Study on Mutual Coupling Reduction Technique for MIMO Antennas IRAM NADEEM AND DONG-YOU CHOI , (Member (original) (raw)
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Mutual Coupling Reduction Techniques on a Multiband Compact Planar MIMO Antenna
International Journal for Research in Applied Science and Engineering Technology IJRASET, 2020
In wireless communication era, reduction of total size of devices is a challenge faced. Miniaturization results in placing the antenna elements closely. This in turn results in mutual coupling between the elements of the antenna due to which it suffers from high signal correlation and low antenna efficiency. This paper manifests a comparative study of numerous mutual coupling reduction techniques developed to improve the performance of MIMO antenna. A multiband compact planar MIMO antenna is designed and Neutralizing Line, Electromagnetic Band Gap, Meander Line and Defected Ground Structure are implemented on the proposed antenna to reduce the mutual coupling and to enhance isolation. The structure consists of two C-shaped monopoles, each operating at 2.4-2.45 GHz and 5.2-5.25 GHz frequency bands. The antenna design is simulated and the performance is measured in terms of S-parameters (return loss i.e. S11 <-10 dB; isolation i.e. S21 <-15 dB) and Voltage Standing Wave Ratio (1 < VSWR < 2) for the propounded mutual coupling reduction technique. MIMO antennas are prevailing in WLAN, Wi-Max, LTE (Long term evolution), and many other RF technologies like portable devices, automotive devices etc. as they are helping in improving the spectral efficiency. I. INTRODUCTION Wired network used cables to connect numerous devices. The connecting cables included fiber optic, optical fiber, twisted pair, coaxial cables etc. Though wired technology helped in establishing connections over various parts of the globe, the mobility, data rate and many other factors were limited. To overcome the limitations of wired network, there was a shift from wired to wireless technology. As transmission and reception of data in wireless communication requires antennas, the importance of antennas increased. In conventional wireless technology, SISO antennas were used for transmission and reception of data. SISO antennas were the simplest antennas to implement but their performance was degraded due to data rate limitation [1]. As SISO antennas lacked diversity, the performance was improved by SIMO and MISO antennas as they improved the transmitter and receiver diversity respectively. MIMO antennas provided robustness by providing multiple path and improving SNR [2]. Today, high channel bandwidth and high rate of transmission of data has become a necessity. MIMO antennas helped in achieving high speed wireless communication, improving channel capacity, through-put and have overcome the multipath effect and fading which existed before [3]. MIMO antennas have the advantage of MISO and SIMO. Depending upon the requirement of different frequency bands, various designs of MIMO antennas are proposed: monopoles, cross-polarized dipoles, Planar Inverted-F Antennas (PIFAs) for WLAN, and planar antennas for Ultra Wide Band (UWB). MIMO antennas have multiple transmitters and receivers and thus suffer from mutual coupling thus increasing the coupling power which can be due to surface currents flowing from one element to another element or due to electromagnetic interaction between the antenna elements [4]. The issue of mutual coupling is a major issue which results in changing the radiation patterns and also degrading the radiation characteristics [5]. It increases as the space between the antennas decreases. Several mutual coupling reduction techniques have been proposed to enhance isolation thus reducing the problem of mutual coupling and improving the overall performance of MIMO antenna. The performance of the MIMO antennas can be achieved by using different strategies which can be classified as circuit level decoupling and antenna level decoupling. Circuit level decoupling technique can be used when the antenna impedances are known, limiting its usefulness when used with distributed elements. This technique is suitable for LTE but the total efficiency is compromised. DGS, neutralizing line, parasitic scatterers and polarization diversity comes under antenna level decoupling where the antenna structure needs to be modified. Among the various technique mentioned parasitic scatterers are proven to be more efficient (0.5dB efficiency loss for an isolated single monopole) [6]. The isolation problem in a dual band antenna was simplified to a single band problem by using stub resonator technique.
