I think, it's impossible. Simple calculation gives Ql=1500 or greater for 300-500 MHz VCO. If you have -120 at 1 kHz, then at 100 kHz will be approx. -170...-160. In most cases noise floor of oscillators is -170...-160. Then f0/2Ql=100 kHz and Ql=1500...2500. Only YIG can give such Q in octave tuning. Or you can use swiched VCO's. For 90-140 MHZ Ql=450...700.I need a VCO:
1st option:
Freq: 300~500MHz
Phase Noise: <-120dBc/Hz@1KHz
2nd option:
Freq: 90~140MHz
Phase Noise: <-120dBc/Hz@1KHz
I need VCO, not DDS, because of the DDS spurs.
Who know such a part number?
I need a VCO:
1st option:
Freq: 300~500MHz
Phase Noise: <-120dBc/Hz@1KHz
2nd option:
Freq: 90~140MHz
Phase Noise: <-120dBc/Hz@1KHz
I need VCO, not DDS, because of the DDS spurs.
Who know such a part number?
I don't think so. Using low noise Si bjt's one can achieve 100-1000 Hz flicker corner. So phase noise at 1 kHz is determined by Ql.Loaded Q is one of the factors that affect the phase noise, but is not the first. At this offset the biggest contributor is 1/f flicker noise.
The list of VCO's that I posted in the link above, made by Synergy Microwave, use the feedback noise patent of Ulrich Rohde who is the Chairman of the company. Check the technical articles of the company.
The VCO in the link below have -128dBc/Hz @ 10kHz and about -106dB/Hz @ 1kHz.
**broken link removed**
If the feedback noise network is tuned only to achieve best phase noise @ 1kHz offset, better results can get (of course at greater offsets the phase noise it will degrade somehow).
100 MHz is relative low frequency, and if you have room for bigger inductors (with higher Q), and trying different discrete JFET's at various bias currents, it is possible to get good results, maybe better than above.
And oscillating power!I don't think so. Using low noise Si bjt's one can achieve 100-1000 Hz flicker corner. So phase noise at 1 kHz is determined by Ql.
I mean, that power in resonator is constant.And oscillating power!
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