2022 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2022

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Lighting conditions in home office and occupant’s perception: Exploring drivers of satisfaction
- Natalia Giraldo Vasquez
- Cláudia Naves David Amorim
- Barbara Matusiak
- Julia Kanno
- Natalia Sokół
- Justyna Martyniuk-Pęczek
- Sergio Sibilio
- Michelangelo Scorpio
- Yasuko Koga
2022 Full text ENERGY AND BUILDINGS
This paper depicts lighting home office conditions within different countries and continents, emphasizing the user’s satisfaction with the visual environment. The scope of this article is to investigate the drivers of participants’ satisfaction with the lighting conditions at the home office. The study was developed by a team of international experts working together on Subtask A: User perspective and requirements, Task 61 IEA (International Energy Agency): Solutions for daylighting and electric lighting. An online survey was launched in December 2020 and closed on March 2021. The survey was implemented in the native languages of six participant countries (Brazil, Colombia, Denmark, Italy, Poland, and Japan) using Google Forms, and its dissemination was via various social media platforms. Measures of association between variables and predictive tests were run to explore which investigated aspects drove participants’ satisfaction with the lighting conditions at the home office. We found some differences in satisfaction due to participants’ sex, occupation, and participants’ continent of residence. Females were more satisfied with daylight than males. Associations between the perception of seven light descriptors and satisfaction showed differences between East Asians and the rest of the participants, which might be related to the high dependence of the formers on electric lighting even when daylight is available. Design features as southern facades, the distance from the working area to the window, type of internal sun shading were related to daylighting satisfaction. Moreover, satisfaction with the general light level and the electric light was higher for those participants who did not need to switch on the ceiling, floor, or desk lamp when daylight was available. We found that an external view composed of 3 layers and the sky’s visibility afforded a higher satisfaction with the window view. Having an independent room for the home office appeared to be related to a higher willingness to continue in the home office. Likewise, higher satisfaction with the overall visual environment and window view appeared to increase the willingness to continue working from home. Bridging the gap amid cultural differences and daylighting and lighting satisfaction is needed, particularly, relational studies between design features –as a response of cultural, climatic, and local practices- and occupants’ preferences and acceptability.
Limits of enhanced of macro- and meso-scale continuum models for studying size effect in concrete under tension
- Patryk Chodkowski
- Jerzy Bobiński
- Andrzej Tejchman-Konarzewski
2022 European Journal of Environmental and Civil Engineering
The paper investigates a mechanical quasi-static size effect in concrete during splitting tension at the macro- and meso-level. In experiments, five different diameters of cylindrical concrete specimens were tested. Twodimensional plane strain finite element (FE) simulations were carried out to reproduce the experimental size effect. The size effect in experiments by Carmona et al. was also simulated. Two enhanced continuum concrete models (elasto-plastic and damage) were used which were enriched in softening by a characteristic length of micro-structure with the help of a nonlocal theory. In macro-level simulations, the effect of crucial geometric and material parameters on the size effect was carefully studied such as the width of loading/supporting strips, concrete fracture energy in tension,concrete compressive strength and stiffness of loading/supporting strips. The focus was on the distribution of primary and secondary strain localization zones. In addition, some 2D size effect calculations were performed within enriched elasto-plasticity at the meso-scale by considering the real heterogeneous meso-structure of concrete from the front side of experimental specimens. The calculated size effect on the splitting tensile strength at the macro- and meso-scale proved to be weaker than in our experiments. Shortcomings of enhanced continuum models for size effect simulations were outlined.
Limits Theorems for Random Walks on Homeo(S1)
- Gabriela Łuczyńska
- Tomasz Szarek
2022 JOURNAL OF STATISTICAL PHYSICS
The central limit theorem and law of the iterated logarithm for Markov chains corresponding to random walks on the space Homeo(S1) of circle homeomorphisms for centered Lipschitz functions and every starting point are proved.
