Ultra-broadband and Low Phase Noise Frequency Synthesizer

This paper proposes a high performance frequency synthesizer system featured by ultra-broadband, low phase noise. In order to achieve frequency synthesizer covering 0.4 similar to 18GHz with 10MHz step, two PLL (Phase Locked Loop), mixer, microwave switch, multiplier, frequency divider, and band-pass filter are been used. The three-section frequency VCO is use to generate 4.5 similar to 9GHz frequency signal. The 0.4 similar to 0.45GHz frequency signal is obtained by division of 4.5 similar to 9GHz frequency signal, and the 9 similar to 18GHz signal is obtained by frequency doubler of 4.5 similar to 9GHz frequency signal. The frequency synthesizer's output power level is -50dBm similar to 0dBm, the phase noise is better than -85dB/Hz@1KHz, and the suppression to spurious is better than -55 dBc.