Title :
SAW pulse oscillator sensor with optimized PSK waveforms
Author :
Stab, Helmut ; Hofmann, Heinz
Author_Institution :
Semicond. & Microsyst. Technol. Lab., Tech. Univ. Dresden, Germany
Abstract :
Surface acoustic wave (SAW) devices have been studied for use as gas microsensors for some time. Chemical SAW sensors are based upon delay-line sine-wave oscillators. In this work an alternative pulse oscillator sensor type is presented which improves SAW gas sensor performance. This sensor type consists of a pulse oscillator with a SAW delay-line, its interdigital transducers (IDT) being designed properly to produce phase shift keyed (PSK) waveforms. To optimize the correlation filter layout concerning the PSK waveforms, an optimization method was used which applies principles of biological evolutionary strategy. New results are presented obtained by using optimized PSK waveforms with CuPc sensing layers for detecting NO2 gas. The sensitivity of the pulse oscillator sensor proved to be higher than that of the sine-wave oscillator sensor
Keywords :
air pollution measurement; gas sensors; genetic algorithms; interdigital transducers; phase shift keying; surface acoustic wave correlation; surface acoustic wave delay lines; surface acoustic wave oscillators; surface acoustic wave sensors; NO2; SAW delay-line; SAW pulse oscillator sensor; biological evolutionary strategy; copper phthalocyanine sensing layers; correlation filter layout; gas microsensors; interdigital transducers; optimization method; optimized PSK waveforms; Acoustic pulses; Acoustic sensors; Biosensors; Chemical sensors; Gas detectors; Optimization methods; Oscillators; Phase shift keying; Surface acoustic wave devices; Surface acoustic waves;
Conference_Titel :
Ultrasonics Symposium, 1998. Proceedings., 1998 IEEE
Conference_Location :
Sendai
Print_ISBN :
0-7803-4095-7
DOI :
10.1109/ULTSYM.1998.762207
