Oblon, Spivak, McClelland, Maier & Neustadt, P.C.
Feed forward amplifier for multiple frequency bands
The present invention has for its object to provide, in an environment where plural radio systems coexist, a feed forward amplifier for multiple frequency bands, capable of adaptively selecting the frequency band which is used.The feed forward amplifier of the present invention comprises a distortion detection circuit and a distortion elimination circuit and has first and second variable frequency band extractors 25a and 25b provided in series with respective vector adjustment paths 21a and 21b. Also, the feed forward amplifier comprises a frequency band controller which varies the frequency band of variable frequency band extractors 25a and 25b and has been designed, by changing the frequency band of first and second variable frequency band extractors 25a and 25b in response to a frequency switching request from the outside, to be able to adaptively control the frequency band in which distortion is compensated.
NTT DoCoMo, Inc.
H
H03F
inventional
Yasunori Shoichi
Suzuki Narahashi