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. 08, 1998
Filed:
May. 29, 1996
Applicant:
Inventors:
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03H / ; H03H / ;
U.S. Cl.
CPC ...
333193 ; 333194 ; 3103 / ;
Abstract
A balanced-type surface acoustic wave filter is provided which can attain a balanced-type of high frequency circuit without connecting a balance-unbalanced conversion circuit. A substrate of tantalic acid lithium substrate with 36 degrees rotation, Y cut, and X propagation is used, and aluminium is used for electrode to form resonators. Then, two resonators in a serial arm and two resonators in a parallel arm are connected in the form of symmetry and lattice to form a balanced-type surface acoustic wave filter. In this configuration, antiresonance frequency in the serial arms and resonance frequency in the parallel arms are substantially equal to each other.