Range correlation and I/Q performance benefits in single-chip silicon Doppler radars for noncontact cardiopulmonary monitoring
Range correlation and I/Q performance benefits in single-chip silicon Doppler radars for noncontact cardiopulmonary monitoring
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DOI：
10.1109/tmtt.2004.823552
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发表时间：
2004-03-01
影响因子：
4.3
通讯作者：
Kovacs, GTA
中科院分区：
文献类型：
--
作者：
Droitcour, AD;Boric-Lubecke, O;Kovacs, GTA
直接转换微波多普勒雷达收发器已完全集成在 0.25-μm 硅 CMOS 和 BiCMOS 技术中。这些芯片工作频率为 1.6 和 2.4 GHz，可检测到距受试者 50 厘米处因心跳和呼吸而产生的运动，这可能有助于婴儿和成人呼吸暂停监测。当使用高相位噪声片上振荡器检测小相位波动时，残余相位噪声的范围相关效应是一个关键因素。通过实验评估了距离相关带来的相位噪声降低，测量到的残余相位噪声与预测值的平均偏差在 5 dB 以内。在直接变频接收器中，接收信号和本地振荡器之间的相位关系对解调灵敏度有显着影响，并且可以使用正交（I/Q）接收器来避免零点。本文介绍了强调 I/Q 接收器性能优势的测量结果。虽然单通道芯片测量心率的准确度在 40% 到 100% 之间，但根据定位的不同，正交芯片的准确度始终优于 80%。
Direct-conversion microwave Doppler-radar transceivers have been fully integrated in 0.25-mum silicon CMOS and BiCMOS technologies. These chips, operating At 1.6 and 2.4 GHz, have detected movement due to heartbeat and respiration 50 cm from the subject, which may be useful in infant and adult apnea monitoring. The range-correlation effect on residual phase noise is a critical factor when detecting small phase fluctuations with a high-phase-noise on-chip oscillator. Phase-noise reduction due to range correlation was experimentally evaluated, and the measured residual phase noise was within 5 dB of predicted values on average. In a direct-conversion receiver, the phase relationship between the received signal and the local oscillator has a significant effect on the demodulation sensitivity, and the null points can be avoided with a quadrature (I/Q) receiver. In this paper, measurements that highlight the performance benefits of an I/Q receiver are presented. While the accuracy of the heart rate measured with the single-channel chip ranges from 40% to 100%, depending on positioning, the quadrature chip accuracy is always better than 80%.