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. 21, 2003
Filed:
Jun. 15, 2001
Applicant:
Inventor:
Robert F. Milsom, Redhill, GB;
Assignee:
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03H 9/205 ; H03H 9/56 ;
U.S. Cl.
CPC ...
H03H 9/205 ; H03H 9/56 ;
Abstract
A ladder filter comprises series and shunt resonators ( ). The or each shunt resonator ( ) has a static capacitance which is more than four times the static capacitance of the input or output series resonators ( ). This provides increased shunt resonator capacitance which reduces the effective coupling across the a series-shunt section, thereby enabling a smaller number of series-shunt filter sections to used to achieve good stop-band rejection, while still providing good performance in the pass-band. The invention is based on the recognition that filter bandwidth can be traded for improved out-of-band rejection.