The Pierre Auger Observatory is exploring the potential of the radiodetection technique to study extensive air showers induced by ultra-high energycosmic rays. The Auger Engineering Radio Array (AERA) addresses bothtechnological and scientific aspects of the radio technique. A first phase ofAERA has been operating since September 2010 with detector stations observingradio signals at frequencies between 30 and 80 MHz. In this paper we presentcomparative studies to identify and optimize the antenna design for the finalconfiguration of AERA consisting of 160 individual radio detector stations. Thetransient nature of the air shower signal requires a detailed description ofthe antenna sensor. As the ultra-wideband reception of pulses is not widelydiscussed in antenna literature, we review the relevant antenna characteristicsand enhance theoretical considerations towards the impulse response of antennasincluding polarization effects and multiple signal reflections. On the basis ofthe vector effective length we study the transient response characteristics ofthree candidate antennas in the time domain. Observing the variation of thecontinuous galactic background intensity we rank the antennas with respect tothe noise level added to the galactic signal.
展开▼
