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1

Substrate size impact on the radiation pattern of a sub-THz printed antenna

Yashchyshyn Yevhen, Tokarsky Peter

International Journal of Electronics and Telecommunications

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2026

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Vol. 72, No. 1

art. no. 38, s.1--8

EN

In this paper, we study the effect of the transverse dimensions of a "thick" substrate on the printed antenna radiation properties in the sub-THz range. A four-element seriesfed dipole array operating at 100-116 GHz is chosen as a test antenna. It is printed on a rectangular grounded aluminum oxide substrate (99.5% Alumina) with a thickness of 0.05 mm, 0.1 mm, or 0.2 mm, in which only the fundamental mode of the surface wave can exist. The studies used the full-wave electromagnetic simulation method with Altair FEKO 2022 software. It is shown that pulsations can appear in the main beam of the antenna on atruncated substrate, the frequency of which increases proportionally to the width of the substrate, and the amplitude grows with increasing its thickness. With an increase in the substrate size, quasi-periodic variations in the antenna normalside directivity and gain are also observed, the period of which is equal to two surface wavelengths. The antenna radiation efficiency weakly depends on the substrate width, but increases noticeably with its thickening. It is shown that using a metasurface that significantly weakens the surface wave is an effective means of reducing the substrate edges' effect on the antenna characteristics.

2

Design and analysis of multi-angle diffraction efficiency distribution for all-dielectric transmissive grating

Zhu Jiaze, Feng Huizhen, Huang Wenkang, Xu Jianfeng, Tian Ying, Jia Mian, Gu Manna

Optica Applicata

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2025

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Vol. 55, nr 2

225--239

EN

This paper presents the design of a C-shaped all-dielectric metasurface. The C-shaped dielectric structure and its substrate materials are Si and SiO2, respectively. This unit structure enables independent control of the amplitude and phase of cross-polarized transmitted terahertz electromagnetic waves. Byusing parameter scanning method, four different unit structures were optimized at 0.1 and 1 THz, achieving unit phase distributions with a 45° interval within the range of 0° to 180°. Additionally, a 180° phase jump occurs when the unit structure rotates by 90°, achieving full phase control over the 360° range. By adjusting the orientation of the unit structure, arbitrary amplitude control can also be achieved. The highest transmission coefficients for the unit structures at 0.1 and 1 THz are 0.62 and 0.56, respectively. To verify the control capability of the designed unit structure on transmitted electromagnetic waves, metasurface gratings were designed based on these unit structures, enabling arbitrary control of diffraction angles and orders. At both frequencies, two different metasurface gratings were designed with diffraction orders of (m = +1) and (m = +1, +3). Near-field and far-field simulations of the super-grating structures were conducted using the finite integral method. The designed metasurface grating demonstrates effective control of cross-polarized transmitted waves, and its deflection angles conform to diffraction laws.

3

Analysis and design of superstrate for gain enhancement of meta-surface antenna

Boonying Komkris, Nugoolcharoenlap Ekasit

Przegląd Elektrotechniczny

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2024

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R. 100, nr 5

178--183

EN

This article is focusing on a technical design of superstrate layer using 3x3 unit cells to enhance the antenna gain, operating at the center frequency of 2.50 GHz. In fabrication of the proposed antenna, a microstrip antenna is fed by a 50Ω-SMA 3.50 mm connector, and the superstrate is designed using 9 octagon ring-shaped unit cells, which are integrated to form a meta-surface antenna (MS antenna). A prototype antenna is manufactured on an FR4 substrate material with a relative permittivity (ԑr) of 4.3 and a height of 1.6 mm. The prototype antenna is great matched to achieve |S11| of -31.55 dB, exhibits a gain enhancement of >2.0 dBi and achieves a maximum gain of >6.0 dBi. Additionally, the proposed design has been fabricated to validate |S11|, gain, and radiation patterns as comparing with the simulated results that will be presented. Evidently, the simulated results reasonably align with the experimental findings.

