Illinois University engineers have found a way to minimize the transformer – one of the largest and heaviest elements of the circuit board.
The new 3D rolled-up radio frequency transformer is said to take 10 to 100 times less space, performs better when the power transfer ratio increases and has a simpler fabrication process than its 2D progenitors.
“Transformers are one of the largest and heaviest elements on any circuit board,” said principal investigator, professor Xiuling Li. “When you pick up an LED light bulb, it feels heavy for its size and that is in part because of the bulky transformer inside. The size of these transformers may become a key obstacle to overcome in the future for wireless communication and IoT.”
According to Li, the new transformer design is based on the group’s previously developed technique for rolled inductors. “We are making 3D structures using 2D processing,” Li contends.
The new transformer is made by depositing carefully patterned metal wires onto stretched 2D thin films. Once they release the tension, the 2D films self-roll into tiny tubes, allowing the primary and secondary wires to coil and nest perfectly inside each other.
Co-author Songbin Gong contends that the nested 3D architecture is what leads to high turns ratio coils. An added plus is that rolled transformers receive and process higher frequency signals than the larger devices.
“Wireless communication will be faster and use higher-frequency signals in the future. The current generation of radio frequency transformers simply cannot keep up with the miniaturization requirements and high-frequency operation of the future,” said lead author Wen Huang. “Smaller transformers with more turns allow for better reception of faster, high-frequency wireless signals, as well as high-level integration in IoT applications.”
Image and content: Wen Huang/University of Illinois