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    Tytuł:
    The Different Between the Temperature of the Solar Burst at the Feed Point of the Log Periodic Dipole Antenna (LPDA) and the CALLISTO Spectrometer
    Autorzy:
    Hamidi, Z. S.
    Shariff, N. N. M.
    Monstein, C.
    Powiązania:
    https://bibliotekanauki.pl/articles/411932.pdf
    Data publikacji:
    2014
    Wydawca:
    Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
    Tematy:
    CALLISTO
    Log Periodic Dipole Antenna
    LPDA
    temperature
    solar radio burst
    Opis:
    The article attempts to analyze and compare the temperature of solar radio burst at the (i) feed point and antenna and (ii) at the receiver (CALLISTO spectrometer). The analysis is very important to evaluate the performance for a better observation of solar radio burst. We start our project by developing this antenna with 19 elements of different sizes covers from 45 − 870 MHz. We choose the National Space Agency (PAN), Sg. Lang, Banting, Selangor, Malaysia as our site seems this site has a very minimum of Radio Frequency Interference (RFI). The antenna, then connects to the low noise amplifier and the CALLISTO spectrometer as one complete system. Based on the results, it was found that the temperature of the at the feed point of the antenna and receiver is different up to 3.25 K. The average level burst level above background sky is about 0.41dB. It was found that the power of solar burst at the feed point of the antenna is equivalent to 2.6 x 10-18 W, but decreases to 2.3 x 10-18 W when detected by the CALLISTO spectrometer. These results show a better understanding of how does the system operate in terms of the process of analysis of the temperature of solar radio burst.
    Źródło:
    International Letters of Chemistry, Physics and Astronomy; 2014, 11, 2; 167-176
    2299-3843
    Pojawia się w:
    International Letters of Chemistry, Physics and Astronomy
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    An Analysis of Antenna Temperature and Radar Cross Section of Log Periodic Dipole Antenna
    Autorzy:
    Hamidi, Z. S.
    Saad, M. Azren Mat
    Shariff, N. N. M.
    Monstein, C.
    Powiązania:
    https://bibliotekanauki.pl/articles/1192599.pdf
    Data publikacji:
    2016
    Wydawca:
    Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
    Tematy:
    Sun
    Log Periodic Dipole Antenna
    type III
    radio region
    antenna temperature radar cross section
    Opis:
    The LPDA antenna because it is very suitable and economic amount the types of antennas. It consists of an array of dipoles in which their lengths and spacing are arranged in a log periodic manner, but not all elements in the system are active on a single frequency of operation. The temperature or Antenna Noise Temperature depends on its gain pattern and the thermal environment that it is placed in. We need to design an antenna that can detect the data and monitor the solar burst type III in radio region. It must be sensitive to a broad frequency range and angular distribution of the incident radio pulse and capable to handle the noise issue that is necessary to gain the pure signal. With large instantaneous bandwidths and high spectral resolutions, these instruments will provide increased imaging sensitivity and enable detailed measurements of the dynamic solar burst. For standardized the time, GPS clock is used to control the sampling time of the spectrometer and a tracking controller control the antenna direction. In conclusion, LPDA is the most practical antennas provide general broadband transmission and reception in a wide range of frequency.
    Źródło:
    World Scientific News; 2016, 55; 126-136
    2392-2192
    Pojawia się w:
    World Scientific News
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Determination of Flux Density of the Solar Radio Burst Event by Using Log Periodic Dipole Antenna (LPDA)
    Autorzy:
    Hamidi, Z. S.
    Shariff, N. N. M.
    Powiązania:
    https://bibliotekanauki.pl/articles/412450.pdf
    Data publikacji:
    2014
    Wydawca:
    Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
    Tematy:
    sun
    CALLISTO
    Log Periodic Dipole Antenna (LPDA)
    power flux density
    solar radio burst
    Opis:
    In this article, an evaluation of the flux density of the solar radio burst is presented. A rod aluminium’s type as a conductor with nineteenth (19) elements of different sizes is being prepared to construct a log periodic dipole antenna (LPDA) from 45-870 MHz. The performance was carried out at the National Space Agency (PAN), Sg. Lang, Banting Selangor by connecting to the Compound Low Cost Low Frequency Spectroscopy Transportable Observatory (CALLISTO) spectrometer. The input impedance, R0 = 50 ohm is chosen for this LPDA antenna. From the analysis, the gain of the antenna is 9.3 dB. This antenna potentially captures a signal that covers about 0.08 m2 area of the Sun.The temperature of the burst that detected at the feedpoint of the antenna is 32 K. However, the signal becomes decrease to 28.75 K while by CALLISTO spectrometer as a receiver. It was also found that the isotropic source spectral power is 1576 W/Hz. Since the burst level above the background sky is 0.41 dB , the flux density of the burst is 5.5 x 10-21 W/m2/Hz. Based on the results, we conclude that this antenna is suitable for to observe the Sun activities at low frequency region.
