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Wyniki wyszukiwania dla: COUPLED OSCILLATIONS
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On the Matano Plane Position in Multicomponent Diffusion Couples
PublikacjaEven though several methods of diffusion analysis avoid a necessity for the Matano plane determination, the Matano plane locations are of interest in the multicomponent couples and when tracer experiments are performed. The positions of the Matano plane calculated from the concentration profiles should be exactly the same. However, due to experimental errors, the results can differ significantly. In the paper we consider Matano...
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On the Matano Plane Position in Multicomponent Diffusion Couples
PublikacjaEven though several methods of diffusion analysis avoid a necessity for the Matano plane determination, the Matano plane locations are of interest in the multicomponent couples and when tracer experiments are performed. The positions of the Matano plane calculated from the concentration profiles should be exactly the same. However, due to experimental errors, the results can differ significantly. In the paper we consider Matano...
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Doubly miniaturized rat-race hybrid coupler
PublikacjaTwo complementary miniaturization techniques have beenapplied to reduce the size of a rat-race hybrid coupler: (i) conventional microstrip sections have been replaced with their diminished lowimpedance counterparts as the first step of size reduction and (ii) novel fractal-shaped compact microstrip resonant cells dedicated to efficiently shorten low-impedance transmission line segments have been implemented as the second step of...
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Investigations of four-port circulator utilizing cylindrical ferrite coupled line junction
PublikacjaW pracy przedstawiono wykorzystanie pojedynczej cylindrycznej sekcji ferrytowych linii sprzężonych do realizacji układu cyrkulatora czterowrotowego. Opisany został proces projektowy sekcji FCL oraz planarnych układów zasilające. Otrzymane z symulacji wyniki zostały zweryfikowane eksperymentalnie.
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Investigations of the circulation effects in the structure using ferrite coupled slot-line section
PublikacjaW artykule przedstawiono badania cyrkulatora zrealizowanego w oparciu o magnesowaną wzdłużnie sekcję ferrytowych szczelinowych linii sprzężonych. Zaproponowane rozwiązanie pozwala na minimalizację rozmiarów układu cyrkulatora oraz na uzyskanie parametrów porównywalnych z dotychczas publikowanymi. W treści artykułu opisano kolejne etapy projektu. Wyniki numeryczne zweryfikowano eksperymentalnie. Pomierzony układ charakteryzował...
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Determination of Urinary Pterins by Capillary Electrophoresis Coupled with LED-Induced Fluorescence Detector
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The spectral finite element model for analysis of flexural–shear coupled wave propagation
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Shielded coupled strip and slot guides with a thin omega pseudochiral medium layer
PublikacjaA method of moments combined with mode matching technique is applied to analyze the shielded coupled strip and slot line structures containing a thin plate of Omega pseudochiral medium. The boundary problems are simplified by introducing for omega medium the approximate continuity conditions. Such mathematical model allows to examine the field displacement effect appearing in the considered guide resulting from the coupling between...
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Determination of MDPBP in postmortem blood samples by gas chromatography coupled with mass spectrometry
PublikacjaMDPBP (1-(3,4-methylenedioxyphenyl)-2-(1-pyrrolidinyl)-1-butanone) is a new psychoactive substance sold on the black market. It has been a controlled drug of abuse in Poland and China since 2015 as some toxic and fatal cases connected with use of synthetic cathinone derivatives were observed. The fatal case outlined here concerns a 19 year-old man, who was found dead with an envelope containing white powder lying nearby the cadaver....
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Determination of Metals Content in Wine Samples by Inductively Coupled Plasma-Mass Spectrometry
PublikacjaKnowledge about the metal content of wine is very important, for many reasons. Depending on the element, its quantity varies in wine from ng/L to mg/L. Despite the fact that metals are not directly connected to the taste and aroma of the wine, their content should be determined and controlled, because excess is undesirable, and in some cases prohibited, due to potential toxicity. Several analytical procedures for metal determination...
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Size Exclusion Coupled to Reversed Phase Liquid Chromatography for the Characterization of Cranberry Products
PublikacjaA combination of solvent extraction, size exclusion purification, and reversed-phase liquid chromatography with UV absorption and fluorescence detection was here used for the determination of flavan-3-ols and related oligomeric compounds in cranberry products. The method relied on robust, simple, and inexpensive instrumental equipment present in most of routine analytical laboratories. Sample extracts in methanol/water/hydrochloric...
