A feed horn comprising: an aperture and a base with a port, wherein the feed horn is configured to communicate in a plurality of separate frequency bands and in a plurality of separate waveguide modes, the feed horn further comprising: a first portion and a second portion, wherein: the first portion is located between the base and the second portion, the first portion comprising a mode conversion section configured to convert a portion of TE 11 mode energy from the port into TM 11 mode energy at high frequencies, the mode conversion section comprising sections having different draft angles, wherein a change in draft angle between two of the sections is configured to cause the mode conversion; and the second portion is located between the first portion and the aperture, characterized by the second portion comprising an axial corrugation geometry having protrusions which extend towards the aperture in a direction parallel to the axis of the feed horn, wherein the second portion of the feed horn is configured to manipulate HE 11 mode energy at low frequencies. an aperture and a base with a port, wherein the feed horn is configured to communicate in a plurality of separate frequency bands and in a plurality of separate waveguide modes, the feed horn further comprising: a first portion and a second portion, wherein: the first portion is located between the base and the second portion, the first portion comprising a mode conversion section configured to convert a portion of TE 11 mode energy from the port into TM 11 mode energy at high frequencies, the mode conversion section comprising sections having different draft angles, wherein a change in draft angle between two of the sections is configured to cause the mode conversion; and the second portion is located between the first portion and the aperture, characterized by the second portion comprising an axial corrugation geometry having protrusions which extend towards the aperture in a direction parallel to the axis of the feed horn, wherein the second portion of the feed horn is configured to manipulate HE 11 mode energy at low frequencies. a first portion and a second portion, wherein: the first portion is located between the base and the second portion, the first portion comprising a mode conversion section configured to convert a portion of TE 11 mode energy from the port into TM 11 mode energy at high frequencies, the mode conversion section comprising sections having different draft angles, wherein a change in draft angle between two of the sections is configured to cause the mode conversion; and the second portion is located between the first portion and the aperture, characterized by the second portion comprising an axial corrugation geometry having protrusions which extend towards the aperture in a direction parallel to the axis of the feed horn, wherein the second portion of the feed horn is configured to manipulate HE 11 mode energy at low frequencies. the first portion is located between the base and the second portion, the first portion comprising a mode conversion section configured to convert a portion of TE 11 mode energy from the port into TM 11 mode energy at high frequencies, the mode conversion section comprising sections having different draft angles, wherein a change in draft angle between two of the sections is configured to cause the mode conversion; and the second portion is located between the first portion and the aperture, characterized by the second portion comprising an axial corrugation geometry having protrusions which extend towards the aperture in a direction parallel to the axis of the feed horn, wherein the second portion of the feed horn is configured to manipulate HE 11 mode energy at low frequencies.