how to improve Phase noise

[zeshan102]

how to keep phase noise constant around 90 dbc at 10 Khz for entire bandwidth of synthesizer , it offer different phase noise at different frequency my BW is 575 Mhz RF frequency from 4680 to 5255 Mhz.


Thanks

 

[biff44]

Why bother? Most engineers would design for phase noise at the worst case frequency to meet the specification, and for the phase noise to be better than the requirement at other frequencies.

 

[spikeyang]

If frequency switching time is not required , make the loop filter band as small as possible , less than 1KHz,maybe.

 

[eng_Semi]

less than 1KHz,maybe.

He may need a separate chip to integrate the capacitors and resistors

 

[VSWR]

What do you mean by "keep the phase noise constant"? What variation do you have during PLL tuning from 4680 to 5255 MHz? 0.1 dB, 1 dB, 10 dB, or what? Please be more specific. What is the bandwidth of your PLL?