This paper mainly introduced the UHF RFID RF front end circuit design.In the LNA design
it improved the linearity by using the 2nd-intermodulation injection structure at the input terminal
and achieved the operating frequency adjustable by using switch capacitor at the output terminal;in the mixer design
it improved the linearity by the same way as LNA
and eliminated the noise by using dynamic current injection structure at the output terminal.The circuit has been fabricated with a 0.18 μm CMOS process
the supply voltage is 1.2 V
the simulation results show that:the impedance matching S11 is-23.98 dBm
IIP3 is 5.05 dB
and the overall conversion gain of the front end circuit is 10 dB.