The Microwave Solutions MDU2750LCM Motion Detector Unit is a low power X-Band microwave transceiver that utilises the Doppler shift phenomenon to "sense" motion. The reduced current consumption enables the use of this module in battery powered applications (with suitable duty cycle management). These modules are optimised for Ceiling Mount applications.
The unit, contained in a cast metal housing, features a dielectric resonator stabilised FET oscillator, which provides stable operation over a broad temperature range in either CW or low duty cycle pulse mode and a balanced mixer for enhanced sensitivity and reliability.
This module family is available with either a +3V or +5V supply voltage.
The basic principle of operation consists of detecting the frequency shift between a transmitted and a received signal refelected back from a moving object within the field of view of the unit.
You can view the full outline drawing here