Balanced tapped delay line spectral shaping differentiation circuit for signal detection

DETAILED DESCRIPTION An object of the present invention is to provide a balanced delay line differentiator with built in spectral shaping equalization for waveform compensation.
The above object has been achieved by means of a symmetrically tapped delay line receiving a variable peak amplitude input signal, e.
g.
, representative of magnetically recorded digital data, along differential input lines and connected to a plurality of signal summing junctions each of which, in turn, connected to selected taps and ends of the delay line.
The delay line is end fed by a differential voltage input signal through impedances matched to the characteristic impedance of the delay line so the tapped delay line is used in a balanced differential mode.
The taps are symmetrically spaced between the ends at intervals forming equal delay elements.
The taps provide component signals with incremental delays from the input signal to two summing junctions.
Two linear combinations of these component signals formed at the two summing junctions results in a pair of differential signals incorporating delays of zero, one, two and three delay element times of the differential double ended input signal.
These two signals at the output of the summing junctions are then combined to produce a balanced double ended output differential signal which is the slimmed and differentiated version of the input signal for use in a dual channel signal detector.
An advantage of the present invention is that the signals developed along the symmetrically tapped delay line are self-balanced.
Another advantage is that a single circuit component performs the dual functions of amplitude spectrum equalization for pulse slimming and signal differentiation needed in a dual channel signal detector for sensing the peaks of the signal.