PL

W artykule skupiono się na projekcie technicznym warstwy superstratnej wykorzystującej ogniwa elementarne 3x3 w celu zwiększenia zysku anteny, pracującej na częstotliwości środkowej 2,50 GHz. Podczas produkcji proponowanej anteny antena mikropaskowa jest zasilana przez złącze 50 Ω-SMA 3,50 mm, a superstrata została zaprojektowana przy użyciu 9 ośmiokątnych ogniw elementarnych w kształcie pierścienia, które są zintegrowane, tworząc antenę metapowierzchniową (antena MS). Prototypowa antena jest produkowana na podłożu FR4 o przenikalności względnej (ԑr) wynoszącej 4,3 i wysokości 1,6 mm. Prototypowa antena jest doskonale dopasowana do osiągnięcia |S11| -31,55 dB, wykazuje wzmocnienie wzmocnienia >2,0 dBi i osiąga maksymalne wzmocnienie >6,0 dBi. Ponadto proponowany projekt został opracowany w celu sprawdzenia |S11|, wzmocnienia i wzorców promieniowania w porównaniu z symulowanymi wynikami, które zostaną zaprezentowane. Najwyraźniej symulowane wyniki są w rozsądny sposób zgodne z wynikami eksperymentów.

4

The effect of sound-absorbing walls on the acoustic properties of the modelled unit cell of a sound-absorbing metamaterial

Chojak Aleksandra, Binek Wojciech, Chojnacki Bartłomiej, Pawlik Jan, Idczak Julia

Vibrations in Physical Systems

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2023

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Vol. 34, nr 2

art. no. 2023212

EN

Cavity-based metamaterials are usually designed for sound absorbing or sound scattering properties. They are built of combinations of ducts and slits, which in the case of acoustic absorbers are designed to maximize the sound absorption at resonance frequencies through the appearance of the viscothermal losses. The unit cells are designed under the assumption of perfectly rigid walls, shared by all the analytical models. Sound absorbing properties of the structures result from viscothermal losses in small ducts. The paper discusses the influence of adding sound absorption to the walls in the numerical model on the results of the observed sound absorption coefficient. It is demonstrated that the resulting sound absorption of the structure varies with changing sound absorption coefficient of the walls of the structure. The same observations are made for 3D-printed measurement samples, showing the importance of including the sound absorption of the walls in the modelling process.

5

Modulation Mechanism of Acoustic Scattering in Underwater Corner Reflectors with Acoustic Metasurfaces

Du Jiaman, Peng Zilong, Ge Lili, Lyu Shijin, Zhou Fulin, Liu Yan

Archives of Acoustics

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2023

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Vol. 48, No. 4

465--473

EN

Using the tunderwater corner reflector (CR) to simulate the acoustic scattering characteristics of the military target is a new technology to counter active sonar detection. Existing underwater CRs only have the ability to interfere with the acoustic field, but have limitations in acoustic wave modulation. Therefore, acoustic metasurfaces applied on CRs to enhance the ability of acoustic wave modulation has a great application prospect. A fast prediction method based on the Kirchhoff approximation (KA) and the ray tracing theory is proposed to calculate the acoustic scattering characteristics of CR with acoustic metasurfaces in grooves array type. The accuracy of the method is verified by the finite element method (FEM) simulation. The modulation effect of CR with grooves array in different gradient combinations on the structural scattering acoustic field is analyzed. The research shows that the CR with different combinations of the acoustic metasurface has an obvious modulation effect on the amplitude of the acoustic waves and the deflection of acoustic field. In particular, the grooves array in combination with positive and negative gradients has an obvious deflection impact on the scattering acoustic field.

