Design And Research Of Clock And Power Circuit Of UHF Passive RFID Tag Based On 0.18μm Technology

RFID technology whose identification depends on non-contact bidirectional digital communication by wireless RF carrier is a kind of automatic identification technology. RFID is a rising technology and it is developing into a practical phase due to the mature of VLSI and the decreasing of RFID system volume. Recently, RFID is developing fast as the fast developing of semiconductor technology and other relative technologies. RFID is becoming a very reliable technology. But for UHF RFID products, there is no qualified one in the whole country. We are still underway. Furthermore, our enterprises of RFID system completely rely on the chip of import. They don't have any intellectual property rights. We lack of the capability of designing high frequency and low power circuit, so our developing of UHF RFID products is very slow.A high performance clock recovery and power recovery circuit of UHF RFID transponder which is compatible with ISO 18000-6 Type C Standard is presented in this paper. The power recovery circuit is including rectifier, voltage limiter, regulator, voltage reference and so on. The output voltage of power recovery circuit must need as less power as possible and meet all of the command and current need. The circuit must be simplicity to decrease the power dissipation and we use low power design technique to ensure the desired working range. The clock recovery circuit is composed of a low power and high stabilization oscillator. The power dissipation of oscillator is the main part of the power dissipation of the whole analog front-end, so we need to optimize the power design. At the same time, the clock frequency of the oscillator without trimming is very sensitive to technology, so we should pay attention to that as well. We apply SMIC 0.18μm technology to accomplish our circuit and layout design. The simulation result shows that the chip works well at 915MHz working frequency for all condition and we meet the specification well. The current of the whole analog front-end is less than 13μA for all condition.