Jasmin Grosinger

A silver inkjet printed ferrite NFC antenna

This paper presents a near field communication (NFC) antenna that is printed directly on a ferrite substrate using a silver inkjet printing process. Such a silver inkjet printed ferrite NFC antenna provides a minimum substrate thickness, a good operation on metal objects, and a small assembly effort. The NFC antenna performance is analysed by measurements based on the ISO/IEC standard 10373-6 for proximity identification cards test methods. For this, the antenna is connected to an NFC microchip. Measurements in a non-metal environment show that the ferrite antenna performs equally good a custom-built NFC antenna printed on photo paper substrate, despite additional losses in the ferrite substrate. In a metal environment the ferrite antenna clearly outperforms the photo paper antenna.

A novel 3D packaging concept for RF powered sensor grains

We present a novel three-dimensional (3D) embedded wafer-level ball grid array (eWLB) system in package (SiP) solution for biochips and micro labs. This 3D SiP includes three major components, a complementary metal oxide semiconductor (CMOS)-tunnel magneto resistance (TMR) sensor biochip for magnetic bead-sensing stacked on a radio frequency identification (RFID) microchip and a 13.56 MHz coil antenna for wireless energy and data transfer. The power supply and the serial peripheral interface (SPI) chip interconnections between the CMOS-TMR sensor biochip (slave) and the RFID microchip (master) are implemented with a novel embedded Z-line (EZL) vertical contact technology through the mold compound. The 13.56 MHz antenna is embedded into the fan-out area of the bottom redistribution layer of the eWLB. With this setup we are able to maximize the RFID reading distance and to ensure a displacement to the TMR sensor surface. We achieve an overall volume of the 3D SiP of only 5.6 mm × 3.6 mm × 0.7 mm applying the eWLB technology. Due to the RFID technology the developed 3D SiP does not need any external contacts and cabling. Therefore it can be encapsulated into harsh environments. In addition the top fan-out surface of the eWLB can be used for adhesive bonding to higher level analyzing setups. The results demonstrate that innovative SiP technology using the eWLB technology combined with chip and antenna design allow to realize modern subsystems e.g. for medical applications.

Sensor add-on for batteryless UHF RFID tags enabling a low cost IoT infrastructure

The paper presents an antenna transducer prototype at 915MHz for a batteryless ultra high frequency (UHF) radio frequency identification (RFID) transponder (tag) sensor add-on. By using low cost and low maintenance batteryless RFID sensor tags in a home environment, a low cost internet of things (IoT) infrastructure can be provided. The batteryless or rather passive UHF RFID sensor tag is realized by using the tag antenna as the sensing device. The prototyped antenna transducer allows to detect three specific water filling levels in a can to sense for example the filling level of a coffee machine in a smart home environment. The transducer prototype provides a high efficiency of 92%and thus guarantees for the first time a reliable and stable power supply to the passive RFID tag chip at each sensing state.

Wide-band dielectric resonator antennas for RF energy harvesting

Energy harvesting seems to be a suitable solution for remote device powering in systems like wireless sensor networks, which are becoming ubiquitous. In presented paper, a wide-band Dielectric Resonator Antenna (DRA) for RF energy harvesting is studied. The frequency band of interest lies between 1.84 GHz and 2.445 GHz, covering three main wireless communication systems, namely Global System for Mobile Communications (GSM) operating on 1800 MHz, Universal Mobile Telecommunications System (UMTS) at 2100 MHz and wireless local area network (WLAN) based on 802.11 IEEE standard [9] at 2400 MHz. Two antennas based on identical bow-tie dielectric resonators with different feeding schemes are proposed. The aperture coupled DRA shows superior performance in terms of impedance matching and stability of the radiation pattern when compared to the probe coupled antenna. The simulation results of these two antennas are compared and experimentally verified by measurements.

SDR based RFID reader for passive tag localization using phase difference of arrival techniques

This paper presents a passive radio frequency identification (RFID) reader for a two dimensional localization of tagged objects in the ultra high frequency (UHF) band. The presented prototype is capable of simultaneously estimating the direction and the range of an object. This capability is provided by a single input multiple output (SIMO) antenna configuration in combination with phase difference of arrival (PDOA) techniques. The core of the prototype is a flexible software defined radio (SDR) that allows rapid prototyping and thus a fast system verification. The reader operates at three frequencies that makes the tag localization more robust, especially in multipath environments. The reader verification is shown by measurements in an anechoic chamber. An initial angular accuracy of 3 degrees for the tag direction and 23 cm for the tag range is accomplished in this first stage of the prototype development.