    Źródło:
    International Letters of Chemistry, Physics and Astronomy; 2014, 7; 21-29
    2299-3843
    Pojawia się w:
    International Letters of Chemistry, Physics and Astronomy
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The zigzag pattern construction of Log Periodic Dipole Antenna Based on Rumsey’s Principle
    Autorzy:
    Hamidi, Z. S.
    Saad, M. Azren Mat
    Shariff, N. N. M.
    Monstein, C.
    Powiązania:
    https://bibliotekanauki.pl/articles/1188094.pdf
    Data publikacji:
    2016
    Wydawca:
    Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
    Tematy:
    Log Periodic Dipole Antenna
    zigzag pattern
    solar burst
    radio region
    Rumsey’s principle
    Opis:
    The log-periodic dipole array (LPDA) consist of an array of dipoles in which there have a different lengths and spacing. The wire may be straight or it may be strung back and forth between trees or walls just to get enough wire into the air; this type of antenna sometimes is called a zigzag antenna. Rumsey’s principle requires that the locations of all elements be specified by angles rather than distances, because of this the log periodic dipole array must be correspondingly longer to get very wide bandwidths and gives a very high data rate transmission. The significance of this study is to understand how do the LPDA can be used to monitor solar activities of the sun using the LPDA antenna. The characteristics that need to be considered during construct this antenna is the radiation pattern, polarization, operation of the frequency band, gain and efficiency of an antenna which indicates the power or field strength radiated in any direction relative to that in the direction of maximum radiation. The arrangement of elements in increasing order from the top of the antenna until the bottom part of antenna. Our designed antenna was constructed using aluminum for the further investigation, we can use a copper and check the difference between two of this element. For this study, we just analyzed the source of RFI using this antenna and for the further analysis, we can use this antenna to monitor the solar burst.
    Źródło:
    World Scientific News; 2016, 56; 146-157
    2392-2192
    Pojawia się w:
    World Scientific News
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Zestaw anten pomiarowych do badania emisyjności urządzeń w zakresie częstotliwości od 30 do 1000 MHz
    A set of test antennas for measuring the emissivity of devices in the 30-1000 MHz range
    Autorzy:
    Tyrawa, P.
    Kałuski, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/317366.pdf
    Data publikacji:
    2005
    Wydawca:
    Instytut Łączności - Państwowy Instytut Badawczy
    Tematy:
    anteny pomiarowe
    wzorcowanie
    niepożądana emisyjność
    otwarty poligon pomiarowy (OPP)
    kabina bezechowa
    bikon
    antena logarytmiczna
    dipol
    test antennas
    calibration
    undesirable emissivity
    open field test site
    anechoic chamber
    beacon
    log-periodic antenna
    dipole
    Opis:
    Opisano metodykę projektowania i wzorcowania odbiorczych anten pomiarowych w zakresie częstotliwości od 30 do 1000 MHz, wykorzystywanych do badania niepożądanej emisyjności urządzeń, zgodnie z zaleceniami norm. Zaprezentowano zestaw anten opracowany i oferowany przez Instytut Łączności we Wrocławiu.
    The paper describes the design and calibration methodology for test antennas operating in the 30-1000 MHz frequency range that are used to measure undesirable device emissivity, according to standard recommendations. A set of antennas developed and offered by the National Institute of Telecommunications in Wrocław is presented.
    Źródło:
    Telekomunikacja i Techniki Informacyjne; 2005, 1-2; 81-95
    1640-1549
    1899-8933
    Pojawia się w:
    Telekomunikacja i Techniki Informacyjne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-5 z 5

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