Antenna assembly including feed system having a sub-reflector

A parabolic antenna assembly, comprising:

• a main reflector;
• a feed system in RF communication with the main reflector and including a horn and a dielectric portion;
• and
• a sub-reflector in RF communication with the feed assembly, wherein the sub-reflector includes a body portion and a stem portion mechanically coupled to one another, wherein a reflecting surface of the sub-reflector is defined by at least a portion of the body portion and at least a portion of the stem portion, wherein the dielectric portion spaces the sub-reflector from the horn, wherein the sub-reflector includes an axially-symmetric choke for providing virtual continuity at the reflecting surface, wherein the dielectric portion has a first end in contact with the body portion of the sub-reflector, wherein the dielectric portion includes an internal collar at the first end defining an opening therein, and wherein an extending portion of the body portion is received within the opening in the dielectric portion.

A parabolic antenna assembly, comprising:

• a main reflector;
• a feed system in RF communication with the main reflector including a horn and a dielectric portion;
• and
• a sub-reflector in RF communication with the feed assembly, wherein the sub-reflector includes a body portion and a stem portion mechanically coupled to one another, wherein the body portion extends from a first end to a second end and defines a channel extending therein from the second end, wherein a reflecting surface of the sub-reflector is defined by at least a portion of the body portion and at least a portion of the stem portion, wherein the dielectric portion spaces the sub-reflector from the horn, and wherein the sub-reflector includes an axially-symmetric choke for providing virtual continuity at the reflecting surface, wherein the axially-symmetric choke includes a first axial choke portion and a second radial choke portion having a combined length of approximately λ/2 +/− up to 30%, wherein λ is a wavelength of an electromagnetic signal, wherein the first choke portion is defined by the channel and has a length of approximately λ/4 +/− up to 30% and the second choke portion has a length of approximately λ/4 +/− up to 30%.