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This paper presents a compact, tri-bands, rectangular patch antenna based on H-Tree fractal slots structure for modern wireless communication systems has been introduced. The antenna structure consists of a 70.70×56mm2 rectangular patch printed on 173×173×1.6mm3 FR4 substrate. H-Tree slots fractal geometry with the defective ground plane on the other side to enhance gain and bandwidth. The suggested antenna is fed by a 50 Ω microstrip line. The antenna shows three resonance frequencies: 0.784, 1.158, and 1.772 GHz. The suggested antenna offers a total size reduction of about 75 %. The designed antenna possesses fractional bandwidths of 3.976 %, 7 %, and 2.7866 % for the first, second, and third resonances, respectively. Finally, the proposed antenna is a candidate for Global System for Mobile communications (GSM).

In this study, an investigation is conducted to realise the possibility of organic materials use in radio frequency (RF) electronics for RF-energy harvesting. Iraqi palm tree remnants mixed with nickel oxide nanoparticles hosted in polyethylene, INP substrates, is proposed for this study. Moreover, a metamaterial (MTM) antenna is printed on the created INP substrate of 0.8 mm thickness using silver nanoparticles conductive ink. The fabricated antenna performances are instigated numerically than validated experimentally in terms of S 11 spectra and radiation patterns. It is found that the proposed antenna shows an ultra-wide band matching bandwidth to cover the frequencies from 2.4 to 10 GHz with bore-sight gain variation from 2.2 to 3.43 dBi at maximum. The antenna size is compacted to a 32 mm × 24 mm using a fractal-shaped MTM when mounted on the INP substrate with a relative permittivity e r = 3.106-j0.0314 and a relative permeability μ r = 1.548-j0.0907. Finally, the maximum obtained voltage from the proposed antenna is found about 2 V at 2.45 GHz and 2.5 V at 5.8 GHz, where, the corresponding measured equivalent isotropic radiated power is about 2.35 W at 2.45 GHz and 6.12 W at 5.8 GHz.

This paper presents a method to control gain enhancement of a microstrip antenna based on a reconfigurable metasurface layer. The proposed layer is maintained the antenna and consists of $5 \times 5 -$unit cells. The proposed unit cell is designed to has four PIN diodes for structure reconfiguration into states ON and OFF. Therefore, the layer may have many distribution patters of ON-OFF unit cells. Each certain distribution pattern can enhance antenna gain to a certain value. Four patterns of the layer are suggested to enhance the antenna gain of about 1 dBi to 2, 5, 8, and 11 dBi. An equivalent circuit is introduced to describe the performance of the proposed unit cell. Besides, full CST MWS simulations for the system are conducted. To experimentally verify the presented method, a prototype of the system is fabricated and partially tested. The measurements show a good agreement with simulations.

In this paper a novel tri band, small size microstrip antenna based on fractal slots geometry for wireless and mobile applications has been introduced. The proposed antenna was created by etching out a rectangular radiating patch with two equal slits, yielding three conductors. This process is repeated again for the created patches. The designed antenna was fed with from 50Ω microstrip fed line. The antenna gives three resonance frequencies, (GSM 0.925 GHz, GSM 1.8 GHz and WLAN 2.4 GHz) and has suitable bandwidth for these applications. The antenna shows high reduction in size about 85% at GSM resonance frequency. The antenna is designed for 3.15×31.75mm FR4 substrate material and simulated using HFSS v.13 EM simulator from Ansoft. The simulation results show that the designed antenna possesses impedance bandwidths 11.2%, 7.75% and 3.3% for the first, second and third resonance respectively.

In this paper, a novel compact, low profile, low cost, microstrip fed line with single and double band-notch characteristics ultra wideband (UWB) patch antenna is presented. The proposed antenna satisfying UWB operation from 3 GHz - 11 GHz with two notches and have maximum gain 4.9 dB. The first band-notch is designed to reduce the electromagnetic interference in WiMAX frequency band (3.8 GHz), while the second band notch of WLAN IEEE 802.1a (5.35 GHz). By inserting seven different size arms of a single parasitic split ring resonator (SPSRR) band notch in the range of 3.3501-4.5857 GHz is obtained. Furthermore, the second band notch around from 5.1 - 5.6 GHz for WLAN is obtained by etching circular complementary split ring resonator (CSRR) near the microstrip feed line. A very high agreement between simulation and experimental results is achieved. The proposed antenna can be considered as a good candidate for UWB communication applications with very low electromagnetic interference.