Yogesh Kumar Choukiker
Bio: Yogesh Kumar Choukiker is an academic researcher. The author has contributed to research in topics: Fractal antenna & Reconfigurable antenna. The author has an hindex of 2, co-authored 3 publications receiving 12 citations.
TL;DR: In this paper, a hybrid fractal antenna is proposed for the application in wideband frequency range, which is the combination of Koch curve and self-affine fractal geometries.
Abstract: A compact size hybrid fractal antenna is proposed for the application in wideband frequency range. The proposed antenna structure is the combination of Koch curve and self-affine fractal geometries. The Koch curve and self-affine geometries are optimized to achieve a wide bandwidth. The feed circuit is a microstrip line with a matching section over a rectangular ground plane. The measured impedance matching fractal bandwidth (S11 ≤ −10 dB) is 72.37% from 1.6 to 3.4 GHz. An acceptable agreement is obtained from the simulated and measured antenna performance parameters.
01 Jan 2013
TL;DR: In this article, a wideband fractal monopole antenna is proposed to achieve the acceptable performance in terms of isolation, envelope correlation coefficient, capacity loss, radiation patterns and efficiency.
Abstract: Today’s small handheld and other portable devices challenge antenna designers for ultrathin, and high performances that have the ability to meet multi standards. In the context, fractal geometries have significant role for antenna applications with varying degree of success in improving antenna characteristics. In this thesis, we have investigated several wideband fractal monopole antennas. This work starts with design and implementation of Koch fractal, hybrid fractal, sectoral fractal, semi-circle fractal monopole antennas with discussion, covering their operations, electrical behavior and performances. The performances of these designs have been studied using standard simulation tools used in industry/academia and are experimentally verified. Frequency reconfigurable Koch snowflake fractal monopole antenna is also introduced. The present antenna can be used as an array element and has a wideband frequency of operation. A square Sierpinski monopole antenna has been designed, which is suitable for use in indoor UWB radio system and outdoor base station communication systems. Technique for obtaining a band stop function in the 5-6 GHz frequency band is numerically and experimentally presented. In addition to examining the performance of UWB system, the transfer function and waveform distortion are discussed. Finally, fractal antenna for array with MIMO environment is developed for mobile communication devices. Aim of this work is to achieve the acceptable performances in terms of isolation, envelope correlation coefficient, capacity loss, radiation patterns and efficiency. Furthermore, a wideband feed network prototype based on a modified Wilkinson power divider is designed. The designed feed network has been used in constructing 2-element and 4-element linear antenna arrays for high gain. This research work has addressed the effectiveness of fractal geometries in antenna and to bring-out the true advantages of their in antenna engineering.
TL;DR: This paper presents the design and simulation of microstrip circular antenna arrays and studies the effect of excitation with uniform and Dolph–Chebyshev distribution to find that these antenna arrays are suitable for radar application.
Abstract: This paper presents the design and simulation of microstrip circular antenna arrays and studies the effect of excitation with uniform and Dolph–Chebyshev distribution. With side lobe level of 20 dB and 8 microstrip circular patches, the circular array has been demonstrated with minimum grating lobes. The effects of patch and antenna array length on directivity, radiation patterns, and side lobe are also studied in detail. It is found that these antenna arrays are suitable for radar application.
01 Dec 1992
01 Jan 1992
TL;DR: How to apply the moment method to wire antenna analysis evaluation of the basic performance of microstrip antennas and some considerations of small antenna measurements.
Abstract: How to apply the moment method to wire antenna analysis evaluation of the basic performance of microstrip antennas key points in the design and measurement of microstrip antennas analysis of planar inverted-F antennas and antenna design for portable radio equipment design and analysis of small-aperture antennas design and measurement of small AM broadcasting antennas mutual coupling effects between antenna elements on antenna performance some considerations of small antenna measurements.
01 Jan 2003
TL;DR: In this paper, a new method for the synthesis of low sidelobe beampatterns is presented, which enables beamwidth and sidelobe level to be adjusted with relative independence.
Abstract: A new method for the synthesis of low sidelobe beampatterns is presented, which enables beamwidth and sidelobe level to be adjusted with relative independence. Unlike existing methods for the synthesis of arbitrary beampatterns, the proposed method is based on a modification of the Dolph-Chebyshev design and requires only a few parameters to be optimized, regardless of the array size. Due to its much lower complexity, the method is implementable in wireless communications applications requiring fast and cheap, adaptive algorithms for low sidelobe arrays. The method is applicable, for instance, to the design of adaptive sector-like antennas with uniform circular arrays (UCAs), and to the design of quasi-steering-invariant beampatterns with uniform linear arrays (ULAs).
TL;DR: The bandwidth obtained by the MLAPO technique has been found to be better than that obtained by PSO and normal LAPO algorithm.
Abstract: An inscribed hexagonal fractal slotted patch antenna with some additional geometry and slots is proposed for the optimization in this paper. This research work is concerned with the optimization of this slotted fractal antenna with the help of the curve-fitting method in conjunction with the modified version of Lightning Attachment Procedure Optimization (MLAPO) technique. The data required for the curve-fitting technique and for the optimization technique have been obtained by varying some of the parameters of the proposed antenna. Different equations are developed to know the relations between these parameters of the proposed antenna. The MLAPO technique is applied thereafter to calculate the different optimized geometrical parameters to optimize the bandwidth for the proposed antenna. The optimized geometrical parameters are verified with the help of a parametric variation to justify the reliable optimization. The bandwidth obtained by the MLAPO technique has been found to be better than that obtained by PSO and normal LAPO algorithm. The prototype of the optimized antenna is fabricated and the experimental results are found to be compatible with the results obtained by simulation. The proposed optimized antenna may be utilized in various applications in C and X bands.
01 Jan 2007
TL;DR: In this article, a maximum likelihood estimator for digital sequences disturbed by Gaussian noise, intersymbol interference (ISI) and interchannel interference (ICI) is derived.
Abstract: A maximum likelihood (ML) estimator for digital sequences disturbed by Gaussian noise, intersymbol interference (ISI) and interchannel interference (ICI) is derived. It is shown that the sampled outputs of the multiple matched filter (MMF) form a set of sufficient statistics for estimating the input vector sequence. Two ML vector sequence estimation algorithms are presented. One makes use of the sampled output data of the multiple whitened matched filter and is called the vector Viterbi algorithm. The other one is modification of the vector Viterbi algorithm and uses directly the sampled output of the MMF. It appears that, under a certain condition, the error performance is asymptotically as good as if both ISI and ICI were absent.