Compact antenna with good performance characteristics is always preferred for small IoT (Internet of Things) sensor nodes. The novelty of this proposed work is not in terms of design but in terms of application as Log-Periodic antennas has been so far used for UHF/VHF (Ultra High Frequency/Very High Frequency) and TV reception applications, and in this paper, the advantages of Log-Periodic structure have been exploited for IoT applications. This antenna design consists of two Log-Periodic like structured radiating elements on an FR4 substrate of 1.6\,mm thickness. The compact antenna of size of 15 mm×17 mm covers a bandwidth ranging from 2.01 GHz to 4.04 GHz including the WiMAX (2.3 GHz-2.4 GHz, 2.5 GHz-2.7 GHz and 3.4 GHz-3.6 GHz) and WLAN (2.4 GHz and 3.6 GHz) frequency bands. This system employs Defected Ground Structure (DGS) technique to obtain the required range of bandwidth of operation, for improving the isolation and obtaining mutual coupling suppression between the two individual elements. This miniaturized cheap antenna has a very low ECC (Envelope Correlation Coefficient) value and all other MIMO (Multiple Input Multiple Output) parameters in acceptable range. The isolation obtained over the entire range of operation is below -30 dB, and the performance efficiency is as good as 92.8% with a maximum gain of 2.9 dB. The simulated and measured results of the antenna system are also found to be in good agreement. The MIMO system can be considered as a good candidate for medium range IoT applications for its small size and good performance.
2. Roges, R. and P. K. Malik, "Planar and printed antennas for Internet of Things-enabled environment: Opportunities and challenges," International Journal of Communication Systems, e4940, 2021.
3. Kfle, V. P., Y. Fukushima, and H. Harai, "Internet of things standardization in ITU and prospective networking technologies," IEEE Communications Magazine, Vol. 54, No. 9, 43-49, 2016.
doi:10.1109/MCOM.2016.7565271
4. Agiwal, M., A. Roy, and N. Saxena, "Next generation 5G wireless networks: A comprehensive survey," IEEE Communications Surveys & Tutorials, Vol. 18, No. 3, 1617-1655, 2016.
doi:10.1109/COMST.2016.2532458
5. Chettri, L. and R. Bera, "A comprehensive survey on Internet of Things (IoT) toward 5G wireless systems," IEEE Internet of Things Journal, Vol. 7, No. 1, 16-32, 2019.
doi:10.1109/JIOT.2019.2948888
6. Gorrepotu, R., N. S. Korivi, K. Chandu, and S. Deb, "Sub-1 GHz miniature wireless sensor node for IoT applications," Internet of Things, Vol. 1, 27-39, 2018.
doi:10.1016/j.iot.2018.08.002
7. Roges, R., P. K. Malik, and S. Sharma, "A compact CPW-fed log-periodic antenna for IoT applications," 2021 International Conference on Communication, Control and Information Sciences (ICCISc), Vol. 1, 1-{5, IEEE, June 2021.
8. Chouhan, S., D. K. Panda, and V. S. Kushwah, "Modified circular common element four-port multiple-input-multiple-output antenna using diagonal parasitic element," International Journal of RF and Microwave Computer-Aided Engineering, Vol. 29, No. 2, e21527, 2019.
doi:10.1002/mmce.21527
9. Kumar, P., S. Urooj, and A. Malibari, "Design and implementation of quad-element super-wideband MIMO antenna for IoT applications," IEEE Access, Vol. 8, 226697-226704, 2020.
doi:10.1109/ACCESS.2020.3045534
10. Kumar, N. and R. Khanna, "A compact multi-band multi-input multi-output antenna for 4G/5G and IoT devices using theory of characteristic modes," International Journal of RF and Microwave Computer-Aided Engineering, Vol. 30, No. 1, e22012, 2020.
