Title :
Performance optimization of temperature compensated surface acoustic wave biosensors
Author :
Shuangming Li ; Yan Su ; Ying Wan ; Zheng Tang
Author_Institution :
MEMS Sensor Technol. Res. Center, Nanjing Univ. of Sci. & Technol., Nanjing, China
Abstract :
Temperature has great influences on the surface acoustic wave (SAW) biosensors. Different substrates were tested and the methods for improving the temperature performance of the SAW biosensors were discussed here. The effects of temperature on the SAW sensors mainly result from the temperature coefficient of the SAW device and the oscillating circuit. To eliminate the impact of environment, a twin delay lines SAW biosensor operating at 198 MHz, with a sensor channel and a reference channel, was fabricated on 36°Y-X LiTaO3 piezoelectric crystals. The signals of the two channels were multiplied by a mixer to compensate the influences of temperature. Since the temperature may affect the quiescent point of amplifier, the open loop phase would change, resulting in a frequency shift of the SAW oscillator. Therefore, a simple and effective circuit structure with a comparator limiting the oscillation amplitude was applied to the design of the SAW oscillator. At last, the temperature performance of our design was tested. Our design was demonstrated having a great performance with a temperature coefficient about 2 ppm/°C.
Keywords :
VHF circuits; VHF oscillators; amplifiers; biosensors; comparators (circuits); compensation; lithium compounds; mixers (circuits); optimisation; piezoelectric materials; piezoelectric transducers; surface acoustic wave delay lines; surface acoustic wave oscillators; surface acoustic wave sensors; temperature measurement; temperature sensors; LiTaO3; SAW oscillator; comparator; frequency 198 MHz; mixer; open loop phase; optimization; piezoelectric crystal; quiescent point amplifier; reference channel; sensor channel; temperature compensated surface acoustic wave biosensor; twin delay lines SAW biosensor; Biosensors; Lithium compounds; Oscillators; Substrates; Surface acoustic wave devices; Surface acoustic waves; Temperature sensors; biosensor; oscillating circuit; surface acoustic wave; temperature performance;
Conference_Titel :
Sensing Technology (ICST), 2013 Seventh International Conference on
Conference_Location :
Wellington
Print_ISBN :
978-1-4673-5220-8
DOI :
10.1109/ICSensT.2013.6727617