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:
Apr. 04, 2000
Filed:
Nov. 26, 1997
Mitsutaka Hikita, Hachioji, JP;
Chisaki Takubo, Hachioji, JP;
Nobuhiko Shibagaki, Kodaira, JP;
Kazuyuki Sakiyama, Chigasaki, JP;
Hitachi, Ltd., , JP;
Abstract
A surface acoustic wave signal processing apparatus for processing first and second high-frequency signals having frequencies f.sub.1 and f.sub.2 respectively, which comprises: first and second surface acoustic wave delay elements for receiving the first and second high-frequency signals respectively and independently of each other, the delay elements being formed as surface acoustic wave excitation and reception transducers on a piezoelectric substrate so that a phase delay .phi..sub.1 with respect to the frequency f.sub.1 is substantially equal to a phase delay .phi..sub.2 with respect to the frequency f.sub.2 (that is, .phi..sub.1 .apprxeq..phi..sub.2); and a mixer for mixing first and second high-frequency output signals of the first and second surface acoustic wave delay elements so that a signal having a frequency .vertline.f.sub.1 -f.sub.2 .vertline. which is a difference between the two frequencies f.sub.1 and f.sub.2 is taken out as an output signal of the mixer.