Patent Number: 6,801,083

Title: Feedforward amplifier

Abstract: The object of this invention is to provide a feedforward amplifier that performs precise distortion compensation on a plurality of signal groups without adopting broadband frequency-band characteristics for the auxiliary amplifier. This is achieved by inputting a plurality of signal groups, each having a different frequency bandwidth respectively. In a distortion detection loop, a main amplifier 4 is used to amplify this plurality of input signal groups and detect the distortion arising in said main amplifier 4. In a distortion compensation loop the distortion detected in the distortion detection loop is removed from the amplified signal from said main amplifier 4. At this time, the distortion compensation loop has the same number of distortion amplification systems as the number of input signal groups that use the auxiliary amplifiers 12 and 16 to amplify distortion in each input signal group that contains distortion detected by the distortion detection loop, and that removes the sum total of the distortion of each input signal group amplified by this plurality of distortion amplification systems from the amplified signal from the main amplifier 4.

Inventors: Ishigami; Takeshi (Tokyo, JP), Nanao; Yoshinari (Tokyo, JP)

Assignee: Hitachi Kokusai Electric Inc.

International Classification: H03F 1/32 (20060101); H03F 003/66 ()

Expiration Date: 10/02016