RF Block Down Converter Chassis, SMA Project
Internal photos of Block Down Converter instrument: left - top view of RF brackets (x4), and monitor & control; right - bottom view of DC power supplies (x4), local oscillator plates (x2), and baseband plates (x4). Developed at the SMA project office by Derek Kubo, Ryan Chilson and John Kuroda for the SMA wideband upgrade project, this instrument provides signal conditioning and frequency translation of sixteen 8-12 GHz intermediate frequency channels from the eight SMA antennas. Two of these instruments were deployed to the Mauna Kea facility with a full suite of control software developed by Ranjani Srinivasan.
This instrument was developed specifically for the SMA wideband upgrade project to support an additional 8-12 GHz of intermediate frequency signal bandwidth from the new wideband receivers. Each packaged unit accepts a pair of 8-12 GHz input signals from four antennas and provides automatic level control, frequency separation, and down conversion to baseband for subsequent digitization. Two units were developed to support the eight SMA antennas. The packaging design utilizes custom modular line replaceable units housed within a 19 x 22 x 8.75 inch rack mountable EMI chassis. Operation at 4100 meters is facilitated with forced air cooling and thermal sensors for remote temperature monitoring. Each Block Down Converter unit is self contained, consumes 182 Watts of electrical power, and has a mass of 26 kg.