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. 22, 1983
Filed:
Jun. 08, 1981
Michael J Gay, Vaud, CH;
W David Pace, Tempe, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A cancellation circuit which may be utilized in a subscriber loop interface circuit to allow a tone to be supplied in the receive path of the hybrid circuit to be received by the calling subscriber and for cancelling said tone from being transmitted to a called subscriber that is coupled via a carrier channel to the hybrid circuit. The cancellation circuit comprises circuitry responsive to the tone appearing on the transmit path for supplying in-phase and quadrature phase signals at the frequency of this tone to cancel the same to prohibit transmission thereof while simultaneously varying the output impedance of the hybrid circuit at the frequency of the applied tone.