The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 21, 1986
Filed:
Oct. 12, 1983
Richard W Peters, Algonquin, IL (US);
Industrial Products, Inc., Elk Grove Village, IL (US);
Abstract
An adjustable equalizer network comprises a series chain of N all pass amplifier stages driving M minimum phase shift transversal filters connected to a final summing circuit that includes means to adjust each filter output to obtain a ripple free predetermined frequency response over a given frequency range. Each filter includes N+1 scaling circuits connected to an intermediate summing circuit; the scaling circuits have scaling coefficients, of magnitude and sign determined by Fourier analysis and an appropriate truncation function, such that the filter has a pass band representative of one of M contiguous bands conjointly encompassing the frequency range. The adjustable equalizer, once adjusted for a desired frequency response, may be supplied with a DC reference input and used to determine the contribution (magnitude and sign) to the frequency response from each tap on the all pass chain, thus developing a set of N+1 scaling coefficients for a simplified equalizer network, comprising the all pass chain with just one set of N+1 scaling circuits, that duplicates the response characteristic of the more complex adjustable equalizer. Some embodiments incorporate digital programming and control of the frequency response characteristic.