{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T00:02:33Z","timestamp":1774396953574,"version":"3.50.1"},"reference-count":23,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2019,8,31]],"date-time":"2019-08-31T00:00:00Z","timestamp":1567209600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Electronics"],"abstract":"<jats:p>A low-profile (0.21    \u03bb g     \u00d7 0.35    \u03bb g     \u00d7 0.02    \u03bb g    ) and a simply-structured frequency-switchable antenna with eight frequency choices is presented in this paper. The radiating structure (monopole) is printed on a 1.6-mm thicker, commercially-available substrate of FR-4 (    \u03f5 r     = 4.4, tan   \u03b4    = 0.020). Specifically, it uses three PIN diodes in the designated places to shift the resonant bands of the antenna. The antenna operates at four different modes depending on the ON and OFF states of the PIN diodes. While in each mode, the antenna covers two unique frequencies (Mode 1 = 1.8 and 3.29 GHz, Mode 2 = 2.23 and 3.9 GHz, Mode 3 = 2.4 and 4.55 GHz, and Mode 4 = 2.78 and 5.54 GHz). The performance results show that the proposed antenna scheme explores significant gain (&gt;1.5 dBi in all modes) and reasonable efficiency (&gt;82% in all modes) for each mode. Using a high-frequency structure simulator (HFSS), the switchable antenna is designed and optimized. The fabricated model along with the PIN diode and biasing network is tested experimentally to validate the simulation results. The proposed antenna may also be combined in compact and heterogeneous radio frequency (RF) front-ends because of its small geometry and efficient utilization of the frequency spectrum.<\/jats:p>","DOI":"10.3390\/electronics8090976","type":"journal-article","created":{"date-parts":[[2019,9,2]],"date-time":"2019-09-02T03:16:12Z","timestamp":1567394172000},"page":"976","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":46,"title":["Low-Profile Frequency Reconfigurable Antenna for Heterogeneous Wireless Systems"],"prefix":"10.3390","volume":"8","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8312-7087","authenticated-orcid":false,"given":"Amjad","family":"Iqbal","sequence":"first","affiliation":[{"name":"Centre For Wireless Technology, Faculty of Engineering, Multimedia University Cyberjaya, Selangor 63100, Malaysia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9096-4337","authenticated-orcid":false,"given":"Amor","family":"Smida","sequence":"additional","affiliation":[{"name":"Department of Medical Equipment Technology, College of Applied Medical Sciences, Majmaah University, AlMajmaah 11952, Saudi Arabia"},{"name":"Unit of Research in High Frequency Electronic Circuits and Systems, Faculty of Mathematical, Physical and Natural Sciences of Tunis, Tunis El Manar University, Tunis 2092, Tunisia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0018-8288","authenticated-orcid":false,"given":"Lway Faisal","family":"Abdulrazak","sequence":"additional","affiliation":[{"name":"Computer Science Department, Cihan University Slemani, Sulaimaniya 46002, Iraq"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5154-2382","authenticated-orcid":false,"given":"Omar A.","family":"Saraereh","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Hashemite University, Zarqa 13115, Jordan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0487-4015","authenticated-orcid":false,"given":"Nazih Khaddaj","family":"Mallat","sequence":"additional","affiliation":[{"name":"College of Engineering, Al Ain University (AAU), Al Ain 64141, UAE"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0440-8025","authenticated-orcid":false,"given":"Issa","family":"Elfergani","sequence":"additional","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1762-5915","authenticated-orcid":false,"given":"Sunghwan","family":"Kim","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering, University of Ulsan, Ulsan 44610, Korea"}]}],"member":"1968","published-online":{"date-parts":[[2019,8,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Elfergani, I., Hussaini, A.S., Rodriguez, J., and Abd-Alhameed, R. (2018). Antenna Fundamentals for Legacy Mobile Applications and Beyond, Springer.","DOI":"10.1007\/978-3-319-63967-3"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"859","DOI":"10.1017\/S1759078716000647","article-title":"Fork-shaped planar antenna for Bluetooth, WLAN, and WiMAX applications","volume":"9","author":"Kunwar","year":"2017","journal-title":"Int. J. Microw. Wirel. Technol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1017\/S1759078715001105","article-title":"Inverted L-slot triple-band antenna with defected ground structure for WLAN and WiMAX applications","volume":"9","author":"Kunwar","year":"2017","journal-title":"Int. J. Microw. Wirel. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"79","DOI":"10.2528\/PIERL17041203","article-title":"A compact frequency reconfigurable monopole antenna for Wi-Fi\/WLAN applications","volume":"68","author":"Iqbal","year":"2017","journal-title":"Prog. Electromagnet. Res."