dc.description.abstract | In recent years, the importance of low-cost, accessible and flexible health care has increased dramatically. For all demographics, from the elderly to those inflicted with diseases, the need for remote medical resources is growing every day. Not only is it inconvenient for elders to travel to the doctor, but there is also risk involved due to the exposure to various pathogens within medical facilities that increase the probability of infection. All of this has given rise to an expanding market in the personal homecare service industry. Personal homecare service has numerous benefits. Firstly, it prevents the users from tiring and lengthy traffic, as patients don’t have to leave their homes for the service. Secondly, real time renewal and supervision of patients’ medical data can be performed remotely. Thirdly, a patient’s quality of life can remain unaffected if the sensors and remote medical systems can be made light, portable, self-powered, 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. It allows bi-directional radio communication with medical implants such as pacemakers and other electronic implants. Therefore, a low-cost and ultra-low-power wireless transceiver operating in the MICS band and implemented in s standard 0.18μm CMOS process is the primary aim of this thesis.
In order to realize the challenging <1 mW power requirement a super-regenerative receiver structure is adopted for OOK modulation. In the receiver, the LNA is implemented to amplify the signal and filter out the out-band signals. A digital-controlled oscillator (DCO) is employed to replace the conventional voltage-controlled oscillator (VCO). The DCO is an important component in the transmitter necessary for realizing FSK modulation without the need for another oscillator. Another unique feature different from conventional super-regenerative receivers is the addition of a digital-backend block to perform calibration and signal demodulation. In addition, it also controls the digital-to-analog convertor that controls the current bias of the oscillator.
The integration of the transceiver reduces not only the system power consumption but also the overall system complexity and cost. The integrated solution achieves low cost goal and would be beneficial to the development of personal home care services. | en |