This application provides a phase shifter and an electrically tunable antenna including the phase shifter, where the phase shifter includes a tuning accessory, and the tuning accessory includes a tuning portion for tuning input impedance of the phase shifter. One additional capacitance or inductance parameter is added in the phase shifter by using the tuning portion, to affect input impedance of a port, to further affect a port standing wave, thereby tuning the port standing wave by using the tuning accessory. In addition, the tuning accessory in this application is a molded part with a fixed structure.