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This paper presents the results of design process and scientific investigation of planar low pass filters with cut-off frequencies of 6 and 7 GHz. Main features of this design are high steep performance, high level of rejection out of band (in comparison to conventional topologies), high filter order and small occupied area. The analysis of high absorptive electromagnetic material influence on filter performance are shown as well

The paper presents a semi-analytical method for calculating the shielding effectiveness (SE) of an enclosure with an aperture filled with a dielectric or magnetic material. The method is based on a combination of quasi-static analysis of coplanar strip lines (CPS) and an analytical model of an enclosure equivalent circuit. A simulation of a CPS is reduced to solving a simple electrostatic problem and can be performed by any available numerical method. The SE calculation can be performed using any of the existing models of an enclosure equivalent circuit. In the range up to 1 GHz, a validation of the proposed method was carried out using a standardized enclosure 300×120×300 mm3 as an example. To show the capabilities of the method, the paper presents the results of SE for enclosures with a PVC ventilation grill and a glass in the aperture. Using this method in conjunction with a previously published analytical model, the SE calculations for the enclosure with a conducting plate were also performed. The results show that the proposed method has an acceptable accuracy, and the average value of the absolute error does not exceed 6.4 dB

The paper discusses the methods for harmonic current formation in DC to AC converters. The authors propose a timepulse method for control of switches in a half-bridge inverter for formation of the harmonic load current in a wide range of amplitude and output current frequency adjustment.

Asymmetric coupled double-shielded lines in an inhomogeneous dielectric medium, which have special properties that allow us to create microwave hybrids of a given directionality type are investigated. For the first time, a new model and method of synthesis are proposed, which takes into account both the asymmetry and the inhomogeneity of the dielectric, which makes it possible to synthesize co-, counter- and transdirectional couplers that have both the transforming and required phase properties. The research results will be useful for finding new design solutions of the next generation microwave circuits.