Microwave Sensors

The Microwave Solutions range of microwave Doppler Motion Detector Units, operating at X-Band (10GHz) and K-Band (24GHz), can be incorporated into a wide range of sensors and are suitable for applications including - Lighting and Energy Management - Home Automation - Intrusion Alarms (Room, Vehicle) - Collision Avoidance - Automatic Door Openers - Traffic Control - Speed Measurement - Presence Sensing

The Motion Detector Unit (MDU) is a miniature microwave Doppler radar sensor optimised for low power consumption and low cost, with variants for short range <30m, long range >30m and very long range 50m+ detection requirements. MDUs utilise the Doppler shift phenomenon to "sense" motion and are available in a variety of different formats.

How does it work? The MDU emits a low level microwave signal which is reflected from all objects within its coverage area. The MDU compares the transmitted and received frequencies and produces an output signal, the frequency of which is proportional to the velocity of any object moving towards or away from the sensor. Signal processing circuitry (not provided with the unit) amplifies this signal and analyses its frequency spectrum. If the signal strength is above a threshold level, and has the required frequency spectrum an output signal can be generated. In order to conserve power it is usual for the MDU to be pulsed on and off rapidly so that it is only transmitting for approximately 5% of the time. The circuit 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.

If you don't want to develop your own electronics, then we also offer a range of complete detectors that provide digital outputs suitable for interfacing to your own system.