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:
Feb. 04, 1997
Filed:
May. 26, 1995
Philip P Kwan, Tempe, AZ (US);
Thomas S Hickernell, Mesa, AZ (US);
David Penunuri, Fountain Hills, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A method and apparatus for an acoustic wave filter (110) with reduced bulk-wave scattering loss and a ladder filter (30, 40) incorporating same. The method includes steps of providing an acoustic wave propagating substrate (111) and disposing a first reflector (112) on a first surface thereof. The method also includes disposing a first transducer (115) to a first side of the first reflector (112). The first transducer (115) is separated from the first reflector (112) by a first gap (118) having a first width (114) exceeding one-fourth of the acoustic wavelength. The method also includes disposing a second reflector (112') to a side of the first transducer (115) opposite the first reflector (112). The first (112) and second (112') reflectors each include a group of periodically disposed reflective elements (113, 113'). The second reflector (112') is separated from the first transducer (115) by a second gap (140) having a second width (139). The method also includes disposing a first waveguiding element (116) having a first breadth (117) within the first gap (118).