IoT technology still faces many challenges. Researchers at the University of Arkansas and the KTH Royal Institute of Technology have designed a wireless system for these difficulties. They are in this month's IEEE Electron Device Letters. Published a paper describing a mixer that can operate from room temperature to as high as 500 degrees Celsius, and the mixer is an important component in any wireless system. This is the first to withstand. Such a high temperature integrated mixer circuit.
IEEE Fellow, Alan Mantooth, a professor of electrical engineering at the University of Arkansas, an expert in extreme environmental electronics. In several projects, the most exciting thing is to try to put a probe car or other Some instruments are placed on the surface of Venus. The current working time of the equipment is recorded for more than two hours. The average temperature of Venus on a day is as high as 467 ° C, but this high temperature is sulfur.
You don't need to travel around the world to find this hellish place. On Earth there is an area of interest to Mantutz and his colleagues, such as the interior of a natural gas turbine generator. Currently, turbine generators are regulated. The time interval is closed for maintenance – whether or not components such as turbine blades really need to be inspected. Although redundant turbines can be used to reduce losses, accidental downtime consumes $1 million in electricity per day, Mantuz The professor said. Turbine manufacturers 'recommended to have built-in sensors to tell them when parts need to be replaced'. This way manufacturers can avoid unplanned equipment shut down and set maintenance intervals through actual data. But these sensors need Working in high temperature steam close to 1000 oC, and due to the close proximity of high speed rotating turbine blades, they also need to withstand electromagnetic forces of approximately 14,000 Gauss (Gs) magnetic induction.
The mixer chip and peripheral passive components are embedded in the test board, after which it is heated to 500 degrees Celsius and tested.
The University of Arkansas team is also investigating sensors for diesel engine combustion chambers to allow the computer to better control the efficiency of the diesel engine. And the team is developing an electronic device for driving the drill bit at the bottom of the well. 150 ° C.
In the context of these applications, silicon may not be the optimal semiconductor substrate. The band gap of silicon is too narrow to easily generate electron motion in high temperature environments, even when it is not needed. Materials with wide band gaps do not have such problems, such as gallium nitride, silicon carbide. Considering the wide band gap and better thermal conductivity, the team of Royal Institute of Technology and the University of Arkansas finally chose silicon carbide. 'Carbide does not fail in high temperature environments.' Mantutz said.
The integrated mixer circuit was designed by a team of professors of Royal Institute of Technology, Ana Rusu, and then packaged by the team of Professor Mantutz of the University of Arkansas, and finally returned to the team of Professor Rusu to complete the test. A down conversion from 59MHz to 500kHz is implemented for subsequent signal processing.