Evaluation of signal to noise ratio (SNR) of log periodic dipole antenna (LPDA)

Abstract

Logarithmic periodic dipole antenna (LPDA) was constructed for monitoring Sun in the range of (45 -870) MHz to precisely match the solar monitoring requirements. In our work, we choose rod aluminium's type as a conductor with nineteenth (19) elements of different sizes. Beside established construction techniques, several test setups have done to make sure that we possibly obtain a good data. The performance testing has been done at National Space Agency (PAN), Sg. Lang, Banting Selangor by connecting to the CALLISTO spectrometer. In this case, we choose input impedance, R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> = 50 ohm for this LPDA antenna. We also select element factor (τ) and spacing factor (σ) give in the subtended angle of 3.43 degrees. As a result, a bandwidth ratio (B = 870 MHz /45MHz) of 19.33 gives a bandwidth as 2.14. The power flux density of the burst is 4.53841 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-21</sup> W/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> Hz. From the evaluation, we found that the signal to noise ratio is 3.9 dB. Although there are still needs to be improved, this construction of LPDA is considered successful and suitable for to observe the Sun activities at low frequencies.