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:
Mar. 01, 1994
Filed:
Feb. 10, 1993
Bernard J Arntz, Morris, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A method and apparatus for imparting a positive phase slope (i.e., a negative group delay) to a narrowband signals is disclosed which adjusts the phases of the various frequency components of a signal in a manner opposite to that of a delay line. The invention also permits the amount of phase slope to be adjusted, electronically, without the need for electro-mechanical apparatus or the interchange of cables. Furthermore, embodiments of the present invention are advantageous in that at the center of the operating band they maintain the phase of the delayed signal. These results are obtained in an illustrative embodiment of the present invention which divides the signal to be delayed into two signals which traverse different signal paths and are recombined in a signal combiner. The first signal path advantageously comprises a gain control block. The second signal path advantageously comprises a second gain control block and a fixed line delay which is not found in the first signal path. The amount of phase slope imparted to the signal can be adjusted by varying the gain (or attenuation) of the respective gain control blocks.