论文部分内容阅读
Using the clockwise or anticlockwise stepping pulse code signal, the characteristics of generalquaternary phase shift keying (QPSK) modulation are analysed. This paper gives the spectrumsin several operational conditions and the admittance formulas of related two modulation circuits.Several typical examples of QPSK modulation are calculated. The modulation effect and thephase error can be decided and the QPSK modulator under the dynamic test may be adjusted by usingabove results. The experimental results are in agreement with the theoretical calculations. An X-band QPSK modulator is also presented. The maximum phase error is less than 4°, the phaseaccuracy near ±0.1°, the insertion loss less than 4 dB and the data (transfer) rate up to 68 Mb/s.
Using the clockwise or anticlockwise stepping pulse code signal, the characteristics of general quaternary phase shift keying (QPSK) modulation are analyzed. This paper gives the spectrum of several operational conditions and the admittance formulas of related two modulation circuits. . The modulation effect and thephase error can be decided and the QPSK modulator under the dynamic test may be adjusted by usingabove results. The experimental results are in agreement with the theoretical calculations. An X-band QPSK modulator is also presented. is less than 4 °, the phaseaccuracy is near ± 0.1 °, the insertion loss less than 4 dB and the data (transfer) rate up to 68 Mb / s.