Design of a Low power Transmitter for Biomedical application in 180nm CMOS
In this study, we propose a low-power transmitter system for biomedical applications. In particular, it aims at the development of a low-power transmitter targeting a capsule endoscopy among biomedical applications. It is necessary to transmit about 4 pictures per seconds for 8 hours for accurate endoscope. However, due to the limitation of the battery, it is difficult to transmit 4 pictures per seconds for 8 hours with a general battery. Therefore, by making a low-power transmitter, we improve the accuracy of the wireless endoscope regardless of the capacity of the battery. The proposed transmitter is consisted of counter-assisted digital PLL (Phase Locked Loops) and digital PA(Power amplifier) that consumes lower power than analog PA. The currently targeted low-power transmitter is a transmitter capable of 16 QAM modulation in order to have a data rate of 20Mbps at the frequency of the ISM band (433 ~ 435 MHz) and supply voltage is 1V for low power. This system was designed with TSMC Mixed-Signal RF 0.18um process.