A phased array antenna device, comprising: a distortion compensation unit adapted to compensate distortion of a signal radiated from a phased array antenna by performing distortion compensation processing on a transmission signal using a distortion compensation coefficient; a distribution unit (23, 31) adapted to distribute the transmission signal to which the distortion compensation processing is performed by the distortion compensation unit; a plurality of antenna modules adapted to perform the signal processing steps of: performing adjustment of an amplitude and a phase of the transmission signal distributed by the distribution unit; and amplifying power of the transmission signal, and thereby radiating the transmission signal after the signal processing from an element antenna forming the phased array antenna, and performing adjustment of an amplitude and a phase of a feedback signal by using a part of the transmission signal after the signal processing as the feedback signal such that the phases of feedback signals, each of which is the feedback signal of each of the plurality of antenna modules, is synchronized with each other, and outputting the feedback signal which is adjusted by the adjustment of the amplitude and the phase of the feedback signal; a synthesis unit (24, 32) adapted to synthesize feedback signals each of which is output from each of the plurality of antenna modules to generate a synthesized feedback signal; and a distortion compensation signal output unit adapted to derive, from a difference between the synthesized feedback signal synthesized by the synthesis unit (24, 32) and the transmission signal before the distortion compensation processing by the distortion compensation unit, a distortion compensation coefficient that provides, to the transmission signal, distortion characteristics to be opposite to distortion characteristics of a signal radiated from the phased array antenna and dapted to output the distortion compensation coefficient to the distortion compensation unit, characterized in that the plurality of antenna modules is classified into a plurality of groups in accordance with amplitude distribution provided to suppress side lobes of an antenna pattern in the phased array antenna, and a representative antenna module from among one or more antenna modules belonging to a group having a same amplitude distribution among the plurality of groups is adapted to be switched to output the feedback signal after the adjustment of the amplitude and the phase to the synthesis unit (24, 32), and an antenna module other than the representative antenna module is adapted to be switched to not output the feedback signal to the synthesis unit (24, 32). a distortion compensation unit adapted to compensate distortion of a signal radiated from a phased array antenna by performing distortion compensation processing on a transmission signal using a distortion compensation coefficient; a distribution unit (23, 31) adapted to distribute the transmission signal to which the distortion compensation processing is performed by the distortion compensation unit; a plurality of antenna modules adapted to perform the signal processing steps of: performing adjustment of an amplitude and a phase of the transmission signal distributed by the distribution unit; and amplifying power of the transmission signal, and thereby radiating the transmission signal after the signal processing from an element antenna forming the phased array antenna, and performing adjustment of an amplitude and a phase of a feedback signal by using a part of the transmission signal after the signal processing as the feedback signal such that the phases of feedback signals, each of which is the feedback signal of each of the plurality of antenna modules, is synchronized with each other, and outputting the feedback signal which is adjusted by the adjustment of the amplitude and the phase of the feedback signal; a synthesis unit (24, 32) adapted to synthesize feedback signals each of which is output from each of the plurality of antenna modules to generate a synthesized feedback signal; and a distortion compensation signal output unit adapted to derive, from a difference between the synthesized feedback signal synthesized by the synthesis unit (24, 32) and the transmission signal before the distortion compensation processing by the distortion compensation unit, a distortion compensation coefficient that provides, to the transmission signal, distortion characteristics to be opposite to distortion characteristics of a signal radiated from the phased array antenna and dapted to output the distortion compensation coefficient to the distortion compensation unit, characterized in that the plurality of antenna modules is classified into a plurality of groups in accordance with amplitude distribution provided to suppress side lobes of an antenna pattern in the phased array antenna, and a representative antenna module from among one or more antenna modules belonging to a group having a same amplitude distribution among the plurality of groups is adapted to be switched to output the feedback signal after the adjustment of the amplitude and the phase to the synthesis unit (24, 32), and an antenna module other than the representative antenna module is adapted to be switched to not output the feedback signal to the synthesis unit (24, 32).