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SiC-based T-type modules for multi-pulse inverter with coupled inductors
PublikacjaThe paper presents SiC-based three-level T-type modules designed for a high-performance 30kVA DC/AC inverter operating at high frequency 85 kHz with low THD of the output voltage. This inverter system consists of two integrated parts. The first part is active and contains three parallelconnected three-phase T-type modules built with fast-switching SiC power transistors. The second, passive part of the system is a set of inductors...
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Molecular mechanism of proton-coupled ligand translocation by the bacterial efflux pump EmrE
PublikacjaThe current surge in bacterial multi-drug resistance (MDR) is one of the largest challenges to public health, threatening to render ineffective many therapies we rely on for treatment of serious infections. Understanding different factors that contribute to MDR is hence crucial from the global “one health” perspective. In this contribution, we focus on the prototypical broad-selectivity proton-coupled antiporter EmrE, one of the...
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A Systematic Search for New Coupling Schemes of Cross-Coupled Resonator Bandpass Filters
PublikacjaIn this paper, a systematic approach to an extensive search for topologies of cross-coupled filters with generalized Chebyshev response is presented. The technique applies graph theory to find unique, nonisomorphic filter configurations, and tests whether a specific frequency response can be realized in a given set of topologies. The results of the search are then stored in a database of possible filter configurations.
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Numerical investigation of multiphase blood flow coupled with lumped parameter model of outflow
PublikacjaPurpose The purpose of this paper is the application of the computational fluid dynamics model simulating the blood flow within the aorta of an eight-year-old patient with Coarctation of Aorta. Design/methodology/approach The numerical model, based on commercial code ANSYS Fluent, was built using the multifluid Euler–Euler approach with the interaction between the phases described by the kinetic theory of granular flow (KTGF). Findings A...
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Scattering in a section of ferrite coupled microstrip lines: theory and application in nonreciprocal devices
PublikacjaPrzeprowadzono analizę pełnofalową sekcji sprzężonych ferrytowych linii mikropaskowych wykorzystującą w rozwinięciu pola em fale prowadzone w izotropowych złączach wejściowych sekcji oraz jej fajl ferrytowych. W wyniku określono macierz S sekcji. Przeprowadzono modelowanie własności rozproszenia układu oraz symulację parametrów transmisyjnych układów niewzajemnych projektowanych z wykorzystaniem proponowanego układu ferrytowego.
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Design of quarter-wave compact impedance transformers using coupled transmission lines
PublikacjaPrzedstawiono porównanie wyników symulacji jedno i wielosekcyjnych transformatorów impedancji budowanych w postaci struktur wykorzystujących idealnenie sprzężone linie transmisyjne, idealne sprzężone symetryczne linie transmisyjne oraz rzeczywiste sprzężone linie mikropaskowe. Pokazano, że możliwa jest konstrukcja transformatorów impedancji o bardzo dobrych parametrach technicznych wykorzystująca sprzężone linie mikropaskowe, pomimo...
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On the Mechanism of Coupled Transport of Cu(II) Ions Through Bulk Liquid Membranes.
PublikacjaTransport jonów Cu(II) przez ciekłe membrany za pomocą 5 - nonylosalicyloaldoksimu jako przenośnika wymaga obecności kompleksu o stosunku metalu do przenośnika 1:2. Zbadano dwie możliwości mechanizmu jego tworzenia. Roztrzygnięcie, który mechanizm jest prawidłowy nie jest możliwe w oparciu jedynie o kinteykę chemiczną.
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Analysis of coupled coplanar waveguide with ideal bonding wires between ground conductors
PublikacjaPrzedstawiono zmodyfikowaną analizę sprzężonych linii koplanarnych prowadzącą do uproszczenia procesu modelowania struktur wieloprzewodowych zawierających poprzecznie ułożone względem kierunku propagacji fali mostki dla wyrównania potencjałów na odseparowanych przestrzennie przewodach. Wyniki analizy teoretycznej zweryfikowano doświadczalnie uzyskując potwierdzenie poprawności zastosowanego podejścia.
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Sympathetic Activation Does Not Affect the Cardiac and Respiratory Contribution to the Relationship between Blood Pressure and Pial Artery Pulsation Oscillations in Healthy Subjects
PublikacjaUsing a novel method called near-infrared transillumination backscattering sounding (NIR-T/BSS) that allows for the non-invasive measurement of pial artery pulsation (cc-TQ) and subarachnoid width (sas-TQ) in humans, we assessed the influence of sympathetic activation on the cardiac and respiratory contribution to blood pressure (BP) cc-TQ oscillations in healthy subjects. The pial artery and subarachnoid width response to handgrip...
