2.8.4 Phase Noises and PSD of Precision RF Oscillations
Compared to oscillators with quartz and SAW [70] resonators (Fig. 2.17), OEO with
RF FODL has a benefit by 10–20 dB/Hz in the area of frequency offsets 1–10 kHz
from the carrier of 10 GHz.
The FSS oscillator is the undisputable leader in the area of small offsets
0.001–0.1 Hz. It is necessary to note that at present, in OEO, the potentially possible
ultralow noises and the ultrasmall compact construction are not yet implemented.
As we already mentioned, traditional oscillators of RF oscillations can be divided
into the following two classes: constructed on the base of (1) electromagnetic and
(2) acoustic resonators. Oscillators with dielectric and ceramic dielectric resonators
and oscillators with leuco-sapphire resonators (DDRLS) can be concerned to oscillators with electromagnetic resonators. Oscillators with quartz resonators (QR) and
oscillators with resonators (or delay lines) on surface acoustic waves (SAW) can be
concerned to oscillators with acoustic resonators.
Experimental results of the spectral density of the phase noises S(F) for commercially available low-noise oscillators on DDR are presented in [71], and DDRLS are
presented in [72]. The overall dimensions of DDR are about 70 mm  60 mm  30 mm.
Overall dimensions of the oscillator on the sapphire (DDRLS) is much more than
DDR and are about 100 mm  120 mm  130 mm.
Fig. 2.17 Experimental results of the spectral density of phase noises S(F) of low-noise oscillators
with different types of resonators and RF FODL. The central (mean) generation frequency is
10 GHz. F is the offset in radio frequency from the central frequency. (1) QR—the quartz resonator,
(4) DDR—the disk dielectric resonator from ceramic alloys. (5) DDRLS—the disk dielectric
resonator from the leuco-sapphire, (7) RF FODL—OEO with RF FODL with the MZ modulator
(delay in RF FODL is 90 μs), (9) SDDR—the special disk dielectric resonator, (10) FSS—the
femtosecond synthesizer on the base of the highly stabilized laser and the frequency divider
56
2 Nanostructural Optoelectronic Oscillators with the Fiber-Optical Delay Line
Compared to oscillators with quartz and SAW [70] resonators (Fig. 2.17), OEO with
RF FODL has a benefit by 10–20 dB/Hz in the area of frequency offsets 1–10 kHz
from the carrier of 10 GHz.
The FSS oscillator is the undisputable leader in the area of small offsets
0.001–0.1 Hz. It is necessary to note that at present, in OEO, the potentially possible
ultralow noises and the ultrasmall compact construction are not yet implemented.
As we already mentioned, traditional oscillators of RF oscillations can be divided
into the following two classes: constructed on the base of (1) electromagnetic and
(2) acoustic resonators. Oscillators with dielectric and ceramic dielectric resonators
and oscillators with leuco-sapphire resonators (DDRLS) can be concerned to oscillators with electromagnetic resonators. Oscillators with quartz resonators (QR) and
oscillators with resonators (or delay lines) on surface acoustic waves (SAW) can be
concerned to oscillators with acoustic resonators.
Experimental results of the spectral density of the phase noises S(F) for commercially available low-noise oscillators on DDR are presented in [71], and DDRLS are
presented in [72]. The overall dimensions of DDR are about 70 mm  60 mm  30 mm.
Overall dimensions of the oscillator on the sapphire (DDRLS) is much more than
DDR and are about 100 mm  120 mm  130 mm.
Fig. 2.17 Experimental results of the spectral density of phase noises S(F) of low-noise oscillators
with different types of resonators and RF FODL. The central (mean) generation frequency is
10 GHz. F is the offset in radio frequency from the central frequency. (1) QR—the quartz resonator,
(4) DDR—the disk dielectric resonator from ceramic alloys. (5) DDRLS—the disk dielectric
resonator from the leuco-sapphire, (7) RF FODL—OEO with RF FODL with the MZ modulator
(delay in RF FODL is 90 μs), (9) SDDR—the special disk dielectric resonator, (10) FSS—the
femtosecond synthesizer on the base of the highly stabilized laser and the frequency divider
56
2 Nanostructural Optoelectronic Oscillators with the Fiber-Optical Delay Line