| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high frequency power amplifier that keeps gain intact at high temperature by suppressing temperature dependence of gain. <P>SOLUTION: A PTAT current source 20 generates a current I1 having positive temperature dependence, and a VBE-dependent current source 30 generates a current I2 having negative temperature dependence. A current addition/subtraction circuit 40 adds up the current I1 and the current I2 to generate a current I3 having no temperature dependence, subtracts the current I3 from the current I1 to generate a current I4, and subtracts the current I4 from the current I1 to generate a current I5. The current I5 has a temperature characteristic in which the amount of current increases with increasing temperature up to a predetermined temperature and remains temperature-independently constant over the predetermined temperature. The supply of the current I5 to an emitter-grounded amplification circuit 10 can suppress temperature dependence of gain to prevent a sharp drop in gain even at high temperature. <P>COPYRIGHT: (C)2012,JPO&INPIT |
