A radio frequency power amplifier 1 includes a former-stage transistor 2,
a latter-stage transistor 3, and an inter-stage matching circuit 4 for
connecting the former-stage transistor 2 and the latter-stage transistor
3. The inter-stage matching circuit 4 includes a high-pass filter circuit
including a transfer line m1, a capacitor C1 and a capacitor C2; and a
transfer line m2 with which a passage phase of a secondary harmonic
signal is 15 degrees or greater.