Mirbozorgi S Abdollah, Bahrami Hadi, Sawan Mohamad, Rusch Leslie A, Gosselin Benoit
IEEE Trans Biomed Circuits Syst. 2016 Jun;10(3):643-53. doi: 10.1109/TBCAS.2015.2466592. Epub 2015 Oct 12.
We present a novel, fully-integrated, low-power full-duplex transceiver (FDT) to support high-density and bidirectional neural interfacing applications (high-channel count stimulating and recording) with asymmetric data rates: higher rates are required for recording (uplink signals) than stimulation (downlink signals). The transmitter (TX) and receiver (RX) share a single antenna to reduce implant size and complexity. The TX uses impulse radio ultra-wide band (IR-UWB) based on an edge combining approach, and the RX uses a novel 2.4-GHz on-off keying (OOK) receiver. Proper isolation (>20 dB) between the TX and RX path is implemented 1) by shaping the transmitted pulses to fall within the unregulated UWB spectrum (3.1-7 GHz), and 2) by space-efficient filtering (avoiding a circulator or diplexer) of the downlink OOK spectrum in the RX low-noise amplifier. The UWB 3.1-7 GHz transmitter can use either OOK or binary phase shift keying (BPSK) modulation schemes. The proposed FDT provides dual band 500-Mbps TX uplink data rate and 100 Mbps RX downlink data rate, and it is fully integrated into standard TSMC 0.18- μm CMOS within a total size of 0.8 mm(2). The total measured power consumption is 10.4 mW in full duplex mode (5 mW at 100 Mbps for RX, and 5.4 mW at 500 Mbps or 10.8 pJ/bit for TX). Additionally, a 3-coil inductive link along with on-chip power management circuits allows to powering up the implantable transceiver wirelessly by delivering 25 mW extracted from a 13.56-MHz carrier signal, at a total efficiency of 41.6%.
我们提出了一种新颖的、完全集成的低功耗全双工收发器（FDT），以支持具有不对称数据速率的高密度双向神经接口应用（高通道数刺激和记录）：记录（上行链路信号）所需的数据速率高于刺激（下行链路信号）。发射器（TX）和接收器（RX）共享一根天线，以减小植入物的尺寸和复杂度。TX采用基于边缘合并方法的脉冲无线电超宽带（IR-UWB），RX采用新型2.4 GHz开关键控（OOK）接收器。TX和RX路径之间实现了适当的隔离（>20 dB）：1）通过对发射脉冲进行整形，使其落在未监管的UWB频谱（3.1-7 GHz）内；2）通过在RX低噪声放大器中对下行链路OOK频谱进行节省空间的滤波（避免使用环行器或双工器）。UWB 3.1-7 GHz发射器可以使用OOK或二进制相移键控（BPSK）调制方案。所提出的FDT提供500 Mbps的TX上行链路数据速率和100 Mbps的RX下行链路数据速率，并且完全集成到标准的台积电0.18-μm CMOS中，总尺寸为0.8 mm²。全双工模式下的总测量功耗为10.4 mW（RX在100 Mbps时为5 mW，TX在500 Mbps时为5.4 mW或10.8 pJ/bit）。此外，一个3线圈电感链路以及片上电源管理电路允许通过从13.56-MHz载波信号中提取25 mW来无线为可植入收发器供电，总效率为41.6%。
