Meta-Wearable Antennas: Comparison
View Latest Version
Please note this is a comparison between Version 2 by Vicky Zhou and Version 1 by Sen YAN.

Wireless Body Area Network (WBAN) has attracted more and more attention in many sectors of society. As a critical component in these systems, wearable antennas suffer from several serious challenges, e.g., electromagnetic coupling between the human body and the antennas, different physical deformations, and widely varying operating environments, and thus, advanced design methods and techniques are urgently needed to alleviate these limitations. Recent developments have focused on the application of metamaterials in wearable antennas, which is a prospective area and has unique advantages.

 

  • Meta-Wearable Antennas
  • Wireless Body Area Network

1. Introduction

The emergence of the Internet has brought about tremendous changes in the communication of human. Wireless Body Area Network (WBAN) is one of the emerging technologies that is capable of enabling the communication between people and things. The development of body area network will result in a more context-aware and personalized communication in an intelligent wireless environment. WBAN is a network distributed around human, which is mainly used to detect and transmit physiological data of users, and cooperate with other networks to integrate the human into the overall network [1,2,3,4,5][1][2][3][4][5]. Through WBAN, communication and data synchronization can take place to complete the other communication networks, such as wireless sensor networks and mobile communication networks [1,2,6,7][1][2][6][7]. An important application of WBAN is in healthcare, where the body area network can transmit physiological information obtained from patients through various physiological sensors, such as blood pressure, blood sugar concentration, temperature, weight, and heartbeat [1,8,9,10][1][8][9][10] to the hospital’s medical monitoring equipment or the user’s personal mobile terminal [11]. In entertainment, a personal media device with high speed communication capability will enable augmented/virtual/mixed reality interaction with users, and wirelessly communicate with a device such as glasses [12] or headset [13]. In military applications, WBAN can provide personal location and mobile communications by a helmet [14,15][14][15] or a smart watch [16], etc. Figure 1 shows some typical applications of WBANs.

Figure 1. A Wireless Body Area Network (WBAN) and its applications [1,8,9,10,11,12,13,14,15,16][1][8][9][10][11][12][13][14][15][16].

Wearable antennas, as a vital component in WBAN systems, enable wireless communication with other devices on or off human bodies [17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. Compared to traditional antennas, the design of wearable antennas are facing many development bottlenecks: The electromagnetic coupling between the human body and the antenna, the varying physical deformations, the widely varying operating environments, and limitations of the fabrication process [27,28,29,30,31,32,33][27][28][29][30][31][32][33]. Further, the requirements for these wearable antennas include mechanical robustness, low-profile, lightweight, user comfort, fabrication simplicity [17,18,19,20,21,22[17][18][19][20][21][22][23][24],23,24], wideband [25,26][25][26], and multiband [20,27,29][20][27][29]. Thus, advanced design methods and techniques are urgently needed to address these problems and demands of wearable antennas. In recent years, there has been much literature reporting the fabric material manufacturing and treatment: Embroidered fabric material, sewn textile materials, woven fabrics, materials that are not woven, knitted fabrics, spun fabrics, braiding, coated fabrics through/lamination, printed fabrics, and chemically treated fabrics [18,19][18][19]. Furthermore, novel forms of flexible devices such as a fully inkjet-printed antenna [30[30][31],31], a polydimethylsiloxane (PDMS)-based antenna [21[21][22],22], embroidery [32], and a silicone-based antenna [33], and devices combined with new design methods such as substrate-integrated waveguide (SIW) technology [34], miniature feeding network [23], magneto-electric dipole [35], characteristic mode theory [27[27][36][37],36,37], textile-type indium gallium zinc oxide (IGZO)-based transistors [30], and thin-film transistor technologies [24], are presented for special application scenarios. Furthermore, miniaturization methods, such as inductor/capacitor-loaded antennas [38[38][39][40],39,40], loop antennas [41], and planar inverted F antennas (PIFA) [42,43][42][43] are involved in WBAN devices design, which is helpful to improve the design flexibility of the wearable antennas.