doi:10.1002/mmce.22012
11. Maurya, N. K. and R. Bhattacharya, "Design of compact dual-polarized multiband MIMO antenna using near-field for IoT," AEU --- International Journal of Electronics and Communications, Vol. 117, 153091, 2020.
doi:10.1016/j.aeue.2020.153091
12. Moradi, A., R. Ngah, and M. Khalily, "Polarized diversity compact planar MIMO antenna for wireless access point applications," Progress In Electromagnetics Research C, Vol. 91, 115-127, 2019.
doi:10.2528/PIERC18101905
13. Malik, P., J. Lu, B. T. P. Madhav, G. Kalkhambkar, and S. Amit, Smart Antennas: Latest Trends in Design and Application, Springer, ISBN 978-3-030-76636-8, 2021, doi: 10.1007/978-3-030-76636-8.
14. Malik, P. K., Planar Antennas: Design and Applications, Taylor and Francis, ISBN 9781032034461, August 4, 2021.
15. Dkiouak, A., A. Zakriti, and M. El Ouahabi, "Design of a compact dual-band MIMO antenna with high isolation for WLAN and X-band satellite by using orthogonal polarization," Journal of Electromagnetic Waves and Applications, Vol. 34, No. 9, 1254-1267, 2020.
doi:10.1080/09205071.2019.1657504
16. Kiem, N. K. and D. N. Chien, "A transmission line decoupling technique for enhancement of port isolation of dual-band MIMO antennas," Journal of Electromagnetic Waves and Applications, Vol. 32, No. 10, 1195-1211, 2018.
doi:10.1080/09205071.2018.1426501
17. Kim, D. W. and S. Nam, "Systematic design of a multiport MIMO antenna with bilateral symmetry based on characteristic mode analysis," IEEE Transactions on Antennas and Propagation, Vol. 66, No. 3, 1076-1085, 2017.
doi:10.1109/TAP.2017.2787607
18. Yu, K., Y. Li, and X. Liu, "Mutual coupling reduction of a MIMO antenna array using 3-D novel meta-material structures," The Applied Computational Electromagnetics Society Journal (ACES), 758-763, 2018.
19. Khurshid, A., J. Dong, M. S. Ahmad, and R. Shi, "Optimized super-wideband MIMO antenna with high isolation for IoT applications," Micromachines, Vol. 13, No. 4, 514, 2022.
doi:10.3390/mi13040514
20. Rezapour, M., J. Rashed-Mohassel, A. Keshtkar, and M. Naser-Moghadasi, "Isolation enhancement of rectangular dielectric resonator antennas using wideband double slit complementary split ring resonators," International Journal of RF and Microwave Computer-Aided Engineering, Vol. 29, No. 7, e21746, 2019.
doi:10.1002/mmce.21746
21. Hu, W., L. Qian, L. Wen, X. Yang, and Y. Yin, "Compact dual-band antenna based on CRLH-TL for WWAN/LTE terminal applications," International Journal of RF and Microwave Computer-Aided Engineering, Vol. 29, No. 4, e21587, 2019.
doi:10.1002/mmce.21587
22. Sanad, M. and N. Hassan, "Orthogonally polarized MIMO LTE/5G terminal antennas for handsets and IoT applications," 2019 IEEE Radio and Wireless Symposium (RWS), 1-4, IEEE, January 2019.
23. Jha, K. R., B. Bukhari, C. Singh, G. Mishra, and S. K. Sharma, "Compact planar multistandard MIMO antenna for IoT applications," IEEE Transactions on Antennas and Propagation, Vol. 66, No. 7, 3327-3336, 2018.
doi:10.1109/TAP.2018.2829533
24. Chouhan, S., D. K. Panda, V. S. Kushwah, and P. K. Mishra, "Octagonal-shaped wideband MIMO antenna for human interface device and S-band application," International Journal of Microwave and Wireless Technologies, Vol. 11, No. 3, 287-296, 2019.
doi:10.1017/S1759078718001381