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Vol 70, No 12 (2025)
- Year: 2025
- Articles: 13
- URL: https://journals.rcsi.science/0033-8494/issue/view/25603
ELECTRODYNAMICS AND RADIO WAVE PROPAGATION
Design of a coplanar Ω-resonator for excitation of optically detected magnetic resonance
Abstract
We present a miniature two-port resonator with an Ω-shaped coplanar coil designed to excite optically detected magnetic resonance at 2.87 GHz in a diamond sample hosting nitrogen-vacancy (NV-centers). The resonator architecture was chosen because its fabrication does not require patterning planar structures on the diamond. The dimensions were calculated, and electromagnetic simulations using the finite-element method were performed to obtain the S-parameters both without and with the diamond included. After fabrication, the S-parameters were measured with a vector network analyzer. For the resonator with the diamond mounted on it, at 2.87 GHz we obtained a minimum reflection coefficient |S11| ≈ −24.85 dB, a loaded quality factor QH ≈ 44.2, and a −3 dB bandwidth of about 66 MHz.
Journal of Communications Technology and Electronics. 2025;70(12):1137–1149
1137–1149
About propagation of super-Gaussian electromagnetic pulse in a resonantly absorbing gas medium
Abstract
Based on the direct calculation (without the introduction of simplifying assumptions and transformations) of the Fourier integral, an analysis was made of the nature and features of the deformation of a nanosecond radio pulse with a super-Gaussian envelope and an energy spectrum belonging to the frequency interval occupied by the spectral line in a resonantly absorbing gaseous medium. The pulse propagates along the nearground path, the resonant absorption is due to the strong spectral line of water vapor with a frequency of 988.2 GHz, and its interaction with the medium is described by the Drude-Lorentz model. It has been established that in the case of a super-Gaussian pulse one should expect a significant change in the nature of distortions in comparison with a Gaussian pulse. In particular, it is shown that, with increasing optical path depth, the super-Gaussian pulse gradually transforms to the form of a set of two subpulses separated along the time axis, while the separation of the Gaussian pulse does not occur, all other conditions being equal.
Journal of Communications Technology and Electronics. 2025;70(12):1150–1162
1150–1162
Waveguide structure design for a sideband-separating heterodyne receiver operating in the 0.8…1 mm wavelength band
Abstract
A waveguide structure is presented for the RF front end of a sideband-separating heterodyne receiver operating in the 0.8–1 mm band, based on two single-ended superconductor–insulator–superconductor (SIS) mixers. The microwave properties of the following elements are investigated: a 90° quadrature hybrid, a directional coupler, a T-junction power divider, and a transition section; their amplitude and phase frequency responses are calculated. For the 90° hybrid, the amplitude imbalance does not exceed 1.5 dB, the phase imbalance including reflections stays within 2°, and both return loss and isolation are better than –25 dB. In addition, a full waveguide assembly was simulated with the SIS-mixer reflections taken into account. The resulting sideband rejection of the entire waveguide structure, including mixer reflections, is no worse than 20 dB across the band.
Journal of Communications Technology and Electronics. 2025;70(12):1163–1174
1163–1174
Development and experimental study of a dual-band traveling-wave antenna array
Abstract
This study investigated a one-dimensional traveling wave waveguide antenna array including two types of longitudinal resonant slots. The slots of the first type are located with the period P1 and are tuned to the resonance frequency f1, and the slots of the second type are located with the period P2 and are tuned to the frequency f2. The periods P1,2 are chosen in such a way that at frequencies f1,2 the antenna emits in the same directions, which are determined by the angle of radiation θp. It has been experimentally shown that an array of this type effectively operates in two sub-ranges in the vicinity of frequencies f1,2 = 9.5 and 10.8 GHz. Moreover, the width of each sub-range is approximately twice wider the operating frequency range of the array with non-resonant radiators.
Journal of Communications Technology and Electronics. 2025;70(12):1175–1183
1175–1183
СТАТИСТИЧЕСКАЯ РАДИОФИЗИКА
Increasing the sensitivity of the marine electrode electric field sensor
Abstract
The possibility of increasing the sensitivity of the marine electrode sensor several times when receiving long-term narrow-band low-frequency radio signals is shown due to compensation for the noise component caused by pulsations in the speed of movement of the liquid relative to the sensor electrodes.
