Title :
Combination of SAW-transponder and RF-semiconductor devices offers new perspectives for passive radio sensors
Author :
Steindl, R. ; Pohl, A. ; Heinrich, N.
Author_Institution :
Inst. for Ind. Electron. & Mater. Sci., Tech. Univ. Wien, Austria
Abstract :
SAW ID-tags can be employed as passive transponders for impedance sensors. An interdigital transducer (IDT) is used as a loadable reflector, other fixed reflectors are used as reference to compensate cross sensitivities. A varactor diode is applied as capacitive sensor to measure electric voltage with extremely high impedance with minor effect to the measurand. The voltage and consequently the load of the programmable reflector influences both, the phase and amplitude of the reflected acoustic wave and the response signal of the radio sensor. The principle is discussed, the tuning for an application to measure force with a piezoelectric cable is presented
Keywords :
cable testing; force measurement; interdigital transducers; piezoelectric devices; radio equipment; semiconductor devices; surface acoustic wave delay lines; surface acoustic wave sensors; transponders; varactors; voltage measurement; IDT; RF-semiconductor devices; SAW delay lines; SAW-transponder; amplitude; capacitive sensor; cross sensitivities compensation; electric voltage measurement; force measurement; impedance sensors; interdigital transducer; loadable reflector; passive radio sensors; phase; piezoelectric cable; programmable reflector; reflected acoustic wave; response signal; tuning; varactor diode; Acoustic measurements; Diodes; Electric variables measurement; Force measurement; Impedance measurement; Surface acoustic waves; Transducers; Transponders; Varactors; Voltage;
Conference_Titel :
EUROCOMM 2000. Information Systems for Enhanced Public Safety and Security. IEEE/AFCEA
Conference_Location :
Munich
Print_ISBN :
0-7803-6323-X
DOI :
10.1109/EURCOM.2000.874793