Directional loudspeaker arrays for acoustic warning systems with minimised noise pollution

This paper describes numerical and experimental results of beamforming algorithms for generation of directional sound. The intended application is a sound source for cars with the objective to warn vulnerable road users while minimising noise pollution. Nowadays, sensors exist which are able to reveal the position of the vulnerable road users,...

A multi-band, high bandwidth, short duration linear chirp generation IC for phased-array applications

This work presents a fully integrated multi-band frequency synthesizer that is capable of creating wide-band linear frequency sweeps of very short duration. The main aim is to create a flexible waveform generation system, requiring distribution of a low frequency reference rather than RF signals. By using a phase-locked loop, frequency...

Directional sound sources using real-time beamforming control

Quiet vehicles may be noticed relatively late and therefore constitute a potential risk for vulnerable road users such as pedestrians and bicyclists. The ideal acoustic warning signal generator notifies vulnerable road users while minimizing noise pollution. Several sensor systems exist which are able to reveal the position of the vulnerable...

Multi-Mode FMCW Radar Array with Independent Digital Beam Steering for Transmit and Receive

A phased-array FMCW radar has been design and built from COTS components. The generation of the frequency sweep is done by mixing a central local oscillator signal with a baseband sweep of a direct digital synthesizer (DDS). To ensure maximum flexibility the receive side has been equipped with it's own swept signal. The transmit frequency...