At analysis of presented characteristics, we can see that in the offset area of
1–10 kHz from the carrier frequency 10 GHz, the oscillator on the leuco-sapphire
has the noises on the level À140 to À160 dB/Hz. Such minimal values of the phase
noise are achieved not only owing to the high Q-factor of the leuco-sapphire
resonator, but thanks to application of PLL systems for frequency adjustment
[73]. The oscillator with DCR has the appropriate dependences at mentioned offsets,
and we have as result of phase noise À90 to À100 dB/Hz. We note that overall
dimensions of such oscillators (not taking into account of regulated power supply
units) are about 200 Â 100 Â 50 mm. Such relatively small sizes play critical
importance at placing of oscillators in the onboard complexes of flying vehicles.
From fulfilled analysis, we may conclude that OEO with RF FODL is able to
compete with well-known electronic oscillators with DCR and DDRLS by all main
characteristics. Although OEO with RF FODL yields in PSD of the phase noise in
the area of frequency offsets 1–10 kHz from the nominal carrier frequency 10 GHz
by 5–15 dB/Hz to the oscillator with the leuco-sapphire resonator (DDRLS). Nevertheless, OEO with RF FODL [69] has quite noticeable advantages: less (almost
two-orders) frequency dependence on the temperature variations and higher
mechanical resistance and almost less to one order the frequency dependence on
mechanical loads.
2.9 Modern Optoelectronic Methods for Precision RF
Oscillation Formation
Together with usual electronic methods of oscillation formation, optoelectronic
methods of precision RF oscillation formation in microwave and mm-wave ranges
are successfully developed. Utilization of electromagnetic emission of the optical
frequency range with wavelengths of 0.4–2.0 μm besides RF oscillation is the main
difference from traditional electronic methods.
In addition to the laser optoelectronic oscillator investigated in this book, which
can be concerned to the modem type, we can mark out several types of such
formation devices of microwave and mm-wave oscillations: the quantum frequency
standard, the laser femtosecond synthesized on the base of the high-stabilized laser
and the frequency divide, the synthesizer with the optical micro-resonator, and the
laser oscillator with optical synchronization of two lasers [74].
2.9.1 Commercial Bulky and Compact Frequency Standards
with Optical Pumping on Cesium and Rubidium Cells
The commercially available quantum frequency standard (QFS) on the Cs cell,
which has the long-term frequency stability of 10
À12 , possesses large dimensions
2.9 Modern Optoelectronic Methods for Precision RF Oscillation Formation
57
1–10 kHz from the carrier frequency 10 GHz, the oscillator on the leuco-sapphire
has the noises on the level À140 to À160 dB/Hz. Such minimal values of the phase
noise are achieved not only owing to the high Q-factor of the leuco-sapphire
resonator, but thanks to application of PLL systems for frequency adjustment
[73]. The oscillator with DCR has the appropriate dependences at mentioned offsets,
and we have as result of phase noise À90 to À100 dB/Hz. We note that overall
dimensions of such oscillators (not taking into account of regulated power supply
units) are about 200 Â 100 Â 50 mm. Such relatively small sizes play critical
importance at placing of oscillators in the onboard complexes of flying vehicles.
From fulfilled analysis, we may conclude that OEO with RF FODL is able to
compete with well-known electronic oscillators with DCR and DDRLS by all main
characteristics. Although OEO with RF FODL yields in PSD of the phase noise in
the area of frequency offsets 1–10 kHz from the nominal carrier frequency 10 GHz
by 5–15 dB/Hz to the oscillator with the leuco-sapphire resonator (DDRLS). Nevertheless, OEO with RF FODL [69] has quite noticeable advantages: less (almost
two-orders) frequency dependence on the temperature variations and higher
mechanical resistance and almost less to one order the frequency dependence on
mechanical loads.
2.9 Modern Optoelectronic Methods for Precision RF
Oscillation Formation
Together with usual electronic methods of oscillation formation, optoelectronic
methods of precision RF oscillation formation in microwave and mm-wave ranges
are successfully developed. Utilization of electromagnetic emission of the optical
frequency range with wavelengths of 0.4–2.0 μm besides RF oscillation is the main
difference from traditional electronic methods.
In addition to the laser optoelectronic oscillator investigated in this book, which
can be concerned to the modem type, we can mark out several types of such
formation devices of microwave and mm-wave oscillations: the quantum frequency
standard, the laser femtosecond synthesized on the base of the high-stabilized laser
and the frequency divide, the synthesizer with the optical micro-resonator, and the
laser oscillator with optical synchronization of two lasers [74].
2.9.1 Commercial Bulky and Compact Frequency Standards
with Optical Pumping on Cesium and Rubidium Cells
The commercially available quantum frequency standard (QFS) on the Cs cell,
which has the long-term frequency stability of 10
À12 , possesses large dimensions
2.9 Modern Optoelectronic Methods for Precision RF Oscillation Formation
57