| 摘要 |
PURPOSE: A multiple FA separator using CQPSK/QPSK modulator-demodulator is provided to minimize system delay and select one fixed form FA having excellent spurious characteristic in the multiple FA. CONSTITUTION: The first mixer(100) mixes a multiple FA signal and a local signal transmitted through an input terminal. A primary PLL(110) processes a predetermined signal supplied to the first mixer(100). The first amplifier(120) amplifies the predetermined signal outputted from the primary PLL(110). The second amplifier(130) amplifies an IF signal outputted from the first mixer(100). A CQPSK/QPSK demodulator(140) demodulates the signal amplified in the second amplifier(130). A BRF(150) respectively separates base band I, Q channels of a predetermined band signal demodulated in the CQPSK/QPSK demodulator(140) for firstly separating adjacent FAs of the FA selected by each channel. A CQPSK/QPSK modulator(160) modulates the I, Q signals for transmitting to an output terminal. A secondary PLL(170) supplies the predetermined signal of the CQPSK/QPSK modulator and demodulators(140,160). The third amplifier(180) amplifies the signal outputted from the secondary PLL(170). A power distributor(190) transmits power of same phase, same amplitude to the CQPSK/QPSK modulator and demodulators(140,160). An elastic surface-wave filter(200) improves the efficiency of the system delay and cut off by receiving the CQPSK/QPSK modulator(160). The fourth amplifier(210) amplifies the signal outputted from the elastic surface-wave filter(200). The second mixer(240) outputs the IF signal and the RF signal amplified in the fourth amplifier(210). A tertiary PLL(220) processes the predetermined signal supplied to the second mixer(240). The fifth amplifier(230) amplifies the signal outputted from the tertiary PLL(220) for transmitting to the second mixer(240). |
