W-band Low Phase Noise Phase-locked Source

As the most crucial techniques that apply in electronic systems, a high performance frequency synthesizer is absolutely necessary that ensure modern electronic systems such as radar and communication systems to achieve high performance, so to design a high performance frequency synthesizer is very important research field.First of all, the basic theory of PLL and passive frequency multiplier as well as their characteristics has been analyzed detailedly. The times-90 multiplier chains make the output frequency expand to C-band. Then the power performance has been designed reasonably, and the feasibility about the phase noise, spur and output power have been analyzed. According to the request of the system, the PLL chip ADF4106, the×2 frequency multiplier chip RK-2, the Schottky diode multiplier HSMP3822 and HSMP8202, the amplifier and so on, have been chosen to establish the system circuit.Secondly, a PLL frequency synthesizer working in W-band is researched. Based on the blueprint of 'fundamental wave being phase-locked and then output harmonic wave', the methods of multiplier, mixing and digital PLL are used for higher working frequency of the frequency source. The frequency source working in millimeter microwave is not easy to be locked and usually has the problem of bad phase noise. This paper overcomes these difficulties and finally finishes the design of the frequency source.Finally through the EMC design of the layout and grounding, the request has been achieved by debugging all the whole circuits and programs time after time.The results show that the output power is up to 10mW at 91.8GHz, with phase noise -84dBc/Hz at 10kHz offset.