Researchers at Adelaide University have developed a noninvasive method to remotely monitor the electrical activity of transistors inside packaged chips using terahertz waves. The system uses a vector network analyzer (VNA) with a frequency extender to direct terahertz radiation at a chip, then analyzes the reflected signal using a homodyne quadrature receiver to detect tiny changes in amplitude and phase caused by transistor switching. Unlike X-ray inspection, this approach can observe live electrical behavior without disturbing chip operation, and terahertz waves can penetrate nonmetallic packaging materials. Currently tested on discrete devices and small ICs with up to six FETs, the technique faces challenges with sensitivity and multi-layer opacity in modern chips. Potential applications include safety-critical high-power electronics monitoring and reading encrypted data in chips.
Sort: