From Symmetry to Asymmetry: The Use of Additional Pulses to Improve Protection against Ultrashort Pulses Based on Modal Filtration

For the first time, the paper considers in a unified work the possibility of the appearance of additional pulses in various structures based on modal filtration technology, which is used to improve protection against ultrashort pulses (USP). We analyzed meander lines (ML) with broad-side coupling, structures with modal reservation (MR), reflection symmetric MLs, and modal filters (MF) with a passive conductor in the reference plane cutout and obtained the following results. It was found that the main reason for the additional pulses to appear in these structures is the introduction of asymmetry (of the cross-section, boundary conditions, and excitation). It is theoretically and experimentally established that additional pulses are a new resource for increasing the efficiency of protective devices with modal decomposition, but the highest effectiveness could be achieved through careful optimization.

Design of subwavelength metamaterial resonator based on new self-coupling strategy

In this paper, edge-broad-side coupled spiral resonator (EBC-SR) is proposed to enhance the miniaturization of the metamaterial resonators. After a comparative analysis, it is found that the proposed strategy can drastically reduce the electrical size of metamaterial resonators. This is due to the use, at the same time, advantages of edge coupling, broad-side coupling, and self-coupling. A lumped element equivalent circuit model is proposed for the EBC-SR-loaded transmission line. This model is validated by comparing the results of electromagnetic simulations with the circuit simulations using the extracted parameter values. To validate the proposed strategy, a prototype of the EBC-SR embedded inside a drive loop is fabricated. The experimental results are presented with the simulation results.