Metamaterials are widely defined as an artificial periodic structure, in which the length of the unit cell p is much smaller than the guided wavelength λg, with unusual properties not available in nature in the electromagnetic field [44,45,46][44][45][46]. The use of metamaterials has been hugely successful in adapting conventional antenna designs into a wearable form, including composite right/left-handed transmission lines (CRLH TLs) based antennas [45[45][46][47][48][49][50][51][52][53][54],46,47,48,49,50,51,52,53,54], zero-order antennas [55[55][56],56], metamaterials-inspired antennas [32[32][57],57], artificial magnetic conductor (AMC) [58[58][59][60][61],59,60,61], electromagnetic band-Gap (EBG) [62[62][63][64][65],63,64,65], and High-Impedance Surface (HIS) [16]. Wearable antennas have been designed with properties such as multiple band operations [48,55][48][55], multiple functionalities [66,67,68,69][66][67][68][69], and gain enhancement [70,71][70][71] while maintaining a low profile and compact size [56,72,73][56][72][73] due to the development of the electromagnetic metamaterials tech. Besides the methods above, characteristic mode theory is also an excellent analysis approach to study the metamaterials-based antennas [74,75[74][75][76],76], and it improves the efficiency of antennas design in WBAN. Several initial attempts have shown that it is an effective method to design wearable antennas based on metamaterials.

2. Reconfigurable Wearable Antennas with Metamaterials

The space limitation in wearable antennas and the need for these antennas to operate in multiple wireless standards is spurring the development of reconfigurable antennas. Yan et al. presented a pattern-reconfigurable wearable antenna based on a metamaterial structure, as shown in Figure 12Figure 2 [105][77]. This wearable antenna consists of three CRLH TL unit cells, which are capable of switching between the zero-order resonance and +1 resonance in the patch using switchable stubs connected using vias. The two states of this antenna operate in the same frequencies but radiate differently, providing a monopole-like or a patch like radiation pattern as shown in Figure 13Figure 3, and the performances detail are listed in Table Table 31.

Figure 12. Radiation pattern-reconfigurable wearable antenna based on metamaterial structure [105][77]. (a) The photo of the wearable antenna. (b) Two electrical field distributions at 2.45 GHz in z-direction. The first distribution is Patch mode (n = +1) and second one is monopole mode (n = 0). The arrows in the figures represent the direction of the equivalent magnetic current.

Figure 13. The radiation pattern of the antenna in [105][77]. Measured and simulated radiation patterns. (a) Monopole mode in xz-plane, (b) monopole mode in yz-plane, (c) patch mode in xz-plane, and (d) patch mode in yz-plane.

Table 31.

Performances among the reconfigurable wearable antennas with metamaterials.

Ref. Frequenncy

(GHz)		 Bandwidth Gain (dBi) Size (λ2) SAR (W/kg) Substrate (εr)
[105][77] 2.4 0.086 (State1)

0.055 (State2)		 2.9

4.5		 0.64 0.05

0.01		 Felt substrate

(1.3)
[106][78] 2.92 10% (2.64–2.94) −0.02 0.009 - Tortuous Cu mesh/PDMS (2.8)
[107][79] 2.45/3.3 * -

** 7%/3%		 2.6/0.6

6.2/3.0		 ***0.5 (@2.45) 2

0.29/-		 RO3003

(3)
* the antenna without metasurface; ** the antenna with metasurface; *** (@2.45) means that the λ is the wavelength in free space at 2.45 GHz.

Besides that, Jang et al. proposed a method to fabricate a small semitransparent and stretchable antenna using a stretchable micromesh structure, as shown in Figure 14Figure 4 [106][78]. This antenna consists of a 4.7 μm thick Cu mesh pattern and a PDMS layer as the substrate. The PDMS is flexible and optically transparent, and it can maintain the shape of a micromesh as well as protect the metal wire from mechanical damage when stretched. The increase in tensile strain reconfigures the resonant frequency of the antenna almost linearly from 2.46 to 2.94 GHz. However, this antenna suffers from low radiation efficiency due to the reduced surface currents flowing through the micromesh patch.

