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Wyniki wyszukiwania dla: NARROW-BAND ANTENNAS
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Design of compact self-quintuplexing antenna with high-isolation for penta-band applications
PublikacjaThis article presents a novel compact self-quintuplexing antenna architecture based on a substrate-integrated rectangular cavity (SIRC) for pentaband applications. The proposed self-quintuplexing antenna is constructed by employing an SIRC, one Pi-shaped slot (PSS), one T-shaped slot (TSS), and five 50Ω microstrip feedlines. The PSS and TSS are engraved on the top of the SIRC to create five radiating patches, which are excited...
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Application of Dispersive Liquid-Liquid Microextraction in Narrow-Bore Tube for Preconcentration and Spectrophotometric Determination of Cadmium in Aqueous Samples
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Legal and economic identification and assessment of pharmacy substitution in narrow therapeutic index drugs, on the example of epileptic medications in Poland
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A system for Direction-Of-Arrival estimation in ISM 2.4 GHz frequency band based on ESPAR antenna and SDR technology
PublikacjaDetermination of the direction of the signal arrival (DOA) finds many applications in various areas of science and industry. Knowledge of DOA is used, among others to determine the position of a satellite with a low Earth orbit (LEO), localization of people and things as well as in research of wireless communication systems, for instance the determination of the number of...
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Modified monopole ring antennas as a solution for HiperLAN1/2 and IEEE 802.11b/g standard devices
PublikacjaZaprojektowano, wykonano i przebadano pierścieniową antenę planarną przeznaczona do aplikacji multisystemowych. Zastosowano system zasilania poprzez linie mikropaskową oraz dobrano wymiary i kształty pierścieni (promienników) w taki sposób, aby odpowiednio ''ulokować'' podzakresy pracy anteny. Zrealizowany prototyp anteny pracuje w zakresie standardów IEEE 802.11b/g oraz HiperLAN1/2.
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Mutual Coupling Between IFF/SSR Microstrip Antennas with Reduced Transversal Size- Experimental Study
PublikacjaW artykule opisano wyniki symulacji oraz pomiarów sprzężeń wzajemnych anten systemu IFF. Wyniki poprzedza analiza konfiguracji i działania pojedynczej anteny zasilanej szczeliną typu H. Badania przeprowadzono dla szyku poziomego i pionowego, w zakresie wejściowego współczynnika odbicia oraz współczynnika sprzężenia na dwóch częstotliwościach pasma IFF.
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Low-Cost Multi-Objective Optimization of Antennas By Means Of Generalized Pareto Ranking Bisection Algorithm
PublikacjaThis paper introduces a generalized Pareto ranking bisection algorithm for low-cost multi-objective design optimization of antenna structures. The algorithm allows for identifying a set of Pareto optimal sets of parameters (that represent the best trade-offs between considered objectives) by iterative partitioning of the intervals connecting previously found designs and executing a Pareto-ranking-based poll search. The initial...
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Efficient RSS-Based DoA Estimation for ESPAR Antennas Using Multiplane SDR Calibration Approach
PublikacjaIn this paper, we have introduced a new method to improve overall efficiency of direction-of-arrival (DoA) estimation scheme relying on received signal strength (RSS) values measured at the output port of electronically steerable parasitic array radiator (ESPAR) antenna. The proposed approach uses software-defined radio (SDR) setup and power pattern cross-correlation (PPCC) estimator involving multiple calibration planes. By placing...
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Compact Electromagnetic Lens Antennas Using Cascaded Metasurfaces for Gain Enhancement and Beam Steering Applications
PublikacjaElectromagnetic (EM) lens antenna designs using cascaded metasurfaces for gain enhancement and beam steering applications are proposed. Two different lens aperture designs are proposed and populated with aperiodic unit cells of size 0.2λo × 0.2λo. In lens Design 1, the unit cells of different phases are distributed in concentric circular zones, whereas in lens Design 2, the unit cells of different phases are distributed in vertical...
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Opportunistic tri-band carrier aggregation in licensed spectrum for multi-operator 5G hetnet
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Wide-band modulation and adaptive equalization techniques for fast and reliable underwater data transmission.
