STUDYING MULTILAYERED GRAPHENES BY ELECTROPHYSICAL METHODS

The paper studies multilayer graphenes in the form of free-standing films. The authors provide data about the morphology and electrical properties of films treated with plasma of various chemical composition. It is shown that it is possible to control the electrical properties of the surface and electron work function without significantly affecting its morphology. The obtained samples, combining mechanical flexibility with unreactiveness and high electrical conductivity, are promising for application in flexible charge storage devices.

PECULIAR PROPERTIES OF ELECTROMAGNETIC RADIATION PROPAGATION IN PHOTONIC CRYSTALLINE METAL-DIELECTRIC SYSTEMS BASED ON OPALS

The article studies the propagation of electromagnetic waves in metal-dielectric systems based on opals. We revealed anomalous transmission and absorption of light by hybrid plasmon- photonic layered heterostructures associated with the excitation of surface plasmon polaritons propagating along the metal-dielectric interface. The position of maxima in the reflection spectra of nanocomposites, obtained by filling the opal matrix with metal by the electrothermodiffusion method, is explained by the Bragg diffraction, and the asymmetric form of the spectral curves is attributed to the Fano resonance.

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.

IMPLEMENTATION OF THE TWO-FREQUENCY METHOD FOR MEASURING THE DERIVATIVE OF CAPACITANCE-VOLTAGE CHARACTERISTIC

The article presents an example of the implementation of the two-frequency method for measuring the derivative of the capacitance-voltage characteristic. The authors describe the diagram of the measuring system and the software package for the measurement process control. The article also gives the results of measurements of the capacitance-voltage characteristic and its derivative of the silicon-based metal-insulator-semiconductor structure. The qualitative differences between the derivatives of the capacitive characteristics of the metal-insulator-semiconductor structure were obtained as a result of numerical differentiation and its direct measurement by the two-frequency method. The authors offer an explanation for this difference.

USE OF THE FAN-SHAPED IDTS – EFFICIENT METHOD FOR CREATING THE WIDEBAND SAW FILTERS WITH A LOW INSERTION LOSS AND HIGH RECTANGULARITY OF FREQUENCY RESPONSE

This paper presents an efficient method for creating the wideband SAW filters with high rectangularity, flat amplitude response and low insertion loss in passband – use of fan-shaped IDTs with inclined electrodes. The authors consider the approaches for realization of the fan-shaped filters. The quantitative and qualitative characteristics of the fan-shaped SAW filters with a relative bandwidth ∆f/f0 = 4–75 %, shape factor 1,1–1,96 and insertion loss of 5–18 dB are given for each approach.

SOLAR TERMINATOR AND IONOSPHERIC PROPAGATION OF RADIO WAVES

The paper provides a review of studies devoted to the peculiarities of the propagation of radio waves in the ionosphere in the area of the solar terminator, which is the only global and regular source of acoustic-gravitational waves and other disturbances of the ionosphere. It describes the results of theoretical works devoted to the study of perturbations created by the solar terminator in the area of the difference in the intensity of solar radiation in the atmosphere. The paper gives a review of experimental studies of the effects created by the solar terminator in the entire thickness of the atmosphere. These effects, in particular, include the multipath propagation of radio waves, their phase variations, and variations in amplitudes during the propagation of radio waves in the area of the solar terminator. In the interests of science and practice, a number of problems have been proposed for the further study of wave perturbations arising as a result of the movement of the temperature gradient at sunrise and sunset hours.

INCREASING ENERGY INDICATORS OF HF TRANSMITTER WITH SINGLE-BAND MODULATION OF VOICE INFORMATION WHEN APPLYING AUTOMATIC MODE CONTROL

The article is devoted to the determination of the energy parameters of the transmitter when using automatic mode control for powering the output stages of single-sideband HF transmitters without taking into account losses in the controlled power supply.

DEPLOYMENT OF PROFESSIONAL VHF COMMUNICATION SYSTEMS IN THE ARCTIC REGION

The importance of the Northern Sea Route as a global transport corridor, used for transportation of national and international cargo, will only increase because of the currently observed climatic changes. Currently, the only stable communication system there is satellite. The paper presents the results of software modeling of a technological radio communication line based on the VHF trunking network for sea vessels following a group along the Northern Sea Route.

VI International Scientific and Technical Conference "Radio Engineering, Electronics and Communication"

VI International Scientific and Technical Conference "Radio Engineering, Electronics and Communication"

IMPLEMENTATION OF ADAPTIVE PRODUCT CUSTOMIZATION PROCESSES IN MASS PRODUCTION

The article presents the results of research and implementation of adaptive calibration systems used in setting up mass-produced products. The proposed method allows you to speed up the tuning of the HF transceiver. In the process of tuning, with the help of a neural network, an adaptive correction of the approximating function of the incident wave sensor is made according to the accumulated data, which makes it possible to reduce the time for tuning the transceiver. The introduction of the mathematical apparatus of neural networks can be applied in the process of mass production for other products.