“Researchers have made significant strides in the development of a dual-band filtering push‒pull power amplifier. The team designed a filtering power dividing/combining network using a hybrid-mode filtering balun with microstrip line and substrate integrated waveguide. This innovative approach enables the amplifier to achieve a large frequency ratio and effective second-harmonic suppression. The prototype demonstrates excellent performance, with a peak output power of 36.8 dBm at low frequencies and 36 dBm at high frequencies, while maintaining out-of-band spurious rejection.”