In a wireless communication device, baseband variable gain amplifiers amplify a baseband signal. Mixers convert the amplified baseband signal into a high-frequency transmission signal. Hybrid variable gain amplifiers amplify an in-phase local signal and an orthogonal local signal which are input to the mixers. The level detection controller changes respective gains of the baseband variable gain amplifiers and the hybrid variable gain amplifiers, in response to power of the high-frequency transmission signal.