LINK AMPLIFIER AS A CODED-PULSE GENERATOR AND MATCHED FILTER

A new coded-ptl/e generator and matched-filter system was realized using tapped delay lines as the plate and grid lines of the link amplifier. If the grid line of the link amplifier is supplied with an input of the form sin t/t, the output taken from the normally unused end of the plate line forms the coded-pulse signal in the ideal case. The matched filter to this coded signal is the same amplifier with the coded pulse supplied to the normally unused end of the grid line. In this method the summing operation is distributed n the link-coupled system; the output stray capacitances of the active elements are absorbed in the delay line and do not add to lower the gain-bandwidth product of the system. As a result matched filters with larger bandwidths than the conventional type, which have a tapped delay line and summing amplifier, can be constructed successfully. All-pass constant-resistance delay sections are synthesized for maximally flat delay using even-order Bessel polynomials. Since the ideal input sin t/t is not realizable, other practical signals suitable toserve as the input to the coded-pulse generator are discussed. (Author)