Linear and Nonlinear Optical Properties of Azobenzene Derivatives Modified with an (Amino)naphthalene Moiety
- Marta Dudek
- Anna Kaczmarek-Kędziera
- Radosław Deska
- Jakub Trojnar
- Patryk Jasik
- Piotr Młynarz
- Marek Samoć
- Katarzyna Matczyszyn
2022 Full text JOURNAL OF PHYSICAL CHEMISTRY B
The design of two-photon absorbing azobenzene (AB) derivatives has received much attention; however, the two-photon absorption (2PA) properties of bis-conjugated azobenzene systems are relatively less explored. Here, we present the synthesis of six azobenzene derivatives and three bisazobenzenes substituted (or not) at para position(s) with one or two amino group(s). Their linear and nonlinear absorption properties are studied experimentally and theoretically. The switching behavior and thermal stability of the Z-isomer are studied for unsubstituted mono- (1a, 2a) and bis-azobenzene (3a) compounds, showing that when the length of the π system increases, the half-life of the Z-isomer decreases. Moreover, along with the increase of π-conjugation, the photochromic characteristics are impaired and the photostationary state (PSS) related to E−Z photoisomerization is composed of 89% of the Z-isomer for 2a and 26% of the Z-isomer for 3a. Importantly, the 2PA cross-section increases almost five-fold on extending the π-conjugation (2a vs 3a) and by about one order of magnitude when comparing two systems: the unsubstituted π-electron one (2a, 3a) with D-π-D (2c, 3c). This work clarifies the contribution of π-conjugation and substituent effects to the linear and nonlinear optical properties of mono- and bis-azobenzene compounds based on the experimental and theoretical approaches.
Linking music data in executable documents
- Adam Kaczmarek
2022
This paper presents the application of Interactive Open Document Architecture (IODA) to music and video data. This architecture was design to create multilayer documents which consist of many files. The paper shows the method of creating media documents on the basis of IODA. These kind of documents were called IODA Media Documents (IMD). IMD have links that connect many different kinds of files containing music and video data. A group of files became a single entity which can be easily processed by computer applications.
Linking optical and electronic properties to photoresponse of heterojunctions based on titania nanotubes and chromium, molybdenum, and tungsten oxides
- Łukasz Haryński
- Adrian Olejnik
- Jakub Karczewski
- Jacek Ryl
- Katarzyna Grochowska
- Katarzyna Siuzdak
2022 OPTICAL MATERIALS
The development of photosensitization strategies for titanium dioxide is necessary for the enhancement of its optical and electronic properties towards its application potential in solar photoelectrochemistry. In this work, significant differences in the photosensitizing capability of the 6th group transition metal oxides applied on the surface of titania nanotubes are reported. For the first time, correlations between the experimentally determined Tauc coefficients, sample photoresponse, and ab-initio simulated properties of the heterojunctions are established. Experimental results show undoubtedly that the decoration of TiO2 nanotubes with chromium oxides leads to the enhanced photoresponse, which originates from the interplay of mid-gap states and both direct and indirect nature of the transitions contributing to the optical absorption. The opposite tendency and decrease of photocurrent were found for molybdenum and tungsten oxides which exhibited forbidden nature of dominating transition. Although computations report intraband states in all interfaces, experimentally only chromium oxides contribute to the photocurrent. The uniqueness of this interface lies in the highest density of states in the vicinity of the conduction band and the low energy difference between the direct and indirect transitions of the innate chromium oxide. The obtained results demonstrate that the determination of the Tauc exponent and the nature of optical transition are more reliable experimental predictors of the photoactivity enhancement in the heterojunctions than the value of the band gap.
Ln2(SeO3)2(SO4)(H2O)2 (Ln=Sm, Dy, Yb): A Mixed‐Ligand Pathway to New Lanthanide(III) Multifunctional Materials Featuring Nonlinear Optical and Magnetic Anisotropy Properties
- Ebube E. Oyeka
- Michał Winiarski
- Hanna Świątek
- Wyatt Balliew
- Colin D. McMillen
- Mingli Liang
- Maurice Sorolla II
- Thao Tran
2022 Full text ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
Bottom-up assembly of optically nonlinear and magnetically anisotropic lanthanide materials involving precisely placed spin carriers and optimized metal-ligand coordination offers a potential route to developing electronic architectures for coherent radiation generation and spin-based technologies, but the chemical design historically has been extremely hard to achieve. To address this, we developed a worthwhile avenue for creating new noncentrosymmetric chiral Ln3+ materials Ln2(SeO3)2(SO4)(H2O)2 (Ln=Sm, Dy, Yb) by mixed-ligand design. The materials exhibit phase-matching nonlinear optical responses, elucidating the feasibility of the heteroanionic strategy. Ln2(SeO3)2(SO4)(H2O)2 displays paramagnetic property with strong magnetic anisotropy facilitated by large spin-orbit coupling. This study demonstrates a new chemical pathway for creating previously unknown polar chiral magnets with multiple functionalities.