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Increased inspiratory resistance alters the cardiac contribution to the dynamic relationship between blood pressure and pial artery pulsation oscillations in healthy subjects
PublikacjaThere is increasing evidence that heart performance directly influences cerebral perfusion. We hypothesised that increased inspiratory resistance will affect the cardiac contribution to the relationship between blood pressure and pial artery pulsation oscillations.
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On the new possibility of applying oscillating liquid membrane systems for melecular recognition substances responsible for taste.
PublikacjaSugerowano wczesniej, że układy osylacyjne z membraną ciekłą mogą być uzyte do opracowania sensora smaku. zbadano wpływ substancji odpowiedzialnych za smak należacych do czterech klas samku na charakterystyki osylacyjne oscylatora z mambrana ciekłą i kationowym surfaktantem chlorkiem benzylodimetylotetradecyloamonionowym. Wykazano,że niezaleznie od natury rozpuszczalnika organicznego w membranie ciekłej charkterystyki oscylacyjne...
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AN ATTEMPT AT IDENTIFYING THE INFLUENCE OF TEST HEAD ASSEMBLY STIFFNESS ON THE RESULTS OF A TRIBOLOGICAL EXPERIMENT CONDUCTED UNDER MICRO-OSCILLATION CONDITIONS
PublikacjaThe outcome of experimental research on a group of dry bearing materials carried out under small oscillation conditi ons and using a test rig designed and made at Gdansk University of Technology inspired the decision to find out if the stiffness of test head elements in fluenced the generated results. Therefore, a computer model utilising finite elements was devised and used to simulate the workings of the test head. The mode l...
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The investigations of influence of isotropic coupling betweenferrite coupled slot-lines on parameters of FSLS circulator
PublikacjaW pracy zaprezentowano badania cyrkulatora wykorzystującego magnesowaną wzdłużnie sekcję ferrytowych, sprzężonych linii szczelinowych (FSLS). Przedstawione badania oraz ich wyniki dotyczą wpływu wielkości sprzężenia izotropwego występującego pomiędzy sprzężonymi liniami szczelinowymi sekcji FSLS. Na podstawie uzyskanych wyników oraz weryfikacji ekperymentalnej stwierdzono, iż zapewnienie jak najniższej wartości sprzężenia izotropwego...
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Experimental frequency-domain characterization of fundamental guided mode parameters in coupled coplanar waveguide
PublikacjaW pracy przedstawiono metodę wyznaczania współczynnika propagacji oraz impedancji charakterystycznej rodzajów podstawowych w strukturze sprzężonych linii koplanarnych. Metoda, oparta o wykorzystanie specjalnych struktur pobudzających oraz klasyczne pomiary w dziedzinie częstotliwości przy pomocy wektorowego analizatora sieci wykazała przydatność do wyznaczania zależnych od częstotliwości parametrów struktury.
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Impedance of cation-coupled electron transfer reaction: teoretical description of one pathway process
PublikacjaPrzyjęto możliwość występowanie dwóch wzajemnie sprzężonych reakcji. Opisana została impedancja sprzężonej reakcji przeniesienia elektronu z kationem. Wyznaczony został również model elektrycznego schematu zastępczego. Całkowita impedancja Faradayowska jest sumą impedancji przeniesienia elektronu i impedancji przeniesienia kationu. Przykłady pomiaru impedancyjnego w warunkach potencjostatycznych i potencjodynamicznych zostały omówione....
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A hybrid, coupled reactors based 18-pulse diode rectifier with active power filter
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Characteristics of thermal behavior of photoluminescent copolymers studied by the TG/DTG/FTIR coupled method
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Determination of hormones in water samples using liquid chromatography coupled with tandem mass spectrometry
PublikacjaOver the past few years, many synthetic (ethinylestradiol) and natural (estradiol,estriol, estrone) compounds present in the environment have been affecting the hormonalbalance of humans and animals. Steroid hormones are very often used for medical purposesand have high estrogenic activity what makes them endocrine disrupters. Most hormonalcompounds are released into the water as a result of their incomplete removal in wastewatertreatment...
