Kiani Mehdi, Ghovanloo Maysam
IEEE Trans Biomed Circuits Syst. 2015 Feb;9(1):1-11. doi: 10.1109/TBCAS.2014.2304956. Epub 2014 Apr 17.
A fully-integrated near-field wireless transceiver has been presented for simultaneous data and power transmission across inductive links, which operates based on pulse delay modulation (PDM) technique. PDM is a low-power carrier-less modulation scheme that offers wide bandwidth along with robustness against strong power carrier interference, which makes it suitable for implantable neuroprosthetic devices, such as retinal implants. To transmit each bit, a pattern of narrow pulses are generated at the same frequency of the power carrier across the transmitter (Tx) data coil with specific time delays to initiate decaying ringing across the tuned receiver (Rx) data coil. This ringing shifts the zero-crossing times of the undesired power carrier interference on the Rx data coil, resulting in a phase shift between the signals across Rx power and data coils, from which the data bit stream can be recovered. A PDM transceiver prototype was fabricated in a 0.35- μm standard CMOS process, occupying 1.6 mm(2). The transceiver achieved a measured 13.56 Mbps data rate with a raw bit error rate (BER) of 4.3×10(-7) at 10 mm distance between figure-8 data coils, despite a signal-to-interference ratio (SIR) of -18.5 dB across the Rx data coil. At the same time, a class-D power amplifier, operating at 13.56 MHz, delivered 42 mW of regulated power across a separate pair of high-Q power coils, aligned with the data coils. The PDM data Tx and Rx power consumptions were 960 pJ/bit and 162 pJ/bit, respectively, at 1.8 V supply voltage.
一种全集成近场无线收发器已被提出，用于通过电感链路同时进行数据和功率传输，该收发器基于脉冲延迟调制（PDM）技术运行。PDM是一种低功耗无载波调制方案，它提供宽带宽以及对强功率载波干扰的鲁棒性，这使其适用于可植入神经假体设备，如视网膜植入物。为了传输每个比特，在发射器（Tx）数据线圈上以与功率载波相同的频率生成窄脉冲模式，并带有特定的时间延迟，以启动调谐接收器（Rx）数据线圈上的衰减振铃。这种振铃会改变Rx数据线圈上不需要的功率载波干扰的过零时间，从而导致Rx功率和数据线圈上信号之间的相位偏移，从中可以恢复数据比特流。一个PDM收发器原型采用0.35-μm标准CMOS工艺制造，占用面积为1.6 mm²。在8字形数据线圈之间距离为10 mm时，该收发器实现了测量的13.56 Mbps数据速率，原始误码率（BER）为4.3×10⁻⁷，尽管Rx数据线圈上的信号干扰比（SIR）为-18.5 dB。同时，一个工作在13.56 MHz的D类功率放大器通过与数据线圈对齐的另一对高Q值功率线圈提供42 mW的稳压功率。在1.8 V电源电压下，PDM数据Tx和Rx的功耗分别为960 pJ/比特和162 pJ/比特。
