| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive linear channel amplifier including a nonlinear linearizer circuit by controlling the attenuator in a channel amplifier and the output attenuator of a linearlizer and controlling the current for a phase shifter, a distortion generator and a bridge circuit attenuator. SOLUTION: Control function of a channel amplifier 20 comprises the selection of a fixed gain(FG) mode and an automatic gain level control(ALC) mode and a control possible gain, namely, the power level. A linearizer 30 changes the output of the channel amplifier 20, by adding the enlargement of the gain and phase advance (or delay) as the function of the power level, compensates for the gain of a high power amplifier and offsets phase delay (or advance) up to a saturation region and causes is to exceed the region. A control circuit 40 supplies different currents which are temperature-compensated, controls as attenuator 23 in the channel amplifier 20 and an output attenuator 23 in the linearizer 30 and controls current to a phase shifter 34, a distortion generator 35 and a bridge circuit attenuator 36.
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