With the idea of developing two projects related to the detection of the 22GHz water steam and 55-65GHz oxygen band, it was required to build the \ac{DSP} stage for the radiometer based on a \ac{ROACH} board. Since this \ac{FPGA}-based platform was relatively new in the market, research was needed in order to configure the customized toolflow process, which consists primarily in a Red Hat\texttrademark\ Linux machine, with Matlab\texttrademark\ for Simulink\texttrademark\ and Xilinx ISE\texttrademark\ Foundation including System Generator for \ac{DSP}. The toolflow was configured for allowing Simulink\texttrademark\ models were able to be converted into a \ac{HDL} representation and be synthesized in ISE\texttrademark . The system was configured for allowing a \ac{ROACH} board to boot and obtain its file-system from a \ac{NFS} enabled computer, the synthesized hardware from Simulink\texttrademark\ and ISE\texttrademark\ environments were stored on this server and \ac{ROACH} board can access them by means of a working \ac{NFS}.
The spectrometer found with preliminary \ac{ROACH} designs were a double-input \ac{ADC} of 400[MHz] bandwidth. Since this design was insufficient for the project objectives, it was then modified for working with a single input and a spectral window of 1000[MHz]. This increase of specifications was mainly achieved by removing the second \ac{ADC} channel and enabling interleaved sampling, which yields to capture analog data in both edges of the reference clock. In addition, the needed resources had to be increased for processing the doubled data rate coming from the \ac{ADC} step. Furthermore, system clock speed was increased from the original 800[MHz] to 1000[MHZ], this change brought problems in some critical paths of the processing blocks, delays were carefully studied and applied in order to relieve these timing constraints. A \ac{GUI} was developed on Python under the \ac{KATCP} protocol for capturing the data and producing the spectrometer plots, controls were added to interact with the \ac{ROACH} board and to set up plot parameters such as the axis limits. During the development of this work, wide collaboration was achieved with the design team in University of Berkeley, under the \ac{CASPER} group.