{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T21:17:07Z","timestamp":1777929427346,"version":"3.51.4"},"reference-count":32,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2022,7,25]],"date-time":"2022-07-25T00:00:00Z","timestamp":1658707200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100010418","name":"ICT R&amp;D program of MSIT\/IITP","doi-asserted-by":"publisher","award":["2019-0-00102"],"award-info":[{"award-number":["2019-0-00102"]}],"id":[{"id":"10.13039\/501100010418","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This paper presents the design and realization of a flexible and frequency-reconfigurable antenna with harmonic suppression for multiple wireless applications. The antenna structure is derived from a quarter-wave monopole by etching slots. Afterward, the high-order unwanted harmonics are eliminated by adding a filtering stub to the feedline to avoid signal interference. Lastly, frequency reconfigurability is achieved using pin diodes by connecting and disconnecting the stubs and the rectangular patch. The antenna is fabricated on the commercially available thin (0.254 mm) conformal substrate of Rogers RT5880. The proposed antenna resonates (|S11| &lt; \u201310 dB) at five different reconfigurable bands of 3.5 GHz (3.17\u20133.82 GHz), 2.45 GHz (2.27\u20132.64 GHz), 2.1 GHz (2.02\u20132.29 GHz), 1.9 GHz (1.81\u20132.05 GHz), and 1.8 GHz (1.66\u20131.93 GHz), which are globally used for 5G sub-6 GHz in industrial, medical, and scientific (ISM) bands, 4G long-term evolution (LTE) bands, and global system for mobile communication (GSM) bands. The simulated and measured results show that the antenna offers excellent performance in terms of good impedance matching with controllable resonant bands, high gain (&gt;2 dBi), stable radiation patterns, and efficiency (&gt;87%). Moreover, the conformal analysis shows that the antenna retains its performance both in flat and bending conditions, making it suitable for flexible electronics. In addition, the antenna is compared with the state-of-the-art works for similar applications to show its potential for the targeted band spectrums.<\/jats:p>","DOI":"10.3390\/s22155558","type":"journal-article","created":{"date-parts":[[2022,7,26]],"date-time":"2022-07-26T00:17:27Z","timestamp":1658794647000},"page":"5558","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":29,"title":["A Frequency-Reconfigurable Filtenna for GSM, 4G-LTE, ISM, and 5G Sub-6 GHz Band Applications"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4397-4211","authenticated-orcid":false,"given":"Wahaj Abbas","family":"Awan","sequence":"first","affiliation":[{"name":"Department of Information and Communication Engineering, Chungbuk National University, Cheongju 28644, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9730-4622","authenticated-orcid":false,"given":"Niamat","family":"Hussain","sequence":"additional","affiliation":[{"name":"Department of Smart Device Engineering, Sejong University, Seoul 05006, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sunggoo","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Information and Communication Engineering, Chungbuk National University, Cheongju 28644, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nam","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Information and Communication Engineering, Chungbuk National University, Cheongju 28644, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,7,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"020003","DOI":"10.1063\/5.0074088","article-title":"Review on communication technologies in telecommunications from conventional telephones to smart phones","volume":"2407","author":"Kolluru","year":"2021","journal-title":"AIP Conf. Proc."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"64","DOI":"10.26866\/jees.2021.21.1.64","article-title":"Harmonic dual-band diode mixer for the X-and K-bands","volume":"21","author":"Park","year":"2021","journal-title":"J. Electromagn. Eng. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Chowdhury, M.Z., Shahjalal, M., Hasan, M.K., and Jang, Y.M. (2019). The role of optical wireless communication technologies in 5G\/6G and IoT solutions: Prospects, directions, and challenges. Appl. Sci., 9.","DOI":"10.3390\/app9204367"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"316","DOI":"10.26866\/jees.2021.4.r.39","article-title":"Compact tri-band bandpass filter based on asymmetric step impedance resonators for WiMAX and RFID systems","volume":"21","author":"Basit","year":"2021","journal-title":"J. Electromagn. Eng. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Abbas, A., Hussain, N., Jeong, M.-J., Park, J., Shin, K.S., Kim, T., and Kim, N. (2020). A Rectangular Notch-Band UWB Antenna with Controllable Notched Bandwidth and Centre Frequency. Sensors, 20.","DOI":"10.3390\/s20030777"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"425","DOI":"10.26866\/jees.2021.5.r.51","article-title":"Simple patch antenna with filtering function using two U-slots","volume":"21","author":"Sung","year":"2021","journal-title":"J. Electromagn. Eng. Sci."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Wu, K., Andrew Zhang, J., Huang, X., Guo, Y.J., Nguyen, D.N., Kekirigoda, A., and Hui, K.P. (2022). Analog-domain suppression of strong interference using a hybrid antenna array. Sensors, 22.","DOI":"10.3390\/s22062417"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Ni, C., Wen, B., Wu, W., and Ren, P. (2022). Wideband filtering slot antenna design with stable gain using characteristic mode analysis. Sensors, 22.","DOI":"10.3390\/s22072780"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Liu, J., Liu, M., Bai, Y., Zhang, J., Liu, H., and Zhu, W. (2020). Recent progress in flexible wearable sensors for vital sign monitoring. Sensors, 20.","DOI":"10.3390\/s20144009"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Mohamadzade, B., Simorangkir, R.B.V.B., Maric, S., Lalbakhsh, A., Esselle, K.P., and Hashmi, R.M. (2020). Recent developments and state of the art in flexible and conformal reconfigurable antennas. Electronics, 9.","DOI":"10.3390\/electronics9091375"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1695","DOI":"10.1109\/TCPMT.2018.2848459","article-title":"Inkjet printing of wideband stacked microstrip patch array antenna on ultrathin flexible substrates","volume":"8","author":"Li","year":"2018","journal-title":"IEEE Trans. Compon. Packag. Manuf. Technol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1373","DOI":"10.1109\/LAWP.2015.2406391","article-title":"Quad-band CPW-fed monopole antenna based on flexible pentangle-loop radiator","volume":"14","author":"Liu","year":"2015","journal-title":"IEEE Antennas Wirel. Propag. