Design and Performance Evaluation of Transmitarray Lenses for Remote Cardiac Monitoring in the W-Band
Received: 13 January 2026 | Revised: 16 March 2026 and 12 April 2026 | Accepted: 17 April 2026 | Online: 6 June 2026
Corresponding author: Fitri Yuli Zulkifli
Abstract
Non-contact radar offers a promising alternative to conventional electrocardiography for cardiac monitoring, yet its effectiveness is constrained by limited electromagnetic focusing capability toward deep cardiac structures. This paper presents transmitarray lenses operating in the 76–81 GHz band to enhance far-field focusing for radar-based cardiac sensing. A multi-layer unit cell with hexagonal split-loop topology is optimized to achieve 260.79° phase coverage and 75% transmission efficiency. Two lens apertures—8×8 and 16×16—are designed and evaluated in conjunction with a WR-10 horn antenna. Full-wave simulations incorporating biological tissue models demonstrate that both lenses preserve impedance matching while significantly increasing on-axis gain (16.5 dBi and 22.6 dBi, respectively) and concentrating electric field energy at the 50 mm cardiac depth. The 16×16 configuration achieves the sharpest focus with SAR levels well within IEEE safety standards. These results validate the feasibility of W-band transmitarray lenses for improving spatial resolution and detection accuracy in remote cardiac monitoring applications.
Keywords:
transmitarray lens, W-band, wearable, radar, cardiac sensing, vital sign monitoringReferences
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Copyright (c) 2026 Fitri Yuli Zulkifli, Adhirama Dwi Syaputra, Aditya Inzani Wahdiyat, Nurhayati Nurhayati, Dewiani Djamaluddin
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