A Low Power Transceiver for Wireless Sensor Nodes and Biomedical Systems
Date Issued
2015
Date
2015
Author(s)
Tsai, Lin-Ching
Abstract
In recent years, with the advance of medical, the importance of low-cost, accessible and flexible health care has increased dramatically. The need for remote medical resources is growing every day. The inconvenient is that elders need to regularly receive medical treatment to the hospital for tracking and checking. It takes not only time and money, but also increasing the risk of getting infection with bacteria. With the fast progress of wireless communication and internet, the homecare technology achieves health monitoring and remote medical diagnosis to acquire the timely physiological parameter of patients by wireless communication have third benefits. First, it prevents the users from tiring and lengthy traffic, as patients don''t have to leave their homes for the service. Furthermore, homecare technology reduces unnecessary pain and financial cost but also dampen the work burden of medical staff. Secondly, real time renewal and supervision of patients'' medical data can be performed remotely to help doctor find some symptoms of disease in time, such as cardiac dysrhythmia. Thirdly, a patient''s quality of life can remain unaffected if the sensors and remote medical systems can be made light, portable, highly-integrated and capable of wireless communication. For these and other reasons, the Medical Implant Communication Service (MICS) has been developed and operates in a dedicated frequency band between 402 and 405 MHz. The characteristic of wireless health monitoring devices are short distance communication, low power consumption, and low cost. To achieve above requirement. The thesis proposes low power wake-up receiver and super-regenerative receiver. Firstly, we introduce the wake-up architecture. The receivers is implemented in producing TSMC 0.18um COMS process. By using frequency which is much lower than carrier frequency as operating frequency and removing the power hungry circuit, such as LNA, we decline the power consumption of receiver. The Mixer and five stages differential amplifier are used to amplify the signal. And the envelope detector circuit sample the voltage from OOK signal. By comparator we separate signal “1” from “0”. Secondly, we introduce the super-regenerative receiver and integrate the receiver into Smart Oral Appliance. The receivers are both implemented in producing UMC 0.18um COMS process. By careful design, the LNA can send ISM band signal to DCO. And the DCO will oscillate earlier when signal is “1” and vice versa. The backside circuit will define signal “1” or “0” by oscillation time of DCO. Thirdly, we introduce two transmitter LC tank voltage control oscillator and ring oscillator, respectively. The receivers is implemented in producing UMC 0.18um COMS process and TSMC 0.35um COMS respectively. The LC-tank voltage-controlled transmitter can communicate in OOK or FSK mode. The other transmitter is voltage control ring oscillator transmitter, which communicates in OOK mode. Finally, we integrate the super-regenerative receiver into smart oral appliance. The receiver can communicate in OOK or FSK mode. The low power consumption of receiver make whole system achieve long-term health monitor.
Subjects
Low power consumption
OOK
Wake-up Receiver
Super-Regenerative OOK transceiver
Matching Network
Type
thesis