| 摘要 |
<p>A dual-PLL type RFID reader is provided to enhance isolation between transmission and reception signal paths, restrict a feedback component signal, and easily separate frequency signals of a transmission/reception band by improving the mixing structure between an intermediate frequency signal and an RF signal. First/second PLL circuits(172,174) respectively generates first/second reference frequency signals. An RF receiver(120) mixes an RFID reception signal with the first reference frequency signal. A baseband receiver(130) separates the mixed RFID reception signal into more than two modulated signals, and mixes the modulated signals with the second reference frequency signal. A baseband transmitter(150) transmits the baseband signal as an RF transmission signal by using the second reference frequency signal. The RF receiver includes a first mixer(126) mixing the RFID reception signal, a signal separator separating the mixed RFID reception signal into an I(In-phase) signal and a Q(Quadrature phase) signal, a second mixer(132a) mixing the I signal with the second reference frequency signal, and a third mixer(132b) mixing the Q signal with the second reference frequency signal.</p> |