Passive RFID Sensor Tag Concept and Prototype Exploiting a Full Control of Amplitude and Phase of the Tag Signal

This paper presents a passive radio-frequency identification (RFID) sensor transponder (tag) concept that uses the antenna as the sensing device and exploits a full control of amplitude and phase of the tag signal by optimizing the tag antenna impedances in the different sensing states. This optimization is based on a sensor tag efficiency that evaluates the quality of the tag signal in terms of its amplitude for a reliable power transfer toward the passive tag chip and in terms of its phase for a transmission of the sensing states toward the RFID reader. An antenna transducer prototype for an RFID sensor tag is presented that verifies the concept by detecting three different water filling levels. The prototype achieves a high sensor tag efficiency of 92% at 915 MHz. A reliable power transfer to the passive tag chip is ensured by constant power transmission coefficients of about 90% in all three sensing states. In addition, the phase modulation quality is high and thus shows a high robustness for the detection of the sensing states at the reader. Furthermore, reasonably high tag modulation efficiencies are achieved with a minimum of 11% that ensure a reliable tag ID transmission in each sensing state.

A secure miniaturized wireless sensor node for a smart home demonstrator

Recently, the technology of wireless sensor networks (WSNs) experiences a growing use in home automation or advanced industry infrastructure applications. Despite a strong interest of industries in this technology, key issues like miniaturization and security of WSN nodes has not been solved yet. State-of-the-art WSN nodes do not provide credible security nor satisfying configurability and miniaturized implementations. This publication deals with these limitations and presents a WSN node that provides security, configurability, and a miniaturized design. To show the sensor node feasibility, the WSN node is implemented within a smart home demonstrator. Additionally, a miniaturized pre-study WSN node design is presented using the novel embedded wafer level ball grid array (eWLB) packaging technology. Furthermore, an eWLB based WSN node design is proposed that further miniaturize the presented WSN node.

SIMO RFID system performance in an engine test bed

This paper presents a performance evaluation of a radio frequency identification (RFID) system in an indoor multipath environment at 890 MHz. A single input multiple output RFID system is investigated with respect to the feasibility of localizing tagged measurement equipment in an engine test bed. Based on the available signal power within the test bed, the system performance is evaluated with respect to state-of-the-art RFID system components. The evaluations show that an exemplary RFID system experiences no outages when using a passive RFID transponder (tag) with a chip sensitivity of -17:5 dBm and an RFID reader with a transmit power of 30 dBm and a receiver sensitivity of -95 dBm. Additionally, the evaluation allows to deduce system requirement parameters for the further realization of such an RFID reader, e.g., the minimum transmit power for the reliable operation in the engine test bed is 24:5 dBm.

Measurement based indoor SIMO RFID simulator for tag positioning

In this research, a single-input multiple-output simulator for passive UHF RFID is developed in MatlabR/SimulinkR. Tag localization is achieved via a phase difference of arrival technique. A channel measurement campaign was conducted in an engine test environment. Scattering parameters were measured at several line-of-sight and non-line-of-sight tag positions. The measured S parameters were used in the simulator to emulate a real indoor multipath channel. The simulator estimates accurate direction of arrival at several tag positions of the measurement campaign. There is a maximum error of 32° and minimum of 0.4° between the geometrically calculated and simulated angles.

A miniaturized dual band RFID tag

This paper presents a novel highly miniaturized dual band radio frequency identification (RFID) transponder (tag) with an on-chip antenna. The tag has a size of 1.32mm2 and was fabricated in a low cost 130nm complementary metal-oxidesemiconductor process. The dual band RFID tag supports the electronic product code (EPC) generation (gen) 2 high frequency (HF) standard at 13.56MHz and the EPC gen2 ultra high frequency (UHF) standard at 868MHz. The custom built onchip antenna comprises two connected resonanting coils. The antenna enables inductive coupling to an RFID reader in the HF and UHF bands. The maximum tag read range is 2.5mm at 13.56MHz and 4.4mm at 868MHz. This limited read range can be further increased by different types of booster antennas.