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Methods of Cyclist Training in Europe
- Joanna Wachnicka
- Alicja Jarczewska
- Giuseppina Pappalardo
2023 Pełny tekst Sustainability
The following study aims to address the issue of cyclist training methodologies. Recent European bicycle accident statistics reveal a troubling upward trend. A potential solution to mitigate such incidents involves providing cyclists with comprehensive training encompassing traffic regulations and interactions with fellow road users. We conducted a comparative analysis of the cycling education approaches and cyclist training systems in several countries, including the Netherlands, Germany, Austria, England, Slovenia, Poland, and Italy. This analysis underscored the importance of standardizing training protocols and criteria across Europe. The training model should draw inspiration from countries with well-established cycling cultures and serve as a foundation for harmonizing training practices.
Metoda diagnostyki cieplno-przepływowej turbin parowych wykorzystująca elementy algorytmów genetycznych
- Marta Drosińska-Komor
2023 Pełny tekst
Rozprawa doktorska poświęcona jest opisowi budowania metody diagnostyki cieplno-przepływowej z wykorzystaniem elementów algorytmów genetycznych. Do tworzenia założeń i algorytmów metody posłużono się przykładem funkcjonowania bloku elektrowni kondensacyjnej ze szczególnym uwzględnieniem układu łopatkowego turbiny parowej. Celem pracy jest zbudowanie metody diagnostyki cieplno-przepływowej. Zadaniem metody jest przeprowadzenie procesu diagnozy dla pogorszonych parametrów eksploatacyjnych procesu przemian energetycznych bloku energetycznego (np. sprawności) polegająca na detekcji, lokalizacji i identyfikacji przyczyn degradacji urządzeń składowych bloku energetycznego. Motywacją do podjęcia badań jest coraz ważniejsza rola procedur diagnostycznych w eksploatacji obiektów energetycznych Zbudowana w trakcie pracy kwalifikacyjnej metoda diagnostyczna poszukiwania niesprawności i uszkodzeń jest przewidziana do użycia tylko w procedowaniu off-line. Badania nad zastosowaniem metod algorytmów genetycznych dla celów diagnostyki cieplno-przepływowej pokazały, że nie można użyć klasycznego algorytmu genetycznego do wykrywania degradacji wielokrotnych. Intensywne badania wykorzystujące symulacje degradacji eksploatacyjnej turbin doprowadziły do modyfikacji jednego z elementów algorytmu genetycznego – procesu selekcji. Wyniki badań umożliwiły zbudowanie nowej metody diagnostycznej pozwalającej na przeprowadzenie z dobrą dokładnością procesu lokalizacji i identyfikacji przyczyn degradacji wielokrotnych występujących potencjalnie w turbinach parowych.
Metoda obliczania skutków wdrożenia strategii zarządzania popytem na energię elektryczną (DSM/DSR) w systemach elektroenergetycznych
- Wiktoria Stahl
2023 Pełny tekst
W niniejszej rozprawie poruszono zagadnienie strategii zarządzania popytem na energię elektryczną (DSM/DSR) i sposobów obliczania efektów ich wdrożenia. W związku z tym opisano oczekiwane efekty wdrożenia tych rozwiązań oraz ich zalety i wady. Zaprezentowano i przeanalizowano istniejące już metody obliczania skutków wdrożenia DSM/DSR. Zaproponowano nową metodę, która poprzez formę algorytmu uporządkowuje proces obliczania i oceny efektów realizacji tych rozwiązań. W ramach metody zaproponowano także zestaw wskaźników opisujących efekty wdrożenia DSM/DSR. Ponadto, metoda pozwala na symulowanie i prognozowanie spodziewanych rezultatów poprzez wykorzystanie symulacji Monte Carlo i modelów ekonometrycznych. Przy pomocy modeli, przedstawiono także czynniki mogące mieć wpływ na powodzenie realizacji strategii zarządzania popytem. W rozprawie przedstawiono również przykład obliczeniowy z wykorzystaniem zaproponowanej metody. Przykład oparty jest na zgromadzonych danych dotyczących preferencji odbiorców w sprawie realizacji strategii zarządzania popytem na energię elektryczną. W ramach obliczeń symulacyjnych przedstawiono potencjał realizacji rozwiązań DSM/DSR w Polsce.
