Research on the Wideband & Low Spurs Remote Sensing Satellites Simulator Frequency Synthesizer
Hongwei Wei · Chuangan jishu xuebao · 2009
The techniques of direct digital synthesizer and harmonic spurs reduction were applied in the system of remote sensing satellites simulator frequency synthesizer.Key technologies and principle of DDS are introduced.Main harmonic spurs of DDS devices are discussed,and the primary means of spurious suppression methods are introduced,which use the techniques of 7th order elliptical differential low-pass filter and cosine correction.The wideband and low spurs frequency synthesizer was designed,which based on FPGA and new DDS devices.And finally,a conclusion is made through experiments that the frequency synthesizer features wide-band(1 MHz~400 MHz),precise resolution,rapid frequency and phase turning.