Compact and Efficient FSK‐CDR Design for Forward Data Transfer Over Wireless Inductive Link

• DOI: 10.1002/cta.4522
• Publication Date: 2025-03-16T22:36:36Z
• Authors: Naqeeb Ullah; Adel Barakat; Mohd Khairi Bin Z...; Haruichi Kanaya; Ramesh K. Pokharel
• Keywords: Frequency-shift keying; Link (geometry)

ABSTRACT Frequency shift keying (FSK) is a robust modulation scheme widely used in biomedical implants for wireless power and data transfer over inductive links due to its low sensitivity amplitude noise coil misalignment. However, conventional FSK faces challenges achieving high rates consumption, as it requires multiple cycles encode bits (0 or 1), limiting carrier utilization. This paper proposes novel clock recovery (CDR) that minimizes the required number of bits, improving rate reducing consumption. Using only two one enables efficient transmission at higher with lower energy usage, offering promising solution forward communication. A prototype modulator CDR circuit are designed implement this approach using 0.18 μm CMOS process. The proposed recovers signals from FSK‐modulated signal up 4 Mb/s occupies an active area 0.002747 mm 2 (67 × 41 μm). consumes 15.4 μW 1.4 V supply transfer. design achieves efficiency 3.5 pJ/bit demonstrates improved rate‐to‐carrier frequency (DRCF) ratio greater compactness than existing demodulators. These features make suitable energy‐constrained applications.