Figure 14. The photo of the mechanically reconfigurable electrically small antenna in [106][78]. The antenna made of flexible wire mesh and a frequency shift is generated in different stretch.

Next, a wearable reconfigurable antenna with AMC structure consisting of a folded slot and a stub was proposed in [107][79]. This antenna operates between a single and dual-band mode, with two orthogonal polarizations controlled by the ON/OFF states of the PIN diodes. When the PIN diode is in the ON state, the stub is symmetrical with respect to the CPW feed line and does not radiate. This results in a single operating frequency of the antenna. When the PIN switch is in the OFF state, the asymmetrical stub with respect to the feed line causes the current on the stub to be redirected, producing dipole-like radiation. Both the slot and the stub resonate with orthogonal polarizations.

3. Conclusions

The design of wearable antennas is rather different from the design of conventional antennas. The main challenge is to ensure that the designed wearable antenna still operates with minimal coupling to the human body and under different deformations. Nonetheless, several studies have proven that the integration of metasurfaces onto the antenna design based can significantly improve their performance. This review also highlighted the recent progress in the literature on metamaterial-based wearable antennas, including the classification of the main approaches in their integration. As for the wearable antennas based on CRLH TLs, there are electrically small antennas based on ZOR consisting of ENR, MNR, and DNR modes and dual-band patch antennas, and their electromagnetic property, single-negative, or double-negative material parameter, may exhibit exciting performances, which can be utilized flexibly for different WBAN applications. For the wearable antennas based on metasurface, two methodologies have been presented: One approach is that the zero reflection phase of the unit cell of AMC is design at the resonance frequency so that the feeding antenna can be placed on the AMC reflection plane, decreasing the profile of the wearable antenna Another one is derived from the principle of CRLH TLs that the reflector is as a radiator by exciting the metasurface, and the main merit of it is decrease the size of the wearable antenna dramatically. Finally, three reconfigurable wearable antennas were described briefly. In summary, the radiation properties of these antennas can be improved by using metamaterials as follows:

  • The radiation properties of wearable antennas can be enhanced by restraining the surface wave and the coupling between antennas and the human body.
  • A low-profile of a wearable antenna can be realized by using the zero-reflection phase available from metasurfaces such as AMC structures.
  • The bandwidth of wearable antennas can be broadened by loading reactive metasurfaces.
  • The direction of radiation and level of gain can be controlled by modification of the field distributions and propagation directions.

Nonetheless, with the various requirements of today’s wireless communication systems, it should be emphasized that there is not a single type of wearable antenna that is capable of meeting all of the requirements simultaneously. However, metamaterial-based wearable antennas have been demonstrated to be capable of significantly improve the performance of antennas when applied to the human body compared with traditional antennas. It is foreseeable that wearable antennas would endeavor towards miniaturization, multifunction, multi-band frequency, and broadband in the future, and metamaterials-based antennas, which have unique properties, provide a new approach for these goals. Thus, a deeper understanding of the operation of metamaterials will result in more applications of such structures in future WBAN antennas.

