Fast Startup LC Oscillator Used in OOK Modulated Wireless Body Communication System With Reconfigurable Output Buffer

We present a fast startup LC oscillator used in on-off keying modulation mode, whose carrier frequency is 4.2GHz. To increase the transmission data rate, we reduce the turn-on time of the oscillator by adding a logic structure to provide a significant injection current. This part will be cut off when the oscillator usually works. So, the power can be kept as low as possible with this structure. For the output buffer, we choose a buffer with three levels output power, featuring different load-carrying capabilities. This enables it to meet the readability requirements of the received signal at the receiving end under various channel attenuation conditions. This circuit is implemented using 65nm CMOS technology, and the tuning range is from 3.5GHz to 4.4GHz. The simulation results show that the startup cycles were reduced by 55% compared to conventional LC oscillator. The system consumes only 8mW under a 1.2V supply, and the maximum data rate is up to 100Mbps.