Design of the Frequency Synthesizer Integrated L-Band VCO

The noise contribution of the main circuit was analyzed by the noise model and structure of frequency synthesizer.The noise impact factors of each frequency synthesizer model were studied,and the noise models of different modules were set up.The structure of current source and delay circuit of the phase detector were improved based on the noise model,and the noise performance of the frequency synthesizer was improved.A low power and low noise frequency synthesizer was implemented in a standard 0.18 μm RF CMOS process.The power consumes of the frequency synthesizer is only 54 m W under 1.8 V supply voltage,the noise is-98 d Bc / Hz in-band.The main performance of the frequency synthesizer has met the level of similar foreign products.It provides a very good reference for the design and development of the high integrated RF transceiver system chips.