The sensor design on surface acoustic waves (SAW), representing the delay line with unidirectional inter-digital transducers (IDT) is considered. The factor of reflection of SAW from the unidirectional IDT loaded on impedance depending on value of resistance connected to it is investigated. On dependence of factor of reflection on size of resistance there is almost linear site at values of resistance more than 50 Ohm. The new design of the connected lattices of nanowire of zinc oxide, having the general resistance in a range of 50-250 Ohm which is connected to reflective IDT as loading is developed.
Keywords: passive sensors, ZnO nanowire, surface acoustic waves, interdigital transducer.
Analog-to-digital converter, with modulation, amplification and demodulation of the input signal is carried out. To compensate the additional error of voltage conversion, concerned with temperature instability, used dynamic cancellation technique, based on the correlation between offset voltage and modulator temperature fluctuation. ADC with response time 0.85 s performs the threshold of sensitivity 1 nV; 8,5 s - 0,31 nV, 85 s - 0.13 nV, 850 s - 0.1 nV, respectively, in the full-scale range 400 mV. Estimation of offset voltage temperature drift is 40 pV / ºC, time drift - 100 pV / h.
Keywords: analog-to-digital converter, ADC, error cancellation.