References

  1. Bariya, M.; Nyein, H.Y.Y.; Javey, A. Wearable sweat sensors. Nat. Electron. 2018, 1, 160–171.
  2. Januszkiewicz, Ł.; Di Barba, P.; Hausman, S. Optimal Design of Switchable Wearable Antenna Array for Wireless Sensor Networks. Sensors 2020, 20, 2795.
  3. El Gharbi, M.; Fernández-García, R.; Ahyoud, S.; Gil, I. A Review of Flexible Wearable Antenna Sensors: Design, Fabrication Methods, and Applications. Materials 2020, 13, 3781.
  4. Abd Rahman, N.H.; Yamada, Y.; Amin Nordin, M.S. Analysis on the Effects of the Human Body on the Performance of Electro-Textile Antennas for Wearable Monitoring and Tracking Application. Materials 2019, 12, 1636.
  5. Zhang, K.; Vandenbosch, G.A.E.; Yan, S. A Novel Design Approach for Compact Wearable Antennas Based on Metasurfaces. IEEE Trans. Biomed. Circuits Syst. 2020, 14, 918–927.
  6. Smida, A.; Iqbal, A.; Alazemi, A.J.; Waly, M.I.; Ghayoula, R.; Kim, S. Wideband Wearable Antenna for Biomedical Telemetry Applications. IEEE Access 2020, 8, 15687–15694.
  7. Tian, X.; Lee, P.M.; Tan, Y.J.; Wu, T.L.Y.; Yao, H.C.; Zhang, M.Y.; Li, Z.P.; Ng, K.A.; Tee, B.C.K.; Ho, J.S. Wireless body sensor networks based on metamaterial textiles. Nat. Electron. 2019, 2, 243–251.
  8. Abdi, A.; Ghorbani, F.; Aliakbarian, H.; Geok, T.K.; Rahim, S.K.A.; Soh, P.J. Electrically Small Spiral PIFA for Deep Implantable Devices. IEEE Access 2020, 8, 158459–158474.
  9. Alqadami, A.S.M.; Bialkowski, K.S.; Mobashsher, A.T.; Abbosh, A.M. Wearable Electromagnetic Head Imaging System Using Flexible Wideband Antenna Array Based on Polymer Technology for Brain Stroke Diagnosis. IEEE Trans. Biomed Circuits Syst. 2019, 13, 124–134.
  10. Harun Al Rasyid, M.U.; Lee, B.H.; Sudarsono, A. Wireless body area network for monitoring body temperature, heart beat and oxygen in blood. In Proceedings of the Intelligent Technology and Its Applications (ISITIA), Surabaya, Indonesia, 20–21 May 2015; pp. 95–98.
  11. Singh, M.; Jain, N. Performance and Evaluation of Smartphone Based Wireless Blood Pressure Monitoring System Using Bluetooth. IEEE Sens. J. 2016, 16, 8322–8328.
  12. Hong, S.; Kang, S.H.; Kim, Y.; Jung, C.W. Transparent and Flexible Antenna for Wearable Glasses Applications. IEEE Trans. Antennas Propag. 2016, 64, 2797–2804.
  13. Qu, L.; Zhang, R.; Kim, H. High-Sensitivity Ground Radiation Antenna System Using an Adjacent Slot for Bluetooth Headsets. IEEE Trans. Antennas Propag. 2015, 63, 5903–5907.
  14. Lee, H.; Yang, H.; Myeong, S.; Lee, K. Dual-band MNG patch antenna for smart helmet. Electron. Lett. 2018, 54, 1101–1102.
  15. Alqadami, A.S.M.; Trakic, A.; Stancombe, A.E.; Mohammed, B.; Bialkowski, K.; Abbosh, A. Flexible Electromagnetic Cap for Head Imaging. IEEE Trans. Biomed. Circuits Syst. 2020, 14, 1097–1107.
  16. Chen, Y.S.; Ku, T.Y. A Low-Profile Wearable Antenna Using a Miniature High Impedance Surface for Smartwatch Applications. IEEE Antennas Wirel. Propag. Lett. 2016, 15, 1144–1147.
  17. Gao, G.P.; Hu, B.; Wang, S.F.; Yang, C. Wearable Circular Ring Slot Antenna with EBG Structure for Wireless Body Area Network. IEEE Antennas Wirel. Propag. Lett. 2018, 17, 434–437.
