Controlling chaos in Colpitts oscillator

Reviewing the mathemetical models and electrical circuits of deterministic chaos transistor oscillators

“…The most widespread and investigated deterministic chaos transistor oscillator is the Colpitts oscillator [1][2][3][4][5][6][7][8][9][10][11]. There two main Colpitts oscillator's circuits: with symmetrical feeding (Fig.…”

“…Similarly, the obtained mathematical model of the Colpitts oscillator with non-symmetrical feeding in non-dimentional variables is [10,11] …”

“…3-6 with non-symmetrical feeding on a bipolar transistor 2N3904 with passive elements' parameters: L=850 uH, C 1 =C 2 =470 nF, C 0 =47 uF , R=36 Ohm, R e =510 Ohm, R1=R2=3 kOhm, V 0 =15 V. In such case values of the normalized variables of the differential equation system (5) considering (7) are: =1, a=30, b=0.8, c=20, d=0.08, e=10. Transistor chaotic Colpitts oscillator is widely used [1][2][3][4][5][6][7][8][9][10][11]. This chaotic oscillator is the most high-frequency one among well-known oscillators [2,3].…”

“…For solving these problems phase portraits of the deterministic chaos oscillators are required as well as time and frequency relationships of chaotic oscillation. The aim of this work is reviewing the mathematical models and phase portraits of the deterministic chaos transistor Colpitts oscillators [1][2][3][4][5][6][7][8][9][10][11].…”

Chaotic operation by a single transistor circuit in the reverse active region

“…This can be seen in the upper waveform in Fig. 1, 2 Following the above and aiming to explore the ability to externally control the possible chaotic operation of the considered RLT circuit, we assume that the expected base region width-modulation ͑known also as Early effect͒ when a BJT operates in the reverse active region may affect more or less heavily the considered circuit's chaotic operation. Of particular interest, however, is the lower waveform shown in Fig.…”