RFID tag

Subramanian, V. Frechet, J. Chang, P. Huang, D. Lee, J. Molesa, S. Murphy, A. Redinger, D. Volkman, S. 2005. Progress toward development of all-printed RFID tags Materials, processes, and devices. Proc. IEEE 93 1330-1338. 

RFID tags carry a serialized tag data construct. As an example, a 64-bit class 0 tag offered by a supplier includes 64 bits of total user memory on the tag itself,... 

Glidden, R., Bockorick, C., etal. (2004), Design of ultra-low-cost UHF RFID tags for supply chain applications, IEEE Commun. Mag. 42(8), 140-151. 

Sangoi, R., Smith, C. G., et al. (2004), Printing radio frequency identification (RFID) tag antennas using inks containing silver dispersions, J. Dispersion Sci. Technol. 25(4), 513-521. 

Another major technology area that can utflize conductive IJ ink is the display market. Inkjet can be applied for both flexible and rigid displays such as electroluminescent and electrophoretic displays (including e-paper), hquid crystal displays (LCD), plasma display panels (PDP) and touch screens some functionalities have already been printed by IJ technology in certain display apphcations, for example RGB color filters. Conductive IJ is also appropriate for use in thin film transistors (TFT), disposable batteries, radio-frequency identification (RFID) tags, and a range of chemical and electronic sensors. 

RFID tags Organic conductors. Thick film Ag is used for... 

Flexography Lower set-up costs than Prints a "donut", rather than Expected for RFID tags. 

Silicon-based RFID tags are widely available today, and are used in numerous applications ranging from asset management and inventory control to security and transit applications. In its simplest form, an RFID tag consists of a digital finite state machine driving a modem connected to an antenna. The antenna is responsible for uni- or bi-directional communication with a reader, as well as for providing power to the tag. 

The antenna in an RFID is typically implemented as a spiral inductor or as a dipole antenna, depending on the frequency of operation of the tag. This frequency of operation depends on the application, government-imposed standards, physical constraints, etc. The most common frequencies for operating RFID tags are <125 kHz (called the LF band), 13.56 MHz (called the HF band), 900 MHz (called the UHF band), and 2.4 GHz (called the microwave band). For various reasons, 125 kHz tags are not compatible with planar processing and thus will not be considered here. 

The antenna for the other frequencies is typically moderately large, covering an area of several cm square. As a result, in silicon-based RFID tags, the antenna is processed separately on a piece of plastic or paper, and then the silicon chip is mounted onto the antenna using an attachment process. 

Examining a typical RFID tag, several points of note are apparent. The first point is that the size of the tag is dominated by the antenna, which is printed at a relatively low resolution the size of the circuitry is a relatively small fraction of the overall tag size. The second point is that the cost scaling of silicon-based RFID is hmited by the cost of attaching the tiny silicon chip to the antenna thus, silicon-based RFID only benefits partially from cost reduction in the silicon microelectronics industry. The third point is that the transistor performance requirements for simple RF barcodes are not outrageous, and are potentially in the range of what is achievable using printed electronics. 

The rectifier in an HF RFID application needs to be able to rectify at 13.56 MHz, and current standards require the clock be divided from this same frequency as well. The former appears to be possible with printed electronics. The latter is problematic however it is possible to generate a kHz clock locally using an oscillator, i.e., without dividing down from 13.56 MHz. This introduces more variability and noise into the tag, but, for low data rates, the reader can screen this out. As a result, it is hkely that a 13.56 MHz printed RFID tag is realizable, albeit with a local clock and a low data rate. This appears to be usable for many apphcations including authentication, anti-coimterfeiting, etc., and therefore, there is substantial industrial and research institute activity in this regard. The driver, of course, as in displays, is the development of printed transistors. 

Inkjet printed electronics is very attractive as a means of realizing potentially low cost circuits on flexible substrates. Potential applications range from displays to RFID tags to sensors. Over the last decade, a family of high-quality printable electronic materials has been developed, and processes for realizing printed devices have been demonstrated. 

Several tools capable of carrying such information can be used, such as alphanumeric descriptions, bar codes, labels, RFID tags or the freight documentation that accompanies the shipped goods. The use of these tools depends on cost and on the further use of the material. 

Fig. 58 Air-breathing DMFC cell array and methanol cartridge integrated into the handle of an RFID tag reader made by Intermec, Inc.

OFETs are the basis of all logie deviees that are required to eontrol, for example, the intensity of a display pixel (the so ealled all organic display) or the realisation of a radio frequeney identifieation (RFID) tag. Sinee for the latter applieations only limited frequeney bands are available (essentially 13.56 MHz or 900 MHz) this plaees rather strong eonstraints on the required switehing properties of the OFETs. 

Figure 1.1 RFID tag completely printed roll-to-roll, RFID chip approx. 2 cm x 3 cm.

Figure 1.8 RFID tags as an example of use in brand protection.

Figure 2.5 Item-level tagging with fully printed RFID-tags.

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