Antenna-Integrated Millimeter-Wave Identification Tag Chips for Miniature Wireless Sensors

The 5th generation (5G) mobile network to be deployed in 2020 will feature a larger amount of data, faster data rate, shorter latency, and is able to support a larger number of connections with lots of mobile devices at the same time, constructing an internet of things (IoT). In IoT applications, there will be numerous wireless sensors. Among them, some sensors are battery-free and use RFID technology, waiting to be read by base stations or users in a passive manner.In the planning of the carrier frequency bands for the air interface in the 5G physical layer, in addition to the sub-6 GHz RF bands that is ready to be added into the current 4G bands, microwave and millimeter-wave bands, such as 24–28 GHz, 37–40 GHz, and 64–71 GHz, are also opened up. After the 5G millimeter-wave becomes a reality in the near future, wireless sensors will be able to adopt millimeter-wave identification (MMID) technology. Since the wavelength is short for millimeter waves, the size of the antennas for the MMID tags would be very small. The antennas can be realized in package or on chip, thereby good for miniature wireless sensors with size on the order of mm.The proposed project "Antenna-Integrated Millimeter-Wave Identification Tag Chips for Miniature Wireless Sensors" is aimed at developing an MMID chip module that has an on-chip antenna operating in upper 37-GHz band. The chip module to be developed is a passive MMID tag, using the transmit power of a remote MMID reader as its energy source. The antenna and the rectifier/modulator circuits operating at the upper 37-GHz millimeter-wave band will be implemented using a GaAs pHEMT process, whereas the low-frequency signal converted by the rectifier will be processed by circuits realized using a Si CMOS process, including low-dropout regulator and ASK-PPM demodulator. The two chips will be stacked and connected together by flip-chip bonding so that the module is miniaturized.We plan to complete this project in one year of time. The focus for the early stage will be circuit design. In the middle term of the project period, we need to prepare the measurement setup. When the time is near the end, we will measure and test the chips and the module. A miniature upper 37-GHz-band MMID tag chip module will be presented when the project is completed to summarize the research and development efforts.