Torbjörn Olsson

Reduced Amount of Conductive Ink with Gridded Printed Antennas

It becomes more and more common to print tag antennas using electrically conductive ink for mass-produced Radio Frequency IDentification (RFID) tags. Electrical properties of the ink are mostly determined by conductive (e.g. silver) particles mixed into the ink solution. Since silver is relatively expensive it is desirable to minimize the amount of ink used per antenna. This paper illustrates how the printed conductor area of the antenna can be reduced by applying a grid pattern to an existing antenna geometry and to what extent the gridding can be performed without significantly degrading of the antenna electrical properties. Two common antenna structures are used as an example. It is also shown that by slightly modifying the original antenna geometry it is possible to even further reduce the amount of used ink.

Performance degradation of RFID system due to the distortion in RFID tag antenna

In some Radio-Frequency IDentification (RFID) applications, the RFID tag antennas will be printed onto flexible substrates. After sticked onto different objects, possible distortion to the tag antenna such as bending of the tag will be caused due to the flexibility. In this paper, performance degradation of passive RFID systems due to bending of the RFID tag antenna is investigated. The antenna used is the basic folded dipole. Simulation results show that the performance of a passive RFID system, characterized by operating range, can be degraded significantly due to distortion. Thus, antenna structures less sensitive to this should be considered for RFID systems where this kind of effect might occur.

A Distanced RFID Dipole for a Metallic Supply Chain Label

This paper presents a low cost solution for integration of RFID tags with dipole antennas onto traditional metal labels. Metal labels of this shape are used in a hardware supply chain and covered with a plastic layer where information is printed upon it. The RFID tag is a complement to the printed information that goes into the same label and is put away from the metallic surface with the aid of a 10 mm polyurethane foam (foam rubber) spacer that due to its high flexibility have potential to be run through the usual label printer

Characterization of moisture sensor based on printed Carbon-Zinc energy cell

In this work we present a simple printed moisture sensor fabricated using electronic inks on a multilayer paper structure. The sensor is based on a Carbon-Zinc type energy cell and provides power to a readout electronic circuit when activated by moisture. The sensors are based on a number of our filed patents according to which the sensor is used for both event detection and as a power source for the processing electronics. Typical applications are moisture and leakage detection in buildings, water pipe lines, smart packages and health care systems such as smart incontinence sensors. As the detector is triggered, it powers up an electronic circuit (polymer based or silicon based) that starts communication with the alarm server. In the simplest systems a sound or a light alarm is started to alert the user. In this work we present a characterization of some critical parameters of the sensor such as power driving capability, linearity, internal memory effects and saturation. In addition, we examine a specific application, when sensor is used as defrosting alarm for surveillance of frozen articles during transport.

Bow-Tie and Dipole Antenna Feed Robustness Mechanisms

In a previous paper, (Olsson, SidÉn, and Koptioug, ¿Robustness comparison of bow-tie and dipole antennas,¿ IEE Proceedings Microwaves, Antennas and Propagation, vol. 151, no 6, Dec. 2004, pp. 525¿529), it was shown that the dipole antenna is more robust than the bow-tie antenna, with same radiator aperture area, to numbers of small randomly positioned holes penetrating the structures. In present paper it is shown that for a small number of holes the bow-tie antenna is more robust due to lower hit probability in high current density areas. The results show that the bow-tie feed is more robust for a small amount of damage, whereas the strip dipole feed (of width

High-directivity fractal-vee dipoles

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Evaluation of a printed patch antenna for robust microwave RFID tags

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On the behavior of printed RFID tag antennas, using conductive paint

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Statistical analysis of antenna robustness

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Robustness comparison of bow-tie and dipole antennas

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