Impedance matching circuit for radio-frequency amplifier

An impedance matching circuit for an amplifier, the impedance matching circuit comprising:

• a first coil having a first end configured to connect to a voltage source for the amplifier, the first coil having a second end connected to an output of the amplifier;
• a second coil having a first end connected to the second end of the first coil and having a second end connected to an output node, the first coil and the second coil being configured as an autotransformer;
• and
• a capacitor having a first end connected to the second end of the first coil and having a second end connected to at least one of the first end of the first coil, the second end of the second coil, or a ground.

A radio-frequency module comprising:

• a packaging substrate configured to receive a plurality of components;
• an amplifier implemented on the packaging substrate and configured to provide an amplified signal at an output;
• and
• an impedance matching circuit coupled to the output of the amplifier, the impedance matching circuit including a first coil, a second coil, and a capacitor, the first coil and the second coil being configured as an autotransformer, a first end of the first coil configured to connect to a voltage source for the amplifier, a second end of the first coil connected to the output of the amplifier, a first end of the second coil connected to the second end of the first coil, a second end of the second coil connected to an output node, a first end of the capacitor connected to the second end of the first coil, a second end of the capacitor connected to at least one of the first end of the first coil, the second end of the second coil, or a ground.

A wireless device comprising:

• a transceiver configured to generate a signal;
• a front-end module in communication with the transceiver and including an amplifier configured to amplify the signal and provide an amplified signal at an output, the front-end module further including an impedance matching circuit coupled to the output of the amplifier, the impedance matching circuit including a first coil, a second coil, and a capacitor, the first coil and the second coil being configured as an autotransformer, a first end of the first coil configured to connect to a voltage source for the amplifier, a second end of the first coil connected to the output of the amplifier, a first end of the second coil connected to the second end of the first coil, a second end of the second coil connected to an output node, a first end of the capacitor connected to the second end of the first coil, a second end of the capacitor connected to at least one of the first end of the first coil, the second end of the second coil, or a ground;
• and
• an antenna in communication with the front-end module and configured to support transmission of the amplified signal.