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Ultra high frequency radio frequency identification (UHF RFID) is seen as a key technology for future sensor and actuator devices in the Internet of Things. Therefore, improvements of read range and reliability of this technology is highly demanded. In this paper a novel reader is proposed to work on two frequencies simultaneously, intended to improve multipath fading behavior and gain immunity to narrowband disturbance. The current legal situation is reviewed for the proposed device in the European Union and it is compared to existing multifrequency systems. The developed system is based on a software defined radio platform from National Instruments. In the measurement setup a commercially available transponder chip has been connected to the custom built reader which transmits a ''Query'' command on two frequencies −868 MHz and 915 MHz. The results show, that the transponder replies on both channels. Further measurements in a real world multipath environment show the different fading behaviour of the chosen frequencies. Furthermore, it is demonstrated how dead zones can be avoided by using two different frequencies. Additionally, within the reader software a bitwise error correction for FM0 encoded data is implemented, which employs the redundant information on the two carriers. We are able show that a multicarrier system can be implemented with commercially available tags without restrictions in the European Union. Such a system could be used to improve successful read rates in harsh environments or increase reliability in critical applications. When upgrading from an existing UHF RFID system, only the interrogator needs to be exchanged by a new device working on multiple frequencies.

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One of the biggest impacts of the vision ‘Internet of Things’ is the massive number of connected devices, where billions of nodes will exchange data, information and commands. While wireless systems offer advantages such as increased flexibility, they also introduce one major challenge: how to power each individual node. In many cases, there is no way around the use of batteries. To minimize the environmental impact, increasing the battery’s longevity is the most important factor. This paper introduces a wireless battery-assisted node that has a drastically reduced energy consumption in the standby mode. The state (on/off) will be changed by harvesting a radiofrequency signal. A latching switch connects or disconnects the load—for example, a microcontroller—and the battery. The switch is connected to a charge pump which converts an AC (alternating current) signal into a usable DC (direct current) control signal. An antenna is mounted to the charge pump via a matching network. An electromagnetic wave is emitted by a remote control switch that switches the system on and off. The used frequency is 868 MHz and therefore in the UHF RFID (ultra high frequency radio frequency identification) band. The measurement results show that the wireless node consumes less than 16 nW in the standby mode. The remote controlling is possible from a distance of more than 12 m . The presented system can be integrated in further work on a UHF RFID tag. Thus, the existing protocol standard can be used to identify the object to be switched. By custom commands, the switching request can be transmitted from the remote control (UHF RFID reader) to the switching node.