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. 28, 1992
Filed:
Nov. 21, 1990
Mark Whittington, Austin, TX (US);
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Abstract
A circuit for selecting an input to a signal processing network from among several switchable antenna units. Each antenna unit includes a winding which is connected to a common signal bus. The switchable antenna units may be placed in 'on' or 'off' states in response to a controller, such as a microprocessor. One terminal of each winding is connected to a transistor which causes the terminal to be in an open condition when the unit is unselected, attenuating any signal which might otherwise be transmitted to the signal bus. A second winding is inductively coupled to the first winding and is used to improve attenuation of unselected signals.