  18. Stoppa, M.; Chiolerio, A. Wearable Electronics and Smart Textiles: A Critical Review. Sensors 2014, 14, 11957–11992.
  19. Almohammed, B.; Alyani, I.; Aduwati, S. Electro-textile wearable antennas in wireless body area networks: Materials, antenna design, manufacturing techniques, and human body consideration—A review. Textile Res. J. 2020.
  20. Paracha, K.N.; Rahim, S.K.A.; Soh, P.J.; Kamarudin, M.R.; Tan, K.G.; Lo, Y.C.; Islam, M.T. A Low Profile, Dual-band, Dual Polarized Antenna for Indoor/Outdoor Wearable Application. IEEE Access 2019, 7, 33277–33288.
  21. Simorangkir, R.B.V.B.; Kiourti, A.; Esselle, K.P. UWB Wearable Antenna with a Full Ground Plane Based on PDMS-Embedded Conductive Fabric. IEEE Antennas Wirel. Propag. Lett. 2018, 17, 493–496.
  22. Sayem, A.M.; Simorangkir, R.B.V.B.; Esselle, K.P.; Hashmi, R.M.; Liu, H.R. A Method to Develop Flexible Robust Optically Transparent Unidirectional Antennas Utilizing Pure Water, PDMS, and Transparent Conductive Mesh. IEEE Trans. Antennas Propag. 2020, 68, 6943–6952.
  23. Zhang, J.H.; Yan, S.; Vandenbosch, G.A.E. A Miniature Feeding Network for Aperture-Coupled Wearable Antennas. IEEE Trans. Antennas Propag. 2017, 65, 2650–2654.
  24. Myny, K. The development of flexible integrated circuits based on thin-film transistors. Nat. Electron. 2018, 1, 30–39.
  25. Yan, S.; Soh, P.J.; Vandenbosch, G.A.E. Wearable Ultrawideband Technology—A Review of Ultrawideband Antennas, Propagation Channels, and Applications in Wireless Body Area Networks. IEEE Access 2018, 6, 42177–42185.
  26. Poffelie, L.A.Y.; Soh, P.J.; Yan, S.; Vandenbosch, G.A.E. A High-Fidelity All-Textile UWB Antenna with Low Back Radiation for Off-Body WBAN Applications. IEEE Trans. Antennas Propag. 2016, 64, 757–760.
  27. Yoon, J.; Jeong, Y.; Kim, H.; Yoo, S.; Jung, H.S.; Kim, Y.; Hwang, Y.; Hyun, Y.; Hong, W.K.; Lee, B.H.; et al. Robust and stretchable indium gallium zinc oxide-based electronic textiles formed by cilia-assisted transfer printing. Nat. Commun. 2016, 7, 11477.
  28. Yan, S.; Volskiy, V.; Vandenbosch, G.A.E. Compact Dual-Band Textile PIFA for 433-MHz/2.4-GHz ISM Bands. IEEE Antennas Wirel. Propag. Lett. 2017, 16, 2436–2439.
  29. Hu, X.M.; Sen, Y.; Vandenbosch, G.A.E. Wearable Button Antenna for Dual-Band WLAN Applications with Combined on and off-Body Radiation Patterns. IEEE Trans. Antennas Propag. 2017, 65, 1384–1387.
  30. Carey, T.; Cacovich, S.; Divitini, G.; Ren, J.S.; Mansouri, A.; Kim, J.M.; Wang, C.X.; Ducati, C.; Sordan, R.; Torrisi, F. Fully inkjet-printed two-dimensional material field-effect heterojunctions for wearable and textile electronics. Nat. Commun. 2017, 8, 1202.
  31. Genovesi, S.; Costa, F.; Fanciulli, F.; Monorchio, A. Wearable Inkjet-Printed Wideband Antenna by Using Miniaturized AMC for Sub-GHz Applications. IEEE Antennas Wirel. Propag. Lett. 2016, 15, 1927–1930.
  32. Hao, J.; Leblanc, A.; Burgnies, L.; Djouadi, A.; Cochrane, C.; Rault, F.; Koncar, V.; Lheurette, E. Textile split ring resonator antenna integrated by embroidery. Electron. Lett. 2019, 55, 508–509.
