Carrier superposition device and satellite antenna

The utility model discloses a carrier superposition device and a satellite antenna. The carrier superposition device comprises an upper shell (1), a partition plate (2) and a lower shell (3) which are fixedly connected in sequence, the upper shell (1) is provided with a groove which forms an input resonant cavity (11) with the partition plate (2); the lower shell (3) is provided with a groove which forms an output resonant cavity (31) with the partition plate (2); the device is provided with 2n-1 resonance holes (4) in an array mode. An output power amplifier (6) is arranged at the outer end of the resonance hole (4); the output microwave signal is divided by each stage of output resonance arm, is transmitted by the 2n-1 resonance hole (4) through the output power amplifier (6), is superposed in the space to improve the transmitting power and is transmitted; an input microwave signal is received by the 2n-1 resonance hole (4), is superposed by the output resonance arms at all levels, and is input into the ant