Load path sensitivity and multiaxial fatigue life prediction of metals under non-proportional loadings
- Qing-Yun Deng
- Shun-Peng Zhu
- Xiaopeng Niu
- Grzegorz Lesiuk
- Wojciech Macek
- Qingyuan Wang
2022 INTERNATIONAL JOURNAL OF FATIGUE
Engineering components often operate under complex loadings, in which the variable amplitude multiaxial stresses are raised by geometric discontinuities including holes, grooves, fillets and shoulders, etc. Besides, the non-proportional loading will lead to the rotation of maximum principal stress/strain and additional fatigue damage of structural elements in service. Consequently, the multiaxial and non-proportional loading have attracted increasing attentions. In this study, for distinguishing the effects of different load paths on fatigue life, a simple and applicable method to quantify the non-proportionality is defined, which comprehensively considers the influence of loadings on all material planes. A new equivalent strain damage parameter based on critical plane is proposed in this study. Specifically, to quantify the effect of non-proportional loading on fatigue damage, a non-proportional degree of loading on the generalized plane is developed. Coupling with the existing non-proportional coefficient, a novel fatigue damage parameter is derived by combining a non-proportional factor. Experimental data of 304 stainless steel, sintered porous iron and CuZn37 brass are utilized for model validation and comparison. Fatigue lives with different load paths are evaluated respectively. In comparison with the Fatemi-Socie (FS), Chen and Itoh models, proposed method more effectively evaluate the multiaxial fatigue life of materials under non-proportional loadings.
Local variability in snow concentrations of chlorinated persistent organic pollutants as a source of large uncertainty in interpreting spatial patterns at all scales
- Filip Pawlak
- Krystyna Koziol
- Klaudia Kosek
- Żaneta Polkowska
2022 Full text JOURNAL OF ENVIRONMENTAL QUALITY
Single point sampling, a widespread practice in snow studies in remote areas, due to logistical constraints, can present an unquantified error to the final study results. The low concentrations of studied chemicals, such as chlorinated persistent organic pollutants, contribute to the uncertainty. We conducted a field experiment in the Arctic to estimate the error stemming from differences in the composition of snow at short distances (1–3 m), including 13 single organochlorine pesticides and 6 polychlorinated biphenyls, thus providing the most detailed published dataset on the subject. We contrasted this variability with the uncertainty at larger spatial scales, both within one valley (regional scale, this study) and as described in the worldwide literature. The range of values for the coefficient of variation for local samples was 20–58% for single organochlorine pesticides (OCPs) and 33–54% for polychlorinated biphenyls (PCBs), and for regional samples it was 21–69% for OCPs and 65–93% for PCBs. We suggest that, to observe the actual changes in the concentration of selected compounds in snow, they should vary at the level of 40–60%, depending on the compound in question. The uncertainty margin remains much smaller than the current discrepancy between observation data and atmospheric deposition models considering snow, deeming field data on snow concentrations a useful ground-truthing dataset. However, field observations on spatial differences at all scales need to be interpreted with caution, and the dataset provided here on the local sampling uncertainty helps define the margins of such interpretations.
Locally sculptured modification of the electrochemical response of conductive poly(lactic acid) 3D prints by femtosecond laser processing
- Mateusz Cieślik
- Mirosław Sawczak
- Rafał Jendrzejewski
- Joanna Celej
- Wojciech Nogala
- Jacek Ryl
2022 Full text ELECTROCHIMICA ACTA
This manuscript presents an approach to sculpture high electrochemical activity of the 3D printed electrodes with poly(lactic acid) (PLA) matrix and carbon black (CB) filler by femtosecond laser (FSL) ablation. CB-PLA utility for electrochemical applications depends on a surface modification aiming to remove the PLA and uncover the conductive CB. We have discussed how laser pulse energy is critical for such an activation process. The best performance was obtained for 4.1 J cm−2, while scanning electron microscopy (SEM) shows only partial evaporation of PLA at lower energy densities. Next, we have confirmed the efficiency of locally sculptured CB-PLA surface activation by FSL treatment, obtaining high linearity between electrochemically active surface and FSL-treated surface from cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) studies. The electrode's efficient sculpturing of stripes 0.2 mm in width was confirmed with electrochemical microscopy (SECM). Finally, by using X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, we confirmed no significant oxidation of the CB filler after FSL treatment. We revealed significant differences with ablation by longer nanosecond laser pulses, where significant heat transferred to the electrode surface contributed to partial melting and re-solidification of the PLA, negatively influencing the activation efficiency.
