Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: directivity patterns

Sortuj według:

Ogranicz wyniki do:

Antena monoimpulsowa z niesymetrycznymi dipolami ćwierćfalowymi

Jeziorski A., Sędek E., Słomski R.

Elektronika : konstrukcje, technologie, zastosowania

2015

Vol. 56, nr 6

11-14

W artykule przedstawiono koncepcję rozwiązania nowej anteny monoimpulsowej do specjalnych zastosowań w radiolokacji i radiopelengacji. Cechą charakterystyczną prezentowanej anteny jest jej prostota konstrukcyjna i niski koszt wykonania. Przedstawiono przestrzenne charakterystyki promieniowania sumacyjne i różnicowe anteny o dookólnej charakterystyce promieniowania i zaproponowano jej ewentualną modyfikację poprzez zastosowanie walca, który w sposób istotny ułatwia wyprowadzenia przewodów zasilających antenę.

New concept monopulse dipole antenna is presented in the paper. The antenna can be used in radar and telecommunication system. The antenna characterized simple construction and low cost. The spatial radiation sum and difference antenna characteristics are presented. The antenna has a around radiation characteristic, which can be modified by change shape of metal plate placed between quarterwave dipole. For example we propose apply metal cylinder, which additional make easier to bring out transmission lines excited antenna. Four variants realization monopulse dipole antenna is presented and discussed. The antenna characteristic can be optimized in point of view anticipated application.

Numerical Simulation for the Bell Directivity Patterns Determination

Gołaś A., Filipek R.

Archives of Acoustics

2009

Vol. 34, No. 4

415-427

The analysis of various sound sources is performed on the basis of their directivity patterns. The literature does not contain any information about directivity patterns of bells that are instruments broadly applied to sacral purposes or to create a certain sound space from the aesthetic point of view. The paper presents the methodology of determining the bell directivity patterns by an example of the Russian bell. This example was applied because exact values of geometrical parameters and measuring data of the bell were available. The model was created by means of FEA (finite element analysis). It included a coupling between the bell and its surrounding acoustic medium. During the modal analysis, the first three natural frequencies of the bell were calculated, and then, using the harmonic analysis, the directivity patterns were determined for the frequencies. Afterwards, the transient response of the system in selected measuring points was determined. The obtained results are important for bell-founders and architects because thanks to the knowledge of directivity patterns, the constructions supporting the bells can be designed in a better way and the sound propagation can be determined more precisely. The presented method of auralisation of the bell sound makes the cooperation between the designer and the receiver fairly convenient.