Sujit Kumar Mandal

Bio: Sujit Kumar Mandal is an academic researcher from National Institute of Technology, Durgapur. The author has contributed to research in topics: Antenna (radio) & Side lobe. The author has an hindex of 8, co-authored 59 publications receiving 227 citations.

Reduction of mutual coupling and cross-polarization of a MIMO/diversity antenna using a string of H-shaped DGS

Abstract: In this article, a simple string of H-shaped defected ground structure (DGS) is used to reduce the mutual coupling and cross-polarization of a MIMO antenna. A MIMO antenna has been designed using two identical square patches to operate at the frequency of 2.4 GHz. The proposed DGS decreases the direct coupling path among the closely spaced (edge to edge gap 0.038 λ0) patches and thereby reduces the mutual coupling and cross-polarization by 46 dB and 11 dB respectively. To study the amount of mutual coupling is decoupled; a new term namely, coupling to decoupling ratio (CDR) has been defined. A mathematical model is developed using multiple polynomial regression analysis techniques to observe the dependency of CDR as a function of frequency and inter-element spacing. Also, an equivalent circuit of the DGS is constructed and validated. Diversity performance of this MIMO antenna is presented through Envelope Correlation Coefficient (ECC) and Mean Effective Gain (MEG) ratio and well acceptable values of 0.0002 and 0.03 dB are obtained respectively. A prototype is fabricated and measured. The experimental results show good agreement with that of the simulated results. Maximum peak gain of 2dBi and radiation efficiency of 74% also proves the practicality of this design.

Minimization of side lobe level and side band radiation of a uniformly excited time modulated linear antenna array by using Artificial Bee Colony algorithm

Abstract: In this work, the Artificial Bee Colony (ABC) algorithm is used to minimize the side lobe level of the main beam and the first two side band radiation of the uniformly excited time modulated linear antenna array. ABC searches the switch on or excitation time duration of each of the element of the antenna array under consideration. This approach gives satisfactory results without changing the amplitude of the antenna elements.

Differential Evolution Algorithm for Optimizing the Conflicting Parameters in Time-Modulated Linear Array Antennas

Abstract: In this paper, a new technique is proposed to optimize the con∞icting parameters like low value of maximum side lobe level (SLL), narrow beam-width of the main beam and low value of maximum sideband radiation level (SRL) of time-modulated linear antenna arrays (TMLAAs). The method is based on minimizing a multi-objective fltness function by using single-objective difierential evolution algorithm (DEA) technique. The method is applied to both uniformly excited TMLAA (UE-TMLAA) and non-uniformly excited TMLAA (NUE-TMLAA) to synthesize low side lobe optimum pattern at operating frequency by suppressing the sideband radiation level to a su-ciently low value. For UE-TMLAA only the switch- on time durations of the array elements and for NUE-TMLAA the switch-on time durations and the static amplitudes with predetermined dynamic range ratio (DRR) of static amplitudes are taken as the optimization parameters for the DEA. To show efiectiveness of the proposed approach, the single-objective DEA optimized results are compared with those obtained by other single objective and multi- objective techniques that has been reported previously. Also, flrst null beam width (FNBW) and half power beam width (HPBW) of the DEA optimized patterns at fundamental radiation are compared with those of the Dolph-Chebyshev (D-C) pattern of same SLL.

Artificial bee colony algorithm to reduce the side lobe level of uniformly excited linear antenna arrays through optimized element spacing

Abstract: In this work, the effectiveness of a relatively newly developed optimization algorithm, artificial bee colony (ABC) algorithm has been employed to synthesize uniformly excited, non-uniformly spaced, symmetrical linear arrays. ABC is used to reduce the side lobe level (SLL) of uniformly excited linear antenna arrays by taking the element spacing as the optimization parameters. The effectiveness of the proposed approach is demonstrated by considering a linear antenna array of 32 elements. The array of isotropic elements is synthesized for the different search space of the element spacing and a typical variation of the SLL with different limiting values of the maximum element spacing is presented. It is observed that, for the isotropic element array when the search range of the normalized element spacing's relative to the operating wavelength is (0.5, 1), the maximum reduction of side lobe level (-21.22 dB) is obtained. At the end the array with half-wavelength dipole is considered and with the search range of the element spacing's, (0.5, 1), SLL is reduced to -22.99 dB.

Synthesis of simultaneous multiple-harmonic-patterns in time-modulated linear antenna arrays

Abstract: In time-modulated antenna arrays (TMAAs), as a result of periodical switch-on and switch- ofi of the antenna elements, including operating frequency (termed as center frequency) signal, sideband signals are appeared at either sides of the center frequency in integer multiples of the modulation frequency. In this paper, it is shown that without using phase shifters, just by suitably controlling the on-time instants (OTIs) and on-time durations (OTDs) of a time-modulated linear antenna array (TMLAA) elements, simultaneously, along with a pencil beam pattern at the operating frequency, a shaped beam pattern can be obtained at both the flrst positive and negative harmonics of the time- modulation frequency. The important advantage of such a technique is that realization of multi-beam pattern in conventional antenna array (CAA) system generally requires complex feed network, whereas by using simple radio frequency (RF) switching circuit in the feed network of TMLAA, by virtue of the properties of harmonic radiations, synthesis of a shaped pattern at either (positive or negative) harmonic results in generating the same pattern in its opposite harmonic, and the synthesized patterns at difierent harmonics can be simultaneously used as independent communication channels. By employing a difierential evolution (DE) based optimization method, numerical results for a 16-element TMLAA with uniform excitation show that in conjunction with a pencil beam pattern at the center frequency, a ∞at-top or a cosec square pattern at flrst positive and negative sidebands of side-lobe levels (SLL) i20dB can be synthesized by suppressing the higher sideband level (SBL) to below i10dB.

