Eight-element anti-jam aircraft GPS antennas

An aircraft antenna, comprising:

• a cavity assembly including a conductive upper surface spaced above a conductive lower surface;
• four slot elements, each including a slot in said upper surface configured as a radiating element, said slot elements arrayed around a vertical axis and extending radially relative thereto;
• four bent monopole elements extending above said upper surface and arrayed around said vertical axis, each bent monopole element including an upward-extending first portion and a second portion extending inward toward the vertical axis;
• and
• a coupling assembly coupled to said bent monopole elements:
• (i) to provide 90 degree progressive phase excitation of the bent monopole elements to form a right-hand circularly-polarized omnidirectional antenna pattern;
• (ii) to provide 90 degree progressive phase excitation of the bent monopole elements to form a left-hand circularly-polarized omnidirectional antenna pattern;
• (iii) to provide same phase excitation of the bent monopole elements to form a uniform phase omnidirectional antenna pattern;
• and
• (iv) to provide 180 phase progressive excitation of the bent monopole elements to form a four-lobe antenna pattern.

An aircraft antenna, comprising:

• a cavity assembly including a conductive upper surface spaced above a conductive lower surface;
• a plurality of slot elements, each including a slot in said upper surface configured as a radiating element, said slot elements arrayed around a vertical axis;
• and
• a plurality of bent monopole elements extending above said upper surface and arrayed around said vertical axis, each bent monopole element including an upward-extending first portion and a second portion extending inward toward the vertical axis.

An aircraft antenna, comprising:

• four bent monopole elements arrayed around a vertical axis, each bent monopole element including an upward-extending first portion and a second portion extending inward toward the vertical axis;
• and
• a coupling assembly coupled to said bent monopole elements, the coupling assembly configured to provide:
• (i) 90 degree progressive phase excitation of the bent monopole elements to form a first circularly-polarized omnidirectional antenna pattern;
• and to additionally provide at least one of:
• (ii) 90 degree progressive phase excitation of the bent monopole elements to form a second circularly-polarized omnidirectional antenna pattern;
• (iii) same phase excitation of the bent monopole elements to form a uniform phase omnidirectional antenna pattern;
• and
• (iv) 180 phase progressive excitation of the bent monopole elements to form a four-lobe antenna pattern.

An aircraft antenna, comprising:

• a cavity assembly including a conductive upper surface spaced above a conductive lower surface;
• a plurality of slot elements, each including a slot in said upper surface configured as a radiating element, said slot elements arrayed around a vertical axis;
• and
• a plurality of bent monopole elements extending above said upper surface and arrayed around said vertical axis, each bent monopole element including an upward-extending first portion and a second portion extending inward toward the vertical axis;
• said slot elements arrayed around said vertical axis at successive angular separations of nominally 90 degrees and said bent monopole elements also arrayed around the vertical axis at successive angular separations of nominally 90 degrees.