},{"key":"ref_5","first-page":"1611","article-title":"Design, fabrication and measurement of a compact, frequency reconfigurable, modified T-shape planar antenna for portable applications","volume":"12","author":"Iqbal","year":"2017","journal-title":"J. Electr. Eng. Technol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"4572","DOI":"10.1109\/TAP.2015.2456940","article-title":"Compact frequency reconfigurable antenna for LTE\/WWAN mobile handset applications","volume":"63","author":"Lee","year":"2015","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"958","DOI":"10.1002\/mop.30443","article-title":"A compact hexagonal slot dual band frequency reconfigurable antenna for WLAN applications","volume":"59","author":"Ali","year":"2017","journal-title":"Microw. Opt. Technol. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1016\/j.aeue.2017.07.028","article-title":"Design, fabrication and measurement of triple band frequency reconfigurable antennas for portable wireless communications","volume":"81","author":"Ullah","year":"2017","journal-title":"AEU-Int. J. Electron. Commun."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Khan, O.M., Raza, K., Shubair, R., and Islam, Q.U. (2018, January 19\u201322). Frequency Reconfigurable Implant Antenna for MICS and ISM Band Applications. Proceedings of the 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM). IEEE, Waterloo, ON, Canada.","DOI":"10.1109\/ANTEM.2018.8572932"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1760","DOI":"10.1109\/TAP.2007.898575","article-title":"Wideband reconfigurable rolled planar monopole antenna","volume":"55","author":"Ruvio","year":"2007","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.aeue.2017.05.015","article-title":"A quad-polarization and frequency reconfigurable square ring slot loaded microstrip patch antenna for WLAN applications","volume":"78","author":"Bharathi","year":"2017","journal-title":"AEU-Int. J. Electron. Commun."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1080\/03772063.2016.1261049","article-title":"Design and Measurement of Planar Monopole Antennas for Multi-Band Wireless Applications","volume":"63","author":"Shah","year":"2017","journal-title":"IETE J. Res."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Jin, G.P., Deng, C.H., Yang, J., Xu, Y.C., and Liao, S.W. (2019). A New Differentially-Fed Frequency Reconfigurable Antenna for WLAN and Sub-6GHz 5G Applications. IEEE Access.","DOI":"10.1109\/ACCESS.2019.2901760"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1109\/TAP.2018.2877301","article-title":"A Filtering Patch Antenna With Reconfigurable Frequency and Bandwidth Using F-Shaped Probe","volume":"67","author":"Hu","year":"2019","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1016\/j.aeue.2018.10.012","article-title":"Design and analysis of a hexa-band frequency reconfigurable antenna for wireless communication","volume":"98","author":"Shah","year":"2019","journal-title":"AEU-Int. J. Electron. Commun."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1080\/03772063.2017.1347072","article-title":"Design and Analysis of a Hexa-Band Frequency Reconfigurable Monopole Antenna","volume":"64","author":"Ullah","year":"2018","journal-title":"IETE J. Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"991","DOI":"10.1017\/S1759078718000776","article-title":"A multi-band switchable antenna for Wi-Fi, 3G Advanced, WiMAX, and WLAN wireless applications","volume":"10","author":"Ullah","year":"2018","journal-title":"Int. J. Microw. Wirel. Technol."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Singh, A., Goode, I., and Saavedra, C.E. (2019). A Multi-State Frequency Reconfigurable Monopole Antenna using Fluidic Channels. IEEE Antennas Wirel. Propag. Lett.","DOI":"10.1109\/LAWP.2019.2903781"},{"key":"ref_19","unstructured":"Balanis, C.A. (2016). Antenna Theory: Analysis and Design, John wiley & sons."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Iqbal, A., Smida, A., Mallat, N.K., Ghayoula, R., Elfergani, I., Rodriguez, J., and Kim, S. (2019). Frequency and pattern reconfigurable antenna for emerging wireless communication systems. Electronics, 8.","DOI":"10.3390\/electronics8040407"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"e21781","DOI":"10.1002\/mmce.21781","article-title":"A dual-band case-printed planar inverted-F antenna design with independent resonance control for wearable short range telemetric systems","volume":"29","author":"Bouazizi","year":"2019","journal-title":"Int. J. RF Microw. Comput.-Aided Eng."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2944","DOI":"10.1002\/mop.31447","article-title":"A dual-band implantable antenna with wide-band characteristics at MICS and ISM bands","volume":"60","author":"Basir","year":"2018","journal-title":"Microw. Opt. Technol. Lett"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"111135","DOI":"10.1109\/ACCESS.2019.2933913","article-title":"Electromagnetic Bandgap Backed Millimeter-Wave MIMO Antenna for Wearable Applications","volume":"7","author":"Iqbal","year":"2019","journal-title":"IEEE Access"}],"container-title":["Electronics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-9292\/8\/9\/976\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:15:41Z","timestamp":1760188541000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-9292\/8\/9\/976"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,8,31]]},"references-count":23,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2019,9]]}},"alternative-id":["electronics8090976"],"URL":"https:\/\/doi.org\/10.3390\/electronics8090976","relation":{},"ISSN":["2079-9292"],"issn-type":[{"value":"2079-9292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,8,31]]}}}