SHF Band Research Articles

Methodology for selecting the method of mirror antenna protection in SHF-EHF bands from meteorological precipitations

Exhaustion of SHF band capabilities in the organization of space communication channels necessitated the transition to the lower part of the EHF band (up to 95 GHz). At the transition stage space channel antennas function in the dual frequency range. This leads to the fact that the methods of protection of ground sector mirror antennas from the impact of meteorological factors should take into account the peculiarities of propagation of millimeter-wave radio waves in the layer of precipitation that can occur in the antenna reflector. For a scientifically justified choice of the method of protection there should be a methodology that allows taking into account both electrodynamic peculiarities of propagation of radio waves of SHF and EHF ranges, and meteorological peculiarities of the antenna location. The latter determines the relevance of the proposed research topic. The objective of the article is ensuring minimum power losses and fulfillment of the rain unavailability index of the mirror antenna of the SHF-EHF wavelength bands of space communication channels by means of a reasonable choice of the method of protection against the impact of meteorological precipitation characteristic of the antenna location. It has been shown that the functioning of mirror antennas of satellite ground stations in the dual frequency range of SHF-EHF makes it obligatory to take into account the peculiarities of propagation of millimeter-wave range waves in water formations when choosing methods of protection from the effects of meteorological precipitation. The most important of these features is the increase in energy losses of millimeter-wave radio waves in the layer of water formations, the thickness of which becomes comparable to the wavelength. In addition, the methods of antenna protection should also take into account the peculiarities of digital communication lines, in particular, the fulfillment of an additional requirement (rain readiness index), assuming the restoration of the operating state of the reflector within a time of up to 10 s. The above features allowed us to formulate a criterion for a scientifically justified choice of the method of protection of the antenna of dual frequency range. The developed methodology for selecting the method of protection of the mirror antenna of the dual wavelength range is based on the theory of meteorological electromagnetism. This allows not only modeling the radio wave energy losses in the layer of precipitation taking into account strict electrodynamic models, but also assigning the parameters of the layer of water formations (thickness, type of precipitation) taking into account the climatic features of the location of the mirror antenna. Thus, the developed method provides the following algorithm for selecting the method of protection. By geographic coordinates the climatic region of antenna location is determined. For abnormal climatic regions (temperature from ‑60° to +50°, wind force up to 70 m/s, snow load up to 250 kg/m3) the application of radio transparent shelter (radome) is an alternative protection method. For other climatic regions the choice of the method of protection of the mirror antenna implies three steps: 1) estimation of energy losses in the precipitation layer on the antenna reflector at refusal of protection methods (maximum possible losses); 2) calculation of the complex criterion; 3) selection from the proposed table of the method that most fully satisfies the criterion and is the most effective for the climatic region of antenna placement. The proposed methodology allows on a scientific basis to choose the method of protection of mirror antennas of the dual frequency SHF-EHF range taking into account the meteorological features of the climatic region of its location.

Sensitivity enhancement of an antenna sensor by using sextuple notch bands for application in cancer detection

In this study, a sextuple band-notched ultra-wideband (UWB) antenna sensor with slots in the feedline and parasitics is proposed. This is used for cancer detection in breast and skin phantom. The antenna sensor operates a bandwidth of 2.45–16 GHz. The dielectric properties of malignant cells are completely distinct from healthy cells, EM waves passing through the cells recognize a malignant. S11 parameters of the antenna are analyzed with the help of a Vector Network Analyzer (VNA) after placing the antenna on the phantoms. Further, the statistical machine learning concept of Principal Component Analysis (PCA) is utilized for more vivid detection of malignant cells. The bands WiMax (2.8–3.4 GHz), radio astronomy (4.75–5.8 GHz), satellite communication (6.7–7.5 GHz, 9.2–10.9 GHz and 12.95–13.55 GHz) and SHF band (15.43–15.63 GHz), create interferences within the UWB spectrum. The interfering bands are removed by slot loading and parasitics. Thus, the sensitivity of the antenna sensor improved.

