Title:
LINEAR POWER AMPLIFIER USING ACTIVE BIAS TO IMPROVE EFFICIENCY AND METHOD THEREFOR
Document Type and Number:
Japanese Patent JPH09181533
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide the bias circuit for a doherty-type amplifier which is capable of preventing negative pinch off voltage from generating and executing an operation with high efficiency. SOLUTION: A doherty-type active bias power amplifier 90 which is suitable for a satellite electric communication system performs the linear amplification of a noisy RF input signal 100 having plural carrier waves diffusing to a large instantaneous band width. As the RF input signal 100 for the active bias power amplifier 90 is increased, negative pinch off voltage normally generating negative voltage in a gate/base is not generated within a carrier wave amplifier 115. Therefore, a dynamic RF input driving range in which the improvement of RF output power is attained and an operation with high efficiency can be performed is increased. By the active bias, the proper bias on point of a peaking amplifier 135 is obtained and an operation with maximum RF efficiency is realized.
Inventors:
BAANAADO YUUJIIN SHIGUMON
ROBAATO MITSUSHIERU JIYAKUSON
ROBAATO MITSUSHIERU JIYAKUSON
Application Number:
JP33890496A
Publication Date:
July 11, 1997
Filing Date:
December 03, 1996
Export Citation:
Assignee:
MOTOROLA INC
International Classes:
H03F1/02; H03F1/07; H03F3/21; H03F3/20; H03F3/60; H03F3/68; (IPC1-7): H03F1/02; H03F3/20
Attorney, Agent or Firm:
Shinsuke Onuki (1 person outside)
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