A signal transmitter is provided. The signal transmitter includes a signal splitting module, including M output interfaces, where the signal splitting module is configured to split a signal into N sub-signals, and output the N sub-signals through N of the M output interfaces, where M and N are integers, M≥2, N≥1, and M≥N, an integrated array traveling-wave tube amplifier, including M radio frequency channels, where the M channels one-to-one correspond to the M output interfaces, each channel is configured to perform power amplification on a sub-signal that is output from a corresponding output interface, and each channel is openable and closeable, a power supply module, configured to supply power to the integrated array traveling-wave tube amplifier, and at least one transmit antenna, configured to send a signal obtained through power amplification.