[SOLVED] RF amplifiers Phase Noise Information

[ali ghafoor]

I want to have a rough estimate of PHASE NOISE of General purpose RF Amplifiers (as manufactured by Mini-circuits, Hittite etc). Manufacturers provide no information about Phase Noise in Datasheet. Kindly, provide some quantitative figure of PHASE NOISE (of General Purpose RF amplifiers) ??

 

[jiripolivka]

Phase noise in amplifiers is some 60 dB or more under the PN of oscillators. Where important, manufacturers do include it in data sheets.

 

[chuckey]

If you draw a vector representing your wanted RF carrier, then at one end draw a circle of the noise generated by the amplifier. The resultant vector addition will the "phase" modulated RF carrier. So it all rests on the amplitude of the two vectors. Also if the RF signal is large it can cause parametric modulation, i.e. modulate the collector to base capacitance which causes REAL phase modulation, which might or might not result in what you call noise.
Frank

 

[biff44]

https://www.hittite.com/content/documents/data_sheet/hmc606.pdf

for a ball park number

 

[vfone]

If you are not using the amplifier in a radar design, is not worth to bother about its phase noise, because there are many other parameters that breaks before failing the system phase noise.

 

[biff44]

If you are not using the amplifier in a radar design, is not worth to bother about its phase noise, because there are many other parameters that breaks before failing the system phase noise.

that is very true. Radars need low phase noise, any amplifier that is part of an oscillator loop, anytime you are processing signals where the modulation very close to the carrier (like at 100 Hz offset) such as with ultralow noise crystal oscillators....things like that require you to use low phase noise amps.