Frequency as Aperture: Enabling Embeddable Near-Field Sensing for 6G Wireless Radios
This work addresses the challenge of integrating sensing and communication in cost- and power-constrained 6G nodes, where conventional millimeter-wave sensing relies on dedicated radar hardware incompatible with compact form factors. To overcome this limitation, the paper introduces a novel “Frequency-as-Aperture” (FaA) paradigm that shifts spatial sampling from the antenna domain to the frequency domain. By leveraging the inherent frequency agility of communication signals, FaA constructs a virtual sensing aperture using a single RF chain and a leaky-wave antenna. The approach reuses the communication local oscillator’s frequency-sweeping waveform, embedding radar-grade spatial sensing capability without increasing RF front-end complexity. This enables low-power, privacy-preserving, and embeddable integrated sensing and communication (ISAC) nodes. Under identical physical and spectral constraints, the proposed architecture significantly outperforms conventional multi-channel MIMO sensing in efficiency while achieving high-resolution near-field two-dimensional angle and range estimation, making it suitable for smart homes, wearable devices, and industrial edge applications.