PublikacjaSzybkość transmisji w płytkim kanale podwodnym jest ograniczona ze względu na wielokrotne odbicia fal dźwiękowych oraz niestacjonarność kanału. Dla zapewnienia szybkiej i niezawodnej transmisji danych w systemach komunikacji stosowane są złożone techniki modulacji oraz equalizacji kanału. W artykule zaproponowano zastosowanie modulacji OFDM oraz equalizacji adaptacyjnej w systemie komunikacji podwodnej. Modulacja OFDM stosowana...
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4x4 Butler matrix in microstrip-slot technology for 5.4 - 5.7 GHz frequency band
PublikacjaW pracy zaprezentowano projekt, realizację oraz wyniki pomiarów parametrów 8-wrotowej, mikropaskowej matrycy Butlera wykonanej w technice wielowarstwowej. Poprzez odpowiednie rozmieszczenie wrót układu oraz zastosowanie sprzęgaczy wykorzystujących efekt sprzężenia poprzez szczelinę w płaszczyźnie wspólnej masy wyeliminowano konieczność zastosowania skrzyżowań linii mikropaskowych. Zrealizowany układ wydaje się obiecujący, ze względu...
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Band structure, Born effective charges, and lattice dynamics of CuInS2 from ab initio calculations
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New Type of Small Broad-Band Internal Antenna for Third Generation Mobile Phone Handsets.
PublikacjaW pracy przedstawiono nową szerokopasmową antenę łatową przeznaczoną dla telefonów komórkowych trzeciej generacji. Proponowana struktura zawiera obwód (rezonator) w kształcie litery U i zaliczana jest do klasy PIFA (planar inverted-F antenna). W trakcie procesu projektowania przeprowadzono szereg symulacji elektromagnetycznych (metoda momentów), których wyniki zweryfikowano w oparciu o pomiary charakterystyk wykonanego prototypu....
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Multi-instrument analysis of L-band amplitude scintillation observed over the Eastern Arabian Peninsula
PublikacjaThe study of scintillation-causing ionospheric irregularities is important to mitigate their effects on satellite communications. It is also important due to the spatial and temporal variability of these irregularities, given that their characteristics differ from one region to another. This study investigates the spatial and temporal characteristics of L1 amplitude scintillation-causing ionospheric irregularities over the Eastern...
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Forecasting values of cutting power for the sawing process of impregnated pine wood on band sawing machine
PublikacjaW artykule przedstawiono prognozowane wartości mocy skrawania dla pilarki taśmowej (ST100R firmy STENNER), które są stosowane w polskich tartakach. Wartości mocy skrawania oszacowano dla drewna sosny zwyczajnej (Pinus sylvestris L.), które zostało poddane impregnacji. Dla porównania wyznaczono również wartości mocy skrawania dla drewna niezaimpregnowanego. Wartości te określono za pomocą innowacyjnej metody prognozowania sił skrawania,...
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Microfluidic SIW-Based Tunable Self-Diplexing Antenna for Sub-6 GHz Band Applications
PublikacjaThis 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...
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Analysis of specific cutting resistance while cutting frozen pine blocks with narrow-kerf stellite tipped saws on frame sawing machines.
PublikacjaPrzedstawiono wyniki analizy oporów skrawania drewna zmrożonego podczas przecierania pryzm sosnowych na pilarce ramowej za pomocą cienkich pił. Badania prowadzono dla temperatur drewna -5 st. C, -20 st. C oraz dla porównania w temperaturze +18 st. C. Wilgotność drewna wynosiła 30%. Zaobserwowano znaczacy wzrost oporów skrawania wraz ze spadkiem jego temperatury.
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Empty in summer, crowded during migration? Structure of assemblage, distribution pattern and habitat use by bats (Chiroptera: Vespertilionidae) in a narrow, marine peninsula
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Toward Wide-Band High-Resolution Analog-to-Digital Converters Using Hybrid Filter Bank Architecture
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Person Tracking in Ultra-Wide Band Hybrid Localization System Using Reduced Number of Reference Nodes
PublikacjaIn this article a novel method of positional data integration in an indoor hybrid localization system combining inertial navigation with radio distance measurements is presented. A point of interest is the situation when the positional data and the radio distance measurements are obtained from less than thee reference nodes and it is impossible to unambiguously localize the moving person due to undetermined set of positional equations....
