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.

Date of Patent:
Mar. 22, 2011

Filed:

Dec. 18, 2006
Applicants:

Takahiro Sato, Yokohama, JP;

Tsuyoshi Sugiura, Yokohama, JP;

Inventors:

Takahiro Sato, Yokohama, JP;

Tsuyoshi Sugiura, Yokohama, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04L 27/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

A complex coefficient transversal filter using a SAW filter and a complex frequency converter using the complex coefficient transversal filter are provided, in which a first SAW filter receives a real signal as an input signal and generates a real component of a complex signal, and a second SAW filter receives the real signal as an input signal and generates an imaginary component of the complex signal. Accordingly, feed-through waves between the input and output stages can be cancelled, and a phase difference between real and imaginary signals can be maintained at 90° without a phase shift. In addition, when a low-IF frequency converter is implemented using the complex coefficient transversal filter, an image suppression characteristic is improved. When a zero-IF frequency converter is implemented using the complex coefficient transversal filter, an error vector magnitude (EVM) characteristic is improved.


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