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Four-Port Circulator Using Reduced Ground Plane Ferrite Coupled Line Junction
PublikacjaIn this paper the investigations of four-port circula-tor using longitudinally magnetized ferrite coupled line section are presented. The device is designed by cascading ferrite section with magic-T junction ensuring its even and odd mode excitation. The scattering parameters of ferrite coupled line junction are calculated using own software and verified with the use of commercial software. The even and odd excitation of ferrite...
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Longitudinally magnetized left-handed cylindrical ferrite coupled line junction for nonreciprocal devices
PublikacjaThis paper presents investigations of longitudinally magnetized left-handed cylindrical ferrite coupled line junction for nonreciprocal devices. The proposed junction is formed as a quasi periodic arrangement of N unit cells. Each unit cell is realized as a cascade of short cylindrical ferrite coupled lines with reactance circuit composed of series capacitors and parallel inductors. The left-handed cylindrical junction with π/4...
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Impedance of cation-coupled electron transfer reaction: Theoretical description of one pathway process
PublikacjaIt has been assumed that cation electron coupled charge transfer can be conducted in accordance with two mutually coupled reactions. Using a differential method an expression was introduced which describes the impedance of a cation electron coupled transfer reaction. Also, an electrical equivalent circuit has been defined. The total faradaic impedance is the sum of electron transfer impedance and cation transfer impedance. Issues...
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Dimensional Synthesis of Coupled-Resonator Pseudoelliptic Microwave Bandpass Filters with Constant and Dispersive Couplings
PublikacjaIn this paper, we propose a novel technique for the dimensional synthesis of coupled-resonator pseudoelliptic microwave filters with constant and dispersive couplings. The proposed technique is based on numerical simulations of small structures, involving up to two adjacent resonators, and it accounts for a loading effect from other resonators by replacing them with terminations coupled through appropriately scaled inverters. The...
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The Conceptual Research over Low-Switching Modulation Strategy for Matrix Converters with the Coupled Reactors
PublikacjaIn this paper, different Pulse Width Modulation (PWM) strategies for operating with a low-switching frequency, a topology that combines Conventional Matrix Converters (CMCs), and Coupled Reactors (CRs) are presented and discussed. The principles of the proposed strategies are first discussed by a conceptual analysis and later validated by simulation. The paper shows how the combination of CMCs and CRs could be of special interest...
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A Comparison of STI Measured by Direct and Indirect Methods for Interiors Coupled with Sound Reinforcement Systems
PublikacjaThis paper presents a comparison of STI (Speech Transmission Index) coefficient measurement results carried out by direct and indirect methods. First, acoustic parameters important in the context of public address and sound reinforcement systems are recalled. A measurement methodology is presented that employs various test signals to determine impulse responses. The process of evaluating sound system performance, signals enabling...
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Simultaneous detrmination of selected phenoxyacid herbicides and chlorophenols in surface and seawater by HPLC coupled to DAD.
PublikacjaDo badań wykorzystano metodę ekstrakcji do fazy stałej (SPE) w celu wzbogacenia analitów. Ekstrakty analizowano techniką wysokosprawnej chromatografii cieczowej (HPLC) z detekcją DAD. Opracowana metoda umożliwia oznaczenie 14 związków z grupy kwasów fenoksyoctowych i chlorofenoli w czasie 22 min. Odzysk analitów wynosił powyżej 60% dla fenoksykwasów i powyżej 70% w przypadku chlorofenoli. Granica oznaczalności dla oznaczania...
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Modelling of strain localization in quasi-brittle materials with coupled elasto-plastic-damage model
PublikacjaW artykule przedstawiono wyniki numerycznej dla zginania belki betonowej przy zastosowaniu połączonego modelu sprężysto-plastycznego z degradacja sztywności. Do opisu rys, model rozszerzono o nielokalność.
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On the effective properties of foams in the framework of the couple stress theory
PublikacjaIn the framework of the couple stress theory, we discuss the effective elastic properties of a metal open-cell foam. In this theory, we have the couple stress tensor, but the microrotations are fully described by displacements. To this end, we performed calculations for a representative volume element which give the matrices of elastic moduli relating stress and stress tensors with strain and microcurvature tensors.
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Multipath Complex Root Tracing
PublikacjaThe problem of multipath root tracing is being addressed in this communication. The self-adaptive complex root tracing algorithm, which was previously utilized for the investigation of various propagation and radiation problems, is analyzed here for the cases when the traced characteristic bifurcates. A procedure of multiroute detection is proposed and demonstrated on the coaxially loaded cylindrical waveguide example.
