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In this work, a printed coplanar waveguide (CPW) fed single band antenna based on expanded graphite material is introduced. The proposed antenna is based on a CPW-monopole antenna with a U-shape conductor strip connected with the ground. Expanded graphite, a grade of graphene, is used as a conductor to design the uniplanar antenna over a flexible paper substrate. The antenna is designed for 2.4 GHz applications. The antenna design procedures are discussed. The material preparation and analysis are illustrated. Finally, the antenna fabrication and measurements of the reflection coefficient are discussed. The measured antenna reflection coefficient agrees with the simulated one, ensuring the antenna validity for serving the required applications. The radiation antenna parameters are discussed and simulated results from two-simulation software are included for comparison. The antenna has a simulated gain of 4 dBi and simulated efficiency of around 90% at 2.4 GHz. [ABSTRACT FROM AUTHOR]

This paper presents a compact dual-band filtering antenna without extra employing of filter structures. The antenna is designed using a planar dual-composite right/left-handed (D-CRLH) transmission line unit cell, where the filtering function is achieved through current cancellation between the D-CRLH resonators. The antenna is designed to function at 3.0 and 5.1 GHz, which can serve different WLAN applications. The antenna is a co-planar waveguide fed with a very compact size of only 30 × 16 mm2. Compared to the conventional patch antenna, the antenna size is only 17% at 3.0 GHz and 31% at 5.1 GHz. Despite the small size, the antenna preserves a good omni-directional radiation pattern at the two resonant frequencies with a measured realized gain of 2 and 2.7 dB, respectively. At the stopband in-between the two resonant bands, the reflection coefficient is almost 0 dB at 4.25 GHz and complete non-radiation is proved with a −11 dB measured realized gain. The different antenna filtering functions are verified by full-wave simulation and measurements. [ABSTRACT FROM AUTHOR]

This paper introduces a novel design of compact tunable monopole antenna array, employing composite right/left handed (CRLH) feeding network. The feeding network configuration is coplanar waveguide (CPW). A graphene sheet is placed beneath the CRLH cell to achieve the tunability behavior in the antenna design. The antenna array configuration achieves the tunability function with an accepted gain. The surface conductivity of the graphene sheet is tuned by changing the applied DC bias voltage. The DC voltage changes the chemical potential of the graphene sheet. The antenna array is tuned from 2.5–2.46, 2.43, and 2.42 GHz when the chemical potential of graphene is changed from 0.0, 0.15, and 0.2 eV, respectively. The array antenna has a reasonable gain of 5.34 dB without placing the graphene sheet. By placing the graphene and changing the chemical potential, the array gain values become 4.42, 3.82, and 3.74 dB at the specified chemical potential. The radiation properties of the array are studied at the desired resonant frequency. The proposed design can be fabricated by using the transparent transfer process. All the presented designs are verified using the electromagnetic solver CST Studio. [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]