Doppler effect detection method using ultrasonic radiation, Doppler effect detection device and anti-intrusion alarm device for passenger compartment including vehicle.

摘要

The present invention relates to a method for detecting Doppler motion using ultrasonic radiation. It also relates to a device for detecting motion by Doppler effect and its application to an intruder alarm device for a vehicle interior. BR/ According to the invention, a single ultrasonic capsule (4) operates simultaneously in transmission and reception by operating on an operating point regulated by an adaptation dipole (5) on the minimum quality factor of the capsule. A phase comparison (6) produces a Doppler detection signal (9) whose level (10) is compared to a threshold that triggers a motion detection alarm (10). BR/ Anti-theft security application. / P