  The Mexican Array Radio Telescope (MEXART), located in the state of Michoacan
in Mexico, has been operating in an analog fashion, utilizing a Butler Matrix
to generate fixed beams on the sky, since its inception. Calibrating this
instrument has proved difficult, leading to loss in sensitivity. It was also a
rigid setup, requiring manual intervention and tuning for different observation
requirements. The RF system has now been replaced with a digital one. This
digital backend is a hybrid system utilizing both FPGA-based technology and GPU
acceleration, and is capable of automatically calibrating the different rows of
the array, as well as generating a configurable number of frequency-domain
synthesized beams to towards selected locations on the sky. A monitoring and
control system, together with a full-featured web-based front-end, has also
been developed, greatly simplifying the interaction with the instrument. This
paper presents the design, implementation and deployment of the new digital
backend, including preliminary analysis of system performance and stability.