Journal of Communications Technology and Electronics. 2025;70(12):1184–1189
1184–1189
РАДИОФИЗИЧЕСКИЕ ЯВЛЕНИЯ В ТВЕРДОМ ТЕЛЕ И ПЛАЗМЕ
Interaction of the resonant modes in the canted antiferromagnet/ferromagnet heterostructure
Abstract
The interaction of the resonant modes in the exchange-coupled two-layer canted antiferromagnet/ferromagnet heterostructure has been theoretically investigated. Expressions describing the dependence of the resonant frequencies of magnetization oscillations on the external magnetic field have been obtained by the method of Hamiltonian formalism. The effect of the coupling strength between the ferro- and antiferromagnetic layers on the width of the anti-crossing gap between the resonant mode of ferromagnet and the soft mode of antiferromagnet and on the magnitude of the external magnetic field at which hybridization is observed has been investigated. It is shown that increase in the antiferromagnet/ferromagnet exchange coupling constant leads to increase in the width of the anti-crossing gap and the magnitude of the external magnetic field at which hybridization is observed.
Journal of Communications Technology and Electronics. 2025;70(12):1190–1199
1190–1199
Spectral characteristics of coupled magnonic structures under spin-wave damping compensation
Abstract
The magnetization dynamics in two dipolarly coupled ferromagnet–normal metal (FM–NM) structures is investigated under symmetric and asymmetric compensation of intrinsic spin-wave damping mediated by the spin Hall effect. Within the framework of a linear model of complex amplitudes, the spectral characteristics of the normal modes are analyzed, including their degeneracy at an exceptional point in the asymmetric case. It is demonstrated that asymmetric compensation leads to a transition from a two-frequency to a single-frequency regime at the exceptional point, accompanied by a narrowing of the spectral linewidth, whereas symmetric compensation preserves the two-frequency regime. The results are of relevance for the development of magnonic devices such as filters and sensors.
Journal of Communications Technology and Electronics. 2025;70(12):1200–1205
1200–1205
Structure and magnetic properties of ZnxFe3–xO4 nanoparticles obtained by mechanochemical synthesis
Abstract
A scalable method for the synthesis of zinc ferrites ZnxFe3–xO4 (with a doping degree of x = 0; 0.125; 0.25; 0.5; 1) by controlled oxidation of an iron and zinc mixture during mechanochemical synthesis is proposed. Comprehensive studies of the processes occurring during mechanochemical synthesis were carried out using X-ray diffraction analysis, Mössbauer spectroscopy and measurement of magnetic properties. It was shown that zinc ions in the synthesized ferrites occupy both tetrahedral and octahedral positions, which leads to a decrease in the saturation magnetization to 44 Am2/kg with an increase in the doping degree to x = 1. An increase in the doping degree leads to a monotonic decrease in the coercivity to 40.3 Oe, which can be used to obtain materials with desired properties.
Journal of Communications Technology and Electronics. 2025;70(12):1206–1214
1206–1214
НАНОЭЛЕКТРОНИКА
Impact of Hf0.5Zr0.5O2 ferroelectric film thickness on the wake-up effect and endurance of memory cells
Abstract
This work presents a comprehensive study of the correlation between the structural/ferroelectric properties of Hf0.5Zr0.5O2 (HZO) thin films – the functional layers for ferroelectric non-volatile memory – and their thickness in the 5–10 nm range. X-ray diffraction analysis revealed the predominant presence of the polar orthorhombic Pca
2
1 phase in all samples. The highest content of (002)-oriented domains, corresponding to the vertical orientation of the polar axis, was found in the 8 nm thick films. Electrical measurements demonstrated an inverse relationship between film thickness and the breakdown field, which varied from 6.5 MV/cm (5 nm) to 4.5 MV/cm (10 nm). A pronounced improvement in switching endurance was observed with decreasing thickness: films of 5–6 nm maintained stable ferroelectric characteristics up to 109–1010 switching cycles at an electric field of 3.0 MV/cm. Analysis of the I–V characteristic dynamics during wake-up with bipolar pulses showed that the parameter stabilization process is accompanied by a merging of the switching current peaks and an increase in the remanent polarization up to 30 μC/cm2. It was established that degradation in thin films begins significantly later (after >106 cycles) than in thick ones (104–105 cycles). This is presumably associated with the inhibitory effect of the amorphous phase on the kinetics of diffusion and drift of charged defects. The obtained results are valuable for the development of reliable ferroelectric memory devices, demonstrating an optimal combination of high remanent polarization and cycling stability in ultra-thin HZO films.
