The invention is suitable for the technical field of communications, and particularly relates to a spurious suppression device and method. The device comprises a power
amplifier, a
duplexer and a
harmonic suppression circuit, wherein an output end of the power
amplifier is connected with a transmitting end of the
duplexer; a common port of the
duplexer is connected with an input end of the
harmonic suppression circuit; and the
harmonic suppression circuit is used for controlling
input impedance of the harmonic suppression circuit to be matched with
output impedance of the harmonic suppression circuit, and controlling resonant frequency of the harmonic suppression circuit to be the same as transmitting frequency of a
signal to be transmitted. Through arrangement of the harmonic suppression circuit which is connected with the common port of the duplexer, the
input impedance of the harmonic suppression circuit is controlled to be matched with the
output impedance, and the resonant frequency of the harmonic suppression circuit is controlled to be the same as the transmitting frequency of the
signal to be transmitted, so that the influence of the harmonic suppression circuit on the transmitting frequency of the
signal to be transmitted is relatively small; harmonic signals are attenuated greatly; spurious interference can be reduced; and the receiving sensitivity is increased.