US 5,848,167 A · Distributed pre-emphasis equalizer

Abstract

A distributed pre-emphasis equalizer comprises a partial pre-emphasizer and a (50) microsecond pre-emphasizer. The partial pre-emphasizer receives an input signal and produces a partially pre-emphasized output signal. The (50) microsecond pre-emphasizer receives the partially pre-emphasized output signal from the partial pre-emphasizer and adds a (50) microsecond equalization to produce a pre-emphasized output signal equal to a standard (75) microsecond pre-emphasis curve. The distributed pre-emphasis equalizer allows an FM audio processor to produce only the "dulling" effect of a (50) microsecond pre-emphasis even when generating a (75) microsecond pre-emphasis curve. The distributed pre-emphasis equalizer also creates a pre-emphasizing method which is inherently compatible with both the (75) microsecond and (50) microsecond standards. Furthermore, the distributed pre-emphasis equalizer creates a pre-emphasizing method which is easily switchable between the (75) and (50) microsecond standards.

Claims17

Dependent claims

A distributed pre-emphasis equalizer, comprising:

a. a first partial pre-emphasizer means having an input for receiving an input signal, an output for producing a partially pre-emphasized output signal, and a transfer function;
b. a signal processor means having an input coupled with said output of said first partial pre-emphasizer means for receiving and controlling the amplitude of said partially pre-emphasized output signal, and an output for producing a control partially pre-emphasized output signal;
c. a second pre-emphasizer means having an input, an output and a transfer function, the input coupled to said output of said signal processor means for receiving said control partially pre-emphasized output signal and adding a pre-emphasis characteristic to produce a final pre-emphasized output signal;
d. said transfer function of said first partial pre-emphasizer means being equal to a transfer function of said final pre-emphasized output signal divided by said transfer function of said second pre-emphasizer means;
and
e. a limiter means having an input coupled to said output of said second pre-emphasizer means for receiving and limiting the amplitude of said final pre-emphasized output signal.

3 more elements

Dependencies are inferred from the claim text.

Distributed pre-emphasis equalizer

Life of this patent

Distributed pre-emphasis equalizer

Life of this patent

Abstract

Claims17