Lokalizowanie terminala użytkownika z użyciem interfejsu NB-IoT
- Piotr Rajchowski
- Krzysztof Cwalina
- Jarosław Sadowski
2022 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
W artykule przedstawiono metodę estymacji położenia terminala użytkownika korzystając z sygnałów okazjonalnych nadawanych w łączu w dół w interfejsie NB-IoT. Zweryfikowano praktyczną zdolność estymacji położenia na testowym obszarze korzystając z sygnałów wzorcowych o zmiennej wartości stosunku sygnału do szumu oraz z różnym emulowanym profilem kanału radiowego. Dodatkowo przedstawiono metodę umożliwiającą zwięk-szenie dokładności estymacji położenia terminala bez konieczności zwiększania częstotliwości próbkowania sygnału radiowego
Long-Term GNSS Tropospheric Parameters for the Tropics (2001-2018) Derived from Selected IGS Stations
- Zofia Baldysz
- Grzegorz Nykiel
- Mariusz Figurski
2022 Full text
This paper describes dataset “Tropospheric parameters derived from selected IGS stations in the tropics for the years 2001-2018” contains GNSS-derived zenith tropospheric delay (ZTD), a posteriori corrected zenith wet delay (ZWD), and precipitable water vapour (PWV) time series. These troposphere-related data were estimated for the Jan 2001 – Dec 2018 period for 43 International GNSS Service (IGS) stations located across the global tropics. As one coherent strategy for the processing of the GNSS observations was adopted, the dataset is a robust source of long-term, homogeneous tropospheric time series, which can be used in meteorological and climate-related studies. It enables the examination of moisture patterns on numerous time scales, including seasonal and interannual variability.
Long-Term Measurement of Physiological Parameters – Child Dataset
- Małgorzata Szczerska
2022 Full text
The dataset titled “Long-term measurement of physiological parameters – child is one dataset” of the bigger series named Long-term measurement of physiological parameters. The dataset contains physiological parameter measurements such as skin temperature and resistance, blood pulse, as well as the stress detection marker, which can have a value of 0 when there is no stress detected or 1 when stress appeared. Additionally, the dataset contains information about the value of the device battery charge. The measurements were conducted for a long period of 120 minutes.
Long-term operating conditions for different sorption materials to capture phosphate from domestic wastewater
- Andrzej Jucherski
- Andrzej Walczowski
- Piotr Bugajski
- Krzysztof Jóźwiakowski
- Joanna Rodziewicz
- Wojciech Janczukowicz
- Shubiao Wu
- Magda Kasprzyk
- Magdalena Gajewska
- Artur Mielcarek
2022 Full text Sustainable Materials and Technologies
This paper presents the results of a study on the possibility of applying various configured filters filled with a mixture of Rockfos® and Leca® material for the effective capture of phosphate from domestic wastewater. The tests were carried out for two years at two wastewater flow rates (20 and 40 L/day) in three pairs of filtration columns with a volume of filter material equal to 20 liters each. Columns 1A and 1B were filled only with Rockfos®. Columns 2A and 2B contained Rockfos® and two 5-cm layers of Leca®. Columns 3A and 3B were filled with Rockfos® and a 10% addition of Leca®. A high phosphate removal efficiency was obtained at a level of 93.2 – 94.9% for all columns tested at a flow rate of 20 L/day with a retention time of 12 h. After 250 days of the experiment, the efficiency of phosphate removal decreased significantly, which was associated with a drop in the temperature of the inflowing wastewater (<10°C). The alkaline characteristic (11–12 pH) of the filter material promoted the removal of phosphate from the wastewater. The pH value of the treated wastewater gradually decreased from pH 12 on the first days of an experiment to pH below 9.0 after about 300 days of operation. Studies showed that Rockfos® material can be used successfully to capture phosphate from wastewater for the sustainable development of rural areas in the circular economy. When designing and building phosphate removal filters, it is recommended to use 1 m3 Rockfos® with the addition of Leca® in 1 m3/day of wastewater inflow.
