Pole movement in electronic and optoelectronic oscillators

Abstract

An RLC circuit with poles on the left half of the complex frequency plane is capable of executing transient oscillations. During this period, energy conversion from potential to kinetic and from kinetic to potential continuously goes on, until the stored energy is lost in dissipation through the resistance. On the other hand, in an electronic or optoelectronic oscillator with an embedded RLC circuit, the poles are forcibly placed on the right-half plane (RHP) and as far as practicable away from the imaginary axis in order to help the growth of oscillation as quickly as possible. And ultimately, it is imagined that, like the case of an ideal linear harmonic oscillator, the poles are frozen on the imaginary axis so that the oscillation neither grows nor decays. The authors feel that this act of holding the poles right on the imaginary axis is a theoretical conjecture in a soft or hard self-excited oscillator. In this article, a detailed discussion on pole movement in an electronic and opto-electronic oscillator is carried out from the basic concept. A new analytical method for estimating the time-dependent part of the pole is introduced here.

A study on the effect of synchronization by an angle modulated signal in a single loop optoelectronic oscillator

“…In this paper, we have followed the same cyclic passage theory using Barkhausen's criteria as Biswas et al [10,11]. We have presented a method to calculate the locking range of a synchronized angle modulated OEO.…”

Laser induced microwave oscillator under the influence of interference

“…The output power [7, 17] of the MZM can be expressed as where “ α ” is the fraction of insertion loss of the modulator, “ V π ” is the half-wave voltage, “ V B ” is the bias voltage, “ P 0 ” is the input optical power, “ v in ( t )” is the input RF voltage to the modulator and, “ η ” determines the extinction ratio of the modulator. Therefore, the output voltage of the photo detector when the output of the MZ modulator shines on it is where “ ρ ” is the sensitivity, “ Z ph = R − ( j /ω C )” is the output impedance of the photo-detector and “τ 1 = RC ” is the time-constant of photo-detector.…”

“…The effect of interfering signal on a synchronized oscillator has been studied in detail by earlier workers [13–15]. The contribution of phase noise in a multi-loop OEO has been investigated [16] and the movement of poles in OEO has been analyzed by Chatterjee et al [17].

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