Patent ID: 8358172

Claim:
A peaking circuit for adjusting peaking of a high-frequency signal, comprising: a first inductor; a second inductor which is electromagnetically coupled with the first inductor; a signal input section which receives an input signal; a transistor which adjusts electric current passing through the second inductor, with the input signal in a predetermined high frequency range inputted via the signal input section, in accordance with an amount of electric current applied to the transistor from a variable current source; and a signal output section which outputs a signal whose peaking has been adjusted by the first inductor, wherein: mutual inductance of the electromagnetically coupled first and second inductors is changed by the adjustment of the electric current passing through the second inductor, according to the amount of electric current applied from the variable current source to the transistor, thereby adjusting the peaking of signal waveform of electric current passing through the first inductor to improve gain drops in the high-frequency range, and the signal subjected to the peaking adjustment is outputted from the signal output section.