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[ACER] ADF4158 Synthesizer+VCO phase noise improve method

Question asked by AnthonyTung on Aug 25, 2016
Latest reply on Sep 22, 2016 by rbrennan

Hi ADI members,


This is ACER RD Anthony.

We use the synthesizer ADF4158, and have some question to ask you.


As attached picture,

Now, our VCO(Zcomm V940ME03-LF) phase noise reached to -86 dBc using the external synthesizer(datasheet as attachment, phase noise:- 90dBc) to lock frequency 5800 MHz.


My questions:

  1. We want to improve the synthesizer + VCO architecture phase noise. (Target: -90dBc)

  So how to improve it? Would you have improve method or idea?


  1. The synthesizer phase noise: -90dBc.

  The VCO phase noise: -85dBc.

 We combined them to PLL architecture.

  The phase noise whether dummy by VCO(-85dBc)=> Is it possible?


  1. VCO(V940ME03-LF) output power is -1dBm. (VCO datasheet typical is 2dBm)

  Why we measure lower 3dBm? (we use spectrum to measured it)





Best Regards,


Anthony Tung 董家銓
Communication Dept. I
Acer Incorporated
Tel: +886-2-26963131 Ext. 5704

Mobile: +886-972-037-805