Path Loss Prediction Model for Propagating Radio Wave in Woodland

This paper presents new empirical prediction models for loss estimation in forest environment. Experimental investigations were carried out on groups of trees in form of woodland and lines of trees at SHF band under different operational contexts. In the experimentations, two major measurement geometries (propagation “into” and propagation “inside” forest) were adopted on site to site basis. Results from all the sites displayed a common trend, in that they all showed a persistent decay in signal power with the depth of vegetation and which is dependent on the measurement geometries.
 Using a “Power Law” theory, a new empirical loss prediction model has been proposed for each propagation scenario using parametric equations which are in line with the general formulations of the ITU-R models. These new models were tested with the standard empirical loss prediction models and gave a statistical adherence with the fitted ITU-R model.
 It is anticipated that these new models will address the inadequacy in the existing prediction models which have not taken cognizance of the differences in operational contexts of each propagation scenario in their formulations.

Modified symmetrical slot line for integrated circuits of SHF and EHF bands

Modified symmetrical slot line for integrated circuits of SHF and EHF bands

Cost Benefit Analysis: Evaluation among the Millimetre Wavebands and SHF Bands of Small Cell 5G Networks

Cost Benefit Analysis: Evaluation among the Millimetre Wavebands and SHF Bands of Small Cell 5G Networks

Electromagnetic Properties of Composite Materials Based on ABS Plastic with Carbon Nanotubes Obtained by the Additive Technology in the SHF and EHF Bands

The results of study of the electromagnetic characteristics of polymer composite materials containing multiwall carbon nanotubes are presented. New radio filaments for 3D printing with MWCNTs have been created. Experimental samples were obtained from composite filaments by 3D printing. Also investigated is the ABS plastic brand Conductive with carbon fibers. Studies of electromagnetic characteristics were carried out in the SHF and EHF ranges. The frequency dependences of the complex permittivity for these materials are shown. The results show that ABS Conductive plastic has the best absorbing properties on microwave frequency, and composite plastics with MWCNTs of 2% or more on EHF.

A Compact Triple-Notch Band Ultra-Wideband Antenna

This paper proposed a compact ultra-wideband (UWB) antenna (17.5 × 20.5 mm2) with a triple-notch band characteristic to overcome the interference caused by the three narrow frequency bands that coexist within the ultra-wideband frequency ranging from 3.1 to 10.6 GHz as stipulated by the Federal Communication Commission (FCC). Two slots on the radiating patch and a copper trace on the ground plane of the antenna were introduced to reject the WiMAX, WLAN and SHF frequency bands. The dimensions of the slots and copper trace are optimized to achieve the desired band rejections. The compact size of the antenna is in line with the miniaturization requirement of modern wireless communication devices but at the same time is able to support multiple wireless communication services. The simulation result shows that the antenna can function over the UWB frequency range but with band rejections on the WiMAX band (from 3.2 GHz to 3.6 GHz, WLAN band) (from 5.15 GHz to 5.85 GHz) and SHF band (from 7.25 GHz to 8.395 GHz). The proposed antennas are simulated and designed in CST Microwave Studio® software and fabricated on a FR-4 substrate with a relative dielectric constant, er of 4.5, loss tangent, tan δ of 0.019 and thickness, h of 1.6 mm.

Dual Band Paper Substrate CPW Antenna for Wireless Applications

In this paper, a 15* 80 sized antenna is designed over a paper substrate to test its flexible properties. The proposed antenna feed by a grounded coplanar waveguide(GCPW) is stimulated and the measured results show the operating Dual Band of the antenna cover(3.34-3.62 GHz) and (5.92-6.24 GHz) with the reflection coefficient |S11|< -15dB.These frequency bands operate over SHF bands and hence supports Fixed Mobile Communication and WLAN applications.

Frequency Characteristics of Geometry-Based Clusters in Indoor Hall Environment at SHF Bands

This paper presents an analysis of geometry-based cluster frequency dependency at super-high-frequency bands, including 3, 10, and 28 GHz. First, multipath components were extracted from the measured data by using the space-alternating generalized expectation-maximization algorithm. Then, geometry-based clusters were estimated by using the enhanced scattering point-based KPowerMeans (SPKPM) algorithm. Finally, the frequency dependencies of their scattering intensities were discussed with the assistance of physical optics. The analysis results showed that the SPKPM could also be applied to obtain reasonable scattering locations at multiple frequencies in most cases. In addition, reflection on smooth surfaces was the dominant mechanism of clustering where there was no frequency dependence, whereas diffraction, scattering, and shadowing were significant causes of frequency dependence. Assuming that the line-of-sight is obstructed, diffraction, scattering, and shadowing accounted for 30–40% of the entire channel in terms of power, which was not negligible and thus the channel was largely frequency-dependent. The analysis results are expected to provide crucial insights for multiple-frequency channel modeling for fifth-generation wireless systems.

