Low Intensity Microwave Fields and Radiation and Their Interaction with the Human Body

Sources of low-intensity microwave signals formation, which affect the metabolism processes when they interact with human body, are considered in the article. It’s noticed that increasing intensity level of the technogenic signals in environment significantly exceeds natural electromagnetic fields and radiation (EMR). The peculiarities of the registration and measurement of low-intensity signals parameters of the microwave range are considered. The processes of the interaction of the microwave signals and human organism are analyzed. Formation mechanisms of the positive and negative microwave flows of the electromagnetic radiation are revealed. Particularly, possible formation mechanism of the microwave EMR fluxes of implants in the human body. The results of the experimental study of the EMR signals levels of the objects contacting with human body, partly materials for bone defects replacement and soft tissues regeneration so as materials for physiotherapy, are given. The use of the term “electromagnetic compatibility” for materials which contacting the human body, is proposed. The expediency of its use is proven. Microwave properties of materials for clothes, minerals and building materials, which can affect the human body and environment, have been also studied.

Bidirectional Interface Resonant Converter for Wide Voltage Range Storage Applications

In this paper, a bidirectional zero voltage switching (ZVS) resonant converter with narrow control frequency deviation is proposed. Wide input–output voltage range applications, such as flywheel or supercapacitors storage units are targeted. Due to symmetrical topology of resonant circuit interfaces, the proposed converter has similar behavior in bidirectional operating mode. We call it Dual Active Bridge Converter (DABC). The proposal topology of the converter is subjected to multi resonant circuits which make it necessary to study with multiscale approaches. Thus, first harmonic approximation and use of selective per unit parameters are established in (2) Methods. Then, the forward direction and backward direction of power flux exchange are detailed according to switching sequences. Switching frequency control must be completed within a narrow range. So, the frequency range deterministic parameters are emphasized in the design procedure in (3) Methods. A narrow range of switching frequency and a wide range voltage control must be ensured to suit for energy storage units, power electronic devices capabilities and electromagnetic compatibility. A 3 kW test bench is used to validate operation principles and to proof success of the developed design procedure. The interest of proposed converter is compared to other solutions from the literature in (4) Results.

DETERMINATION OF THE NORMS OF FREQUENCY-TERRITORIAL DIVERSION DURING THE DEVELOPMENT OF 5G TECHNOLOGY IN 3,4–4,2, 4,4–5, 14,5–15,35 GHZ FREQUENCY RANGES

The article presents scientific and technical proposals on the possibility of joint use of radio frequency spectrum of the fifth-generation mobile radio communication means and existing departmental radio-electronic facilities. On the basis of the load analysis, using the method of theoretical assessment of electromagnetic compatibility, the norms of territorial diversion between radio means are obtained. On the basis of the results of the calculations, it is possible to determine the subbands in which the joint use of radio means is possible, subject to optimization of the frequency-territorial plan and implementation of technical and organizational measures to ensure electromagnetic compatibility.

Electromagnetic Spectrum of the Corona Discharge and Their Fundamental Frequency

Historically, the Electromagnetic Compatibility (EMC) began with the disturbances at the radio navigation systems generated by the electrical power distribution lines; hence it was referred to as Radio Interference (RI). This disturbance is an Electromagnetic Interference (EMI). Although this type of EMI has been studied since the first decades of the past century, it still maintains a continued interest of the researchers, especially with the Corona Discharge (CD), generated by High Voltage Direct Current (HVDC) systems. Because of its design criterion and the concern that this phenomenon may affect the new radio communication systems in the very high frequency (VHF), ultra high frequency (UHF), and microwave bands, interest in their studies continues. In this chapter, an analysis of the electromagnetic spectrum of the CD is presented. The CD is generated at a short transmission line located within a semi-anechoic chamber. To be sure of the phenomenon, the CD is identified by its current pulse, which is well studied. The instruments used are an oscilloscope of 2 GHz and 2 GS/s, a spectrum analyzer, and an EMI test receiver. The results show that the CD concentrates its energy at frequencies below 70 MHz. In the UHF band, only narrowband signals very separated were found, with levels that cannot affect radio communication systems.

Design and Implementation of Highly Integrated Electronic System for Small-Size Spacecraft

Due to the tight installation space, strict weight requirements, numerous functional units and dense wireless equipments of small-size spacecraft, the traditional electronic system design of aircraft cannot meet the requirements of miniaturization and lightweight for small-size spacecraft. In this paper, a highly integrated electronic system suitable for small-size spacecraft is designed, in which many key technologies such as miniaturization and lightweight design technology, multi frequency wireless electromagnetic compatibility design technology, small aircraft low delay cooperative networking and high-precision differential positioning are adopted. The proposed highly integrated electronic system makes timing control, attitude and orbit control, wireless telemetry, networking communication, satellite navigation, power distribution and other functions integrated. The total weight of the system is about 7.62kg, which is much lighter than existing electronic system. The experiment results that the highly integrated electronic system achieves good effect. This technology has broad application prospects in small-size aircraft with strict weight and space requirements.