This paper presents a millimeter-scale crystal-less wireless transceiver for volume-constrained insertable pills. Operating in the 402–405 MHz medical implant communication service (MICS) band, the phase-tracking receiver-based over-the-air carrier recovery has a ±160 ppm coverage. A fully integrated adaptive antenna impedance matching solution is proposed to calibrate the antenna impedance variation inside the body. A tunable matching network (TMN) with single inductor performs impedance matching for both transmitter (TX) and receiver (RX) and TX/RX mode switching. To dynamically calibrate the antenna impedance variation over different locations and diet conditions, a loop-back power detector using self-mixing is adopted, which expands the power contour up to 4.8 VSWR. The transceiver is implemented in a 40-nm CMOS technology, occupying 2 mm ² die area. The transceiver chip and a miniature antenna are integrated in a 3.5 × 15 mm ² area prototype wireless module. It has a receiver sensitivity of −90 dBm at 200 kbps data rate and delivers up to − 25 dBm EIRP in the wireless measurement with a liquid phantom.

中文翻译：

---

用于可插入智能药丸的毫米级无晶体 MICS 收发器

本文介绍了一种用于体积受限的可插入药丸的毫米级无晶体无线收发器。在 402–405 MHz 医疗植入通信服务 (MICS) 频带中运行，基于相位跟踪接收机的空中载波恢复具有 ±160 ppm 的覆盖范围。提出了一种完全集成的自适应天线阻抗匹配解决方案来校准人体内部的天线阻抗变化。具有单个电感器的可调匹配网络 (TMN) 为发射器 (TX) 和接收器 (RX) 以及 TX/RX 模式切换执行阻抗匹配。为了动态校准不同位置和饮食条件下的天线阻抗变化，采用了使用自混合的环回功率检测器，将功率轮廓扩展到 4.8 VSWR。收发器采用 40 纳米 CMOS 技术实现，占用 2 毫米 ²模具区。收发器芯片和微型天线集成在一个 3.5 × 15 mm ²面积的原型无线模块中。它在 200 kbps 数据速率下具有 −90 dBm 的接收器灵敏度，并在使用液体幻像的无线测量中提供高达 − 25 dBm EIRP。