| 摘要 |
An RFID(Radio Frequency IDentification) system is provided to stabilize an instable spectrum mask with restriction to spurious response property of an output side of a driving amplifier by smoothing a control signal generated from a digital processor and supplying the smoothed control signal to the driving amplifier to adjust the gain of the driving amplifier. A gain adjuster(170) smoothes and provides the control signal generated from the digital processor(110) to the driving amplifier to adjust the gain of the driving amplifier(151) when a reader generates a frequency selection signal of the digital processor for hopping. The gain adjuster is equipped with a smoother(171) smoothing the control signal supplied from the digital processor and an amplifier amplifying an output signal of the smoother. The smoother includes the second resistor(R2) and the first capacitor(C) smoothing the control signal bypassed by the first resistor(R1). The amplifier is an OP(OPeration) amplifier(173) for amplifying the output signal of the smoother to a resistance value of the third and fourth resistor(R3,R4). |
