Evaluation of influences of radome on vibration sensing capability of millimeter-wave sensor

Millimeter-wave radars have been utilized to detect and perceive various objects in traffic environments: people, cars, bicycles, motorcycles, and other stationary objects. In addition to them, millimeter-wave radars can be utilized as vibration sensors using the analysis of the micro-Doppler phenomenon. Millimeter-wave vibration sensors have various applications, such as the heart rate and the respiration rate sensing of humans, the motion detector of humans, and vibration sensing of various objects. In recent years, heart rate and respiration rate sensing have been studied well because of the high demand for health monitoring systems. One of the most critical issues of millimeter-wave vibration sensors is the influence of a radome on the vibration sensing capability. A radome of general millimeter-wave radar is designed to minimize the reflection of the electromagnetic waves on the surface of the radome. On the other hand, it is difficult to suppress the influences of a radome for a millimeter-wave vibration sensor because of phase errors between received chirps. In this paper, the influences of radome design on the vibration sensing capability of millimeter-wave vibration sensors were evaluated using the proposed evaluation method.