6

Broadband convolutional scattering characteristics of all dielectric transmission Pancharatnam–Berry geometric phase metasurfaces

Li Yiyun, Jin Yongxing, Jing Xufeng, Shi Lijiang, Li Chenxia, Hong Zhi

Optica Applicata

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2022

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Vol. 52, nr 2

297--323

EN

In order to obtain the broadband scattering characteristics, we propose a superperiodic cell structure with all-dielectric material to construct Pancharatnam–Berry geometric phase encoding metasurfaces. Because we cannot design or prepare infinitesimal coding unit particles, according to the generalized Snell’s law, we can only obtain discrete scattering angle regulation for the basic coding metasurface sequence. In order to obtain multi-angle scattering characteristics, we introduce the Fourier convolution principle in digital signal processing on the Pancharatnam–Berry geometric phase encoding metasurfaces. By using the addition and subtraction operations on two encoding metasurface sequences, a new encoding metasurface sequence can be obtained with different deflection angle. Fourier convolution operations on the encoding metasurfaces can provide an efficient method in optimizing encoding patterns to achieve continuous scattering beams. The addition and subtraction methods are also applicable to the checkerboard coding mode. The combination of Fourier convolution principle and Pancharatnam–Berry phase coded metasurface in digital signal processing can realize more powerful electromagnetic wave manipulation capability.

7

Oddziaływanie płaskiej fali elektromagnetycznej z metapowierzchnią złożoną z rezonatorów SRR 2,5 GHz

Budnarowska Magdalena, Mizeraczyk Jerzy

Przegląd Elektrotechniczny

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2021

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R. 97, nr 2

39--42

PL

W artykule przedstawiono wyniki numerycznej symulacji oddziaływania płaskiej fali elektromagnetycznej z metapowierzchnią zbudowaną z pojedynczych rozszczepionych rezonatorów pierścieniowych SRR (Split-Ring Resonator) o częstotliwości rezonansowej 2,5 GHz (znajdującej się m.in. w paśmie LTE/WiFi obecnym w środowisku elektromagnetycznym). Obliczenia numeryczne wykonano w środowisku CST Studio dedykowanym rozwiązywaniu zagadnień pola elektromagnetycznego. Symulacje oddziaływania płaskiej fali elektromagnetycznej z metapowierzchnią SRR wykonano dla odległości między pojedynczymi strukturami metamateriałowymi SRR wynoszącej λ/20, gdzie λ = 119,916 mm (odpowiadającej częstotliwości f = 2,5 GHz). W symulacji zastosowano nowe wizualizacyjne podejście do analizy i sposobu opisu oddziaływania promieniowania elektromagnetycznego z badaną strukturą metamateriałową. Obliczenia współczynników absorpcji, odbicia i transmisji płaskiej fali elektromagnetycznej padającej na metapowierzchnię SRR wykazały, że powierzchnia metamateriałową SRR jest strukturą silnie odbijającą promieniowanie elektromagnetyczne o częstotliwości równej częstotliwości rezonansu magnetycznego struktury. Obliczenia te zostały potwierdzone przez wizualizację zjawiska odbicia płaskiej fali elektromagnetycznej od metapowierzchni SRR. Zastosowana w tej pracy metoda numeryczna wydaje się być atrakcyjna dla wizualizacyjnego sposobu opisu zjawisk elektromagnetycznych w metamateriałach.

EN

Results of the numerical simulation of the interaction of a plane electromagnetic wave with a metasurface consisting of split-ring resonator (SRR) unit cells of a resonant frequency f = 2.5 GHz (located, among others, in the LTE / WiFi band present in the electromagnetic environment) are presented in this paper. The numerical calculations were performed using the CST Studio solver dedicated to solving electromagnetic problems The simulations of the interaction of the plane electromagnetic wave with the SRR metasurface were performed for a distance between the SRR metamaterial unit cells equal to λ/20, where λ = 119.916 mm (corresponding to f = 2.5 GHz. A new visualization approach has been introduced in this work to present effects of the interaction of the electromagnetic radiation with the metamaterial structure. The calculations of the absorption, reflection and transmission coefficients of the incident plane electromagnetic wave showed that the SRR metasurface strongly reflects the plane electromagnetic wave at a frequency equal to the magnetic resonance frequency of the SRR metasurface. These calculations were confirmed by visualizing the phenomenon of plane electromagnetic wave reflection from the SRR metasurface. The numerical method used in this work seems to be attractive for the visualization of the electromagnetic phenomena in metamaterials.

