1 results about "Band notch" patented technology

The application discloses a zero intermediate frequency satellite communication signal processing method and system based on an embedded microcontroller, and the method comprises the following steps: encoding and framing original data, generating I / Q digital baseband waveforms through QPSK mapping, upsampling and shaping filtering, and converting analog signals through a double-channel DAC. In view of Sinc fading and adjacent channel leakage caused by the zero-order holding effect of the DAC, two-stage cascade suppression is adopted: the first stage of attenuation is performed in the digital domain; the second stage of physical filtering is performed in the analog domain between the DAC and the mixer by using the stop band notch characteristic of the symmetrical active differential low-pass filter circuit, and the independent direct current bias adjustment is used for IQ balance adjustment to eliminate the carrier leakage. Finally, the mixer is used for one-step up-conversion, and a power amplifier is used for emission. The method does not need closed-loop digital IQ correction, significantly reduces resource consumption, and improves the adjacent channel power ratio and radio frequency quality.