Digitally scanned antenna array for remote assessment of driver´s fatigue level

The paper presents the concept of a microwave Doppler radar destined for driver´s drowsiness assessment. The transmitter of the developed radar consists of a microwave oscillator, an SSB (single-sideband) modulator, a frequency doubler, and a transmitting antenna array, whereas, the receiving part is composed of eight linear antenna arrays at the output of which eight quadrature mixers are placed. The IF output signals from all mixers are independently gathered and converted into digital form. The digital beam scanning is implemented at the intermediate frequency after A/D conversion and subsequently the SSB signals are demodulated to extract Doppler signals.