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:
Aug. 03, 1999
Filed:
Nov. 04, 1997
Applicant:
Inventor:
Richard S Kommrusch, Albuquerque, NM (US);
Assignee:
Motorola Inc., Schaumburg, IL (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03H / ; H03H / ;
U.S. Cl.
CPC ...
333193 ; 3103 / ;
Abstract
An acoustic wave ladder filter (30) with lossy inductances (42) connected in parallel with resonators (40). Shunt sections (36,37) of the ladder filter (30) include impedance inverters having pass frequencies within the stopband of series resonators (33,34,35). The filter (30) additionally includes variable capacitors (44) connected in parallel with the inductances (42) to provide adjustment capabilities. The use of lossy inductances (42) actually increases effective coupling coefficient of the filter (30) and improves insertion loss thereby allowing improved design flexibility.