  33. Quarfoth, R.; Zhou, Y.S.; Sievenpiper, D. Flexible Patch Antennas Using Patterned Metal Sheets on Silicone. IEEE Antennas Wirel. Propag. Lett. 2015, 14, 1354–1357.
  34. Yan, S.; Soh, P.J.; Vandenbosch, G.A.E. Dual-Band Textile MIMO Antenna Based on Substrate-Integrated Waveguide (SIW) Technology. IEEE Trans. Antennas Propag. 2015, 63, 4640–4647.
  35. Yan, S.; Soh, P.J.; Vandenbosch, G.A.E. Wearable Dual-Band Magneto-Electric Dipole Antenna for WBAN/WLAN Applications. IEEE Trans. Antennas Propag. 2015, 63, 4165–4169.
  36. Chen, J.; Berg, M.; Somero, V.; Amin, H.Y.; Prssinen, A. A Multiple Antenna System Design for Wearable Device Using Theory of Characteristic Mode. In Proceedings of the 12th European Conference on Antennas and Propagation, London, UK, 9–13 April 2018; pp. 1–5.
  37. Elias, B.B.Q.; Soh, P.J.; Al-Hadi, A.A.; Vandenbosch, G.A.E. Design of a compact, wideband, and flexible rhombic antenna using CMA for WBAN/WLAN and 5G applications. Int. J. Numer. Model. Electron. Netw. Devices Fields 2020, e2841.
  38. Yue, T.W.; Jiang, Z.H.; Werner, D.H. Compact, Wideband Antennas Enabled by Interdigitated Capacitor-Loaded Metasurfaces. IEEE Trans. Antennas Propag. 2016, 64, 1595–1606.
  39. Le, T.T.; Yun, T.Y. Miniaturization of a Dual-Band Wearable Antenna for WBAN Applications. IEEE Antennas Wirel. Propag. Lett. 2020, 19, 1452–1456.
  40. Yue, T.W.; Jiang, Z.H.; Werner, D.H. A Compact Metasurface-Enabled Dual-Band Dual-Circularly Polarized Antenna Loaded With Complementary Split Ring Resonators. IEEE Trans. Antennas Propag. 2019, 67, 794–803.
  41. Maleszka, T.; Pawel, K. Bandwidth properties of embroidered loop antenna for wearable applications. In Proceedings of the 3rd European Wireless Technology Conference, Paris, France, 27–28 September 2010.
  42. Casula, G.A.; Montisci, G. A Design Rule to Reduce the Human Body Effect on Wearable PIFA Antennas. Electronics 2019, 8, 244.
  43. Gao, G.P.; Yang, C.; Hu, B.; Zhang, R.F.; Wang, S.F. A Wide-Bandwidth Wearable All-Textile PIFA with Dual Resonance Modes for 5 GHz WLAN Applications. IEEE Trans. Antennas Propag. 2019, 67, 4206–4211.
  44. Caloz, C.; Itoh, T. Electromagnetic Metamaterials: Transmission Line Theory and Microwave Applications; Wiley: Hoboken, NJ, USA, 2005.
  45. Lai, A.; Caloz, C.; Itoh, T. Composite right/left-handed transmission line metamaterials. IEEE Microw. Mag. 2004, 5, 34–50.
  46. Sanada, A.; Caloz, C.; Itoh, T. Characteristics of the composite right/left-handed transmission lines. IEEE Antennas Wirel. Propag. Lett. 2004, 14, 68–70.
  47. Sun, K.P.; Han, S.; Choi, J.H.; Lee, J.K. Miniaturized Active Metamaterial Resonant Antenna with Improved Radiation Performance Based on Negative-Resistance-Enhanced CRLH Transmission Lines. IEEE Antennas Wirel. Propag. Lett. 2018, 17, 1162–1165.
  48. Ahdi Rezaeieh, S.; Antoniades, M.A.; Abbosh, A.M. Bandwidth and Directivity Enhancement of Loop Antenna by Nonperiodic Distribution of Mu-Negative Metamaterial Unit Cells. IEEE Trans. Antennas Propag. 2016, 64, 3319–3329.
