Antenna Array with Low Side Lobe Levels for MIMO Applications

Abstract

To design a single element microstrip patch antenna at a frequency of 4 GHz. A uniform planar array with 4 patch elements is designed. A non uniform planar array is designed to overcome the mutual coupling effect. Simulation of the designed uniform planar array and non uniform planar array antenna array is performed on HFSS tools. A single microstrip feed patch antenna element is designed at a frequency of 4 GHz. The substrate material used is Rogers 6002. A 2*2 array is designed by using 4 similar patch elements. The proposed model has dimensions of the substrate as 58mm x 68mm, the dimensions of the patch is 20mm x 22mm. For the proposed model slots are added to each patch with the dimensions 5mm x 1mm. The substrate material used is FR4 epoxy. It is further improved by changing the dielectric material variations, slot arm length variations, slot arm thickness variations.

Introduction

I. INTRODUCTION

A single antenna is employed at the source and a second one is used at the destination in typical wireless communication methods. It occasionally runs into issues with multipath effects. High data rate speed is required for future wireless applications like the Internet of Things, as large amounts of information must really be transferred in a relatively short period of time. This means that using two or more antenna elements and sending out numerous signals both at the source and the destination will both solve the problem of multipath wave propagation and even benefit from it. Multiple Input and Multiple Output (MIMO) antenna arrays have generated interest due to their straightforward construction and superior performance. In a MIMO array, it is feasible to use the entire antenna array at once, but it is also conceivable to use a subset or a single element of the same array for various purposes, such as separate elements for various channels. MIMO is thus one of many types of smart antenna technology.

One of the key issues is that many different types of antenna arrays experience the mutual coupling (MC) effect, which reduces the performance of the antenna array [2]. The designers' biggest task will be to lower the MC between two close antenna array elements. As a result, numerous research projects have been putting forth fresh ideas every day for the past few decades to lessen the MC impact. Increasing the distance between neighbouring items, which also increases the array size, is the most typical method of lowering MC. Other techniques to lessen the MC effect include the use of metamaterial arrays [3], stacked arrays, non-uniform planar arrays (NPA), conformal arrays, circular arrays [4], unevenly placed planar arrays [5], sequentially rotated planar arrays [6], [7], planar arrays with electromagnetic band gaps [8], and planar arrays with deficient ground structures (DGS) [9]. In addition, other kinds of non-uniform arrays have gained popularity and acceptance among academics during the past few years. It still has trouble coming up with workable answers, though. Research is also required in the area of antenna array design to lessen the MC impact. In [3], a four-element (22) MIMO array with (25) metamaterial unit cells on the ground plane was suggested. With a peak gain of 9.2 dBi, 73% radiation efficiency, and more than 18 dB isolation, the suggested array has been successful. The metamaterial structure has accomplished the MC reduction. For MC reduction, an intriguing circular MIMO array with a central element has been presented in [4]. The array's highest gain with 9 radiating elements was 15.7 dB. With the suggested approach, a -17.6 dB side lobe level reduction has been made. Authors have suggested planar arrays in some works by arranging antenna elements unevenly [5]. As a result, within the same array, the antenna elements are positioned at varied distances from one another. In [6], [7], a different method of MC reduction has been suggested. To lessen the MC effect, the 22 antenna array elements in [6] are successively rotated. As a result, the proposed array has a - 24 dB insertion loss. In order to reduce MC, half-loop monopole antennas are rotated successively in a proposed four-element compact MIMO array in [7]. The suggested array has a 34.3% working bandwidth and a 3.18 dBi gain on average. The two elements are sufficiently isolated by greater than 16 dB. Antenna arrays with various slotted structures on the radiating plane or ground plane have been shown in several studies. A planar MIMO array with an EBG structure on the top plane has been suggested in [8], for example, to lessen MC. The suggested array offers improved isolation by 10 to 25 dB at 5.8 GHz thanks to the EBG construction.

In [9], [10], a 22 MIMO array with DGS has been suggested. Circular polarisation was obtained and MC was reduced by using slots on the radiating patch. Since there is more than 33 dB of isolation between two ports, the array has achieved this. According to the literature cited above, MC reduction has been accomplished by using a variety of strategies. However, researchers had to take a sophisticated design into account in order to attain great results. An innovative method for designing.

In this paper the proposed model has dimensions of the substrate as 58mm x 68mm, the dimensions of the patch is 20mm x 22mm.  For the proposed model slots are added to each patch with the dimensions 5mm x 1mm. The substrate material used is FR4 epoxy. It is further improved by changing the dielectric material variations, slot arm length variations, Slot arm thickness variations to get low return loss, low VSWR.

The paper is organized in the following way : Section 1 has the introduction of the proposed model, Section 2 discusses the existing model and its summary. Section 3 discusses the proposed model 1 and 2. Section 4 shows results of the proposed models with respective figures. Section 5 briefly discusses the conclusion and future scope of this paper.