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Al-Adhami, A., and Ercelebi, E. (2021). A flexible metamaterial based printed antenna for wearable biomedical applications. Sensors, 21.","DOI":"10.3390\/s21237960"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Wissem, E.L., Sfar, I., Osman, L., and Ribero, J.M. (2021). A textile EBG-based antenna for future 5G-IoT millimeter-wave applications. Electronics, 10.","DOI":"10.3390\/electronics10020154"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"6175","DOI":"10.1109\/TAP.2021.3069422","article-title":"A conformal, dynamic pattern-reconfigurable antenna using conductive textile-polymer composite","volume":"69","author":"Mohamadzade","year":"2021","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Agarwal, S., Masotti, D., Nikolaou, S., and Costanzo, A. (2021). Conformal design of a high-performance antenna for energy-autonomous UWB communication. Sensors, 21.","DOI":"10.3390\/s21175939"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1049\/el.2015.3060","article-title":"Diode-switched thermal-transfer printed antenna on flexible substrate","volume":"52","author":"Kgwadi","year":"2016","journal-title":"Electron. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2396","DOI":"10.1109\/LAWP.2017.2720558","article-title":"Wearable flexible reconfigurable antenna integrated with artificial magnetic conductor","volume":"16","author":"Saeed","year":"2017","journal-title":"IEEE Antennas Wirel. Propag. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1109\/TAP.2017.2772036","article-title":"A method to realize robust flexible electronically tunable antennas using polymer-embedded conductive fabric","volume":"66","author":"Simorangkir","year":"2017","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1979","DOI":"10.1109\/LAWP.2016.2547338","article-title":"Inkjet-printed flexible reconfigurable antenna for conformal WLAN\/WiMAX wireless devices","volume":"15","author":"Saeed","year":"2016","journal-title":"IEEE Antennas Wirel. Propag. Lett."},{"key":"ref_21","first-page":"22401","article-title":"Semicircular shape hybrid reconfigurable antenna on jute textile for ISM, Wi-Fi, Wi-MAX, and W-LAN applications","volume":"30","author":"Sandeep","year":"2020","journal-title":"Int. J. RF Microw. Comp.-Aided Eng."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"194497","DOI":"10.1109\/ACCESS.2020.3033502","article-title":"A compact grounded asymmetric coplanar strip-fed flexible multiband reconfigurable antenna for wireless applications","volume":"8","author":"Sreelakshmi","year":"2020","journal-title":"IEEE Access"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1946","DOI":"10.1002\/mop.31278","article-title":"A wideband printed slot antenna with harmonic suppression","volume":"60","author":"Li","year":"2018","journal-title":"Microw. Opt. Technol. Lett."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"977","DOI":"10.1017\/S1759078716001082","article-title":"2.45-GHz wideband harmonic rejection rectenna for wireless power transfer","volume":"9","author":"Kang","year":"2017","journal-title":"Int. J. Microw. Wirel. Technol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2459","DOI":"10.1109\/LAWP.2018.2877974","article-title":"Compact ring slot antenna with harmonic suppression","volume":"17","author":"Li","year":"2018","journal-title":"IEEE Antennas Wirel. Propag. Lett."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"45","DOI":"10.2528\/PIERL18080603","article-title":"Harmonic suppressed compact stepped impedance uniplanar dipole antenna for WLAN applications","volume":"79","author":"Mani","year":"2018","journal-title":"Prog. Electromagn. Res. Lett."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1228","DOI":"10.1109\/LAWP.2019.2913170","article-title":"A dual-polarized frequency-reconfigurable low-profile antenna with harmonic suppression for 5G application","volume":"18","author":"Nie","year":"2019","journal-title":"IEEE Antennas Wirel. Propag. Lett."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Almegbel, K.A., Saeed, S.M., Shaman, H.N., Balanis, C.A., and Alomar, W.A. (2018, January 8\u201313). Flexible reconfigurable i-shaped folded slot antenna for wireless devices. Proceedings of the IEEE International Symposium on Antennas and Propagation & USNC\/URSI National Radio Science Meeting, Boston, MA, USA.","DOI":"10.1109\/APUSNCURSINRSM.2018.8608557"},{"key":"ref_29","unstructured":"(2022, May 10). Rogers Corporation. Available online: https:\/\/www.rogerscorp.com."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"963","DOI":"10.1049\/el.2015.1056","article-title":"Compact planar UWB MIMO antenna with on-demand WLAN rejection","volume":"51","author":"Khan","year":"2015","journal-title":"Electron. Lett."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1049\/iet-map.2019.0401","article-title":"Low-profile dual-band antenna with on-demand beam switching capabilities","volume":"14","author":"Iqbal","year":"2020","journal-title":"IET Microw. Antennas Propag."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1151","DOI":"10.1109\/TAP.2019.2938668","article-title":"A compact frequency-reconfigurable antenna with independent tuning for hand-held wireless devices","volume":"68","author":"Subbaraj","year":"2019","journal-title":"IEEE Trans. Antennas Propag."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/15\/5558\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:56:19Z","timestamp":1760140579000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/15\/5558"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,7,25]]},"references-count":32,"journal-issue":{"issue":"15","published-online":{"date-parts":[[2022,8]]}},"alternative-id":["s22155558"],"URL":"https:\/\/doi.org\/10.3390\/s22155558","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,7,25]]}}}