The estimation of the characteristics of secondary radiation of the model of SU-27 swing fighter in SHF, UHF and VHF band

У статті обґрунтована актуальність дослідження характеристик радіолокаційного розсіяння сучасних повітряних об'єктів за допомогою методів математичного моделювання. Сучасний рівень розвитку обчислювальної техніки дозволяє вирішити це завдання і реалізовувати достатньо складні методи математичного моделювання вторинного випромінювання повітряних об'єктів з необхідною точністю для використання на практиці. Проведено аналіз існуючих методів оцінювання вторинного випромінювання повітряних об'єктів, які дозволяють досягти поставленої мети – отримання характеристик радіолокаційного розсіяння моделі багатоцільового винищувача Су-27. Ряд переваг у цьому випадку мають методи, що засновані на інтегральних уявленнях класичної електродинаміки та їх короткохвильових асимптотиках. Розроблена модель поверхні літака Су-27 та наведені основні розрахункові співвідношення, на основі яких розроблено метод чисельного моделювання. Наводяться результати розрахунку характеристик радіолокаційного розсіяння (ефективної поверхні розсіяння, некогерентної ефективної поверхні розсіяння, середніх та медіанних значень ефективної поверхні розсіяння) літака Су-27 для різних частот опроміювання зондувального сигналу. Отримані результати можуть бути використані на етапі модернізації існуючих і проектування перспективних вітчизняних радіолокаційних систем з метою оцінювання можливостей різних конструктивних варіантів систем, що розглядаються, щодо виявлення, супроводження та розпізнавання повітряних об’єктів даного типу. Крім того використання результатів, які отримуються за допомогою розробленого методу математичного моделювання, дозволить оптимізувати конструкцію перспективних вітчизняних літальних апаратів з метою зменшення їх радіолокаційної помітності. Розроблений метод дозволяє проводити чисельне моделювання радіолокаційних характеристик повітряних об'єктів різних типів при заданих поляризаціях, просторових і часово-частотних параметрах зондувальних сигналів в інтересах розв'язання широкого кола прикладних задач радіолокації.

Electromagnetic Noise Suppression Composite Sheets Made of Hexagonal Ferrite Particles

