This study focuses on the radiation performance of a system composed of a room-temperature C-band Phased Array Feed (PAF) illuminating the 64-m diameter Sardinia Radio Telescope (SRT) main reflector from its primary focus (f/D=0.328). The PAF, a square array with 8x8 dual-polarized antennas, is the first version of a prototype designed for radio astronomy applications in the framework of an R&D (Research and Development) project of the Italian National Institute for Astrophysics (INAF). To guarantee high sensitivity and low noise temperature, the PAF elements have been designed for an optimum coupling with the SRT main reflector by trading off between maximizing the illumination efficiency and minimizing the spillover. In this paper, first, we present the results of the electromagnetic simulation of the PAF element radiation patterns in the Far Field (FF) region, both by assuming no interaction with the reflector and by taking into account the reflection from the SRT main reflector primary focus; second, we present the performance of the beamformed patterns obtained by applying two different beamforming methods; finally, we assess the aperture blockage effect due to the SRT sub-reflector. Results are shown at three frequencies within the operative band of the C-band PAF, i.e. at 4.5, 5.5 and 6.0 GHz.
KEYWORDS: Pulsars, Radio telescopes, Analog to digital converters, Radio astronomy, Electromagnetic coupling, Field programmable gate arrays, Receivers, Digital signal processing, Telescopes, Spectroscopy
SKARAB is the acronym for Square Kilometer Array Reconfigurable Application Board, a digital platform that was initially designed for the MeerKAT digital correlator. Being equipped with a reprogrammable chip like a Virtex7 FPGA, SKARAB is a not application-specific computing node 19’’ 1U dimension, thus suitable to be employed for single-dish applications as well. Here we present a SKARAB pulsar machine that has been engineered and built for the Sardinia Radio Telescope (SRT, Italy). The high dynamic range provided by the high-performing ADC mezzanine card (which provides digital samples coded with up to 16 bits) coupled with the SKARAB guarantees a proper functionality also in presence of strong Radio Frequency Interference (RFI), and the 4x40G I/O mezzanine card allows handling data rates up to 160 Gbit/sec.
Both pulsar search and pulsar timing are provided in different bandwidths and number of channels; we also present on-field results that we have achieved at the Sardinia Radio Telescope by observing the pulsar B0355+54 at 5 GHz.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.