7.7.1 Systems of Frequency and Phase Automatic Control
with RF FODL for OEO
Systems of frequency (FLL) and phase (PLL) automatic control systems are widely
used in radio engineering for solution of the oscillator frequency stabilization
problems, for synthesis of the discrete variety of stable frequencies, for extraction
of signal informational parameters from its mixture with the noise, in manifold
devices for radio signal formation and oscillation control including OEO. Development of technology of RF FODL manufacture with reference (etalon) characteristics
makes perspective the creation of the specific class FLL and PLL systems, operation
of which is based on the utilization of elements of precision delay.
The great delay time τ achieved in modern RF FODL at the wide passband B, i.e.,
at the product B Á τ % 10
6 , gives a possibility to develop the FLL and PLL systems
with new useful, often unique, properties. On the other hand, investigating variations
of FLL and PLL modes happening at variation of RF FODL parameters, we can use
the obtained regulations for measurement of the signal delay value in RF FODL.
Figure 7.36a depicts the FLL structure, in which the role of the frequency
discriminator (FD) is played by RF FODL and by the phase detector together. The
error signal e ¼ e(t) from the FD output, through the control circuit (CC), under
action of the signal g ¼ g(t), regulates the frequency of the controlled OEO in such a
manner that in the vicinity of any nominal frequencies of RF FODL: ω nom, n ¼ 2πn/
τ, where τ is the delay time of RF FODL; n ¼ 1‚ 2, 3,. . . As the result, the initial
instability of the OEO natural frequency significantly decreases. Since RF FODL
can provide significant delay in rather wide frequency band, we can realize in
microwave range the great variety of stable frequencies with rather small discrete
step: Δω nom ¼ ω nom, (n + 1) À ω nom, n ¼ 2π/τ.
Fig. 7.36 Stabilization of discrete variety of frequencies in the system of frequency automatic
control with RF FODL: (a) the structure, (b) frequency regulation curves
450
7 Optoelectronic oscillator (OEO) as the Time and Spatial Correlator of Random. . .
with RF FODL for OEO
Systems of frequency (FLL) and phase (PLL) automatic control systems are widely
used in radio engineering for solution of the oscillator frequency stabilization
problems, for synthesis of the discrete variety of stable frequencies, for extraction
of signal informational parameters from its mixture with the noise, in manifold
devices for radio signal formation and oscillation control including OEO. Development of technology of RF FODL manufacture with reference (etalon) characteristics
makes perspective the creation of the specific class FLL and PLL systems, operation
of which is based on the utilization of elements of precision delay.
The great delay time τ achieved in modern RF FODL at the wide passband B, i.e.,
at the product B Á τ % 10
6 , gives a possibility to develop the FLL and PLL systems
with new useful, often unique, properties. On the other hand, investigating variations
of FLL and PLL modes happening at variation of RF FODL parameters, we can use
the obtained regulations for measurement of the signal delay value in RF FODL.
Figure 7.36a depicts the FLL structure, in which the role of the frequency
discriminator (FD) is played by RF FODL and by the phase detector together. The
error signal e ¼ e(t) from the FD output, through the control circuit (CC), under
action of the signal g ¼ g(t), regulates the frequency of the controlled OEO in such a
manner that in the vicinity of any nominal frequencies of RF FODL: ω nom, n ¼ 2πn/
τ, where τ is the delay time of RF FODL; n ¼ 1‚ 2, 3,. . . As the result, the initial
instability of the OEO natural frequency significantly decreases. Since RF FODL
can provide significant delay in rather wide frequency band, we can realize in
microwave range the great variety of stable frequencies with rather small discrete
step: Δω nom ¼ ω nom, (n + 1) À ω nom, n ¼ 2π/τ.
Fig. 7.36 Stabilization of discrete variety of frequencies in the system of frequency automatic
control with RF FODL: (a) the structure, (b) frequency regulation curves
450
7 Optoelectronic oscillator (OEO) as the Time and Spatial Correlator of Random. . .