A Bimodal Low-Power Transceiver featuring a Ring Oscillator-based Transmitter and Magnetic Field-based Receiver for...

Area of Science:

• Electronics
• Biomedical Engineering
• Wireless Communication

Background:

• Insertable smart pills require miniaturized, low-power wireless communication systems for in-body diagnostics.
• Existing transceivers often face challenges with power consumption, size, and reliable data transmission within the gastrointestinal tract.

Purpose of the Study:

• To present a novel, mm-scale, bimodal transceiver for insertable smart pills.
• To demonstrate a low-power, efficient wireless communication solution for ingestible electronic devices.

Main Methods:

• Developed a novel PA-less, 915 MHz uplink transmitter (TX) using a current-starved ring oscillator (RO) with an integrated on-chip antenna.
• Implemented the RO-based uplink TX and a power management unit in 180 nm CMOS.
• Designed an orientation-insensitive magnetic field-based downlink receiver (RX) utilizing an external 3-D magnetic sensor.

Main Results:

• The uplink TX achieved a data rate of 33 Mb/s with a power consumption of 210 μW, yielding an energy efficiency of 6.4 pJ/bit.
• The downlink RX consumed 270 μW and achieved a data rate of 0.02 kb/s.
• Demonstrated wireless measurements in saline over 150 cm with a 3.2x13.6x2.3 mm³ insertable pill prototype.

Conclusions:

• The proposed transceiver design offers a highly energy-efficient and compact solution for smart pill applications.
• The bimodal communication approach provides flexibility and reliability for in-body wireless data transfer.
• This technology paves the way for advanced ingestible diagnostic and therapeutic devices.