Fractal geometry has been proven to be useful in several disciplines. In the field of antenna engineering, fractal geometry is useful to design small and multiband antenna and arrays, and high-directive elements. A historic overview of the most significant fractal mathematic pioneers is presented, at the same time showing how the fractal patterns inspired engineers to design antennas.

Sidelobe level suppression is a major problem in circular array antenna (CAA) synthesis. Many conventional numerical techniques are proposed to achieve this which are time consuming and often fail to handle multimodal problems. In this paper, a method of circular array synthesis using nature inspired flower pollination algorithm (FPA) is proposed. The synthesis technique considered here adapts one and two degrees of freedom, namely, amplitude only and amplitude spacing. The effectiveness of the FPA is studied by comparing the results with genetic algorithm (GA) and uniform circular array antenna (UCAA) with uniform spacing. Also the effect of additional degree of freedom on the aperture size and the computational time is analyzed. A relative side lobe level (SLL) of −25 dB is achieved using the algorithm under both no beam scanning (0°) and beam scanning (15°) conditions for 20 and 40 elements of CAA.

To meet the augmented load power demand, the doubly-fed induction generator (DFIG) based wind electrical power conversion system (WECS) is a better alternative. Further, to enhance the power flow capability and raise security margin in the power system, the STATCOM type FACTS devices can be adopted as an external reactive power source. In this paper, a three-level STATCOM coordinates the system with its dc terminal voltage is connected to the common back-to-back converters. Hence, a lookup table-based control scheme in the outer control loops is adopted in the Rotor Side Converter (RSC) and the grid side converter (GSC) of DFIG to improve power flow transfer and better dynamic as well as transient stability. Moreover, the DC capacitor bank of the STATCOM and DFIG converters connected to a common dc point. The main objectives of the work are to improve voltage mitigation, operation of DFIG during symmetrical and asymmetrical faults, and limit surge currents. The DFIG parameters like winding currents, torque, rotor speed are examined at 50%, 80% and 100% comparing with earlier works. Further, we studied the DFIG system performance at 30%, 60%, and 80% symmetrical voltage dip. Zero-voltage fault ride through is investigated with proposed technique under symmetrical and asymmetrical LG fault for super-synchronous (1.2 p.u.) speed and sub-synchronous (0.8 p.u.) rotor speed. Finally, the DFIG system performance is studied with different phases to ground faults with and without a three-level STATCOM.

The research article presents a novel energy saving routing algorithm for wireless sensor networks (WSNs) to meet the demand of present research trend. In contrast to conventional methods, a new concept of dominant node has been introduced in this paper. Unlike the conventional algorithms, the proposed method can be applied to both homogeneous and heterogeneous networks. The proposed method focuses on the proper energy distribution among the sensor nodes so that it can offer an energy efficient solution while maintaining improved network lifetime and throughput. The proposed idea has been validated through simulation results. Moreover, the supremacy of the proposed method has been established over existing ones.