介紹了一種基于聲表面波諧振器的無源無線溫度傳感系統(tǒng)。作為傳感器的諧振器受到正弦脈沖串的無線激勵。因激勵信號的中心頻率不同于諧振器的諧振頻率,所以回波信號是一調(diào)幅信號,其包絡(luò)的主頻就是諧振器的諧振頻率和激勵信號中心頻率的差頻。給出了傳感系統(tǒng)的電路設(shè)計(jì)以及信號處理方法。實(shí)驗(yàn)數(shù)據(jù)和器件的溫度系數(shù)吻合。
關(guān)鍵詞: 傳感器; 聲表面波諧振器; 無源無線檢測
Abstract : An passive and wireless sensor system using a surface acoustic wave ( SAW) resonator is described. Functioning as a temperature sensor ,the passive SAW resonator is excited by the wireless interrogating sinusoidal bursts with a fixed frequency which is different from the natural oscillating frequency of the resonator. So the re2 sponse is an AM signal. Consequently the primary frequency of the envelope in the AM signal is the difference
frequency of the two frequencies. The design of circuits and signal processing concerning this sensing system are presented. The experimental data show that the sensing results correspond with the resonator’s temperature coef2 ficients well.
Key words : sensor ; SAW resonator ; passive and wireless sensing