Metodologia i metodyka odtworzenia stolarki okiennej w zabytkowych obiektach na przykładzie Muzeum Bursztynu w Wielkim Młynie w Gdańsku
- Ksenia Piątkowska
- Elżbieta Ratajczyk-Piątkowska
- Katarzyna Darecka
2023 Pełny tekst Wiadomości Konserwatorskie
W artykule przedstawiono metodologię i metodykę odtworzenia stolarki okiennej w obiekcie zabytkowym, o zachowanej średniowiecznej formie, przy realizacji Muzeum Bursztynu w Wielkim Młynie w Gdańsku. Omówiono wyniki wykonanych badań w tym zakresie i decyzje projektowe odtworzenia okien. Opisano wpływ współczesnych wymagań dotyczących stolarki w obiektach muzealnych na jej kształt i formę. Wykonane dla Muzeum Bursztynu okna są autorską syntezą historii Wielkiego Młyna przedstawiającą współcześnie elewacje ze stolarką okienną w konfiguracji, w której prawdopodobnie nigdy nie istniała, ale która w pełni ilustruje jego przeszłość zgodnie z obecnym stanem wiedzy na temat faz rozwoju obiektu oraz obowiązujących wymagań techniczno-użytkowych.
Metody generowania energii
- Ewa Klugmann-Radziemska
- Katarzyna Januszewicz
2023
Generowanie energii stanowi podstawę funkcjonowania społeczeństw i rozwoju gospodarki światowej. W różnych krajach kluczowe technologie, na których opiera się energetyka, są inne, co zależy zarówno od historycznych podstaw rozwoju tego sektora, postępu technicznego, jak i uwarunkowań politycznych, a co za tym idzie – legislacyjnych. W krajach Unii Europejskiej od wielu lat dominuje trend rozwoju energetyki opartej na źródłach odnawialnych. Jest to często trudne do pogodzenia z istniejącymi rozwiązaniami, gdy – tak jak w naszym kraju – przeważa energetyka oparta na węglu. W krajach wysoko rozwiniętych świadoma polityka państw zaowocowała rozwojem energetyki wiatrowej, słonecznej czy jądrowej. W bilansie niektórych krajów zagospodarowanie energetyczne odpadów stanowi nie tylko uzupełnienie niedoborów paliwowych, lecz także skuteczny sposób pozbycia się tego niewygodnego problemu. Wszystkie omówione w rozdziale technologie pozyskiwania energii elektrycznej i ciepła należy rozważać w ścisłym powiązaniu z polityką zrównoważonego rozwoju i ochroną środowiska, stanowi on więc niejako wprowadzenie do kolejnych rozdziałów.
Metody wzmacniania krótkich wsporników słupa w świetle badań eksperymentalnych
- Krystyna Nagrodzka-Godycka
2023 Inżynieria i Budownictwo
W artykule podano metody wzmacniania wsporników słupów, których skuteczność została zweryfikowana badaniami eksperymentalnymi. Niezależnie od zastosowanej metody efektywność wzmocnienia wspornika jest głównie uzależniona od smukłości ścinania wspornika, ilości zbrojenia wewnętrznego i jego wytężenia przed wzmocnieniem.
Miasto w działaniu. Nowe pola aktywności społecznej
- Małgorzata Dymnicka
- Jarosław Załęcki
2023
Miasto od wieków jest areną sporów, przestrzenią konfliktów i miejscem uzgadniania interesów. Już sama relacja mieszkańców z miastem polega na konstytuowaniu przestrzeni, organizacji i reorganizacji współistnienia. Oznacza to, że od socjologicznie rozumianej przestrzeni należy oczekiwać, że uchwyci ona społeczny proces stanowienia. Przestrzeń miasta, w obrębie której żyje dana społeczność, jest jednym z najważniejszych obszarów oddziaływania ze względu na niedostatki, ograniczenia i bariery w dostępie do zasobów. Politycy miast i wielokulturowych metropolii coraz częściej zdają sobie sprawę, że ich zadaniem jest minimalizowanie napięć pomiędzy wyobrażoną wspólnotą podzielanych (lokalnych) tożsamości a konstruującymi ją regułami prawnymi. Można przywołać wiele przykładów, które obrazują skuteczne działania na rzecz zmiany rzeczywistości, jako dowód na aktywność zwyczajnych i niekoniecznie najbardziej zaawansowanych w sztuce życia obywatelskiego i społecznego obywateli, którzy korzystają z prawa i wolności do określonych działań na rzecz szeroko pojętego środowiska zbudowanego.
