A long article written by Senior Editor Sally Cole of Military Embedded Systems and published on October 1, 2015, reported on the research of Joseph C. Bardin and Qiangfei Xia, electrical and computer engineering, who have developed ultra-tiny, electronic, radio-frequency (RF) switches with reprogrammable features and based on “memristor” technology.
As the Military Embedded Systems article reported, “So, what exactly is a memristor and its role in the “nanoscale memristive RF switches” invented by the duo? ‘It’s essentially a nonvolatile device whose resistance depends on the history of the current/voltage applied to the device,’ Bardin explains. ‘By using appropriate programming protocols, the DC resistance of these devices can be switched over ten orders of magnitude. There are many flavors of memristors, but the device that we demonstrated is specifically tailored for RF applications by minimizing OFF-state capacitance and ON-state resistance.’”
The article went on to explain that reconfigurable RF systems in use by the military today depend upon the availability of tiny switches that can be integrated into chips and easily reprogrammed to serve different RF functions. So far, though, the use of reconfigurable RF switches has been severely limited by performance drawbacks such as added noise, size, power consumption, functional instability, and a lack of durability.
“Now,” the article noted, “new nanoscale RF switches based on memristor technology can overcome these challenges,” thanks to the collaboration between Bardin and Xia. Professor Bardin’s main area of expertise is RF devices, circuits, and systems, while Professor Xia is an expert in nanoscale memristive devices.
Both Bardin and Xia have received the U.S. Defense Advanced Research Projects Agency (DARPA) Young Faculty Award (YFA). “Our collaboration was encouraged by DARPA’s Microsystems Technology Office Director Bill Chappell, who served as our mentor within the YFA program,” Bardin says.
In fact, the Embedded Military Systems article was preceded by a related article posted in August of 2015 on the DARPA news website. The DARPA story about the research of Xia and Bardin was entitled “New Nanoscale Programmable Switches Promise Faster, More Versatile Chip-scale Devices.”
As the DARPA article explained, “By combining complementary mindsets on the leading edges of electronic and radiofrequency device engineering, a pair of researchers in DARPA’s Young Faculty Award program has devised ultra-tiny, electronic switches with reprogrammable features resembling those at play in inter-neuron communication. These highly adaptable nanoscale switches can toggle on and off so fast, and with such low loss, they could become the basis of not only computer and memory devices but also multi-function radiofrequency (RF) chips, which users might reprogram on the fly to behave first like a cell-phone’s signal emitter but then, say, as a collision-avoidance radar component or a local radio jammer.”
In June of 2015 the College of Engineering also reported on a related academic journal article in Nature Communications. The title of that Nature Communications article was “Nanoscale Memristive Radiofrequency Switches,” and the authors were Shuang Pi, Mohammad Ghadiri-Sadrabadi, Bardin, and Xia.
The College of Engineering news page recounted that “Memristive devices are resistance switches whose internal states are determined by the history of applied voltage and/or current. Switching is typically related to the formation/rupture of one or more conductive filaments through either electrochemical reactions or the migration of mobile ions that modulate the interfacial properties. Because of a number of attractive features (such as non-volatility, low switching energy, fast switching speed, high endurance, excellent scalability, and CMOS compatibility), memristive devices are currently pursued by both industry and academia for applications in the next generation non-volatile memory and unconventional computing.”