13-09-2017, 03:00 PM
A miniature wireless RFID chip with on-chip antennas (OCA) and wideband (UWB) signals by real-world measurements. With the antenna approach on the chip, no external antennas are required, and the overall label size is identical to the size of the single chip (3.5 mm x 1 mm). The chip is fed through inductive coupling and controlled by an RFID signal at 866 MHz in the downlink, while the uplink transmits a pulse-modulated quaternary (4-PPM) quaternary UWB signal at 5.64 GHz with pulses which have a duration of the order of nanoseconds. In this contribution, the hybrid or asymmetric communication scheme between the chip prototype and the reader, the embedded OCA and the measurement configuration is described. The prototype achieves a 4-PPM transmission rate of 126 Mbit / s based on a pulse train transmission with a duration of 10 μs. The reduced size, high data rate and good temporal resolution of the UWB pulse radio offer new features and detection capabilities for future RFID applications.
These CMOS prototypes with OCAs were controlled and fed through bondwires. In order to compare the radiation of different types of OCAs, a voltage controlled oscillator (VCO) was swept over a huge range of frequencies of several octaves. In addition, the nanosecond pulses were transmitted with a simple on / off pulse transmitter - created by a fault generator, whose output was multiplied with the VCO frequency. A proof of concept was performed on energy transfer, with inductive coupling using a magnetic OCA. With a modulated backscatter technique, the induced voltage in the miniaturized loop antenna was analyzed over the area and over the distance. The concept of energy harvesting was studied and characterized with a small system of 3 mm x 1 mm, where two different OCAs were used to receive energy and to transmit data. The powerharvesting concept should be able to pick up the power of some μW in the long run. This energy, stored efficiently with batteries or on-chip capacitors, is used for driving the UWB front, which requires a little mW in a short period of time. The asymmetric scheme allows replacing the concept of collection used, if clock and data is provided to configure the chip through another communication channel.
These CMOS prototypes with OCAs were controlled and fed through bondwires. In order to compare the radiation of different types of OCAs, a voltage controlled oscillator (VCO) was swept over a huge range of frequencies of several octaves. In addition, the nanosecond pulses were transmitted with a simple on / off pulse transmitter - created by a fault generator, whose output was multiplied with the VCO frequency. A proof of concept was performed on energy transfer, with inductive coupling using a magnetic OCA. With a modulated backscatter technique, the induced voltage in the miniaturized loop antenna was analyzed over the area and over the distance. The concept of energy harvesting was studied and characterized with a small system of 3 mm x 1 mm, where two different OCAs were used to receive energy and to transmit data. The powerharvesting concept should be able to pick up the power of some μW in the long run. This energy, stored efficiently with batteries or on-chip capacitors, is used for driving the UWB front, which requires a little mW in a short period of time. The asymmetric scheme allows replacing the concept of collection used, if clock and data is provided to configure the chip through another communication channel.