Modern power systems encompass multiple prosumers, smart grid technologies, and renewable energy resources (RERs). These prosumer-based smart grids are facing the reliability issues that can be mitigated through the adoption of competitive storage technologies. A range of competitive storage technologies have been developed by scientists. However, the systematic selection of best storage technologies is still one of the main challenging research issues in the current literature. To fill this literature gap, this paper proposes a multi-criteria decision framework for energy storage selection in prosumer-based networks. First, a decision-making hierarchy was developed based on the three main criteria including energy flow management for prosumers, technical features, and sustainability. Under these criteria, various sub-criteria were identified. Second, multi-criteria decision making (MCDM) problem was solved for two cases using Analytic Hierarchy Process (AHP) and Preference Ranking Organization Method for Enrichment of Evaluations (PROMETHEE) methods separately. Third, a hybrid AHP and PROMETHEE method was proposed for the selection of an efficient storage system for prosumers based smart grid. Finally, a comprehensive outlook has been provided for prosumer energy storage evaluation. Findings revealed several implications for more accurate storage evaluation decision making. For instance, sensitivity analysis reveals that the lithium ion battery (LIB) has the first preference in AHP method, and the lead acid battery (LAB) has the first preference in PROMETHEE method. However, the second preference for AHP method was the LAB, and the second preference for PROMETHEE method was the LIB. Hence, separate application AHP and PROMETHEE offered a slightly different ranking. According to the proposed hybrid procedure, LIB was ranked as the first option by both AHP and PROMETHEE methods. As a result, the hybridization of AHP and PROMETHEE methods offered a more robust and unique solution to the storage selection problem as compared to the individual method. Storage evaluation decision making has several implications for prosumer-based power systems. In future, only a few storage alternatives would not meet the needs of the large scale emerging power systems, such as peer-to-peer networks. In this situation, the rapid and accurate ranking of various competitive storage alternatives would be a challenging problem. This study is valuable because it offers a comprehensive and flexible decision making tool for storage evaluation for prosumer-based smart grids. For instance, the proposed model can be evaluated with addition or removal of criteria and storage alternatives under different situations.

A small-sized quasi-stepped impedance resonator (SIR) based single-band to dual-band reconfigurable bandpass filter is presented in this work. The proposed quasi-SIR filter is modular in nature and can be easily scaled to higher- or lower-frequency bands. To this end, a single- to dual-band reconfigurable modified SIR is designed. The designed reconfigurable resonator was then used to develop a single-band to dual-band reconfigurable filter. The proposed filter structure comprises two resonators loaded with PIN diodes to provide the switching. The filter allows switching between single and dual-band frequencies. In the OFF state, PIN diodes provide single-band resonance with a resonant frequency of 3.8 GHz. While the ON state of PIN diodes provides dual-band resonance of 3.35 GHz and 4.3 GHz. The structure of the filter is modular and is designed, analysed, and fabricated on a low-cost FR4 dielectric substrate with a 4.3 dielectric constant and 0.78 mm thickness. The measured results are in good agreement with the simulation results. The filter is designed to operate in the sub-6 GHz band, a designated band for 5G communication, and is thus suitable for incorporation in 5G devices with reconfigurability applications.

The implementation of convolutional perfectly matched layer (CPML) is presented and validated on the face-centered cubic (FCC) grids. The standard Cartesian (Yee) grid can be competently substituted by the FCC grid. Although the FCC grid has more lattice points when compared with the Yee grid, yet it shows better grid isotropy and reveals stability criterion which is much more relaxed. In this work, the iterative equations of CPML in the FCC grid are formulated, for using it as an absorbing boundary condition to truncate the computational domain. Numerical results are provided to prove the effectiveness of CPML.

Tapered transmission line resonators can be used to achieve specific frequency responses and enhance the performance of microwave devices and impedance transformers. To develop a mathematical model (transfer function) of such a wideband resonator will facilitate the construction of an equivalent circuit and the synthesis of resonators of this type. This study discusses the system modeling of tapered transmission line (TTL) resonators using the singularity expansion method (SEM). The transfer function is analytically established for two types of wideband TTL resonators: exponential tapered transmission lines (ETTL) and linear tapered transmission lines (LTTL). The analytical transfer function is derived for the general tapered ratio (k/β). The physical poles of the structures are identified using the pole-energy matrix pencil (MP) approach. The transfer function expression is then utilized to develop an accurate equivalent lumped-element circuit for the TTL resonator. This study’s simplified approach for estimating the transfer function and associated poles and zeros from the S-parameters is the main contribution, whereas it is known that the transfer function becomes complicated for wideband frequency response. A direct synthesis approach is presented to develop two-stage and four-stage ultra-wideband (UWB) bandpass filters. The agreement between the frequency response data and the derived transfer function of the system model of the synthesized TTL filters demonstrates the reliability of the presented method. The proposed system modeling and synthesis methodology can be applied to more sophisticated filter TTL architectures.

This article highlights the collaboration between the EdTech and Computational, Photonics, and Electromagnetics departments at the LINKS Foundation ( Figure 1 ), in initiating an innovative research program for creation of educational toys in the field of RF and microwaves. The LINKS Foundation was founded more than 20 years ago with the collaboration of Compagnia di San Paolo and Politecnico di Torino, Italy. It is a versatile research center where 160 researchers in various fields work together creating collaborations with more than 2,500 partners. It bridges the gap between students of the Politecnico and industry by offering projects in various fields [1] .