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Comparative investigations of two kind of electronic circuits for multichannel saw-based gas sensors (2009).
| Content Provider | CiteSeerX |
|---|---|
| Author | Urzędniczok, Henryk |
| Abstract | Abstract − Gas sensors based on surface acoustic wave transducer equipped with two types of primary electronic circuit, oscillatory circuit and a circuit of phase shift detection, are described. Modal character of oscillatory circuit is analyzed, and consequence of this fact are discussed. Results of investigations for this type of circuit are presented. A conception of SAW transducer with phase shift detection is proposed, a simple electronic circuit for this method is described and results of investigations are presented. Keywords gas sensor, conditioning circuit, surface acoustic wave 1. SAW TRANSDUCER AS A GAS SENSOR Systems with surface acoustic wave (SAW) have been applied in the construction of gas detectors for a long time [1-4]. The SAW gas sensors are composed of at least one acoustic delay line with a sensitive thin film layer on a top of the piezoelectric substrate and a pair of interdigital transducers (IDT) for excitation and detection of Rayleigh wave (see Fig. 1). In this paper results of investigations of two types of primary electronic circuits are presented and discussed. The first one is the oscillator with frequency output signal and the second is the phase-shift output circuit. 2. FREQUENCY OUTPUT CONDITIONING CIRCIUT As a conditioning circuit for SAW sensors the electronic oscillators are often applied – the delay line with SAW transducer is placed in the feedback loop of an amplifier. The acoustic delay line ensures the phase condition for oscillation, whilst the amplifier ensures the amplitude condition. The main disadvantages of this simple configuration are high output frequency range (30 – 150 MHz) and a weak thermal stability. Therefore a much more suitable configuration in practical applications is the dual delay line design with the active and the reference acoustic paths, as shown in Fig. 2. |
| File Format | |
| Publisher Date | 2009-01-01 |
| Access Restriction | Open |
| Subject Keyword | Saw Transducer Phase Shift Detection Surface Acoustic Wave Acoustic Delay Line Primary Electronic Circuit Oscillatory Circuit Gas Sensor System Dual Delay Line Design Saw Gas Sensor Frequency Output Signal Frequency Output Conditioning Circiut Simple Electronic Circuit Long Time 1-4 Phase-shift Output Circuit Amplitude Condition Rayleigh Wave Surface Acoustic Wave Transducer Suitable Configuration Conditioning Circuit Sensitive Thin Film Layer Simple Configuration High Output Frequency Range Weak Thermal Stability Keywords Gas Sensor Phase Condition Practical Application Modal Character Piezoelectric Substrate Paper Result First One Interdigital Transducer Main Disadvantage Feedback Loop Abstract Gas Sensor Saw Sensor Delay Line Gas Detector Reference Acoustic Path Electronic Oscillator |
| Content Type | Text |
| Resource Type | Article |
