Design of self-sampling based ASK demodulator for implantable microsystem

In most of bioimplantable or wireless sensor network systems, ASK is one of the most commonly used schemes to modulate the baseband signal with reference to the intermediate or even the carrier frequency. In this study, a novel demodulator architecture is proposed. It is based on a simple self-sampling scheme which is a truly low-cost high-efficiency implementation and has excellent ability to work on a very small difference (0.15 V) between the two modulated levels, which represent the binary '0' and '1' separately. The results show the presented type can be designed to fit the operation carrier for the special need and has a quite area efficiency than the ever published similar works due to its existent digital benefit. In addition, a comforting robustness is also demonstrated under different process variations. According to the merits mentioned above, both the chip cost and the complexity in the design of on-chip voltage regulator for stable DC extraction are greatly reduced. This design has been verified and realized by using a TSMC (Taiwan Semiconductor Manufacturing Company) 0.18-μm 1P6M standard CMOS technology.