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Proposed in this paper is a new configuration for a quad-band antenna based on using a metamaterial-inspired defected ground structure. The presented structure is introduced as a new modified metamaterial Complementary Split Ring Resonator (CSRR) with a compact electrical size. The new modified CSRR has been employed in Composite Right/Left-Handed (CRLH) transmission line configuration for ultra-size reduction. Validation for the particle small size is introduced and the detailed analysis for the NRI characteristics has been discussed by extracting the cell constitutive parameters. Hence, a multi-band antenna is designed based on using only one cell of the proposed NRI-TL. Subsequently, a small multi-band antenna is presented for different multi-band functionalities and different radiation properties. The antenna displays quad-resonances at 1.78 GHz, with the typical omnidirectional radiation pattern, 3.28 GHz, 4 GHz, and 4.3 GHz, with the directive broadside radiation properties. The proposed antenna footprint is 10 × 10 cm2, which exhibits a size reduction of up to 80% in comparison with a rectangular patch antenna operating at the lowest frequency band. [ABSTRACT FROM AUTHOR]

A dual-band, low profile, high gain, and low specific absorption rate (SAR) triangular slotted monopole antenna backed with a $4\times 4$ artificial magnetic conductor (AMC) array is presented for wireless body area network (WBAN) applications. The antenna is printed on a Rogers ULTRALAM 3850 substrate, whereas the AMC array is printed on a RO3003 substrate. The design operates at 3.5 GHz, for WiMAX wireless applications, and at 5.8 GHz for the ISM Band. The proposed antenna preserved the dual-band resonance and exhibited acceptable gain and SAR at a separation of 15 mm from the human body model. To reduce such separation and achieve enhancements to gain and SAR, an AMC array was utilized. In free space, gain enhancements by 6.8 and 3.7 dBi were achieved at both frequencies, respectively. Furthermore, over a gap of 1 mm from the human body, gain enhancements by 23.3 and 13.9 dBi were achieved at both frequencies, respectively. In addition, SAR reductions by almost 99% were attained. The antenna was fabricated and measured where a very good agreement was observed between simulated and measured results, with and without the incorporated AMC array. With such results, the proposed design can be highly recommended for wearable medical applications, specifically for diabetic patients. [ABSTRACT FROM AUTHOR]

This paper presents analysis and experimental measurements of CPW and microstrip compact monopole antennas loaded with resonator circuits inspired from simplified half-mode composite right / left-handed unit cell. The antennas were designed to have a typical omnidirectional radiation pattern. The CPW fed dual-band antenna resonates at 2.4 and 5.8 GHz, respectively. The antenna size is 20 × 30 mm2 and the radiator patch is only 25% at 2.4 GHz and 60% 5.8 GHz in comparison with a conventional patch antenna. The microstrip triple-band antenna covers the frequency bands from 2 to 2.4 GHz, 5.4 to 6 GHz and 6.8 to 8 GHz. The antenna size is 28 × 25 mm2 which is less than 25% at lower frequency band compared to the size of the conventional patch antenna. Detailed theoretical and full-wave analysis is presented and experimental results demonstrate a good agreement between the measured and the simulated. The suggested antennas can be employed for compact size and multi-band functionalities in wireless applications. The loading technique can be adapted for more frequency bands. [ABSTRACT FROM AUTHOR]

This article presents a new small size dual band metamaterial antenna. The antenna is realized using a single cell of a suggested modified version of composite right left handed transmission line terminated by a hybrid capacitive loading with short circuit termination. The hybrid termination leads to decrease the size of the antenna whereas the modified composite right left handed cell configuration leads to introduce dual band antenna functionality at 2.5 and 2.92 GHz. The antenna size is only 31 × 26 mm2. Compared to, single band, non-selective, conventional patch antenna, the size of the proposed antenna is only 9 and 11.5% at the two former frequencies, respectively. Despite the small size, the antenna gain is more than 3.5 dBi at the two operating frequencies. Moreover, the antenna has a high roll off beyond the operating frequency band which leads to high selective characteristics. The antenna can suppress 100% of the nearby signal power beyond its bands by 300 MHz at lower band and 200 MHz at upper band. The antenna design is discussed; the full wave simulation and experimental measurements are introduced for validating the results. [ABSTRACT FROM AUTHOR]