Slot-Based Mutual Coupling Reduction Technique for MIMO Antenna
SN Computer Science
This paper reports the results of a two-element MIMO (Multiple input multiple output) antenna with a mutual coupling reduction technique based on slots. The proposed antenna resonates over the frequency band from 3.9 GHz to 8.25 GHz. The gain of the antenna varies from 0.6 dBi to 4 dBi and is suitable for C band applications. Simulation is carried out using 3DEM of mentor graphics, and the performance evaluation is done by comparing the results of the antenna with and without slot-based mutual coupling reduction technique. A significant reduction in mutual coupling is achieved due to the slot and slotted strip on the ground. In the entire resonant band |S 12 | and |S 21 | are found to be less than − 12 dB, and in most of the band, it is found that mutual coupling is less than − 20 dB.
Mutual Coupling Reduction of MIMO Antennas using Parasitic Elements for Wireless Communications
A compact two element MIMO (Multiple Input Multiple Output) system is proposed using H-shape antenna with parasitic elements employing polarization diversity. The proposed MIMO system offers improved bandwidth; return loss, separation between antenna elements and isolation characteristics. The system resonates at 2.36GHz and 5.2 GHz frequencies with VSWR ≥2, which can be used for 4G & WiMAX applications. The simulation results of return loss, mutual coupling, correlation coefficient and gain are presented. The design is performed by using Ready-made software package Zeland-IE3D. The antennas are fabricated using thin film and photolithographic technique and measured using the Vector Network Analyzer. Good agreements were found between the simulated and measured results.
International Journal of RF and Microwave Computer-Aided Engineering, 2017
The present technology fulfills the requirement of high data rate and high channel capacity using multiple input multiple output (MIMO) technology. The MIMO capacity of the system is increased linearly but due to the multiple antennas placed near to each other, problem of mutual coupling exists, which degrades the maximum achievable performance of the system. The problems of multipath propagation can be solved using MIMO system. The isolation improvement methods decrease the mutual coupling among antenna elements, and improve the gain and efficiency of the system. In this paper, decoupling network isolation approach, parasitic element approach, defected ground structure, Neutralization line, isolation improvement based on metamaterials, isolation improvement using PIN diode, varactor diode, and feeding structure have been incorporated, and their merits and demerits have been discussed. The effect of different permittivity material on antenna parameters has also included.
Mutual Coupling Reduction For Triple Band MIMO Antenna Using Stub Loading Technique
Sule Lamido University Journal of Science and Technology (SLUJST) Vol. 2 No. 1, 2021
This paper presents a mutual coupling reduction using stub and partial ground structure. The driven analysis comprises four antennas that are placed orthogonal to each other. A decoupling network is proposed, which consists of one long stub extended between the four defected ground structure for electromagnetic interaction reduction. The proposed antenna has triple-band frequencies at 3 GHz, 5.5 GHz, and 7.1 GHz. The performance of the four by four antenna arrays is evaluated based on envelope correlation coefficient, isolation, mean effective gain, channel capacity loss, total active reflection coefficient, and diversity gain. The results strongly support the applicability of fifth-generation sub 6 GHz applications.
Mutual Coupling Reduction of Two Elements Antenna for Wireless Applications
This paper presented a planar printed multiple-inputmultiple-output (MIMO) antenna with a dimension of 100 x 45 mm 2 . It composed of two crescent shaped radiators placed symmetrically with respect to the ground plane. Neutralization line applied to suppress mutual coupling. The proposed antenna examined both theoretically and experimentally, which achieves an impedance bandwidth of 18.67% (over 2.04-2.46 GHz) with a reflection coefficient < -10 dB and mutual coupling minimization of < -20 dB. An evaluation of MIMO antennas is presented, with analysis of correlation coefficient, total active reflection coefficient (TARC) and capacity loss.
