Outer sheet harmonic absorbing circuit

The invention discloses an off-chip harmonic wave absorbing circuit for a power amplifier, and belongs to the technical field of communication. The off-chip harmonic wave absorbing circuit is applied to a radio-frequency power amplifier circuit, and is separated from a microwave monolithic integrated circuit (MMIC) of the radio-frequency power amplifier; and the harmonic wave absorbing circuit ismainly realized based on a PCB (printed circuit board), and is formed by connecting a PCB upper microstrip line, a surface mount capacitor element, a PCB upper grounding through hole and a pressure welding gold wire used for connecting an on-chip circuit and an off-chip circuit. The absorbing circuit and the output end of the MMIC are connected in parallel through gold wire connection. Elements in the absorbing circuit are used for generating serial resonance points to absorb the harmonic components generated when the MMIC works. The inductance of the gold wire is changed through flexible control of the length of the gold wire so that the harmonic waves generated in a working frequency band are effectively absorbed, and the linearity of the amplifier circuit is improved.