Long-Term Stability of Benzodiazepines and Z-Hypnotic Drugs in Blood Samples Stored at Varying Temperatures
- Laura Banaszkiewicz
- Mateusz Woźniak
- Ewa Domagalska
- Michal Kaliszan
- Agata Kot-Wasik
2022 JOURNAL OF ANALYTICAL TOXICOLOGY
Benzodiazepines (BZDs) and Z-drugs are among the most commonly prescribed pharmaceuticals in the world and are considered standard care for various mental illnesses and for treatment of sleeping and anxiety disorders, alcohol withdrawal, muscle spasms and epilepsy. Some BZDs are not allowed as pharmaceuticals in many countries, and they are used as "designer benzodiazepines" (DBZDs). All these compounds are typically screened in routine toxicological analyses for forensic purposes. Knowledge of time-dependent decreases in drug concentrations during storage or transport of samples is of considerable significance and allows forensic toxicologists to achieve reliable data, proper interpretation and high-quality results. The aim of this study was to evaluate changes in the amounts of selected BZDs, DBZDs and Z-drugs in blood samples stored at various temperatures. The study involved BZDs (19), DBZDs (3) and Z-drugs (2) spiked into blank blood. Subsequently, the blood samples were stored at various temperatures (room temperature, 4°C, -20°C and -80°C) for up to six months. Analyses were performed at 1-2 week intervals using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The stability of compounds were evaluated under four temperature conditions over a 6 month. Some benzodiazepines were stable at all temperatures tested (e.g., diazepam, oxazepam, nordazepam, prazepam) and degradated of only 0-10%. The highest instability was observed for analyte samples kept at room temperature, and the losses in content for some compounds, e.g., lorazepam and chlordiazepoxide, were almost 100%. For other compounds, the stability was clearly different at each tested temperature. To the best of our knowledge, this is one of the first such comprehensive study of the long-term stability of benzodiazepines covering a wide range of different storage temperatures.
Low energy inelastic electron scattering from carbon monoxide: II. Excitation of the b3Σ+, j3Σ+, B1Σ+, C1Σ+ and E1Π Rydberg electronic states
- Mateusz Zawadzki
- Murtadha Khakoo
- Ahmad Sakaamini
- Logan Voorneman
- Luka Ratkovich
- Zdeněk Mašín
- Amar Dora
- Russ Laher
- Jonathan Tennyson
2022 JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
In this second part of a two part paper (first part: Zawadzki et al (2020 J. Phys. B: At. Mol. Opt. Phys. 53 165201)) we present differential scattering cross sections for excitation of several Rydberg electronic states of carbon monoxide by electron impact. The first part concerned the low-lying valence states of CO. In the present study cross sections are obtained experimentally using low-energy electron energy-loss spectroscopy and theoretically using the R-matrix method. Incident electron energies range from near-threshold of 12.5 eV to 20 eV while the scattering angles range from 20° to 120°. The R-matrix calculations use three distinct close-coupling models and their results are compared to available experimental and theoretical cross sections. The overall comparison leads to significantly improved description of the excitation cross sections for this target.
Low-Cost Design Optimization of Microwave Passives Using Multi-Fidelity EM Simulations and Selective Broyden Updates
- Anna Pietrenko-Dąbrowska
- Sławomir Kozieł
2022 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
Geometry parameters of contemporary microwave passives have to be carefully tuned in the final stages of their design process to ensure the best possible performance. For reliability reasons, the tuning has to be to be carried out at the level of full-wave electromagnetic (EM) simulations. This is because traditional modeling methods are incapable of quantifying certain phenomena that may affect operation and performance of these devices, such as cross-coupling effects. As a consequence, the designs yielded with the use of equivalent network models, may only serve as starting points that need further refinement. Unfortunately, simulation-driven numerical optimization is computationally demanding even in the case of local search procedures. Thus, significant research efforts have been aimed toward identifying effective ways of expediting EM-driven optimization procedures, critical from the point of view of cost of design cycles. Among these, one may list the recently proposed multi-fidelity optimization frameworks. Another option for accelerating simulation-driven design procedures are sparse sensitivity updating schemes, where costly gradient estimation through finite-differentiation (FD) is suppressed for selected variables. This work proposes a novel algorithm that capitalizes on both aforementioned mechanisms to reduce the optimization cost of local gradient-based parameter tuning of compact microwave components. In our approach, multi-fidelity optimization is further expedited by replacing expensive FD sensitivity updates with the Broyden formula for selected design variables. Verification using two microwave structures, a branch-line coupler and a power divider, demonstrates average savings of around eighty percent over the basic trust-region (TR) routine, with only minor degradation of the design quality.