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Design process as complex system
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COMPLEX ISSUES IN ARCHITECTURAL DESIGN
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THIRD-ORDER EXPONENTIAL INTEGRATOR FOR LINEAR KLEIN–GORDON EQUATIONS WITH TIME AND SPACE-DEPENDANT MASS
PublikacjaAllowing for space- and time-dependance of mass in Klein–Gordon equations re- solves the problem of negative probability density and of violation of Lorenz covariance of interaction in quantum mechanics. Moreover it extends their applicability to the domain of quantum cosmology, where the variation in mass may be accompanied by high oscillations....
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THIRD-ORDER EXPONENTIAL INTEGRATOR FOR LINEAR KLEIN–GORDON EQUATIONS WITH TIME AND SPACE-DEPENDANT MASS
PublikacjaAllowing for space- and time-dependance of mass in Klein–Gordon equations re- solves the problem of negative probability density and of violation of Lorenz covariance of interaction in quantum mechanics. Moreover it extends their applicability to the domain of quantum cosmology, where the variation in mass may be accompanied by high oscillations....
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Visually validated semi-automatic high-frequency oscillation detection aides the delineation of epileptogenic regions during intra-operative electrocorticography
PublikacjaOBJECTIVE: To test the utility of a novel semi-automated method for detecting, validating, and quantifying high-frequency oscillations (HFOs): ripples (80-200 Hz) and fast ripples (200-600 Hz) in intra-operative electrocorticography (ECoG) recordings. METHODS: Sixteen adult patients with temporal lobe epilepsy (TLE) had intra-operative ECoG recordings at the time of resection. The computer-annotated ECoG recordings were visually...
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Design of novel microstrip directional coupler for differential signal decoupling
PublikacjaThis study describes a concept of a novel microstrip directional coupler for differential signal decoupling, which can be used to digital signal overhearing on printed-circuit-boards. The complete design method is proposed with rules given analytically. Considered methodology is suitable for synthesis of couplers with low coupling factors, which have negligible influence on the transmission in main line. Theoretical considerations...
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Doubly miniaturized rat-race coupler with periodic pbg structures
PublikacjaW referacie zaprezentowano projekt oraz wyniki eksperymentu podwójnie zminiaturyzowanego sprzęgacza pierścieniowego. Wstępny stopień miniaturyzacji uzyskano poprzez modyfikację impedancji charakterystycznych oraz długości elektrycznych odpowiednich sekcji linii mikropaskowych, natomiast dodatkową redukcję powierzchni osiągnięto poprzez implementację kaskad komórek PBG w odcinkach linii mikropaskowych. Wyniki eksperymentu potwierdzają...
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A robust design of a numerically demanding compact rat-race coupler
PublikacjaA fast and accurate design procedure of a computationally expensive microwave circuit has been presented step-by-step and experimentally validated on the basis of a compact rat-race coupler (RRC) comprising slow-wave resonant structures (SWRSs). The final compact RRC solution has been obtained by means of a sequential optimization scheme exploiting the implicit space mapping (ISM) algorithm. A well-suited surrogate optimization...
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A CMRC-based compact rat-race coupler with harmonic suppression
PublikacjaIn this paper, an eective miniaturization technique exploiting compact microstrip resonant cells has been discussed and experimentally validated on the basis of a 3-dB microstrip rat-race coupler. The application of the method proposed has resulted in 91 % circuit area reduction in comparison to a conventional rat-race coupler. Experimental results show good agreement with theoretical characteristics, as well as an additional eect,...
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Miniaturized dual‐band branch‐line coupler with enhanced bandwidth
PublikacjaIn this letter, a miniaturized hybrid dual-band branch-line coupler (BLC) with enhanced fractional bandwidths is proposed. Compact size and bandwidth enhancement are obtained using meandered transmission line sections with broken symmetry between cross-coupling branches. The circuit is designed at a low numerical cost using surrogate-assisted techniques. The optimized design features small size of only 0.25λg×0.19λg(28% miniaturization...
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Wideband Highly-Selective Bandpass Filtering Branch-Line Coupler
PublikacjaThis paper presents a novel design of a wideband highly-selective bandpass filtering branch-line coupler (FBLC). By integrating a coupled microstrip line, and an open-ended stub at each port of a single-section BLC, bandpass filtering characteristics with excellent selectivity and broad operating bandwidth have been achieved. The proposed circuit has been verified through EM simulations and physical measurements of the fabricated...