  49. Ahdi Rezaeieh, S.; Antoniades, M.A.; Abbosh, A.M. Miniaturization of Planar Yagi Antennas Using Mu-Negative Metamaterial-Loaded Reflector. IEEE Trans. Antennas Propag. 2017, 65, 6827–6837.
  50. Park, B.; Lee, J. Circularly Polarized Antenna Based on Mu-Negative Transmission Line. In Proceedings of the 8th European Conference on Antennas Propagation, (EuCAP 2014), The Hague, The Netherlands, 6–11 April 2014; pp. 939–941.
  51. Ahdi Rezaeieh, S.; Antoniades, M.A.; Abbosh, A.M. Compact Wideband Loop Antenna Partially Loaded With Mu-Negative Metamaterial Unit Cells for Directivity Enhancement. IEEE Antennas Wirel. Propag. Lett. 2016, 15, 1893–1896.
  52. Jae-Hyun, P.; Young-Ho, R.; Jeong-Hae, L. Mu-Zero Resonance Antenna. IEEE Trans. Antennas Propag. 2010, 58, 1865–1875.
  53. Li, L.; Jia, Z.; Huo, F.F.; Han, W.Q. A Novel Compact Multiband Antenna Employing Dual-Band CRLH-TL for Smart Mobile Phone Application. IEEE Antennas Wirel. Propag. Lett. 2013, 12, 1688–1691.
  54. Lee, H.M. A Compact Zeroth-Order Resonant Antenna Employing Novel Composite Right/Left-Handed Transmission-Line Unit-Cells Structure. IEEE Antennas Wirel. Propag. Lett. 2011, 10, 1377–1380.
  55. Xiong, J.; Lin, X.Q.; Yu, Y.F.; Tang, M.C.; Xiao, S.Q.; Wang, B.Z. Novel Flexible Dual-Frequency Broadside Radiating Rectangular Patch Antennas Based on Complementary Planar ENZ or MNZ Metamaterials. IEEE Trans. Antennas Propag. 2012, 60, 3958–3961.
  56. Park, J.-H.; Ryu, Y.-H.; Lee, J.-G.; Lee, J.-H. Epsilon Negative Zeroth-Order Resonator Antenna. IEEE Trans. Antennas Propag. 2007, 55, 3710–3712.
  57. Yan, S.; Soh, P.J.; Vandenbosch, G.A.E. Compact All-Textile Dual-Band Antenna Loaded With Metamaterial-Inspired Structure. IEEE Antennas Wirel. Propag. Lett. 2015, 14, 1486–1489.
  58. Yan, S.; Soh, P.J.; Vandenbosch, G.A.E. Wearable dual-band composite right/left-handed waveguide textile antenna for WLAN applications. Electron. Lett. 2014, 50, 424–426.
  59. Saleem, M.; Li, X.-L. Low Scattering Microstrip Antenna Based on Broadband Artificial Magnetic Conductor Structure. Materials 2020, 13, 750.
  60. Cook, B.S.; Shamim, A. Utilizing Wideband AMC Structures for High-Gain Inkjet-Printed Antennas on Lossy Paper Substrate. IEEE Antennas Wirel. Propag. Lett. 2013, 12, 76–79.
  61. Raad, H.R.; Abbosh, A.I.; Al-Rizzo, H.M.; Rucker, D.G. Flexible and Compact AMC Based Antenna for Telemedicine Applications. IEEE Trans. Antennas Propag. 2013, 61, 524–531.
  62. Ashyap, A.Y.I.; Abidin, Z.Z.; Dahlan, S.H.; Majid, H.A.; Shah, S.M.; Kamarudin, M.R.; Alomainy, A. Compact and Low-Profile Textile EBG-Based Antenna for Wearable Medical Applications. IEEE Antennas Wirel. Propag. Lett. 2017, 16, 2550–2553.
  63. Abirami, B.S.; Sundarsingh, E.F. EBG-Backed Flexible Printed Yagi–Uda Antenna for On-Body Communication. IEEE Trans. Antennas Propag. 2017, 65, 3762–3765.
  64. Abbasi, M.A.B.; Nikolaou, S.; Antoniades, M.A.; Stevanovic, M.N.; Vryonides, P. Compact EBG-Backed Planar Monopole for BAN Wearable Applications. IEEE Trans. Antennas Propag. 2017, 65, 453–463.
  65. El Atrash, M.; Abdalgalil, O.F.; Mahmoud, I.S.; Abdalla, M.A.; Zahran, S.R. Wearable high gain low SAR antenna loaded with backed all-textile EBG for WBAN applications. IET Microw. Antennas Propag. 2020, 14, 791–799.