Journal of Communications Technology and Electronics. 2025;70(12):1215–1224
1215–1224
Preparation and study of ferroelectric films of La0.7Sr0.3MnO3
Abstract
This paper presents the results of fabricating ferroelectric La0.7Sr0.3MnO3 (LSMO) thin films on silicon substrates. Oriented LSMO films were obtained using magnetron sputtering followed by annealing. Capacitance-voltage (C–V) measurements of the Ni-LSMO-Si metal-insulator-semiconductor (MIS) structures revealed that thermal treatment at 800 °C induces ferroelectric properties in the LSMO films. This is evidenced by a C–V hysteresis loop with a width of 5 V and a more than two-fold increase in the capacitance switching ratio. The demonstrated method shows promise for the integration of ferroelectric LSMO into silicon technology.
Journal of Communications Technology and Electronics. 2025;70(12):1225–1228
1225–1228
PHYSICAL PROCESSES IN ELECTRONIC DEVICES
Numerical simulation of leaky wedge acoustic wave excitation in piezoelectric structures
Abstract
The excitation of pseudowedge waves in piezoelectric wedges using interdigital transducers on their surface has been investigated. The frequency dependence of propagating waves in a wedge made of lithium niobate on the orientation of the crystal under various boundary conditions has been calculated. This allowed for an evaluation of the effect of wedge face metallization on the propagation characteristics of both wedge and surface acoustic waves within it. Two-dimensional and three-dimensional finite element models were developed to study the conditions for the existence of leaky wedge waves and the possibility of their excitation. The ranges of crystal orientations where pseudowedge waves are observed were determined. Two widely used cuts of lithium niobate were considered: Z-cut and Y-cut. The effect of non-reciprocal wave propagation in lithium niobate was demonstrated for two adjacent rectangular wedges with faces formed by equivalent crystallographic planes.
Journal of Communications Technology and Electronics. 2025;70(12):1229–1239
1229–1239
NEW ELECTRONIC SYSTEMS AND ELEMENTS
Domestic transceiver of ultra-high frequency digital tagging and identification systems
Abstract
This paper presents a reader transceiver for UHF digital tagging and identification systems, designed for fabrication using 180 nm domestic CMOS technology. The architecture of the transceiver and it main IP-blocks are considered. The results of parameter calculations obtained from CAD simulations are presented. The possibility of using the transceiver in ISO 18000-6 standard systems has been confirmed.
Journal of Communications Technology and Electronics. 2025;70(12):1240–1251
1240–1251
A new automatic gain control system for the microwave excitation signal for quantum frequency standards based on rubidium-87 and cesium-133 atoms
Abstract
The need to develop a new automatic gain control system for the microwave excitation signal in quantum frequency standards (QFS) based on rubidium-87 and cesium-133 atoms is substantiated. Factors that negatively affect the operation of the automatic gain control system for the microwave excitation signal during the operation of the standards are identified. A new circuit for automatic gain control in the microwave paths of QFSs based on rubidium-87 and cesium-133 atoms has been developed. The designs of new units of the automatic gain control circuit are considered: a signal amplifier that generates an error signal and a PID controller that controls an attenuator that regulates the output signal. Calculation and modeling of the operation of the new units of automatic gain control of the microwave excitation signal included in the microwave paths of two QFSs have been performed. The obtained results confirm the validity of the new design solutions and methods for adjusting the amplitude of the microwave excitation signal in the automatic gain control circuit for QFSs based on rubidium-87 and cesium-133 atoms.
Journal of Communications Technology and Electronics. 2025;70(12):1252–1262
1252–1262