A feed circuit comprising: first and second polarizers (8a, 8b) each having an output terminal, a first input terminal and a second input terminal, each being configured for outputting, from the output terminal thereof, a signal having polarization whose direction differs between when a signal is inputted to the first input terminal thereof and when a signal is inputted to the second input terminal thereof; a first two-way distributor having a first terminal and a second terminal via each of which a signal is outputted, wherein the first two-way distributor is configured for distributing an input signal to the first terminal and second terminal of the first two-way distributor and for outputting two signals, a second two-way distributor having a first terminal and a second terminal via each of which a signal is outputted, wherein the second two-way distributor is configured for distributing an input signal to the first terminal and second terminal of the second two-way distributor and for outputting two signals, and a third coupler (3c; 3d, 3e) being connected to the second terminal of the first two-way distributor, to the first terminal of the second two-way distributor, to the second input terminal of the first polarizer and to the first input terminal of the second polarizer, and being configured for outputting a signal outputted from the second terminal of the first two-way distributor to the first input terminal of the second polarizer, and being configured for outputting a signal outputted from the first terminal of the second two-way distributor to the second input terminal of the first polarizer, wherein the first terminal of the first two-way distributor is connected to the first input terminal of the first polarizer (8-a); wherein the second terminal of the second two-way distributor is connected to the second input terminal of the second polarizer (8-b); wherein the first two-way distributor, the second two-way distributor and the third coupler (3c; 3d, 3e) are waveguides; and wherein the first two-way distributor is arranged on one side of the third coupler (3c; 3d, 3e) in such a way that a waveguide axial direction of the first two-way distributor which is a propagating direction of a signal is perpendicular to a waveguide axial direction which is a propagating direction of a signal in the third coupler (3c; 3d, 3e), and the second two-way distributor is arranged on another side of the third coupler (3c; 3d, 3e) in such a way that a waveguide axial direction of the second two-way distributor which is a propagating direction of a signal is perpendicular to a waveguide axial direction which is a propagating direction of a signal in the third coupler (3c; 3d, 3e). first and second polarizers (8a, 8b) each having an output terminal, a first input terminal and a second input terminal, each being configured for outputting, from the output terminal thereof, a signal having polarization whose direction differs between when a signal is inputted to the first input terminal thereof and when a signal is inputted to the second input terminal thereof; a first two-way distributor having a first terminal and a second terminal via each of which a signal is outputted, wherein the first two-way distributor is configured for distributing an input signal to the first terminal and second terminal of the first two-way distributor and for outputting two signals, a second two-way distributor having a first terminal and a second terminal via each of which a signal is outputted, wherein the second two-way distributor is configured for distributing an input signal to the first terminal and second terminal of the second two-way distributor and for outputting two signals, and a third coupler (3c; 3d, 3e) being connected to the second terminal of the first two-way distributor, to the first terminal of the second two-way distributor, to the second input terminal of the first polarizer and to the first input terminal of the second polarizer, and being configured for outputting a signal outputted from the second terminal of the first two-way distributor to the first input terminal of the second polarizer, and being configured for outputting a signal outputted from the first terminal of the second two-way distributor to the second input terminal of the first polarizer, wherein the first terminal of the first two-way distributor is connected to the first input terminal of the first polarizer (8-a); wherein the second terminal of the second two-way distributor is connected to the second input terminal of the second polarizer (8-b); wherein the first two-way distributor, the second two-way distributor and the third coupler (3c; 3d, 3e) are waveguides; and wherein the first two-way distributor is arranged on one side of the third coupler (3c; 3d, 3e) in such a way that a waveguide axial direction of the first two-way distributor which is a propagating direction of a signal is perpendicular to a waveguide axial direction which is a propagating direction of a signal in the third coupler (3c; 3d, 3e), and the second two-way distributor is arranged on another side of the third coupler (3c; 3d, 3e) in such a way that a waveguide axial direction of the second two-way distributor which is a propagating direction of a signal is perpendicular to a waveguide axial direction which is a propagating direction of a signal in the third coupler (3c; 3d, 3e).