An RF Power-Harvesting Chipset Featuring 24dB Power Dynamic Range for Wireless Neural-Recording Headstage

A wireless neural-recording headstage enables long-term uninterrupted monitoring of the brain, which acts as an important tool for the neuroscience research. For the experiment on small animals such as a mouse, the neural-recording headstage is required to be miniaturized in size, especially the battery size. One of the solutions is the wireless power-harvesting technology that can complement the energy consumption of the headstage. In this work, a wide-range wireless power-harvesting technique is proposed to ensure the stability of its transmission efficiency within a wide power dynamic range (PDR). The proposed technique is implemented in a wireless power-harvesting chipset composed by an RF power harvester and a DC-DC booster, which are fabricated in 65 nm and 180 nm CMOS processes, respectively. With a 433 MHz input power ranging from 4 dBm to 19 dBm, the proposed chipset can effectively charge a coin battery of a headstage at a WPT distance of $\text{1. 5 m}$. The measured power-conversion efficiency (PCE) can be maintained above 20 % with a 24 dB input range (from -7 dBm to 17 dBm), where the peak PCE reaches 77.6 % at 0.3 dBm input power.