Ultra-broadband and low phase noise frequency synthesizer

Abstract

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∼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∼9GHz frequency signal. The 0.4∼0.45GHz frequency signal is obtained by division of 4.5∼9GHz frequency signal, and the 9∼18GHz signal is obtained by frequency doubler of 4.5∼9GHz frequency signal. The frequency synthesizer's output power level is −50dBm∼0dBm, the phase noise is better than −85dBc/Hz@1KHz, and the suppression to spurious is better than −55dBc.