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RSS-Based DoA Estimation in 802.11p Frequency Band Using ESPAR Antenna and PPCC-MCP Method
PublikacjaIn this paper, the concept of direction of arrival (DoA) estimation using electronically steerable parasitic array radiator (ESPAR) antenna designed to operate in IEEE 802.11p vehicular communication standard has been investigated with respect to different possible elevation angles of a radio frequency (RF) signal impinging the antenna. To this end, two different possible sets of the 3D antenna radiation patterns have been used...
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Hydrophobic PVDF hollow fiber membranes with narrow pore size distribution and ultra-thin skin for the fresh water production through membrane distillation
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Structural modification and band gap engineering of carbon nano-onions via sulphur doping: Theoretical DFT study
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Embedded device for indoor positioning of mobile terminals in ISM 2.4 GHz frequency band integrated with ESPAR antenna
PublikacjaIn the era of multifunctional mobile phones, wireless positioning is one of the most important branches of telecommunications development. This functionality is possible thanks to global positioning systems such as GPS, whose services are available to every average user. Global systems, however, suffer from their low accuracy in confined environments such as forests and building interiors. A popular...
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Revisional bariatric surgery after adjustable gastric band: a multicenter Polish Revision Obesity Surgery Study (PROSS)
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Bandwidth-Controllable Third-Order Band Pass Filter Using Substrate Integrated Full- and Semi-Circular Cavities
PublikacjaThe article presents a novel circular substrate integrated waveguide (SIW) bandpass filter (BPF) with controllable bandwidth. The proposed BPF is configured using two microstrip feedlines, semi- circular SIW cavities, capacitive slots, and inductive vias. The circular cavity is bisected into two halves, with the two copies thereof being cascaded. Two bisected and cascaded structures obtained this way are subsequently connected...
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Application of In-Syringe Dispersive Liquid–Liquid Microextraction and Narrow-Bore Tube Dispersive Liquid–Liquid Microextraction for the Determination of Trace Amounts of BTEX in Water Samples
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Cu-Doped Layered Double Hydroxide Constructs the Performance-Enhanced Supercapacitor Via Band Gap Reduction and Defect Triggering
PublikacjaLayered double hydroxides (LDHs) are regarded as the excellent electrode materials for supercapacitors because of their high theoretical capacitance and abundance. However, the poor conductivity and limited reaction kinetics of LDHs restrict their practical application severely. Herein, Cu is chosen from groups VIII/IB/IIB as dopants for Co-based LDH (CuCo-LDH). The designed metal–organic framework-derived hierarchical CuCo-LDH...
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Bonding of Molybdenum(V) to Poly(ethylene-co-methacrylic acid) Ionomers from X- and W-Band ESR and IR Spectroscopies
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Optimizing Ni–Cr patterned boron-doped diamond band electrodes: Doping effects on electrochemical efficiency and posaconazole sensing performance
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A 1-nS 1-V Sub-1-µW Linear CMOS OTA with Rail-to-Rail Input for Hz-Band Sensory Interfaces
PublikacjaThe paper presents an operational transconductance amplifier (OTA) with low transconductance (0.62–6.28 nS) and low power consumption (28–270 nW) for the low-frequency analog front-ends in biomedical sensor interfaces. The proposed OTA implements an innovative, highly linear voltage-to-current converter based on the channel-length-modulation effect, which can be rail-to-rail driven. At 1-V supply and 1-Vpp asymmetrical input driving,...
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Designing a High-sensitivity Microscale Triple-band Biosensor based on Terahertz MTMs to provide a perfect absorber for Non-Melanoma Skin Cancer diagnostic
PublikacjaNon-melanoma skin cancer (NMSC) is among the most prevalent forms of cancer originating in the top layer of the skin, with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) being its primary categories. While both types are highly treatable, the success of treatment hinges on early diagnosis. Early-stage NMSC detection can be achieved through clinical examination, typically involving visual inspection. An alternative,...
