An Integrated Passive Phase-Shift Keying Modulator for Biomedical Implants With Power Telemetry Over a Single...

Area of Science:

• Biomedical Engineering
• Electrical Engineering
• Implantable Devices

Background:

• Biomedical implants require efficient simultaneous power and data transmission.
• Existing modulation techniques face challenges with high power demands and low coupling coefficients in implants.

Purpose of the Study:

• To present a passive phase-shift keying (PPSK) modulator for uplink data transmission in biomedical implants.
• To enable simultaneous power and data transmission over a single 13.56 MHz inductive link.

Main Methods:

• Developed a PPSK modulator integrated into an application-specific integrated circuit (ASIC) using 0.6-μm high-voltage CMOS technology.
• Evaluated performance through simulations and measurements, including bit error rate (BER) and modulation index variations.
• Compared the PPSK modulator with other state-of-the-art impedance modulation techniques.

Main Results:

• Achieved a data rate of up to 1.35 Mbps with a modulation index between 3% and 38%.
• Demonstrated suitability for low coupling coefficients (0.05–0.26) and high power demands (up to 100 mW).
• Measured BER below 6 × 10^-8 at critical coupling and 1.35 Mbps.

Conclusions:

• The developed PPSK modulator offers a robust solution for high-performance uplink communication in biomedical implants.
• The system integrates power delivery and data transmission efficiently on a single inductive link.
• PPSK modulation is a promising technique for advanced implantable devices requiring reliable data transfer.