Researchers from the University of Waterloo have discovered a way to generate microwaves with inexpensive silicon using powerful supercomputers. This new approach has the potential to cut costs for microwave technology and improve devices such as sensors for self-driving vehicles.
Currently, the microwaves are typically generated by using expensive and toxic semiconductor materials such as gallium arsenide (GaAs). This new technology allows the use of silicon to produce microwave that costs about one-twentieth of GaAs and is far easier to work with for manufacturing.
Generation of low-cost microwaves
The current that passes through GaAs is directly proportional to the voltage applied to it. Hence, as we increase the voltage, current also increases. But after a certain point, it reaches a saturation level beyond which the current decreases. This process is known as Gunn effect that results in the emission of microwaves. Now researchers are using computational nanotechnology to show that this effect could be achieved with silicon.
The new technology involves the use of silicon nanowires so tiny that it would take 100,000 of them bundled together to equal the thickness of a human hair. Complex computer models show that if silicon wires are stretched as the voltage is applied to them, they exhibit Gunn effect thereby emitting microwaves.
“With the advent of new nano-fabrication methods, it is now easy to shape bulk silicon into nanowire forms and use it for this purpose,” said C.R. Selvakumar, an engineering professor at the University of Waterloo. “The theoretical work is the first step in a development process that could lead to much cheaper, more flexible devices for the generation of microwaves”, he added.
Researchers have proposed that this stretching mechanism can also act as a switch to turn on and off or vary the frequency of microwaves for a host of new applications that haven’t even been imagined yet. They believe this is only beginning in producing low-cost microwaves.