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. 29, 2000
Filed:
Oct. 09, 1997
Yuji Kakuta, Tokyo, JP;
Yoshiaki Fukasawa, Tokyo, JP;
Yasuhiro Shirakawa, Tokyo, JP;
Yoshiaki Wakabayashi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An input transformer, used as a transmission-line transformer (11), is provided for connection between an unbalanced transmission line (10) and a balanced broadband amplifier (12), in which the input transformer has a fixed middle potential. The transmission-line transformer (11) converts an input signal into two output signals having opposite phase with respect to each other and which are supplied to the broadband amplifier (12). It is therefore possible to cancel secondary distortion in an amplifying unit. As the transmission-line transformer (11) a forced-balun type transmission-line transformer is used which has two input ports (P1, P2) and three output ports (P3, P4, P5), one (P4) of which is grounded. First and second two-wire parallel lines are arranged between the input ports and the output ports via a single glasses-shaped core. The input port and the two output ports have a respective impedance ratio of 1:(1/2):(1/2).