An ultrasound powering TX ASIC for brain implants with autonomous on-chip standing-wave peak tracking for RX power (PDL) regulation is presented. With a proposed adiabatic power-sensing scheme, the TX consumes 43μW for power tracking, and the system achieves a settling time of <90ms while using the standing-wave peak-tracking FSM. The TX can achieve PDL improvement of up to 2.7× with a power-tracking accuracy of 82%.

In recent years, short-range reliable wireless system with high data rate and low power consumption has drawn sufficient attention and is in great demand in various applications. For biomedical implantable applications such as neural sensing and Brain-computer Interfaces (BCIs), due to the increasing number of sensing channels and elements, not only the precision of the biomedical analysis is increased, but also a wireless system with higher data rate is required. Besides the high data throughput, as an implanted device, settling within a human or animal body requires high reliability and low power consumption. Such a wireless system finds its position in smart wearable devices as well. With a higher data rate and small form factor, more functionalities can be adapted to those smart wearable devices. The energy-efficient characteristic also allows a longer working time and battery life. Similarly, the above-mentioned wireless system is a prime candidate for multi-media applications like virtual reality (VR). A higher data rate means more visual, audio, and sensing data can be transmitted simultaneously, which allows for more advanced functions and a better user experience. Furthermore, this high data rate, low-power wireless system can be also adopted at advanced control system.
Among all possible technologies, Impulse Radio Ultra-Wide-Band (IR-UWB) technology is a promising solution for this short-range wireless system. Within this master thesis project, a transceiver exploiting IR-UWB technology is proposed and implemented as a solution for the above-mentioned short-range, high data-rate, low-power reliable wireless system. The transmitter is from Yu Huang’s hybrid modulation transmitter. A fifth-order wide-band low-power GM-C low-pass filter is implemented with novel closed-loop GM-C BiQuad architecture in the receiver. Besides, the adoption of Electrical Balanced Duplexer (EBD) and Digital Self-interference Cancellation (DSIC) promises strong isolation between transmitter and receiver. Thus, this transceiver is also full-duplex (FD) and achieves simultaneous radar and communication (RadCom). With RadCom, this transceiver accomplishes a higher integration level, higher spectral efficiency, and lower cost. Besides, it enables a newrange of applications since it can serve as a radar and communication device simultaneously. With the ability of ranging, object detection, and tracking, this transceiver is also an excellent solution for automotive sensing and human sensing: social distancing, child presence detection, non-contact vital sign detection, etc.
Designed and fabricated in TSMC 28 nm CMOS process, this chip has a form factor of only 0.155 mm2. The achieved maximum data rate is 1.66 Gbps, while the transceiver DC power is within 20 mW.