Software Defined Radios in Extreme Environments: A Matter of Enclosure
August 11, 2023
Software Defined Radio (SDR) is a tool for RF spectrum monitoring, control, and testing. It is used in drone detection and deterrence, wireless testing, Signals Intelligence (SIGINT), electronic warfare, and wireless communication, among other applications. Rugged or extreme environments can present a challenge to SDR, however, because of the sensitivity of the hardware to moisture, temperature, and shock or vibration.
With the help of Pixus Technologies, The University of Utah wanted to build a wireless communication network for research and development on campus and in the areas surrounding Salt Lake City, Utah. The plan was for users to run experiments using NI SDRs, but they needed to be able to withstand Utah’s wide temperature ranges and protect against dust, moisture, and other elements. The SDR project is funded by the National Science Foundation (NSF) and is part of the Platforms Advanced Wireless Research (PAWR) program.
The communication nodes were deployed in a variety of locations, situations and environments in and around Salt Lake City, and because of the wide temperature variance throughout the year, it wouldn’t have been practical to employ an unmodified commercial SDR in the test setup. Freezing temperatures in the winter would likely cause the units to freeze up, and high summer temperatures could overheat them. In addition, modifications, maintenance, and new equipment installations would expose the SDRs to dust, moisture, and other contaminating elements.
To keep the nodes cool, a conduction-cooled chassis was installed, incorporating a heat-sink that displaced heat to an enclosure designed to maximize surface area for heat dissipation and enable operation in temperatures from -10°C to +55°C . To handle physical shock, the enclosure was designed to provide shock and vibration protection to MIL 810H levels. The solution for preventing dust, sand, moisture and other environmental contaminants from getting inside the enclosures was as simple as installing IP67 interfaces for the SMA, GPIO, power, Ethernet, JTAG, USB, SFP+, LED, and other I/O.
For more information on PAWR and the POWDER (Platform for Open Wireless Data-driven Experimental Research) project, visit www.powderwireless.net.