STUDY OF RADIO-FREQUENCY IDENTIFICATION MARKS ON SURFACE ACOUSTIC WAVES

Abstract

An experimental study of the use of lithium niobate substrates for radio frequency identification 64-bit tags on surface acoustic waves (SAW) in the frequency band of 33 MHz at the center frequency of 870 MHz was carried out. Marks make it easy to distinguish between orthogonal codes, since they have sufficient dynamic range and an acceptable noise level. Aspects of manufacturing technology and the effect of spraying reflectors in marks on the main parameters of products are considered. It is shown that the use of strips in reflectors instead of IDTs improves the uniformity of impulse responses, but leads to an increase in insertion loss. RFID tags were studied, in which the deposition thickness of the aluminum film, from which the IDT and reflectors were made, had different thicknesses. Studies have shown that the deposition thickness has a significant effect on the electrical parameters of the label. The deposition thickness depends on the number of reflectors in the marks and is selected in such a way as to ensure minimum insertion loss and maximum dynamic range. The technology is selected in such a way that, with a high probability, responses are obtained with an unevenness of no more than 3 dB, insertion loss in the range of 38–40 dB.