Design Of A Closed-Loop Serial-L, Parallel Tuned Class-E Power Amplifier For Demic Wireless Energy Transmission System

The demic wireless inductive connectors (DWIC) are the devices capable of supporting wireless energy and data transmission for implanted applications. They can be widely used in various bio-medical systems such as cochlear implants, pacemakers, deep brain stimulators, vagus nerve stimulators, visual implants, intracranial epilepsy stimulators and neural recorders, etc. Typically, one connector comprises two parts:wireless data communication subsystem (WDCS) and wireless energy transmission subsystem (WETS). The former supports transcutaneous communicating function and the latter supplies power to the implanted device. Compared with traditional wired connection or battery-powered systems, WETS is beneficial to improve the portablity, safty, and integration of a system.In this thesis, backgrounded with the fully integrated DWIC for neural recording application, a closed-loop serial-L, parrallel-tuned class-E power amplifier used in the WETS is proposed.Firstly, through thereotical analysis and model simulation of the circuit, the thesis presents the time-domain waveforms of the switching voltage, the switching current and other key electrical parameters in an ideal closed-loop serial-L, parrallel-tuned class-E power amplifier working at the best state, which meets the conditions of zero current switching conduction (ZCS) and the zero current switching derivative conduction (ZCDS). And based on these waveforms, their time-domain analytical expressions are derived.After that, the frequency-domain analytical expressions for these electrical parameters are drived by Fourier transform. And an analytical relationship in the frequency-domain between the eleptrical parameters and the load network is established accordingly. From analytic relationships and the frequency characteristics of the system, the parse equations used to design the serial-L, parrallel-tuned class-E power amplifier and to set the electrical parameters based on the requirements of load network are given.Thirdly, based on equations mentioned above a theoretical design example is extablished by MATLAB programming. In this case, by transforming the composite functional relationships among several sets of parameters and analyzing these functional curves, the closed-loop control strategy of the serial-L, parrallel-tuned class-E power amplifier is designed finally. Then, using the proposed control strategy, the model of the serial-L, parrallel-tuned class-E power amplifier is built and the closed-loop control circuit in SMIC0.18μm3.3V CMOS process by Cadence is completed. Putting them into a complete WETS, the system is simulated to verify the closed-loop control strategy.Besides, to verify the feasibility of the strategy, a PCB testbench of the WETS including serial-L, parrallel-tuned class-E power amplifier is established and the closed-loop control circuit is simulated by combinig different functional chips. And the experimental results were analyzed and demonstrated in detail.Based on the research mentioned above, around the closed-loop serial-L, parrallel-tuned class-E power amplifier, this thesis proposes the design of some main circuits in WETS such as hysteretic voltage detector, communication protocol, signal modulation module and demodulation module, which play important roles in a complete WETS. And a complete design scheme of the WETS bsed on the closed-loop serial-L, parrallel-tuned class-E power amplifier is achieved.