ABSTRACT This study presents the design of an electrically small metamaterial antenna with dual-band characteristics for WLAN and WiMAX applications with coplanar ground. The proposed antenna consists of stepped-impedance closed ring resonator (SICRR) and a small rectangular patch which is designed by etching a split ring resonator (SRR) from a rectangular patch which is turn fed through main feed. Such metamaterial composite exhibits dual-band behavior with first band operating at 2.45 GHz with an impedance bandwidth (| S11| < −10 dB) of 8.16% while second band is resonant at 3.37 GHz having an impedance bandwidth of 23.74% respectively. The proposed antenna is designed specifically to operate at WLAN (2.5 GHz) and WiMAX (3.5 GHz) and shows compact nature with a radiating element size of 0.16λo × 0.097λo × 0.013λo. Equivalent circuit of proposed antenna has also been modeled which is in good agreement with the antenna behavior. The proposed structure shows end fire radiation pattern in H-plane and omni-directional radiation pattern in E-plane at all operating frequencies with low cross polarization levels. The prototype has been fabricated and experimentally tested to validate the simulation results which are in good agreement with the measured results. The antenna is suitable for use in Bluetooth, WLAN and WiMAX. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:573-578, 2017 [ABSTRACT FROM AUTHOR]

In this paper, we introduce a compact dual-band two-element array antenna in a substrate integrated waveguide (SIW) configuration for C-band applications. A new geometry based on an asymmetric composite right–left-handed transmission line cells was suggested for the single antenna element. The proposed geometry has the advantage of having arbitrary dual-frequency design. The array elements are fed with a wideband SIW impedance transformer. The results indicate that the proposed antenna element size is only 15 × 12.8 mm2, which approximately represents up to 70% size reduction at similar frequencies. The radiation properties of the array antenna have broadside radiation pattern at the two bands. The detailed analytical design explanation, full wave simulations, and experimental measurements are introduced. [ABSTRACT FROM AUTHOR]

This article presents a compact meta-surface (MS) based antenna with dual-band operation for 5G applications. The MS-based antenna consists of a layer of MSs on the top of a single-band microstrip patch antenna. The dual-band operation is achieved by adding the MS layer at a height of 0.089λ 0 , where λ 0 is the free space wavelength at the lower resonant frequency. The patch antenna is designed on a 21 mm × 20 mm × 0.508 mm substrate. The MS is comprised of two metallic layers printed on the top and bottom of a 1.575 mm Rogers 5880 substrate. The overall thickness of the proposed antenna is 0.27λ 0. The proposed antenna is fabricated and tested. The configuration achieves dual-band features with bandwidth, and gain of 1 GHz, and 10 dBi at 26.4 GHz, 800 MHz, and 9.6 dBi at 27.6 GHz, respectively. Also, a high radiation efficiency of 91.2 % is achieved at the frequency bands. [ABSTRACT FROM AUTHOR]

A flexible paper based and dual-band antenna is designed for UMTS service (1.9 GHz) and WiMAX services (5.8 GHz). Flexible paper is used as a substrate for the printed antenna. Expanded graphite ink is used to enable printing the antenna on the substrate. The antenna has been designed, simulated, fabricated, and measured. Steps of preparing the conductive printed ink and fabrication of the antenna have been discussed. The conductivity of the printed antenna is measured to be 1 × 104 S/square and the thickness is also measured with an average of 30 µm. Through the whole paper, good agreement between simulated and measured results is satisfied. In addition to the achieved flexibility, the antenna has demonstrated good measurement results. First, the antenna has a bandwidth of 300 MHz at 1.9 GHz and 400 MHz at 5.8 GHz with fractional bandwidth of 15.7% and 6.8% at the both bands, respectively. Second, the measured antenna radiation pattern has indicated that it is omnidirectional at 1.9 GHz and approximately omnidirectional at 5.8 GHz. Third, The antenna gain is 1.266 dB and 0.512 dB at the two bands, respectively. Finally, the antenna's efficiency at the both bands is 35% and 55%. [ABSTRACT FROM AUTHOR]