Recently, the Wireless Technology and Integrated Systems Team from the University of Electronic Science and Technology of China’s (UESTC) School of Electronic Science and Engineering made waves in the academic community by publishing a groundbreaking paper titled “A Multi-Frequency-Excited MIMO Radar Array Architecture Enabling Exponential-Order Improvement in Angular Resolution” in the IEEE Journal of Solid-State Circuits (IEEE JSSC)—a top-tier international journal in the field of integrated circuits. This publication comes on the heels of the team’s presentation of related research at IEEE RFIC 2025, a premier conference in integrated circuits, where their work was selected as a finalist for the IEEE RFIC Symposium Best Student Paper Award and subsequently invited for extended publication in a special issue of IEEE JSSC. The paper’s first author is Liao Ruilin, a doctoral student who enrolled in 2022, with Professor Zhang Jingzhi and Professor Kang Kai serving as the corresponding authors.

Millimeter-wave radars, widely used in applications such as autonomous driving, typically offer angular resolutions ranging from 1° to 10°—far inferior to that of optical sensors. Traditional approaches to improving angular resolution involve increasing the number of transmit-receive channels, which inevitably leads to higher system complexity, power consumption, and costs. To overcome these limitations, the research team proposed an innovative multi-frequency-excited MIMO radar array architecture. This approach introduces frequency as a new degree of freedom without requiring additional transmit-receive channels. By varying the operating frequency of the array, the electrical spacing between antenna elements changes in accordance with the wavelength, effectively creating multiple sub-arrays with distinct detection characteristics. When these sub-arrays are synthesized, they form a virtual array with a significantly larger number of equivalent elements than the physical array, resulting in an exponential improvement in angular resolution.

The team designed a single-channel transmit chip and a dual-channel receive chip based on a 65nm CMOS process, supporting operation at 15GHz, 30GHz, and 60GHz. A radar system prototype built using these chips achieved a 6° angular resolution with a 1-transmit, 4-receive array configuration—a fourfold improvement over traditional single-frequency excitation schemes. This architecture demonstrates remarkable efficiency in physical element utilization and holds substantial promise for high-precision imaging and other advanced applications.