Doppler motion sensor device with high isolation between antennas without increasing device size

摘要

A Doppler motion sensor device is used for detecting a motion of an object. The Doppler motion sensor device includes a first antenna and a second antenna. The first antenna is used to transmit or receive a first wireless signal. The second antenna is used to transmit or receive a second wireless signal. A first straight line passing through a first feed-in point and a first middle point of the first antenna is orthogonal to a second straight line passing through a second feed-in point and a second middle point of the second antenna. One of the first wireless signal and the second wireless signal is a transmission signal. The transmission signal is reflected by the object to form the other one of the first wireless signal and the second wireless signal.