In the early stage 5th generation mobile phone system, it is expected to use high frequencies up to the SHF band (3 to 30 GHz) [1]. Therefore new noise countermeasure material is necessary in this band [2]. In this paper, we studied M-type, Y-type and Z-type hexagonal ferrite fine particles in composite form with epoxy resin, to find candidate for this application through SEM observation, XRD, DC hysteresis loop, high frequency complex permeability, and conduction noise suppression effect on micro stripline(MSL).Preparation and properties of fine particles– While Sr and Ba hexagonal ferrite materials are known as permanent magnet materials, they are also useful as high frequency materials whose ferromagnetic resonance (FMR) frequency exceeds 20 GHz, which corresponds to the center frequency of noise suppression exceeds 20 GHz. Firstly we followed a known direction to reduce magneto-crystalline anisotropy by a 1 – 2 at% substitution of Fe3+ions by a combination of metal ions such as Co2+and Ti4+. Table Ishows list of test perticles; Z-type Ba 3 Zn 2−X Co x Fe 24 O 41 (x=1.25), Y-type Ba 2 Zn 2 Fe 12 O 22 , and M-type SrCo x Ti x Fe 2−x O 19 (x=1.4) [3]. The fired polycrystalline material was pulverized to obtain fine particles. The XRD pattern showed that the crystal structure is mainly composed of hexagonal crystals since the relative intensity and diffraction angle of the main diffraction peak agree with the values of the JCPDS database.Fabrication and properties of composite sheet– The fine particles were mixed with the epoxy resin at a volume ratio of about 50%. This mixed solution was dropped onto a polymer sheet and screen-printed with a metal squeegee to a certain thickness, then a composite sheet was obtained. On the premise of mounting the composite in the gap between the interposer substrate and the IC chip, the coating thickness was chosen as 50 ± 5 μm in total. The Y-type fine particles were almost flat in planar state even after grinding and the Z-type and M-type fine particles were close to spherical and randomly oriented, according to the SEM observation. The coercive force obtained from the DC magnetization curve is 8 to 9 Oe in a composite sheet of Y-type and Z-type fine particles (hereinafter referred to as Y-type sheet, etc.), which is smaller by one order of magnitude than the M-type sheet (90 Oe). Correspondingly, the maximum value of the relative imaginary part permeability was the maximum of 1.8 for the Y-type sheet, and it was 0.9 for the Z-type sheet, and 0.3 for the M-type sheet. As shown in Fig. 1, measured input loss ratio [4] $\mathrm {P}_{{\mathrm {loss}}}/ \mathrm {P}_{{\mathrm {in}}}=1- ( \vert \mathrm {s}_{11} \vert ^{2}+\vert \mathrm {s}_{21} \vert ^{2})$with a network analyzer (Agilent Technologies, Model N5244A) became the larger as the relative imaginary part magnetic permeability became higher. The measured $\mathrm {P}_{\mathrm {loss}}/ \mathrm {P}_{\mathrm {in}}$was as high as 0.21 at 6 GHz, which should correspond to more than 5 dB conduction noise suppression. This research was supported in part by the R&D program of the Radio Use, Ministry of Internal Affairs and Communications, and the Cooperative Research Project Program of the RIEC (H27-B05) Tohoku University.

Frequency Dependency of Path Loss Between Different Floors in An Indoor Office Environment at UHF and SHF Bands

Frequency Dependency of Path Loss Between Different Floors in An Indoor Office Environment at UHF and SHF Bands

Improvement of the Frequency Characteristics for RFID Patch Antenna based on C-Shaped Split Ring Resonator

In this paper, we present a new technique for improving frequency characteristics and miniaturizing the geometric dimension of the RFID patch antenna that operates in the SHF band. This technique consists in implementing a periodic network based on a new model of a split C-ring resonator on the square slots of radiating rectangular patch antenna. The results of the simulation have proved that the proposed technique has an excellent radiation efficiency and size reduction compared to the reference patch antenna.

Design and evaluation of noise suppression sheet for GHz band utilizing magneto-elastic effect

Feasibility of realizing a noise suppression sheet (NSS) coping with the low SHF band such as the 5GHz band was investigated, which was composed of soft magnetic metal flakes dispersed in a polymer. For suppressing noises, the higher frequency one of the bimodal frequency dispersion (lower frequency one: Dispersion DII, higher frequency one: Dispersion DIII) seen in the imaginary permeability (μ″; magnetic loss component) spectrum of the NSS was aimed to utilize. Referring to the previous finding that Dispersion DIII is originated from a magneto-elastic effect, several magnetic composite sheets were prepared using various alloy flakes with different saturation magnetostriction (λs), and their frequency (fr(DIII)) and magnitude (μ″(DIII)) of Dispersion DIII were investigated. It was found that the NSS containing flakes with higher λs exhibited higher fr(DIII) and higher μ″(DIII)/μ″(DII), which was ratio of μ″(DIII) to the magnitude of Dispersion DII (μ″(DII)). The fr(DIII) for the NSS having the highest λs containing Fe-Co alloy flake reached 7.45GHz and μ″ in the 5GHz band was approximately twice as high as the conventional NSS containing Fe-Si-Al alloy flake. For transmission attenuation power ratio (Rtp) when an NSS was placed on a microstrip line with characteristic impedance of 50Ω, NSS with larger fr(DIII)2·μ″(DIII)∝Ms2 (Ms: saturation magnetization), which theoretically gave the frequency limit of imaginary permeability for a thin film, exhibited larger Rtp in the low SHF band. These results suggested that an NSS containing a magnetic flake material with both large λs and Ms was suitable for suppressing low SHF band noises.

