Bias control technique for CDMA driver amplifier to decrease current

Abstract

ACPR requirement is constant over wide power range. ACPR at lower output power is excessive in conventional constant bias current. New bias control technique to decrease bias current at lower power level is proposed by implementing hyperbolic tangent function (tanh) with offsets. It is verified indirectly by measurement.The measured bias current is reduced by amount of 22 YO over control range compared to the conventional one, in addition to meet ACPR requirement simultaneously over all range of output power.