Multi frequency stacked patch antenna with improved frequency band isolation

A stacked patch antenna assembly comprising:

• a first group of patch antennas comprising a plurality of patch antennas arranged in a stack, each said antenna having a respective operating frequency band, and each antenna comprising a radiating conductive patch;
• a first cable comprising a plurality of separate, coaxial conductors;
• wherein a first conductor of said first cable is conductively coupled to said radiating conductive patch of an uppermost one of said antennas and passes through apertures at null points of the other ones of said antennas, said other ones of said antennas in said stack coupled to another one of said plurality of conductors of said cable, said first conductor carrying a feed signal for said uppermost antenna;
• and
• wherein each of said plurality of patch antennas other than said uppermost antenna is fed by a different cable;
• a second group of patch antennas comprising at least one patch antenna having a radiating conductive patch, each antenna of said second group corresponding to one of said antennas of said first group and being inductively coupled to said feed conductor of said corresponding antenna of said first group through said radiating patch of said corresponding antenna of said first group.

A stacked patch antenna assembly comprising:

• a first cable comprising at least first and second coaxial conductors separated from each other by a dielectric;
• a first patch antenna having a first operating frequency band, said first antenna comprising a first radiating conductive patch, said patch conductively coupled to said first coaxial conductor of said first cable, said first coaxial conductor acting as a feed conductor for said first patch antenna;
• a second patch antenna below said first patch antenna having a second operating frequency band, said second antenna comprising a second radiating conductive patch and having an aperture through its null point through which said first conductor of said first cable passes without conductively contacting said second radiating patch, said second antenna inductively coupled to said first conductor of said first cable through said first radiating patch of said first antenna, said first coaxial conductor also acting as a feed conductor for said second patch antenna;
• a third patch antenna below said second patch antenna having a third operating frequency band, said third antenna comprising a third radiating conductive patch and having an aperture through its null point through which said first cable passes without said first conductor thereof conductively contacting said third radiating patch;
• a fourth patch antenna below said third patch antenna having a fourth operating frequency band, said fourth antenna comprising a fourth radiating conductive patch and having an aperture through its null point through which said first cable passes without said first conductor thereof conductively contacting said third radiating patch;
• a ground plane beneath said fourth antenna;
• and
• a second feed conductor conductively coupled to said third patch and inductively coupled to said fourth patch through said third patch, said second feed conductor carrying feed signals for said third and fourth antennas;
• wherein said second coaxial conductor of said first cable is conductively coupled to said ground plane and to said null point of at least one of said third and fourth radiating patches.