A reflector antenna, comprising: a feed array, comprising N feeds (a1, b1), wherein N is an integer greater than 1; a reflector, configured to: reflect a signal from the feed array or reflect a signal to the feed array; and M radio frequency channels, wherein each radio frequency channel comprises an adjustable gain amplifier (132a, 132b), configured to control a signal, M is an integer greater than 1 and less than N, each radio frequency channel (13a, 13b) corresponds to one of the N feeds (a1, b1), a correspondence between each radio frequency channel (13a, 13b) and the one feed of the N feeds (a1, b1) is changeable, and each radio frequency channel (13a, 13b) is configured to transmit or receive a signal by using a corresponding feed (a1, b1), wherein the antenna further comprises M single-pole multi-throw switches (14a, 14b), each radio frequency channel (13a, 13b) corresponds to one single-pole multi-throw switch (14a, 14b), each single-pole multi-throw switch (14a, 14b) corresponds to a plurality of feeds (a1, b1), each radio frequency channel (13a, 13b) is connected to a single-pole end of a single-pole multi-throw switch (14a, 14b), the feeds (a1, b1) of the plurality of feeds are connected to multi-throw ends of a single-pole multi-throw switch (14a, 14b), and a correspondence between each radio frequency channel (13a, 13b) and the feeds (a1, b1) is controlled by a single-pole multi-throw (14a, 14b) switch, characterized in that the reflector antenna further comprises a cross waveguide, wherein the N feeds (a1, b1) are connected to the multi-throw ends of the M single-pole multi-throw switches (14a, 14b) by the cross waveguide. a feed array, comprising N feeds (a1, b1), wherein N is an integer greater than 1; a reflector, configured to: reflect a signal from the feed array or reflect a signal to the feed array; and M radio frequency channels, wherein each radio frequency channel comprises an adjustable gain amplifier (132a, 132b), configured to control a signal, M is an integer greater than 1 and less than N, each radio frequency channel (13a, 13b) corresponds to one of the N feeds (a1, b1), a correspondence between each radio frequency channel (13a, 13b) and the one feed of the N feeds (a1, b1) is changeable, and each radio frequency channel (13a, 13b) is configured to transmit or receive a signal by using a corresponding feed (a1, b1), wherein the antenna further comprises M single-pole multi-throw switches (14a, 14b), each radio frequency channel (13a, 13b) corresponds to one single-pole multi-throw switch (14a, 14b), each single-pole multi-throw switch (14a, 14b) corresponds to a plurality of feeds (a1, b1), each radio frequency channel (13a, 13b) is connected to a single-pole end of a single-pole multi-throw switch (14a, 14b), the feeds (a1, b1) of the plurality of feeds are connected to multi-throw ends of a single-pole multi-throw switch (14a, 14b), and a correspondence between each radio frequency channel (13a, 13b) and the feeds (a1, b1) is controlled by a single-pole multi-throw (14a, 14b) switch, characterized in that the reflector antenna further comprises a cross waveguide, wherein the N feeds (a1, b1) are connected to the multi-throw ends of the M single-pole multi-throw switches (14a, 14b) by the cross waveguide.