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Wideband-multiband reconfigurable elliptical monopole antenna is investigated in this paper. By having conventional elliptical monopole antenna, wideband operating frequency is obtained. With the combination of dual pairs of slotted arms and a band-pass filter on the ground plane of the elliptical monopole, multiband is achieved. Dual-band operating frequencies at 1.6 GHz and 2.6 GHz while wideband operates from 3.35 GHz to 9 GHz. Therefore, wide range of wireless communication systems is obtained from the proposed antenna to support the multiband mode (i.e. GPS and LTE) and UWB systems. Frequency reconfigurable is achieved by controlling the switches integrated on the antenna structure. Simulated results of reflection coefficient, radiation patterns and gain performance are presented. The proposed antenna design is suitable candidate for different wireless communication applications. [ABSTRACT FROM AUTHOR]

ABSTRACT A wideband antenna fed by a coplanar waveguide (CPW) with reconfigurable function is presented. The wideband function is achieved from 1.39 GHz to 8.11 GHz using an elliptical radiator with a CPW feed line. Meanwhile, three pairs of slot dipoles which are fed by CPW are used to achieve triple-band function at 2.4 GHz, 3.5 GHz and 5.2 GHz. Four ideal switches are placed on the proposed antenna. The proposed antenna is designed, simulated, fabricated and tested. All simulated and measured results of return loss, radiation pattern and gain are presented. Good results of return loss and radiation pattern are obtained thus verifying that the proposed antenna is suitable for future multimode radio systems. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2079-2082, 2016 [ABSTRACT FROM AUTHOR]

Graphene is a unique material that can display tuning characteristics. This characteristic originates from its surface complex conductivity, which is controlled by a chemical potential. Most characteristics of tunable graphene antenna have been studied on Terahertz frequency range, thus making it difficult to be realised practically. Besides that, the standard antenna that uses switching components may have trouble during installation, and consume size as can be seen in the reconfigurable antenna. With the integration of this material, a tunable antenna based on graphene operating at microwave frequency range is proposed. The antenna was designed and fabricated at 15 GHz with a gate electrode placed behind it. They are connected to external DC bias during the measurement. The biasing is applied from 0 V to 30 V. The result shows that resonance frequency tuned about 20 MHz and reflection coefficient magnitude improved 1.24 dB. Following this, an analytical calculation on chemical potential was also derived for enhancing the graphene tunability. The count shows that at least 2.85 kV of the gate voltage is needed to vary the chemical potential and less than 0.26 µm of dielectric spacer thickness is suitable for tuning with a given condition, respectively. [ABSTRACT FROM AUTHOR]