Micro‑ and nano‑ bentonite to improve the strength of clayey sand as a nano soil‑improvement technique
- Mohadeseh Cheraghalikhani
- Hamed Niroumand,
- Lech Bałachowski
2023 Pełny tekst Scientific Reports
Nano-additives results in the formation of nano-cementation (NC). This process is recently used to improve the durability of various building materials. NC used to improve the strength of untreated soil materials, also known as nano soil-improvement (NSI). In few years, the role of nano-additives in various types of soils were developed. In this research, the role of micro- and nano- size of bentonite as soil stabilizer was evaluated as first few research to improve geotechnical properties of soils. Nanoadditives prepared by micro- and nano- sizes of bentonite were blend with four formulations. These formulations of micro- and nano- additives at concentrations of 0, 1, 2, and 3%, namely 0% Micro- Bentonite, 1% Micro-Bentonite, 2% Micro-Bentonite, 3% Micro-Bentonite, 0% Nano-Bentonite, 1% Nano-Bentonite, 2% Nano-Bentonite, and 3% Nano-Bentonite, respectively. These formulations of micro- and nano- additives were separately added to soil. Specimens with 3% nano-bentonite showed significant improvement in unconfined compressive strength (UCS) of soil that was more than 2.3-times higher than control specimen in 7-d curing time. Also the performance of micro-bentonite resulted in improvement in UCS of soil that was more than 1.1-times higher than control specimen at 7-d curing time. The secant modulus at 50% of peak stress (E50) of the samples treated with microand nano- additives increased in comparison to untreated specimens. Further, X-ray fluorescence (XRF), scanning electron microscopy, and X-ray diffraction analyses characterized micro- and nanostructures of soil specimens, and showed the performance of nano-additives in improving strength of soils. Results show that nano-bentonite as a type of nano-additives is an effective means of increasing the strength of soils. This research shows the significant of nano-bentonite in soil improvement, as a NSI technique.
Microbiota-derived metabolites in colorectal cancer patients in preoperative period
- Karolina Każmierczak-Siedlecka
- K. Skonieczna-Żydecka
- J. Palma
- Bartosz Kamil Sobocki
- M. Świerblewski
- K. Siedlecka-Kroplewska
- Leszek Kalinowski
- K. Połom
2023 Pełny tekst European Review for Medical and Pharmacological Sciences
Short-chain fat-ty acids (SCFAs) are microbial derived metabo-lites, which have multiple beneficial properties. The amount of SCFAs depends on several fac-tors, such as age, diet (mainly intake of dietary fiber), and overall health condition. The normal proportion between SCFAs is 3:1:1 for acetate, proprionate and butyrate, respectively. In col-orectal cancer (CRC) patients, microbiota alter-ations have been shown. Consequently, metab-olome within the gut might change to a large ex-tent. Therefore, the aim of this study was to anal-yse the content of SCFAs and the proportion be-tween SCFAs in the stool obtained from CRC pa-tients in preoperative period. PATIENTS AND METHODS: This study in-cluded 15 patients with CRC in preoperative pe-riod. The stool samples were taken and stored at -80°C in the Fahrenheit Biobank BBMRI.pl, Med-ical University of Gdansk, Poland. The analysis of SCFAs from stool samples was conducted by means of gas chromatography. RESULTS: This study included mainly males (66.67%, n=10). In all patients, there was abnor-mal proportion between SCFAs. The extreme-ly higher concentration of butyrate was noted in 2 samples (13.33%) compared to the rest of pa-tients. However, based on normal proportion be-tween SCFAs, the results <1 for butyrate were noted in 93.33% of patients. CONCLUSIONS: SCFAs pool is altered in CRC patients, among others characterized by low level of butyrate. It should be considered to administer butyrate supplementation to CRC pa-tients especially prior to surgery to support an appropriate preparation to this treatment.
Microcrack monitoring and fracture evolution of polyolefin and steel fibre concrete beams using integrated acoustic emission and digital image correlation techniques
- Shahzad Ashraf
- Magdalena Rucka
2023 Pełny tekst CONSTRUCTION AND BUILDING MATERIALS
The use of polymer and steel fibres in plain concrete appears to be an excellent solution for limiting crack propagation and improving the post-ductility performance of concrete structures. Based on this premise, this study investigated the fracture evolution of polyolefin fibre-reinforced concrete (PFRC) and steel fibre-reinforced concrete (SFRC) specimens through the integrated application of two diagnostic techniques, acoustic emission (AE) and digital image correlation (DIC), under three-point bending tests. Based on the processing of AE signals, different AE statistical parameters such as the cumulative number of hits, amplitude distribution, and some representative analysis methods including the b-value method, Ib-value method, and AE intensity analysis methods were selected to analyse the early detection of cracking and post-cracking behaviour in PFRC vs SFRC specimens during mechanical degradation. Simultaneously, the DIC technique was used to validate the fracture evolution of the AE results. Furthermore, to verify the reliability of the AE and DIC results, the damage localisation and fracture evolution of the PFRC versus SFRC specimens were confirmed by integrating the AE fracture energies and DIC outcomes. The tests and analysed results showed that the addition of steel fibres to plain concrete significantly improved the ability to restrict crack propagation and provided higher post-cracking resistance compared to PFRC specimens owing to their stronger fibre-matrix bonding, effective fibre bridging, and crack-arresting mechanism. The present study indicates that the combined AE and DIC techniques are highly effective for the early detection of damage and ductility performance in fibre-reinforced concrete structures.
