An S-FSCW Based Multi-Channel Reader System for Beamforming Applications using Surface Acoustic Wave Sensors
Sprache des Titels:
Englisch
Original Kurzfassung:
Interrogating multiple surface acoustic wave
(SAW) sensors located within the same radar beam require
techniques to separate the multiple superposing SAW sensor
responses. The presented multi-channel reader features
four parallel transceiver channels, which are based on the
switched frequency-stepped continuous-wave principle and
high-speed parallelized baseband electronics. Thus classical
beamforming applications including angle of arrival
measurement of single SAW tags and the angular separation
of multiple SAW sensors are presented and compared
to a multiple-input multiple-output (MIMO) approach. Due
to the larger virtual array in the MIMO approach a larger
aperture can be synthesized, which leads to significantly
better angular separation results. The level analysis for the
given system is verified by baseband-power measurements
at different readout distances, considering the hardware
parameters as well as the free-space propagation aspects.
Finally measurements assess the maximum interrogation
distance for the system.