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. 24, 1984
Filed:
Apr. 12, 1982
Robert J Murray, Horley, GB;
John Schofield, Coulsdon, GB;
U.S. Philips Corporation, New York, NY (US);
Abstract
A surface acoustic wave bandpass electrical filter has double electrode input and output transducers (IP and OP) whose combined amplitude-frequency response has a fundamental passband centered on a frequency f.sub.o and a corresponding third harmonic passband. An interposed multistrip coupler (MSA2) has strips (ST) with a mark-to-space ratio of one-to-one and a center-to-center spacing .lambda..sub.S2 /2 chosen such that f.sub.o /f.sub.S2 is in the range 0.80 to 1.14 but excluding substantially 1.0, whereby a stopband in the amplitude-frequency response of the coupler (MSA2) between 2f.sub.S2 and 4f.sub.S2 suppresses the amplitude-frequency response of the input and output transducers (IP and OP) over a range of frequencies including 3f.sub.o .+-.0.5f.sub.o.