BANDWIDTH RELATIONSHIPS APPLICABLE IN ELECTRONIC DIGITAL SIGNAL COMMUNICATIONS

摘要

General Bandwidth relationships [in terms of Trise (digital pulse rise time) - fc (upper critical frequency) product function correlations] are derived applicable to digital signal electronic communication characterization based upon two basic elementary response models: that of a simple RC circuit (Part I) and a Gaussian filter circuit (Part II), respectively. Two results per model are obtained: (1) 'general results' which are a specific function of two parameters (P1 & P2), traditionally held constant but treated now as variables; and (2) 'reduced results' for common standard conditions. The latter is shown, for the RC model case, to be in exact agreement with the familiar and classic -3 dB relationship: (f_c * Trise) = 0.35 (where per standard conditions, P1 is defined as the relative voltage sweep interval between [v1 - v2] = [10% - 90%] levels or segments of a rising (or falling) digital waveform; and P2 is defined as -x dB = -3 dB down value, or standard filter response characteristic defining the upper frequency 1/2 - power point). Extension of the analytical treatment to a Gaussian-like filter response model (Part II) yields a similar but quantitatively different relationship, also parametric in the now variable parameters P1 & P2, respectively. Sensitivity of the bandwidth product relationship to these same parameters is established for both models respectively.