Microstrip Antennas The Analysis And Design Of Microstrip Antennas And Arrays

Abstract: Description: Electrical Engineering/Antennas and Propagation Microstrip Antennas The Analysis and Design of Microstrip Antennas and Arrays Microstrip Antennas contains valuable new information on antenna design and an excellent introduction to the work done in the microstrip antenna area over the past 20 years. The articles are well–chosen and (are) complete with practical design information that is very useful for the working engineer. Stuart Long, University of Houston The editors have done an outstanding job in assembling this updated reprint book. It is a welcome addition to the list of books on microstrip antennas. There is no doubt that it will be a valuable source of information for graduate students, engineers and researchers the original articles are written lucidly and are very informative, and the reprint articles are well chosen. Kai Fong Lee, The University of Toledo Complete with an up–to–date tutorial overview of the field and substantial new, introductory material for each topic, Microstrip Antennas combines in one source a selection of today’s most significant and useful articles on microstrip and antenna design. Eminent experts David M. Pozar and Daniel H. Schaubert guide you through:

Pulse-Shaping Strategy for Time Modulated Arrays—Analysis and Design

Abstract: Time-modulated arrays (TMAs) are antenna systems where the transmitted or received signal is modulated by periodic time pulses. Several strategies have been proposed for defining the characteristics of the pulse sequence to control the antenna radiation pattern starting from the hypothesis of ideal radio-frequency (RF) switches with instantaneous rise and fall time. In this paper, the use of switches having a non-null transition between the on and off state is taken into account and the impact on the radiation features is studied and verified through a set of numerical results also in comparative fashion with ordinary rectangular pulses.

Wideband Four-Port MIMO antenna array with high isolation for future wireless systems

Abstract: A four-port MIMO antenna array with wideband and high isolation characteristics for imminent wireless systems functioning in 5G New Radio (NR) sub-6 GHz n77/n78/n79 and 5 GHz WLAN bands is proposed. Each array antenna element is a microstrip-line fed monopole type. The novelty of the antenna lies in loading an “EL” slot into the radiating element along with two identical stubs coupled to the partial ground in order to improve the impedance matching and radiation characteristics across the bands of interest. To further attain high port isolation without affecting the compactness and radiation performance of each antenna element, the technique of introducing an innovative un-protruded multi-slot (UPMS) isolating element (of low-profile 2 × 19 mm2) between two closely spaced antenna elements (with an edge-to-edge distance of approx. 0.03λ at 4.6 GHz) is also presented. Besides demonstrating a small footprint of 30 × 40 × 1.6 mm3, the proposed four-port MIMO antenna array has also shown wide 10-dB impedance bandwidth of 58.56% (3.20–5.85 GHz), high isolation of more than 17.5 dB, and good gain and efficiency of around 3.5 dBi and 85%, respectively, across the bands of interest. Finally, the MIMO performance metrics of the proposed antenna are also analyzed.

High-Gain Metasurface in Polyimide On-Chip Antenna Based on CRLH-TL for Sub-Terahertz Integrated Circuits.

Abstract: This paper presents a novel on-chip antenna using standard CMOS-technology based on metasurface implemented on two-layers polyimide substrates with a thickness of 500 μm. The aluminium ground-plane with thickness of 3 μm is sandwiched between the two-layers. Concentric dielectric-rings are etched in the ground-plane under the radiation patches implemented on the top-layer. The radiation patches comprise concentric metal-rings that are arranged in a 3 × 3 matrix. The antennas are excited by coupling electromagnetic energy through the gaps of the concentric dielectric-rings in the ground-plane using a microstrip feedline created on the bottom polyimide-layer. The open-ended feedline is split in three-branches that are aligned under the radiation elements to couple the maximum energy. In this structure, the concentric metal-rings essentially act as series left-handed capacitances CL that extend the effective aperture area of the antenna without affecting its dimensions, and the concentric dielectric rings etched in the ground-plane act as shunt left-handed inductors LL, which suppress the surface-waves and reduce the substrates losses that leads to improved bandwidth and radiation properties. The overall structure behaves like a metasurface that is shown to exhibit a very large bandwidth of 0.350–0.385 THz with an average radiation gain and efficiency of 8.15dBi and 65.71%, respectively. It has dimensions of 6 × 6 × 1 mm3 that makes it suitable for on-chip implementation.

PSOGSA-Explore

Abstract: Graphical abstractDisplay Omitted HighlightsWe propose a new algorithm to lower the sidelobes in collaborative beamforming.We achieved up to 100% improvement in sidelobe reduction.Variable parameter tuning is simplified in the proposed algorithm.The proposed algorithm successfully avoids the problem of premature convergence.The proposed method does not increase the computational complexity of the system. A conventional collaborative beamforming (CB) system suffers from high sidelobes due to the random positioning of the nodes. This paper introduces a hybrid metaheuristic optimization algorithm called the Particle Swarm Optimization and Gravitational Search Algorithm-Explore (PSOGSA-E) to suppress the peak sidelobe level (PSL) in CB, by the means of finding the best weight for each node. The proposed algorithm combines the local search ability of the gravitational search algorithm (GSA) with the social thinking skills of the legacy particle swarm optimization (PSO) and allows exploration to avoid premature convergence. The proposed algorithm also simplifies the cost of variable parameter tuning compared to the legacy optimization algorithms. Simulations show that the proposed PSOGSA-E outperforms the conventional, the legacy PSO, GSA and PSOGSA optimized collaborative beamformer by obtaining better results faster, producing up to 100% improvement in PSL reduction when the disk size is small.