Microcracking monitoring and damage detection of graphene nanoplatelets-cement composites based on acoustic emission technology
- Shahzad Ashraf
- Suliman Khan
- Vipin Kumar Oad
2023 Pełny tekst Case Studies in Construction Materials
This study aims to identify the micro-cracking pattern and structural applications of cement composites replaced with 0 wt%, 0.04 wt%, and 0.08 wt% contents of graphene nanoplatelets (GNPs) over cement weight through acoustic emission (AE) monitoring under mechanical degradation. The ultraviolet-visible spectroscopy (UV–vis) results showed that at 60 min sonication period, GNP-4 showed maximum absorbance rate of 16.15% compared to the GNP-8. The microstructural characteristics revealed that during hydration of cement there was no apparent cracks appeared in GNPs-cement composites compared to the reference specimen (GNP-0) which was 1.44 mm. The cracking mode and damaged detection of the tested specimens resulted in three distinct stages i.e., (I) pre-peak, (II) peak, and (III) post-peak under mechanical degradation. GNP-4 achieved 780 N flexural capacity which was increased by 30% and 21.87% compared to the GNP-0 and GNP-8. Similarly, a compressive strength of 63.12 MPa, 57.5 MPa, and 56 MPa at 28 days was obtained by GNP-4, GNP-8, and GNP-0, respectively. Based on AE hits and amplitude analysis, the resistance to fracture, damping capacity, and ductility of GNP-4 was improved by 25.30%, 25.1%, and 22.47% respectively, to that of GNP-0. Shear failure (>35 kHz) was observed in GNP-0, while GNPs cement composites recorded tensile failure (<35 kHz) through RA-AF parameters. The cracking pattern through Ib value with a warning sign of 1.5 between micro and macro-cracks and severity of damages through historical index (HI) and severity index (Sr) of GNPs cement composites was determined. Lastly, it was concluded that GNPs contents can significantly improve bending strength and delay the cracks initiation in cement composites.
Microemulsion Delivery Systems with Low Surfactant Concentrations: Optimization of Structure and Properties by Glycol Cosurfactants
- Patrycja Szumała
- Szymon Mania
- Balbina Makurat-Kasprolewicz
- Jolanta Kaplińska
2023 Pełny tekst MOLECULAR PHARMACEUTICS
Extensive use of microemulsions as delivery systems raises interest in the safe ingredients that can form such systems. Here, we assessed the use of two glycols, i.e., propylene glycol and pentylene glycol, and their mixtures to manipulate the properties and structure of microemulsions. Obtained systems with glycols were extensively characterized in terms of capacity to incorporate water phase, droplet size, polydispersity, structure type, and rheological and thermal properties. The results of these studies indicate that the composition, structure, and viscosity of the microemulsions can be changed by appropriate quantification of glycols. It has been shown that the type of glycol used and its amount may favor or worsen the formation of microemulsions with the selected oils. In addition, a properly selected composition of oils and glycols resulted in the formation of microemulsions with a reduced content of surfactants and consequently improved the safety of using microemulsions as delivery systems.
Microfluidic SIW-Based Tunable Self-Diplexing Antenna for Sub-6 GHz Band Applications
- Nrusingha Pradhan
- Goutham Reddy
- Karthikeyan Subramanian
- Rusan Kumar Barik
- Sławomir Kozieł
- Qingsha Cheng
2023 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
This work introduces a novel frequency tunable self-diplexing antenna (SDA) design based on substrate integrated waveguide (SIW) technology. A modified A-shaped slot is employed on the cavity’s top plane, which is excited by two independent 50 Ω microstrip feed lines to operate at each resonant frequency. The frequency flexibility of the proposed antenna allows for fine-tuning at each resonance frequency. The frequency flexibility has been achieved by employing the substrate’s air- and liquid-filled pockets. The proposed antenna can be configured to operate in the 3.5-3.8 GHz and 5.53-6.2 GHz bands, as demonstrated by the simulation results. With distilled water-filled pockets, the proposed antenna offers peak gains of 5.04 dBi and 5.26 dBi. The proposed SDA exhibits competitive features such as a highly compact size of 0.22λg2 and high isolation (>27dB), which makes it suitable for handheld communication devices. The simulated and measured circuit responses are in good agreement.
