2 research outputs found
The Warm Receiver Section and the Digital Backend of the PHAROS2 Phased Array Feed
We describe the development of a multi-channel
“warm receiver section” (WS) and of a digital beamformer for
the PHAROS2 Phased Array Feed (PAF), a PAF demonstrator
for radio astronomy application across the 4-8 GHz radio
frequency (RF) band. The PAF is based on an array of 10Ă—11
dual-polarization Vivaldi antennas cryogenically cooled at
20 K along with low noise amplification modules (LNAs). The
WS receiver can process the signals from a subset of 24
antenna elements of the array by downconverting them to an
intermediate frequency (IF) range, 375-650 MHz, suitable for
digitization by the digital beamformer. The latter is based on
the iTPM (Italian Tile Processing Module), developed for the
Square Kilometer Array (SKA) Low Frequency Aperture
Array (LFAA). We modified the iTPM firmware to synthesize
four independent beams across the 275 MHz instantaneous IF
bandwidth in the iTPM FPGAs (Field Programmable Gate
Arrays). The 24 signals are sent from the WS to the iTPM
through analogue IFoF (IF over fiber) optical links. In this
paper we present the design and performance of the WS and of
the digital bemaformer for PHAROS2
Future Science Prospects for AMI
The Arcminute Microkelvin Imager (AMI) is a telescope specifically designed
for high sensitivity measurements of low-surface-brightness features at
cm-wavelength and has unique, important capabilities. It consists of two
interferometer arrays operating over 13.5-18 GHz that image structures on
scales of 0.5-10 arcmin with very low systematics. The Small Array (AMI-SA; ten
3.7-m antennas) couples very well to Sunyaev-Zel'dovich features from galaxy
clusters and to many Galactic features. The Large Array (AMI-LA; eight 13-m
antennas) has a collecting area ten times that of the AMI-SA and longer
baselines, crucially allowing the removal of the effects of confusing radio
point sources from regions of low surface-brightness, extended emission.
Moreover AMI provides fast, deep object surveying and allows monitoring of
large numbers of objects. In this White Paper we review the new science - both
Galactic and extragalactic - already achieved with AMI and outline the
prospects for much more.Comment: 20 pages, 11 figures; white paper. Revised author list, section IB,
section IIIC2, reference