  66. Ali Esmail, B.; Majid, H.A.; Zainal Abidin, Z.; Haimi Dahlan, S.; Himdi, M.; Dewan, R.; Kamal, A.; Rahim, M.; Al-Fadhali, N. Reconfigurable Radiation Pattern of Planar Antenna Using Metamaterial for 5G Applications. Materials 2020, 13, 582.
  67. Wang, L.B.; See, K.Y.; Zhang, J.W.; Salam, B.; Lu, A.C.W. Ultrathin and Flexible Screen-Printed Metasurfaces for EMI Shielding Applications. IEEE Trans. Electromagn. Compat. 2011, 53, 700–705.
  68. Gajibo, M.M.; Rahim, M.K.A.; Bala, B.D. Reconfigurable epsilon negative metamaterial antenna. In Proceedings of the 2014 IEEE Asia-Pacific Conference on Applied Electromagnetics (APACE), Johor Bahru, Malaysia, 8–10 December 2014; pp. 265–267.
  69. Senior, D.E.; Yoon, Y. Dual Band Antenna Using the Substrate Integrated Waveguide As An Epsilon Negative Transmission Line. In Proceedings of the 2012 IEEE International Symposium on Antennas Propagation, Chicago, IL, USA, 8–14 July 2012; pp. 1–2.
  70. Das, G.K.; Basu, S.; Mandal, B.; Mitra, D.; Augustine, R.; Mitra, M. Gain-enhancement technique for wearable patch antenna using grounded metamaterial. IET Microw. Antennas Propag. 2020, 14, 2045–2052.
  71. Cao, Y.F.; Cai, Y.; Cao, W.Q.; Xi, B.K.; Qian, Z.P.; Wu, T.; Zhu, L. Broadband and High-Gain Microstrip Patch Antenna Loaded With Parasitic Mushroom-Type Structure. IEEE Antennas Wirel. Propag. Lett. 2019, 18, 1405–1409.
  72. Jang, S.; Lee, B. Meta-Structured One-Unit-Cell Epsilon Negative Antenna. Microw. Opt. Technol. Lett. 2009, 51, 2991–2994.
  73. Alu, A.; Engheta, N. Pairing an epsilon-negative slab with a mu-negative slab: Resonance, tunneling and transparency. IEEE Trans. Antennas Propag. 2003, 51, 2558–2571.
  74. Wen, D.L.; Hao, Y.; Munoz, M.O.; Wang, H.Y.; Zhou, H. A Compact and Low-Profile MIMO Antenna Using a Miniature Circular High-Impedance Surface for Wearable Applications. IEEE Trans. Antennas Propag. 2018, 66, 96–104.
  75. Gao, G.P.; Zhang, R.F.; Geng, W.F.; Meng, H.J.; Hu, B. Characteristic Mode Analysis of a Nonuniform Metasurface Antenna for Wearable Applications. IEEE Antennas Wirel. Propag. Lett. 2020, 19, 1355–1359.
  76. Pei, R.; Leach, M.P.; Lim, E.G.; Wang, Z.; Song, C.Y.; Wang, J.C.; Zhang, W.Z.; Jiang, Z.Z.; Huang, Y. Wearable EBG-Backed Belt Antenna for Smart On-Body Applications. IEEE Trans. Ind. Inform. 2020, 16, 7177–7189.
  77. Yan, S.; Vandenbosch, G.A.E. Radiation Pattern-Reconfigurable Wearable Antenna Based on Metamaterial Structure. IEEE Antennas Wirel. Propag. Lett. 2016, 15, 1715–1718.
  78. Jang, T.; Zhang, C.; Youn, H.; Zhou, J.; Guo, L.J. Semitransparent and Flexible Mechanically Reconfigurable Electrically Small Antennas Based on Tortuous Metallic Micromesh. IEEE Trans. Antennas Propag. 2017, 65, 150–158.
  79. Saeed, S.M.; Balanis, C.A.; Birtcher, C.R.; Durgun, A.C.; Shaman, H.N. Wearable Flexible Reconfigurable Antenna Integrated With Artificial Magnetic Conductor. IEEE Antennas Wirel. Propag. Lett. 2017, 16, 2396–2399.
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)
Video Production Service
Feedback