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:
Dec. 05, 1995
Filed:
Jan. 06, 1993
Applicant:
Inventor:
Aimo Turunen, Oulu, FI;
Assignee:
LK-Products Oy, Kempele, FI;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01P / ; H03H / ;
U.S. Cl.
CPC ...
333132 ; 333133 ; 333193 ; 333202 ; 370 38 ; 370123 ;
Abstract
When the bandwidth of a duplex filter having a certain band-width, intended for a radio telephone, is increased by affecting the coupling between the resonator circuits, the stop band of the filter is at the same time deteriorated. According to the invention, the stop-band attenuation can be improved by coupling a surface-wave filter, coupled as a notch circuit, in parallel with one of the resonator circuits of the duplex filter.