A 2.4-GHz BAW-Based Transceiver for Wireless Body Area Networks

Area of Science:

• Electrical Engineering
• Biomedical Engineering
• Materials Science

Background:

• Wireless transceivers are crucial for biomedical applications, demanding low power and high performance.
• Microelectromechanical-systems (MEMS) resonators offer advantages in frequency synthesis, receiver, and transmitter design.
• Existing wireless solutions may face limitations in power consumption, phase noise, and selectivity for sensitive biomedical data transmission.

Purpose of the Study:

• To present a Bulk Acoustic Wave (BAW)-based transceiver for wireless biomedical networks.
• To leverage high-Q MEMS resonators for improved transceiver performance, including low power consumption and enhanced phase noise.
• To validate the performance of a complete wireless node integrating the transceiver and a microprocessor in a standard CMOS technology.

Main Methods:

• Utilized high-Q microelectromechanical-systems (MEMS) resonators for frequency synthesis, receiver, and transmitter.
• Implemented a phase analog-to-digital converter (ADC) for minimized baseband power consumption.
• Integrated the transceiver and a microprocessing integrated circuit (IC) using a 0.18-μm complementary metal-oxide semiconductor (CMOS) technology.

Main Results:

• Achieved RF carrier phase noise of -136.2 dBc/Hz at a 1-MHz offset.
• Demonstrated 1-Mb/s Gaussian frequency-shift keying (GFSK) modulation with 5.4 dBm output power and 35 mA current consumption.
• The transmitter complies with Bluetooth and Bluetooth low energy output spectrum requirements.

Conclusions:

• The BAW-based transceiver offers a promising solution for low-power, high-performance wireless biomedical applications.
• The integrated wireless node validates the feasibility of the proposed design in standard CMOS technology.
• Further research is required to address the unexpected receiver sensitivity of -75 dBm at 200 kb/s.