Q
The phase noise multiplies with
the square of the frequency
multiplication factor!
The loaded resonator
quality QL defines the
oscillator phase noise!
QL
Variable-frequency
oscillators
29 – Resonator quality Q
Fixed-frequency
oscillators
RC VCO
30↔100
~1
LC resonator
1000↔3000
Cavity resonator
1000↔3000
Ceramic
dielectric resonator
3000↔10000
AT-cut quartz crystal
(fundamental mode)
10000↔30000
AT-cut quartz crystal
(third/fifth overtone)
~105 (noisy!)
Electro-optical
delay line ($)
Sapphire dielectric
resonator ($$$)
~3.105
QL
Red HeNe LASER
~108
RC multivibrator
~1
BWO tube
~1
YIG (Y3Fe5O12) oscillator
10↔30
Varactor-tuned LC VCO
300↔1000