  A 32 GHz bandwidth VLBI capable correlator and phased array has been designed
and deployed at the Smithsonian Astrophysical Observatory's Submillimeter Array
(SMA). The SMA Wideband Astronomical ROACH2 Machine (SWARM) integrates two
instruments: a correlator with 140 kHz spectral resolution across its full 32
GHz band, used for connected interferometric observations, and a phased array
summer used when the SMA participates as a station in the Event Horizon
Telescope (EHT) Very Long Baseline Interferometry (VLBI) array. For each SWARM
quadrant, Reconfigurable Open Architecture Computing Hardware (ROACH2) units
shared under open source from the Collaboration for Astronomy Signal Processing
and Electronics Research (CASPER) are equipped with a pair of ultra-fast
Analog-to- Digital Converters (ADCs), a Field Programmable Gate Array (FPGA)
processor, and eight 10 Gigabit Ethernet ports. A VLBI data recorder interface
designated the SWARM Digital Back End, or SDBE, is implemented with a ninth
ROACH2 per quadrant, feeding four Mark6 VLBI recorders with an aggregate
recording rate of 64 Gbps. This paper describes the design and implementation
of SWARM, as well as its deployment at SMA with reference to verification and
science data.