Microplastics removal from aqueous environment by metal organic frameworks
- Zhila Honarmandrad
- Massoud Kaykhaii
- Jacek Gębicki
2023 Pełny tekst BMC Chemistry
This paper provides an overview of recent research performed on the applications of metal–organic frameworks (MOFs) for microplastics (MPs) removal from aqueous environments. MPs pollution has become a major environmental concern due to its negative impacts on aquatic ecosystems and human health. Therefore, developing effective and sustainable methods for removing them from aqueous environments is crucial. In recent years, MOFs have emerged as a promising solution for this purpose due to their unique properties such as high surface area, renewability, chemical stability, and versatility. Moreover, their specific properties such as their pore size and chemical composition can be tailored to enhance their efficiency in removing MPs. It has been shown that MOFs can effectively adsorb MPs from aqueous media in the range of 70–99.9%. Besides some high price concerns, the main drawback of using MOFs is their powder form which can pose challenges due to their instability. This can be addressed by supporting MOFs on other substrates such as aerogels or foams. Meanwhile, there is a need for more research to investigate the long-term stability of MOFs in aqueous environments and developing efficient regeneration methods for their repeated use.
Microscopic Imaging to Visualize the Distribution of Dietary Nucleic Acids in Food Products of Various Origins
- Anna Kościelak
- Zuzanna Koziara
- Ana Pons Maria
- Rafał Płatek
- Agnieszka Bartoszek-Pączkowska
2023 Pełny tekst Foods
Dietary nucleic acids (dietNAs) are being increasingly recognized as important food components with nutritional value. However, the precise dietary recommendations for dietNAs are limited, because established methods for determining the quantity and nutritional role of dietNAs are still lacking. One of the tools to narrow this gap could be microscopic imaging, as a convenient approach to visualize the abundance and distribution of dietNAs in food products. With the aid of appropriate bioinformatic elaboration, such images may in future enable the direct semiquantitative estimation of these macromolecules in food products. In the presented study, two methods of preparing microscopic sections and staining them with DNA-specific fluorochromes were used for microscopic imaging of dietNAs in food products of plant and animal origin. Procedures for preparing formalin-fixed paraffin-embedded sections and cryosections were compared in terms of their usefulness for routine food analysis. Both methods turned out equally suitable for visualizing dietNA distribution in animal and plant products. However, the use of cryosections allowed a significantly shorter analysis time and reduced the consumption of organic solvents. Both of these advantages make the cryosection method preferable while establishing a dedicated methodology for routine assessment of dietNAs in the food industry.
Microstructure and Mechanical Properties of Combined GTAW and SMAW Dissimilar Welded Joints between Inconel 718 and 304L Austenitic Stainless Steel
- Sachin Sirohi
- Shailesh M. Pandey
- Aleksandra Świerczyńska
- Grzegorz Rogalski
- Naveen Kumar
- Michał Landowski
- Dariusz Fydrych
- Chandan Pandey
2023 Pełny tekst Metals
A dissimilar welded joint of Inconel 718 and 304L austenitic stainless steel was prepared using a combined procedure with the gas tungsten arc welding and shielded metal arc welding processes by employing the Ni-based fillers: ERNiCr-3 and ENiCrFe-3. The welded joints were investigated for metallographic testing and mechanical properties, and a relationship was established between the microstructure and the resultant mechanical properties. Microstructural observation revealed the formation of the unmixed zone on the 304L SS side. The weld metal showed that the fully austenitic microstructure consisted of the Nb- and Ti-rich carbide phases along the inter-dendritic spaces. The tensile test results at room temperature showed the failure from the weld metal which might be due to alloying element segregation along the inter-dendritic spaces. However, a tensile test at 600 ◦C showed the failure from the 304L SS base metal with a tensile strength and % elongation value of 377 MPa and 24%, respectively. The hardness plot showed the average hardness value of the weld metal of 236 ± 5 HV, which was higher than the 304L SS BM (204 ± 4 HV) but lower than the IN718 BM (243 ± 5 HV). The impact toughness of the weld metal was 109 J, which was significantly lower than the base metals. The poor impact strength of the weld metal might be due to the evolution of the NbC phase along inter-dendritic spaces
