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As wireless networks become faster and more demanding, the tiny radio-frequency chips inside smartphones and communication systems are approaching their physical limits. Acoustic wave devices, key components that filter wireless signals, are highly compact and efficient, but they have struggled to handle high power. Excessive heat, mechanical stress and material degradation can reduce performance or permanently damage the device, limiting their use in next-generation communications.
Researchers at the Hong Kong University of Science and Technology (HKUST) have developed a new chip architecture that addresses this long-standing challenge. Called Layered Acoustic Wave (LAW), the design enables acoustic devices to withstand more than 12 times the power of current designs while operating at significantly lower temperatures and maintaining stable performance.
Acoustic chips work by converting radio-frequency electrical signals into microscopic sound waves that travel through a piezoelectric material at gigahertz frequencies. Because sound travels much more slowly than electromagnetic waves, these devices can process high-frequency signals within an extremely small footprint, making them essential for smartphones, mobile base stations and satellite communication equipment.
According to TechXplore, the main obstacle has always been heat. At high power levels, intense vibrations generate mechanical stress that can cause metal atoms in the chip’s electrodes to migrate, which is a phenomenon known as acoustomigration. Over time, this creates microscopic voids and protrusions that damage the circuit. Heat also alters the speed of the acoustic waves, shifting the device away from its intended operating frequency.
Instead of improving heat dissipation from beneath the chip, as previous approaches have attempted, the researchers redesigned the structure above the vibrating surface. The LAW architecture covers the active acoustic layer with a silicon dioxide insulating layer and a thick amorphous silicon layer. This upper structure performs three functions simultaneously: it spreads heat away from hot spots, redistributes mechanical stress to reduce the forces that cause material degradation, and compensates for thermal expansion to keep the operating frequency stable.
Laboratory testing demonstrated substantial improvements. The LAW device reduced temperature rise by 70% compared with a conventional thin-film acoustic device and achieved a record power density of 36.4 W/mm² while operating at more than 2 billion vibrations per second. The researchers also reported improved frequency stability across an exceptionally wide temperature range.
Although the technology is aimed at future communications infrastructure, it also has significant defense and homeland security implications. Military radios, satellite communications, electronic warfare systems and secure tactical networks all rely on compact, high-performance radio-frequency components capable of operating under demanding conditions. More robust acoustic chips could improve the reliability of these systems while supporting emerging applications such as direct-to-device satellite communications and future 6G networks.
Because the LAW architecture can be manufactured using standard fabrication processes, the researchers believe it could be applied to a broad range of acoustic technologies beyond mobile communications, including quantum devices, microfluidics and advanced power-conversion systems. By overcoming one of the biggest limitations of acoustic electronics, the new design may help enable the next generation of high-power wireless technologies.
The research was published here.
