Received November 3, 2017, accepted December 5, 2017, date of publication December 25, 2017, date of current version March 9, 2018. Digital Object Identifier 10.1109/ACCESS.2017.2787018 Textile Antenna With Simultaneous Frequency and Polarization Reconfiguration for WBAN SHAKHIRUL MAT SALLEH 1 , MUZAMMIL JUSOH 2 , (Member, IEEE), ABDUL HAFIIZH ISMAIL 1 , MUHAMMAD RAMLEE KAMARUDIN 3 , (Senior Member, IEEE), PHILIP NOBLES 3 , MOHAMAD KAMAL A. RAHIM 4 , (Senior Member, IEEE), THENNARASAN SABAPATHY 2 , MOHAMED NASRUN OSMAN 2 , MOHD ILMAN JAIS 2 , AND PING JACK SOH 2 , (Senior Member, IEEE) 1 Faculty of Engineering Technology, Department of Electronic Engineering Technology, Universiti Malaysia Perlis , Padang Besar 02100, Malaysia 2 Bioelectromagnetics Research Group, School of Computer and Communication Engineering, Universiti Malaysia Perlis, Arau 02600, Malaysia 3 Centre for Electronic Warfare Information and Cyber, Cranﬁeld Defence and Security, Cranﬁeld University, Defence Academy of the United Kingdom, Shrivenham SN6 8LA, U.K. 4 Advanced RF and Microwave Research Group, Communication Engineering Department, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, Skudai 81310, Malaysia Corresponding author: Muhammad Ramlee Kamarudin (ramlee.kamarudin@cranﬁeld.ac.uk) ABSTRACT This paper proposes the design of a reconﬁgurable circularly polarized textile antenna. The circular polarization feature in the proposed antenna is generated by the edge truncation of a rectangular patch and the incorporation of a slotted ground plane, whilst the frequency reconﬁgurability feature is realized by slot size modiﬁcation via the use of three embedded RF p-i-n diode switches. Consequently, the antenna operation can be switched between six frequencies (1.57, 1.67, 1.68, 2.43, 2.50, and 2.55 GHz) depending on the seven switch conﬁgurations. The proposed antenna is validated experimentally to be operable within the WBAN, WLAN, and GPS range in a compact and wearable format, with gains of up to 4.8 dBi. INDEX TERMS Circularly polarized antenna, reconﬁgurable antenna, textile antenna. I. INTRODUCTION A reconﬁgurable antenna is deﬁned as an antenna with the capability to reconﬁgure one or more characteristic such as frequency, polarization and/or pattern in order to ful- ﬁll a speciﬁed requirement. Such antennas are capable of offering ﬂexible operation across different frequency bands using a single hardware which is compact, ﬂexible, and cost- effective without compromising performance. In recent years, frequency-reconﬁgurable antennas have received attention among the researcher and industry communities, especially for future wireless communication systems. Such oper- ation of frequency reconﬁgurable antenna is potentially capable to reduce the size of front end system and also intended for performances improvement, especially to mini- mize interference with other wireless system and maximizing throughput [1]. Generally, the resonant frequency of an antenna is deter- mined by the effective length of the radiator. There are sev- eral methods of switching that may be used to control the effective length such as; varying the patch [2], [3]; a reconﬁg- urable matching network [4]; changing the current ﬂow [5]; mechanical conﬁguring using a metasurface [6]; and varying the length of the slot [7]. A reconﬁgurable monopole patch antenna proposed in [2] is capable of switching between up to eight different fre- quency bands using four PIN diodes. These RF switches are used to connect the main patch to four different smaller patches to enable the total radiating area of the antenna. Meanwhile, the antenna in [4] proposed a reconﬁgurable matching network using only two PIN diodes. As a result, three different frequencies bands can be realized. However, such method consumes more space for the intended matching and allows limited frequency reconﬁguration. The current ﬂow modiﬁcation technique is described in a reconﬁgurable cedar-shaped microstrip antenna presented in [5]. Frequency re-conﬁgurability is controlled via six RF switches placed on the slits, hence altering the current ﬂow of the cedar-shaped radiator. While copper strips are used to represent switches in this work, greater complexity is expected when this antenna is implemented using PIN diodes. Another alternative to embedded switching circuits for the purpose of enabling frequency re-conﬁgurability is by using metasurfaces [6]. 7350 2169-3536  2017 IEEE. Translations and content mining are permitted for academic research only. Personal use is also permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information. VOLUME 6, 2018