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Lokalizacja osób w środowisku promu pasażerskiego z wykorzystaniem ultra szerokopasmowego interfejsu radiowego
PublikacjaW niniejszym artykule przedstawiono badania efektywności lokalizowania poruszających się osób w środowisku promu pasażerskiego stosując pomiar czasu propagacji ultraszerokopasmowego sygnału radiowego UWB (Ultra-Wide Band) pomiędzy węzłami odniesienia i terminalem ruchomym. Opisano zbudowane stanowisko badawcze oraz uzyskane wyniki pomiarów przeprowadzonych w warunkach rzeczywistych.
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Cardiovascular and Perceptual Responses to Resistance Training with Practical Blood Flow Restriction Induced by a Non-Elastic Band vs. Pneumatic Cuff: A Crossover Randomized Study
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Comparative in vitro studies on liposomal formulations of amphotericin Band its derivative, N-methyl-N-D-fructosyl amphotericin B methyl ester (MFAME)
PublikacjaMFAME, ester metylowy N-metylo-N-D-fruktozylo amfoterycyny B jest półsyntetyczną pochodną antybiotyku przeciwgrzybowego amfoterycyny B (AMB). W przeciwieństwie do wyjściowego antybiotyku pochodna ta jest nietoksyczna dla komórek zwierzęcych oraz tworzy rozpuszczalne sole rozpuszczalne w wodzie. Przeprowadzono badania porównawcze aktywności biologicznej wolnego antybiotyku i wolnej pochodnej oraz ich preparatów liposomalnych. Stosowano...
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Hybrid Technique Combining the FDTD Method and Its Convolution Formulation Based on the Discrete Green's Function
PublikacjaIn this letter, a technique combining the finite-difference time-domain (FDTD) method and its formulation based on the discrete Green's function (DGF) is presented. The hybrid method is applicable to inhomogeneous dielectric structures that are mutually coupled with wire antennas. The method employs the surface equivalence theorem in the discrete domain to separate the problem into a dielectric domain simulated using the FDTD method...
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Simulation-Based Design of Microstrip Linear Antenna Arrays Using Fast Radiation Response Surrogates
PublikacjaFast yet accurate technique for simulation-based design of linear arrays of microstrip patch antennas is presented. Our technique includes: (i) optimization of the corrected array factor of the antenna array under design for a phase excitation taper resulting in reduced side lobes; (ii) simulation-driven optimization of the array element for element dimensions resulting in matching at and about operational frequency, and (iii)...
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On Alternative Approaches to Design of Corporate Feeds for Low-Sidelobe Microstrip Linear Arrays
PublikacjaTwo design approaches, illustrated by simulations and measurements, aiming at a systematic computer-aided design of printed circuit feeds for low-sidelobe microstrip antenna arrays are described. The novelty of these approaches resides in identification of the optimal feed architectures with subsequent simulation-based optimization of the feed and array aperture dimensions. In this work, we consider microstrip corporate feeds realizing...
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Design of a Planar UWB Dipole Antenna with an Integrated Balun Using Surrogate-Based Optimization
PublikacjaA design of an ultra-wideband (UWB) antenna with an integrated balun is presented. A fully planar balun configuration interfacing the microstrip input of the structure to the coplanar stripline (CPS) input of the dipole antenna is introduced. The electromagnetic (EM) model of the structure of interest includes the dipole, the balun, and the microstrip input to account for coupling and radiation effects over the UWB band. The EM...
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A New Expression for the 3-D Dyadic FDTD-Compatible Green's Function Based on Multidimensional Z-Transform
PublikacjaIn this letter, a new analytic expression for the time-domain discrete Green's function (DGF) is derived for the 3-D finite-difference time-domain (FDTD) grid. The derivation employs the multidimensional Z-transform and the impulse response of the discretized scalar wave equation (i.e., scalar DGF). The derived DGF expression involves elementary functions only and requires the implementation of a single function in the multiple-precision...
