SAW RFID with enhanced penetration depth
Some methods to enhance penetration depth further are proposed and demonstrated. A second harmonics SPUDT, new criterion of matching and high reflectivity reflector are utilized to reduce the losses of SAW tag. The enhancement of reading system including high signal processing gain and compensate the center frequency mismatch between reader and SAW tag are achieved. Furthermore, the effect of decreasing working frequency to penetration capability is demonstrated. Mediums such as dry sandy, dry soil and water are compared in the experiments in order to get the achievable penetration depth. In conclusion, the practical penetration depth is superior to the ground penetrating radar with the same center frequency range.
Application of SAW RFID in the inspection management of aerodrome lights
It is increasingly urgent to improve the intelligent level of the equipment management for modern international airports. This is the first attempt of SAW RFID on aerodrome lights. SAW tag with temperature sensing function and anti-metal patch antennas are designed. The position of the tag fixed in different kinds of lights such as the runway light and the taxiway light is demonstrated. The experimental results show that SAW RFID has been successfully applied to the inspection management of aerodrome light.
A new type SPUDT SAW for use in high frequency around 2 GHz
This paper introduces a new type of SPUDT structure, which enables the design of SAW filters or delay-lines up into the 2 GHz range. The structure consists of two groups of spatially harmonic transducers e.g. Se=5 (+ + - + -) or Se=8 (+ + - + - - + -) and one group of reflectors positioned between the two groups of harmonic transducers. In the paper, the general operating principle of the new SPUDT is discussed. To confirm this new technique, a slanted type SAW filter using the new SPUDT structure with central frequency of 2.14 GHz was designed and fabricated. The directionality of this new SPUDT structure has been demonstrated by measurement.