A Digital-Receiver for the Murchison Widefield Array

Abstract

An FPGA-based digital-receiver has been developed for a low-frequency imaging radio interferometer, the Murchison Widefield Array (MWA). The MWA, located at the Murchison Radio-astronomy Observatory (MRO) in Western Australia, consists of 128 dual-polarized aperture-array elements (tiles) operating between 80 and 300\,MHz, with a total processed bandwidth of 30.72 MHz for each polarization. Radio-frequency signals from the tiles are amplified and band limited using analog signal conditioning units; sampled and channelized by digital-receivers. The signals from eight tiles are processed by a single digital-receiver, thus requiring 16 digital-receivers for the MWA. The main function of the digital-receivers is to digitize the broad-band signals from each tile, channelize them to form the sky-band, and transport it through optical fibers to a centrally located correlator for further processing. The digital-receiver firmware also implements functions to measure the signal power, perform power equalization across the band, detect interference-like events, and invoke diagnostic modes. The digital-receiver is controlled by high-level programs running on a single-board-computer. This paper presents the digital-receiver design, implementation, current status, and plans for future enhancements.

14 pages, 7 figures

References in corpus (7)

• The Murchison Widefield Array: Design Overview
• A 189 MHz, 2400 square degree polarization survey with the Murchison Widefield Array 32-element prototype
• A survey for transients and variables with the Murchison Widefield Array 32-tile prototype at 154 MHz
• Field Deployment of Prototype Antenna Tiles for the Mileura Widefield Array--Low Frequency Demonstrator
• The first Murchison Widefield Array low frequency radio observations of cluster scale non-thermal emission: the case of Abell 3667
• A new layout optimization technique for interferometric arrays, applied to the MWA
• The giant lobes of Centaurus A observed at 118 MHz with the Murchison Widefield Array

Cited by in corpus (16)

• First Season MWA EoR Power Spectrum Results at Redshift 7
• Improving the Epoch of Reionization Power Spectrum Results from Murchison Widefield Array Season 1 Observations
• First Limits on the 21 cm Power Spectrum during the Epoch of X-ray heating
• First Season MWA Phase II EoR Power Spectrum Results at Redshift 7
• A new MWA limit on the 21 cm Power Spectrum at Redshifts $\sim$ 13 $-$ 17
• New EoR Power Spectrum Limits From MWA Phase II Using the Delay Spectrum Method and Novel Systematic Rejection
• Observations of Low-Frequency Radio Emission from Millisecond Pulsars and Multipath Propagation in the Interstellar Medium
• A Census of Southern Pulsars at 185 MHz
• The Engineering Development Array: A low frequency radio telescope utilising SKA precursor technology
• Evidence of Ultra-faint Radio Frequency Interference in Deep 21~cm Epoch of Reionization Power Spectra with the Murchison Widefield Array
• A First Look for Molecules between 103 and 133 MHz using the Murchison Widefield Array
• MWA tied-array processing III: Microsecond time resolution via a polyphase synthesis filter
• A Comparative Analysis To Deal With Missing Spectral Information Caused By RFI In Cosmological HI 21CM Observations
• An Ultra-High Time Resolution Cosmic Ray Detection Mode for the Murchison Widefield Array
• The impact of lunar topography on the 21-cm power spectrum for grid-based arrays : Insights for the Dark-ages EXplorer (DEX)
• Bayes-SCF: A Bayesian filter to mitigate foreground leakage in the 21-cm power spectrum