8

A novel type of wearable dual-band antenna based on coplanar waveguide feeding for wearable wireless communications

He Zhengrui, Jin Jie

Optica Applicata

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2021

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Vol. 51, nr 2

159--170

EN

A flexible and compact coplanar waveguide feed (CPW-fed) wearable antenna is introduced for wireless wearable communications applications at the industrial scientific medical (ISM) band. The proposed antenna consists of copper, which is used as the radiation patch and ground planes printed on the same side of polyimide flexible substrate. The overall size of the antenna is 30 mm × 28 mm × 0.08 mm, the results show that the antenna can transmit and receive signals in two frequency bands of 1.89–2.67 GHz and 3.02–3.23 GHz, in which radiating properties are characterized and agree well with the simulation results. The antenna is bent in different directions to further investigate the reflection coefficient and corresponding effect on the antenna under bending. The center frequency of the antenna is slightly shifted towards higher and lower frequencies when antenna is bent in X-axis and Y-axis, respectively. Furthermore, the wearability of the antenna is verified when the antenna is placed on different parts of the human body such as wrist and chest. Hence, the proposed flexible antenna is a suitable candidate for wearable wireless communication applications.

9

Badanie wpływu mechanicznego odkształcenia metapowierzchni bazującej na komplementarnym rezonatorze pierścieniowym na jej właściwości rezonansowe w zakresie mikrofalowym i terahercowym

Łopato Przemysław, Herbko Michał

Badania Nieniszczące i Diagnostyka

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2020

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nr 1-4

32--37

PL

Metamateriały znajdują coraz większe zastosowanie w wielu gałęziach nauki i przemysłu. Składają się z matrycy elementów strukturalnych (komórek) o wymiarach kilkukrotnie mniejszych niż długość fali elektromagnetycznej, przy jakiej mają pracować. Ich unikalne właściwości rezonansowe można stosunkowo łatwo kontrolować przez odpowiednie zaprojektowanie geometrii elementów strukturalnych. Odstępstwa od tej geometrii wpływają na stan rezonansu, co może być wykorzystane do określenia np. stopnia deformacji. W niniejszej pracy przeanalizowano wpływ odkształcenia metapowierzchni powodowanego przez zewnętrzne wymuszenie mechaniczne (rozciąganie) na rezonansową charakterystykę częstotliwościową w zakresie mikrofalowym i terahercowym. Opracowano modele numeryczne metapowierzchni o elemencie strukturalnym w postaci rezonatora z rozdzielonymi pierścieniami (ang. split ring resonator, SRR) oraz określono zmiany częstotliwości rezonansowych wywołane działaniem zewnętrznej siły rozciągającej. Uzyskane liniowe zależności pomiędzy zmianą częstotliwości a stopniem deformacji struktury metapowierzchni pozwalają na wykorzystanie w przyszłości tej technologii w bezprzewodowym monitoringu strukturalnym (ang. structural health monitoring, SHM).

EN

Metamaterials are increasingly used in many branches of science and industry. They consist of a matrix of cells / elements with dimensions several times smaller than the operating wavelength. Their unique resonance properties can be relatively easily controlled by properly designing the geometry of their structural elements (cells). Deviations from this geometry affect the state of resonance which can be used to determine the degree of deformation. In this work, the effect of metasurface deformation caused by external mechanical excitation (stretching) on the resonance frequency in the microwave and terahertz range has been analyzed. Numerical models of the metasurfaces with a structural element in the form of split ring resonators (SRR) were developed and changes in resonance frequencies caused by external tensile force were determined. Obtained linear relationships between the change in frequency and the degree of deformation of the metasurface structure allow for the use of this technology in the future in wireless structural health monitoring (SHM).