Mutual Coupling Reduction of MIMO Antenna for Satellite Services and Radio Altimeter Applications
International Journal of Advanced Computer Science and Applications, 2018
Ground irregularities also known as defected ground structures (DGS) is a freshly presented innovatory way in designing of patch antennas to boost up the performance of antenna constraints. This study presents a novel proposal of ground irregularities or defected ground structure is proposed for suppression of mutual coupling effects among 2x1 multiple input multiple output patch array designed on Roggers Duroid 5880. The two adjacent M shape structures surrounding Dumbbell Shaped structure and sandwiched between Dumbbell shape patterns showed the significant level of surface wave suppression up to-42dB while maintaining the gain of 4.7dB and 5.6dBi of directivity. The patch array operates at 4 to 4.3GHz for Fixed and Radio satellite services (FSS) and (RSS) and radio altimeter application systems. Keywords-Multiple input multiple output (MIMO); mutual coupling; defected ground structures (DGS); fixed satellite services (FSS); radio satellite services (RSS); radio altimeters I.
Design & Analysis of MIMO Microstrip Antenna with Improved Mutual Coupling
2019
2Principal, AISSMS COE, Maharashtra, India 3HOD Dept. of E&TC Engineering, AISSMS COE, Maharashtra, India ------------------------------------------------------------------------***------------------------------------------------------------------------Abstract—: This work presents a defected ground structure (DGS) for a dual component multiple input multiple output (MIMO) antenna with improved mutual coupling. Defected ground structure is accepted as an arising approach for enhancing the different parameters of microwave circuits, which are narrow bandwidth, low gain and isolation. The two-element MIMO antenna operates at 3.3 GHz. The designed mimo antenna has a compress size of 26 mm × 40 mm suitable for practical design of an antenna. The antenna can be applicable for WLAN, Wi-Max, Wi-Fi which covers a patch operating at a frequency range 2.7 GHz to 5.1GHz. The antenna attains peak gain of 1.17 dB. Efficiency of the antenna is 94%.
Mutual Reduction in the Coupling of the MIMO Antenna Network Applied to the Broadband Transmission
Advances in Science, Technology and Engineering Systems Journal, 2020
In this article, a new form of UWB (ultra-wide-band) antenna operating to the desired specifications, obtained from a base antenna to which some modifications are made. The proximity of the antennas causes a mutual coupling phenomenon thus generating an apparent modification of their characteristics. It is therefore crucial to have the minimum level of insulation with a small possible separation distance between the antennas to ensure efficient operation of our multiple input and multiple output (MIMO) system. The separation spacing between the antennas is close to 0.15λ0 (λ0 is the wavelength in free space), where the coupling can be very weak. To overcome this weakness, two efficient methods are applied to minimize mutual coupling in a four-element MIMO antenna, such as the use of the neutralization line and the use of split ring resonator metamaterial (SRR). The objective of our paper is, on the one hand the design of UWB antenna, and on the other hand to minimize the coupling between four UWB-MIMO antennas using the two methods of isolation mentioned above. A coupling minimization of more than 15 dB is obtained using the neutralization line and more than 20 dB with the use of metamaterial while maintaining the operating band and radiation specifications of the MIMO antennas.
Bulletin of Electrical Engineering and Informatics, 2024
This paper reports a design of 2×1 multiple input multiple output (MIMO) structure of antenna with 23×45 mm2 dimension. Each element in the MIMO antenna is a quarter wave transformer fed microstrip patch antenna. To lessen the effect of coupling, a rectangular parasitic decoupler is positioned between the two elements. Results report that antenna resonates at 6 GHz, coupling is reduced by 14 dB using parasitic decoupler S12 and S21 obtained with parasitic decoupler are same which -33.06 dB. The diversity gain (DG) is 9.99 dB, which is nearly close to 10 dB, and the envelope correlation coefficient (ECC) is less than 0.00034. These values reflect the good diversity performance. Measured findings match those from the simulation. As we confront the delicate environment, the proposed antenna is suited for number of wireless applications, including 802.11, 802.16 standards of IEEE.