Design of single-feed circularly polarized (CP) microstrip antenna is proposed in this article. The design employs the concept of E-shape patch with inclined fractal defected ground structure (IFDGS), which can improve the impedance bandwidth, gain, and axial ratio (AR) bandwidth. The excellent enhanced impedance bandwidth, axial ratio bandwidth, and gain are achieved by an inclined E-shaped fractal etched on the ground plane. The parameter studies of the E-shaped IFDGS are given to illustrate the way to obtain CP radiation. The third iterative IFDGS is fabricated on easily available FR4 substrate with a size of 0.494 λ0 × 0.494 λ0 × 0.019 λ0 (λ0 is the wavelength in free space at 3.624 GHz). The measured results verify the simulated results and show good agreement. The proposed antenna shows an impedance bandwidth of 12.7% at a centre frequency of 3.47 GHz and 3-dB AR bandwidth for this band is 2.39% at a centre frequency of 3.626 GHz. The measured peak gain for the proposed antenna is found as 8.1 dBi. The proposed antenna can be suitable for mobile WIMAX operation (IEEE 802.16e-2005 standard), wireless communication in CA-band and FCC.

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Due to ever-increasing demand for capacity and quality in wireless communication links, lead to inspire researchers to innovate new design methodologies and concepts over wireless systems and networks with the ultimate aim of achieving a next-generation network. These researches must ensures data rates similar to those offered by optical fiber systems but at the fraction of its deployment cost. Among the emerging technologies is the new innovative radio on freespace optics system, referred to as Radio over Free Space Optics (RoFSO), which is the main interest of this paper. RoFSO systems have been recognized as a promising wireless interconnecting technology. Such system combines the radio over fiber (RoF) technology comprising heterogeneous wireless services and Fiber Space Optics (FSO) link. In this paper, an analytical time-domain model is presented to analyze the radio over free space optical (RoFSO) systems considering scintillation effect with the log-normal distribution. This analytical model uses a dual-drive MachZehnder modulator (DD-MZM) and photodetector (PD) for optical single sideband (OSSB) signals.