Microwave Chaotic Colpitts Oscillator: Design, Implementation and Applications

In this paper, the mathematic model of Colpitts oscillator is illustrated and the expressions for the main circuit parameters are derived, with which chaotic oscillation can be established. Experimental researches were conducted on the implementations of chaotic Colpitts oscillator using two types of broadband bipolar junction transistors (BJTs), namely BFG520XR and BFG425W with corresponding threshold frequency of 9 GHz and 25 GHz. Experimental results indicate that, chaotic oscillation can be obtained in a wide frequency regime in microwave band. When using BFG425W in the Colpitts circuit, the highest fundamental frequency of the chaotic oscillation can be about 1.6 GHz, and the harmonics observed with Agilent PSA/ESA Spectrum Analyzer are noticeable as far as 12 GHz, which is the highest one reported so far. Several typical applications using such chaotic oscillators are also presented at the end of this paper.

[1]  K. V. Zakharchenko,et al.  Basic principles of direct chaotic communications , 2003 .

[2]  Moe Z. Win,et al.  Impulse radio: how it works , 1998, IEEE Communications Letters.

[3]  Antanas Cenys,et al.  Two-stage chaotic Colpitts oscillator , 2001 .

[4]  Michael Peter Kennedy.  Chaos in the Colpitts oscillator , 1994 .

[5]  Michael Peter Kennedy,et al.  Recent advances in communicating with chaos , 1998, ISCAS '98. Proceedings of the 1998 IEEE International Symposium on Circuits and Systems (Cat. No.98CH36187).

[6]  A. M. Young,et al.  Progress towards a microwave chaotic communications system: triumphs and tribulations in realizing broadband high-frequency chaotic oscillators , 1998, 1998 IEEE International Conference on Electronics, Circuits and Systems. Surfing the Waves of Science and Technology (Cat. No.98EX196).

[7]  M. Razzaghi,et al.  NUMERICAL SOLUTION OF THE CONTROLLED DUFFING OSCILLATOR BY THE INTERPOLATING SCALING FUNCTIONS , 2004 .

[8]  Michael Peter Kennedy,et al.  Robust OP Amp Realization of Chua's Circuit , 1992 .

[9]  A. Tamasevicius,et al.  Experimental demonstration of chaos from Colpitts oscillator in VHF and UHF ranges , 2004 .

[10]  A. Tamasevicius,et al.  Improved chaotic Colpitts oscillator for ultrahigh frequencies , 2004 .

[11]  G. M. Maggio,et al.  Classification of steady-state behavior of the Colpitts oscillator , 1999, ICECS'99. Proceedings of ICECS '99. 6th IEEE International Conference on Electronics, Circuits and Systems (Cat. No.99EX357).

[12]  Cuomo,et al.  Circuit implementation of synchronized chaos with applications to communications. , 1993, Physical review letters.

[13]  Leon O. Chua,et al.  Chua's Circuit: an Overview Ten Years Later , 1994, J. Circuits Syst. Comput..

[14]  A. R. Shehata,et al.  Chaotic radar systems , 2000, 2000 IEEE MTT-S International Microwave Symposium Digest (Cat. No.00CH37017).

[15]  C. Wegener.  RF chaotic Colpitts oscillator , 1995 .

[16]  Michael Peter Kennedy,et al.  Nonlinear analysis of the Colpitts oscillator and applications to design , 1999 .