Provided in the present invention is an electrically tunable antenna feed apparatus, comprising: a cavity and a feed circuit which is accommodated within said cavity, as well as an input port and an output port which are connected to each end of the feed circuit, wherein the feed circuit comprises a first branch circuit, which forms a microwave filter, and a second branch circuit, which forms a blocking capacitor. Further provided in the present invention is a method, comprising the following steps: acquiring a mixed signal comprising radio frequency signals and an electromechanical control signal; filtering out a high-frequency radio frequency signal in the mixed signal so as to output a first separated signal comprising a low-frequency radio frequency signal and the electromechanical control signal; isolating the electromechanical control signal and the low-frequency radio signal in the mixed signal so as to output a second separated signal comprising the high-frequency radio frequency signal; the first separated signal downlinking to a phase shift control module of an antenna; the second separated signal downlinking to a radio frequency module of the antenna. On the basis of said technical solution, the present invention may achieve low intermodulation when a feeder is provided internally.