTR (MSE = 0.71%, MAE = 5.63%, RMSE = 8.42%, and var score = 99.68%) is superior to other ML models. In conclusion, the proposed antenna is a strong contender for operating at the entire X-band and lower portion of the Ku-band frequencies, as evidenced by the simulation results through CST and ADS, it measured and predicted results using machine learning approaches.
Performance Analysis of Linearly Arranged Concentric Circular Antenna Array with Low Sidelobe Level and Beamwidth Using Robust Tapering Technique
(Daffodil International University, 2022-11-11) Rahaman, Imteaz; Haque, Md Ashraful; Singh, Narinderjit Singh Sawaran; Jafor, Md. Shakiul; Sarkar, Pallab Kumar; Rahman, Md Afzalur; Zakariya, Mohd Azman; Abro, Ghulam E. Mustafa; Sarker, Nayan
In this research, a novel antenna array named Linearly arranged Concentric Circular Antenna Array (LCCAA) is proposed, concerning lower beamwidth, lower sidelobe level, sharp ability to detect false signals, and impressive SINR performance. The performance of the proposed LCCAA beamformer is compared with geometrically identical existing beamformers using the conventional technique where the LCCAA beamformer shows the lowest beamwidth and sidelobe level (SLL) of 12.50° and 􀀀15.17 dB with equal elements accordingly. However, the performance is degraded due to look direction error, for which robust techniques, fixed diagonal loading (FDL), optimal diagonal loading (ODL), and variable diagonal loading (VDL), are applied to all the potential arrays to minimize this problem. Furthermore, the LCCAA beamformer is further simulated to reduce the sidelobe applying tapering techniques where the Hamming window shows the best performance having 17.097 dB less sidelobe level compared to the uniform window. The proposed structure is also analyzed under a robust tapered (VDL-Hamming) method which reduces around 69.92 dB and 48.39 dB more sidelobe level compared to conventional and robust techniques. Analyzing all the performances, it is clear that the proposed LCCAA beamformer is superior and provides the best performance with the proposed robust tapered (VDL-Hamming) technique.
Performance Investigation of Linearly Arranged Circular, Circular Planer, Rectangular, and Concentric Circular Antenna Arrays Using Robust NVL Techniques
(Scopus, 22-11-11) Rahaman, Imteaz; Jafor, Md. Shakiul; Singh, Narinderjit Singh Sawaran; Haque, Md Ashraful; Biswas, Antar Kumar; Rahman, Md Afzalur; Zakariya, M Azman B; Abro, Ghulam E Mustafa; Sarker, Nayan
In this research, linearly arranged circular antenna array (LCAA), linearly arranged circular planer antenna array (LCPAA), linearly arranged rectangular antenna array (LRAA), and linearly arranged concentric circular antenna array (LCCAA) are analyzed using robust techniques. These four antenna arrays are briefly investigated to evaluate their beam width performance, ability to detect a false signal, and SINR power pattern performances. Robust techniques—fixed diagonal loading (FDL), optimal diagonal loading (ODL), variable diagonal loading (VDL), and new variable loading (NVL) techniques—are applied, and the NVL technique is found to be superior and provides the best performance with the proposed LCCAA beamformer. With an SINR of 40.45 dB, 40.29 dB, 40.18 dB, and 39.99 dB for 0°, 1°, 2°, and 3° disparity angles, respectively, and output powers of −0.019 dB, −0.076 dB, and −0.171 dB for 1°, 2°, and 3° disparity angles, respectively, LCCAA beamformers using the NVL technique outperform other beamformers with different robust approaches.