Radar modules for touch-free switches and motion detection

November 10, 2016 // By Graham Prophet
Infineon and InnoSenT (Donnersdorf, Germany) have collaborated to produce a surface mountable radar (SMR) motion detector operating in the 24 GHz ISM band. The SMR series from InnoSenT incorporating Infineon's BGT24LTR11 24 GHz transceiver MMIC promises high functionality, low power consumption and an easy-to-install solution.

Operating in the 24.0 GHz to 24.25 GHz ISM band, the Infineon transceiver features a fully integrated low phase noise voltage controlled oscillator (VCO) and built-in temperature compensation circuit for VCO stabilization. It has full ESD protection, 200 GHz bipolar SiGe: C technology B7HF200 and single supply voltage of 3.3V. The ultra-compact design of the SMR offering (20 x 15 x 3 mm) eases integration, allowing installation in small spaces. It provides a solution for security applications, home-automation, lighting control, intelligent machine control, touch-free switches, and movement detection.


Radar used in motion detection applications increases accuracy when compared to passive infrared (PIR) technology. It allows a more precise measurement of object detection and provides new capabilities such as the detection of speed and direction of moving objects. Radar, compared to camera based systems, allows detection of the objects (people) while keeping identities anonymous.

The SMR series currently comprises three types with different antenna characteristics. In addition to the option of simple motion detection with a corresponding evaluation, it is also possible to determine speed information and direction of movement to the detected object from the returned data. The Silicon Germanium radar MMIC from Infineon was designed with the Doppler-radar applications in mind, which enables additional functionalities. Beside 24 GHz fundamental voltage controlled oscillator (VCO) it also brings variants for FMCW (frequency modulated) or FSK (frequency shift keying) operation mode to this series.


Infineon; www.infineon.com/24GHz


InnoSenT; www.innosent.de/en/sensors/smr-radar-series/