Mini mobiles

时间:2019-03-07 12:13:02166网络整理admin

By Paul Marks SMALLER cellphones with better reception could be on the horizon, thanks to a new microchip inductor that’s nearly three times as efficient as today’s devices, say researchers at the Korea Advanced Institute of Science and Technology in Taejon. Their secret is to suspend the device in mid-air. Cellphones need tuners and noise-filtering circuits, which include inductors: conducting spirals that can be etched onto the surface of a semiconductor. The efficiency of such devices is poor because current leaks from the conductor into the chip. Now Jun Bo Yoon and his colleagues at KAIST say they have solved the leakage problem by hoisting the copper coil above the chip, creating an air gap. The team will tell the International Electron Devices Meeting in Washington DC in December how they made their inductors “float” several hundredths of a millimetre above the microchip’s base. The copper spiral is deposited onto a substrate that is then etched away, save for some small support posts. The filtering efficiency of an inductor is indicated by its quality factor (Q). While today’s on-chip devices typically have a Q approaching 20, the new device has a Q of up to 57. Peter Harrison, technology manager at Nokia, says that efficient noise filtering in mobiles is essential. “And we would welcome any new components that let us make smaller cellphones,