Low-Cost Quasi-Global Optimization of Expensive Electromagnetic Simulation Models by Inverse Surrogates and Response Features
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
2022 Full text Scientific Reports
Conceptual design of contemporary high-frequency structures is typically followed by a careful tuning of their parameters, predominantly the geometry ones. The process aims at improving the relevant performance figures, and may be quite expensive. The reason is that conventional design methods, e.g., based on analytical or equivalent network models, often only yield rough initial designs. This is especially the case for miniaturized components featuring considerable electromagnetic (EM) cross couplings, or antenna systems with non-negligible radiator coupling (e.g., MIMO, closely-spaced arrays). For reliability reasons, parametric optimization is carried out using EM simulation tools, which is a time-consuming task. In many cases, designer needs to resort to a global search, especially when handling several objectives and constraints is necessary, or the high-frequency structure under design is overly complex. Combination of both aforementioned factors makes it no longer possible to rely on engineering insight, even to detect a promising region of the design space. Unfortunately, nature-inspired algorithms, commonly employed for solving these tasks typically exhibit significant computational expenditures. This paper proposes a simple yet efficient method for globalized search using a response feature approach and inverse regression surrogates. Owing to less nonlinear dependence of the feature point coordinates on the system variables (as compared to the original responses, e.g., S-parameter frequency characteristics), our methodology permits a rapid identification of the most appropriate regions of the parametric space, and further design tuning by means of local routines. At the same time, the overall optimization cost is comparable to the cost of local procedures. The proposed approach is validated using several high-frequency structures (a dual-band antenna, a microstrip coupler, an impedance matching transformer) optimized under different design scenarios. Global search capability and computational efficiency are demonstrated through comprehensive comparisons with multiple-start local search, as well as particle swarm optimizer, a representative nature-inspired algorithm.
Low-Cost Yield-Driven Design of Antenna Structures Using Response-Variability Essential Directions and Parameter Space Reduction
- Anna Pietrenko-Dąbrowska
- Sławomir Kozieł
- Łukasz Gołuński
2022 Full text Scientific Reports
Quantifying the effects of fabrication tolerances and uncertainties of other types is fundamental to improve antenna design immunity to limited accuracy of manufacturing procedures and technological spread of material parameters. This is of paramount importance especially for antenna design in the industrial context. Degradation of electrical and field properties due to geometry parameter deviations often manifests itself as, e.g., center frequency shifts or compromised impedance matching. Improving antenna performance at the presence of uncertainties is typically realized through maximization of the fabrication yield. This is normally carried out at the accuracy level of full-wave electromagnetic (EM) analysis, which incurs considerable computational expenses. The involvement of surrogate modeling techniques is the most common approach to alleviating these difficulties, yet conventional modeling methods suffer to a great extent form the curse of dimensionality. This work proposes a technique for low-cost yield optimization of antenna structures. It capitalizes on meticulous definition of the domain of the metamodel constructed for statistical analysis purposes. The domain is spanned by a limited number of essential directions being the most influential in terms of affecting antenna responses in the frequency bands of interest. These directions are determined through an automated decision-making process based on the assessment of the circuit response variability. Our approach permits maintaining small domain volume, which translates into low cost of surrogate model setup, while providing sufficient room for yield improvement. The presented method is validated using three antenna structures and favorably compared to several surrogate-assisted benchmark methods. EM-driven Monte Carlo simulation is also conducted to verify reliability of the yield optimization process.
Low-Loss Mechanically Tunable Resonator and Phase Shifters in Groove Gap Waveguide Technology
- Ali Karami Horestani
- Zahra Shaterian
- Michał Mrozowski
2022 Full text IEEE Access
This research is focused on the design and realization of high-performance high-power variable phase shifters in groove gap waveguide technology. Specifically, it is shown that the unique characteristic of groove gap waveguides, which is its proper operation without the need for electrical connection between the top and bottom sections of the waveguide, can be used to design mechanically tunable devices. Using the proposed method, a mechanically tunable cavity resonator and phase shifters with a wide range of achievable phase shifts are presented. To validate the concept, a phase shifter with 540 degrees relative phase shift at 15 GHz is designed, fabricated, and measured. Moreover, a multi-layer version of the proposed phase shifter with stationary feed ports and improved performance is presented.