Generation of high-speed waveforms using nonlinear delay lines
In nonlinear delay lines employing back biased p-n junctions as variable capacitors, the velocity of propagation is a function of signal amplitude. This effect may be used to produce short-risetime pulses which may be of high repetition rate. Two circuit applications are discussed, these being the processing of sinewaves to produce fast-edge triangular pulses, and also the processing of long-risetime pulses to produce short-risetime pulses. The analysis employed is in the time domain, and stems from linear delay-line theory, relying upon certain qualifications and restrictions being imposed when applied to nonlinear delay lines. This approach produces good agreement with experimental results. The questions of ‘ringing’ and overshoot are discussed in some detail, and design criteria are obtained for eliminating these undesirable features from delay lines.