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Development of a compact microstrip resonant cell aimed at efficient microwave component size reduction
PublikacjaA comprehensive comparison of a wide collection of compact microstrip resonant cells (CMRCs) found in the extensive body of literature has been presented. The evaluation of different CMRC designs has led to the selection of the most promising CMRC geometry for the efficient miniaturisation of modern microwave components. In order to showcase the vital effectiveness of the approach, the initially selected CMRC has been notably...
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Characterization of Slow and Fast Fading in Off-Body Communication at 2.45 GHz with Space Diversity Scheme in an Indoor Environment
PublikacjaThe characterization of slow and fast fading in wireless body area networks with space diversity scheme has been presented. The analysis, based on the measurements at 2.45 GHz in an indoor environment, has shown that for all investigated configurations of receiving wearable antennas, the correlation coefficient values of the received signals’ parameters are below the assumed value of 0.5, being close to zero for the vast majority...
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Design and Characterization of a Planar Structure Wideband Millimeter-Wave Antenna with Wide Beamwidth for Wearable off-body Communication Applications
PublikacjaThis letter presents the design of a planar single-layer wideband antenna featuring wide beamwidth has well as high and stable in-band gain. The proposed antenna is a planar monopole fed by a bottom-grounded coplanar waveguide to realize wide beamwidth in both the xz- and yz-planes. Simultaneous optimization of all adjustable antenna parameters, carried out at the full-wave electromagnetic simulation level. The constructive interference...
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Pin-on-Substrate Gap Waveguide: An Extremely Low-Cost Realization of High-Performance Gap Waveguide Components
PublikacjaConsidering the limitations of currently available technologies for the realization of microwave components and antennas, a trade-off between different factors including the efficiency and fabrication cost is required. The main objective of this letter is to propose a novel method for the realization of gap waveguides (GWGs) that take advantage of conventional PCB fabrication technology, thus are low cost and light weight. Moreover,...
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Efficient Simulation-Based Global Antenna Optimization Using Characteristic Point Method and Nature-Inspired Metaheuristics
PublikacjaAntenna structures are designed nowadays to fulfil rigorous demands, including multi-band operation, where the center frequencies need to be precisely allocated at the assumed targets while improving other features, such as impedance matching. Achieving this requires simultaneous optimization of antenna geometry parameters. When considering multimodal problems or if a reasonable initial design is not at hand, one needs to rely...
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Expedited EM-driven multi-objective antenna design in highly-dimensional parameter spaces
PublikacjaA technique for low-cost multi-objective optimization of antennas in highly-dimensional parameter spaces is presented. The optimization procedure is expedited by exploiting fast surrogate models, including coarse-discretization EM antenna simulations and response surface approximations (RSA). The latter is utilized to yield an initial set of Pareto non-dominated designs which are further refined using response correction methods....
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Single-Anchor Indoor Localization Using ESPAR Antenna
PublikacjaIn this paper a new single-anchor indoor localization concept employing Electronically Steerable Parasitic Array Radiator (ESPAR) antenna has been proposed. The new concept uses a simple fingerprinting algorithm adopted to work with directional main beam and narrow minimum radiation patterns of ESPAR antenna that scans 360° area around the base station, while the signal strength received from a mobile terminal is being recorded...
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A Broadband Circularly Polarized Wide-Slot Antenna with a Miniaturized Footprint
PublikacjaThis letter presents a novel and simple feeding technique for exciting orthogonal components in a wide-slot antenna. In this technique, a rectangular bracket-shape parasitic strip is placed at the open end of the straight microstrip line to excite the fundamental horizontal and vertical components of the circular polarization (CP). The proposed technique—when employed in conjunction with the asymmetrical geometry of coplanar waveguide...
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Measurement of Coherence Bandwidth in UHF Radio Channels for Narrowband Networks
PublikacjaThis paper presents results of investigation on the coherence bandwidth of narrowband radio channels in 430MHz band. The coherence bandwidth values were estimated froma power delay profile obtained by recording CDMA2000 forward channel signals during real-fieldmeasurements in various environments:mediumcity, flat terrain, and hilly terrain in northern Poland.The results of measurements are compared with characteristic parameters...