*PolyFiX: Lessons learned from the latest NOEMA Wideband Correlator
System***
In order to support the full 32GHz bandwidth delivered by the NOEMA 2SB
dual polarization receivers, a new wideband correlator has been
developed for the NOEMA interferometer.
This system has been dubbed PolyFiX in reference to the Polyphase
filtering and correlator FX architectures used within this last
generation system.
This FPGA-based correlator can correlate up to four 8GHz IF bands from
12 antennas with a 2MHz spectral resolution in parallel with 128
spectral windows of 64MHz each at a 62.5KHz resolution.
Higher resolution modes will be introduced in the near future thanks to
the flexible configuration offered by FPGAs.
The architecture is well suited to perform beamforming as well and to
provide standard VLBI sub-bands for operation in Phased-Array mode.
Pros and cons of this architecture will be discussed. The encountered
technical challenges will be described and the required skills to build
such a machine in a finite time will be outlined.
