Analysis and Design of a Transistor Blocking Oscillator Including Inherent Nonlinearities

Transistor blocking oscillators are finding application in digital computers1 and transmission systems2 where it is necessary to reconstruct a pulse train that has been dispersed in a noisy medium. In fact, several papers3 A 6 have been published concerning the design and analysis of such circuits. All of the previous analytical approaches have been based on the use of a piece wise linear analysis. Linear circuit approximants have been used which are approximately valid during portions of the circuit operation, and formulas have been derived for the rise time and pulse width of the output pulse. The piece wise linear approach does not deal with the inherent nonlinear character of the circuit, and the approximations involved in linearization are often difficult to justify. The most serious shortcoming of the linearization technique is the fact that 785 792 r lHE BELL SYSTEM TECHNICAL JOURNAL, MAY 1 9 5 9 it does not give information concerning trigger requirements for reliable operation. In view of the inherent restrictions of the approximate analysis, a more detailed analysis which deals directly with the nonlinear nature of the circuit has been undertaken. The following sections of this paper will be concerned with the development of this procedure. First, the equivalent circuit, including the nonlinear dependencies, will be displayed and the assumptions on which the analysis is based will be discussed. The nonlinear integro-differential equations governing the performance of the circuit throughout its entire cycle of operation will be derived.