II. EXISTING MODEL

This section discusses the design of the proposed insert feed antenna using Rogers 5880 as the substrate material, which has a dielectric constant of 2.2 and dielectric loss of 0.0009 [1]. The structure that will be analyzed must first have a geometric model drawn. Selecting the substance from which the various drawn things are constructed is the following step. What comes next is an exact description of the structure's boundaries, such as those of a perfect magnetic or electrical conductor. When the structure in HFSS is fully modelled and the solution is put up, a port source must be specified to excite it. After the simulation is finished, the solution data is post-processed, which could involve showing far-field plots, smith chart graphs, or tables containing s-parameter data.

A. Simulation

The existing model design includes the following:

1. The frequency of a single inset feed patch antenna element is 5.8 GHz
2. Rogers 5880 is the substrate material in used when creating a 2*2 array, 4 comparable patch items are used
3. The patch dimension is 17.5mm x 20mm.
4. The ground dimension is 30mm x 23mm.
5. The feed dimension is 9.45mm x 0.77mm.

Fig. 1 shows the Geometry of existing model with above mentioned properties.

Conclusion

A new technique of designing a non-uniform antenna array has been proposed in this paper . In this research, HFSS software was used to design the proposed microstrip feed antenna with a slot. For the proposed model slots are added to each patch with the dimensions 5mm x 1mm. The substrate material used is FR4 epoxy. It is further improved by changing the dielectric material variations, slot arm length variations, Slot arm thickness variations to get low return loss, low VSWR. Use of a multilayer dielectric design can considerably enhance impedance bandwidth, a crucial aspect of an antenna. The architecture put out in this research work can be expanded to allow MIMO applications for LTE and WiMAX-capable devices. Future research can concentrate on the analysis and design of antennas for cutting-edge technologies like cognitive radio and ultra-wideband. To accommodate Massive Multiple Input Multiple Output (MIMO) for 5G mobile radio transmission technology, the design described in this thesis work can be expanded.

References

[1] Sahad, Asif Jamil & Islam, Md & Islam, Md & Asadullah, G. M. & Adnan, Noor. (2020). Design and Analysis of a Non-Uniform Planar Antenna Array. 10.1109/TENSYMP50017.2020.9230690. [2] M. S. Islam, M. I. Ibrahimy, S. M. A. Motakabber, A. K. M. Z. Hossain, and S. M. K. Azam, “Microstrip patch antenna with defected ground structure for biomedical application,” Bull. Electr. Eng. Inform., vol. 8, no. 2, pp. 586–595, Jun. 2019. [3] N. L. Nguyen and V. Y. Vu, “Gain enhancement for MIMO antenna using metamaterial structure,” Int. J. Microw. Wirel. Technol., vol. 11, no. 8, pp. 851–862, Oct. 2019. [4] M. Zaid, M. R. Islam, M. H. Habaebi, A. Z. Alam, and K. Abdullah, “Optimum concentric circular array antenna with high gain and side lobe reduction at 5.8 GHz,” IOP Conf. Ser. Mater. Sci. Eng., vol. 260, p. 012038, Nov. 2017. [5] W. Liu and Z. Wang, “Non-Uniform Full-Dimension MIMO: New Topologies and Opportunities,” IEEE Wirel. Commun., vol. 26, no. 2, pp. 124–132, Apr. 2019. [6] M. Fairouz and M. A. Saed, “A Sequentially Rotated, Circularly Polarized Microstrip Antenna Array with Reduced Mutual Coupling,” Electromagnetics, vol. 36, no. 7, pp. 422–433, Oct. 2016. [7] N.-S. Nie, X.-S. Yang, and B.-Z. Wang, “A compact four-element multiple-inputmultiple-output antenna with enhanced gain and bandwidth,” Microw. Opt. Technol. Lett., vol. 61, no. 7, pp. 1828– 1834, 2019. [8] Y. Alnaiemy, T. A. Elwi, and L. Nagy, “Mutual Coupling Reduction in Patch Antenna Array Based on EBG Structure for MIMO Applications,” Period. Polytech. Electr. Eng. Comput. Sci., vol. 63, no. 4, pp. 332–342, Oct. 2019. 68 [9] L. Malviya, R. K. Panigrahi, and M. V. Kartikeyan, “Circularly Polarized 2×2 MIMO Antenna for WLAN Applications,” Prog. Electromagn. Res., vol. 66, pp. 97–107, 2016. [10] I. M. Rafiqul, W. S. A, S. Rafiq, M. S. Yasmin, and M. H. Habaebi, “A 2X2 MIMO Patch Antenna for Multi-Band Applications,” Indones. J. Electr. Eng. Inform. IJEEI, vol. 5, no. 4, pp. 383-389– 389, Dec. 2017. [11] N. Majidi, G. G. Yaralioglu, M. R. Sobhani, and T. Imeci, “Design of a quad element patch antenna at 5.8 GHz,” in 2018 International Applied Computational Electromagnetics Society Symposium (ACES), Mar. 2018, pp. 1–2. [12] M. S. Islam, M. I. Ibrahimy, S. M. A. Motakabber, and A. K. M. Z. Hossain, “A Rectangular Inset-Fed Patch Antenna with Defected Ground Structure for ISM Band,” in 2018 7th International Conference on Computer and Communication Engineering (ICCCE), Sep. 2018, pp. 104–108

Copyright

Copyright © 2023 A. Lavanya, G. Srivalli. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.