The present work makes use of the unique features of fractals such as self similarity and space-filling properties to realize antennas that are characterized by multiband and compact size. The application of the geometric partial arrangement property which known as (Koch) with fourth iteration is adopted in this work. Several tests are conducted to make these antennas operate within the frequency bands (2.4 GHz and 5.8GHz) standards IEEE 802.11 b/g and IEEE 802.11a respectively for the purposes of wireless communication applications. Modeling and performance evaluation of the proposed antennas are analyzed and optimized using CST software package, which utilizes the Finite Integral Technique (FIT) for electromagnetic computation. In this work, new four miniaturized antennas with multiband behavior are proposed. Each one of these antennas based on the basis of a well-known antenna called Planar Inverted F-Antenna (PIFA), commonly used as a single-band antenna in mobile terminals.The proposed antennas are Fractal Planar Inverted F-Antenna, Slot-Fractal Planar Inverted F-Antenna, Folded- Fractal Planar Inverted F-Antenna, and Rotated Folded -Fractal Planar Inverted F-Antenna.

This work investigates theoretically the characteristics of various terahertz antenna configurations formed by metallic CNT materials after modeling their conductivity accurately. The frequency dependent complex conductivity of the CNT material is taken into account in the investigation of these advanced antennas. The concept of effective conductivity is introduced for both SWCNT and MWCNT to make them in analogy with conventional antennas made of bulk metallic wires. This is useful to apply Maxwell's equations simply to predict the electromagnetic properties of the CNT antennas. Quantitative predictions of the performance of CNT antenna dipoles, including input impedance, reflection coefficient, gain, and efficiency, are presented as a function of frequency. Simulation is carried further to predict the performance characteristics of square loop, circular loop, and helical antennas. All antenna configurations are simulated using computer simulation technology (CST) microwave studio (MWs) software package which is based on finite integration technique (FIT) instead of MoM. The results indicate that impedance matching is a serious problem in CNT antennas.