An Electrical Model to U-Slot Patch Antenna with Circular Polarization

The microstrip antenna is one of the best antenna structures, due to its low cost and compact design. In this paper, a coaxial feed circularly polarized square patch antenna is designed using the U-slot. The proposed antenna is suited for the RFID readers in the SHF band. This structure of antenna of FR-4 substrate (dielectric constant = 3.5), is capable to cover the range of frequency of 2.4 to 2.5GHz. The size of patch is 25*25 mm2. An equivalent electrical model of this antenna was proposed and simulated by the ADS software. The simulated gain is 4.189 dBi and S11 bandwidth is about 100 MHz. Analysis and modeling of the proposed antenna was carried out using the CST and HFSS simulator based on the finite element method. The simulation results obtained are presented and discussed.

A Study on the Design and Implementation of SHF band OMUX for Satellite Communication

A Study on the Design and Implementation of SHF band OMUX for Satellite Communication

5G Distributed Massive MIMO with Ultra-High Density Antenna Deployment in Low SHF Bands

5G Distributed Massive MIMO with Ultra-High Density Antenna Deployment in Low SHF Bands

Performance Improvement of RFID Reader Antenna Using Spiral Split Ring Resonators

In this paper, a dipole antenna with Spiral Split Ring Resonators (SSRR) for RFID reader is proposed, this novel miniaturized metamaterials is characterized by a very small size compared to the classical resonator introduced by J. Pendry, then by the constituting of a negative permeability (µeff) around the resonance frequency. The dipole antenna based on metamaterials is proposed to increase the performance (Directivity, Gain and bandwidth) and reducing the dimensions of RFID reader antennas that operate in the SHF band (2.4-2.485GHz).

디지털 위성 중계기용 SHF 대역 저잡음 증폭장치 설계 및 구현에 대한 연구

본 연구는 디지털위성중계기용 SHF 대역 저잡음증폭장치의 설계 및 구현에 대해 기술하였다. 잡음지수 최소화를 위하여 저잡음 증폭소자인 HEMT(: High Electron Mobility Transistor)소자를 적용하였고, 우주환경에 대한 사전 시뮬레이션 분석을 통하여 장비 오동작 가능성을 최소화 시켰다. 발사환경 시 발생하는 진동 및 우주방사능에 의한 TID(: Total Ionizing Dose)에 대한 시뮬레이션을 통해 신뢰성 있는 저잡음증폭장치를 설계하였으며, 제작 후 주요 성능지표에 대해 만족여부 확인 및 사전 성능 시뮬레이션 결과와 비교하였다. This study describes the design and implementation of SHF band Low Noise Amplifier of Digital Satellite Communication. We have applied to HEMT part to minimize Noise Figure of system. and minimized the potential for the occurrence of such erroneous operation of equipment through the simulations of the space environment. We designed a reliable Low Noise Amplifier through simulation for a TID according to the vibration generated during the launch and space radiation environment, and compared pre-simulation of main performance results to test results about main performances of Low Noise Amplifier after production.

New CRLH-Based Planar Slotted Antennas with Helical Inductors for Wireless Communication Systems, RF-Circuits and Microwave Devices at UHF–SHF Bands

Two novel planar slotted-antennas (PSAs) are presented that exhibit good radiation characteristics at the UHF---SHF bands. The proposed antennas are constructed using metamaterial unit-cells constituted from capacitive slots etched in the radiating patch and grounded spiral shaped inductive stubs. The proposed PSA design is fabricated on a commercially available dielectric substrate, i.e. Rogers RO4003 with permittivity of 3.38 and thickness of 1.6 mm. The first PSA comprising five symmetrical unit-cells of slot---inductor---slot configuration operates over a wide bandwidth extending from 1 to 4.2 GHz with a peak gain of 1.5 dBi and efficiency of 35 % at 2 GHz. The second PSA consists of ten asymmetrical unit-cells of slot---inductor configuration on the same size of substrate as the first PSA, enhances the antenna gain by 2 dB and efficiency by 25 % and operates over 0.75---4.5 GHz. The asymmetrical unit-cell effectively increases the aperture size of the antenna without comprising its size. The electrical size of the antenna is 0.083ź0 × 0.033ź0 × 0.005ź0, where free-space wavelength (ź0) is 1 GHz.