Mind the framing: Match purpose and context
- Monica Fiore, Di
- Marta Kuc-Czarnecka
- Samuele Lo Piano
- Arnald Puy,
- Andrea Saltelli,
2023
In several ways, the following chapters will allude to the concept of frames. The assumptions of a mathematical model tell us what it can explain and what it cannot (see chapter 5). The trade-off between the usefulness of a mathemati- cal model and the scale of complexity it seeks to capture further conditions the narrative, highlighting or downsizing cognitive elements relevant to responsible modelling (see ‘Mathematics and tales’ in chapter 4). Yet, what determines the choice of a model, its assumptions, and its level of complexity? Answering these questions requires a more general perspective that involves frames—that is, the complex of cognitive schemes through which we reason and which we use to make sense of the world. The notion of the frame owes much to the tradition of social studies. Several disciplines have underlined the importance of worldviews and their causal rela- tionships in giving us the coordinates to classify the situations in which we find ourselves. Since public policies are constructs of considerable complexity, policy inquiry has paid great attention to the frames we use to organize information, ideas, and beliefs. For example, Campbell (2002), analysing the effects of ideas, worldviews, and cognitive paradigms on policy-making, defines frames as ‘nor- mative and sometimes cognitive ideas that are located in the foreground of policy debates’.
Miniatura, mały format, duże możliwości
- Joanna Golińska-Pilarek
- Renata Mazurkiewicz
- Anna Strzebońska
- Joanna Wolszczak-Derlacz
2023 Pełny tekst Forum Akademickie
MINIATURA to program Narodowego Centrum Nauki przeznaczony do realizacji pojedynczego działania naukowego z zakresu badań podstawowych. Zrównoważona dystrybucja środków w MINIATURZE, zarówno pod względem typów jednostek naukowych, jak i województw, pokazuje, że MINIATURA jest ważną formą wsparcia finansowego w ofercie grantowej NCN, która dobrze odpowiada na zapotrzebowanie mniejszych ośrodków na tzw małe granty
Miniaturized Dual-Band SIW-Based Bandpass Filters Using Open-Loop Ring Resonators
- Nrusingha Pradhan
- Sławomir Kozieł
- Rusan Kumar Barik
- Anna Pietrenko-Dąbrowska
- Karthikeyan Subramanian
2023 Pełny tekst Electronics
This article presents two novel architectures of dual-band substrate integrated waveguide (SIW) bandpass filters (BPFs). Initially, two identical open-loop ring resonators (OLRRs) are coupled face-to-face on the top of the SIW cavity to realize a dual-band single-pole BPF. To obtain two-pole dual-band characteristics, two OLRRs resonant units are assembled horizontally within the top metal layer of the SIW, which is a technique used for the first time in the literature. For demonstration purposes, two types of SIW filters loaded with OLRRs are designed and fabricated. The proposed filters feature an extremely compact size, a low insertion loss, and good selectivity. The single- and two-pole filters have an overall size of 0.012λg2 and 0.041λg2, respectively. The simulated and measured circuit responses are in good agreement.
Miniaturized Inline Bandpass Filters Based on Triple-Mode Integrated Coaxial-Waveguide Resonators
- Muhammad Yameen Sandhu
- Sharjeel Afridi
- Adam Lamęcki
- Roberto Gómez-García
- Michał Mrozowski
2023 Pełny tekst IEEE Access
This work presents a design technique to implement miniaturized cross-coupled bandpass filters in inline physical configurations based on triple-mode resonators. Triple-mode resonances are obtained by using integrated coaxial-waveguide cavity resonators. They consist of two coaxial conducting posts placed in the sidewalls of a rectangular waveguide cavity. In the proposed triplet, a transmission zero (TZ) can be positioned at any of the two sides of the passband by simply locating the coaxial posts either on the same wall or on opposite walls of the rectangular waveguide cavity. Coaxial-to-waveguide mode coupling is implemented by means of coupling screws, which adds flexibility in terms of tuning easiness. Three 9.9-GHz proof-of-concept prototypes corresponding to third- and sixth-order integrated coaxial-waveguide bandpass filters are designed at the electromagnetic-simulation level. Furthermore, the triplet with a TZ below the passband is manufactured and characterized to experimentally validate the engineered 3-D RF filter principle and its underlying design theory.