Omni-dualband antenna and system

A dual band, omnidirectional antenna comprising:

• a first array having an elongated, substantially planar first substrate with spaced, oppositely facing first and second sides, a first feed structure with flat, conductive first and second feed lines extending longitudinally along said first and second sides of said first substrate, respectively, a plurality of spaced, linearly arranged, conductive, flat, bifurcated dipole first portions on said first side of said first substrate and serially connected to said first feed line, and a plurality of spaced, linearly arranged, conductive, flat, bifurcated dipole second portions on said second side of said first substrate and serially connected to said second feed line, said first portions being aligned with said second portions to form first elements, said first elements having a first frequency band,
• a second array having an elongated, substantially planar second substrate with spaced, oppositely facing first and second sides, a second feed structure with conductive first and second feed lines extending longitudinally along said first and second sides of said second substrate, respectively, a plurality of spaced, linearly arranged, conductive, bifurcated dipole first portions on said first side of said second substrate and serially connected to said first feed line, and a plurality of spaced, linearly arranged, conductive, bifurcated dipole second portions on said second side of said second substrate and serially connected to said second feed line, said first portions being aligned with said second portions to form second elements, said second elements having a second frequency band that is higher than said first frequency band, said second substrate being aligned with, parallel to, and spaced a selected first distance from said first substrate,
• a third array having an elongated, substantially planar third substrate with spaced, oppositely facing first and second sides, and a plurality of conductive , flat, linearly arranged parasitic third elements on one of said first and second sides, said third substrate being aligned with, parallel to and spaced, opposite said first substrate, a selected second distance from said second substrate
• a plurality of first spacers that extend from said second side of said first substrate to said first side of said second substrate to maintain said first distance,
• a plurality of second spacers that extend from said second side of said second substrate to said first side of said third substrate to maintain said second distance, and
• a diplexer connected to said first and second feed structures to provide common connection of said first and second arrays to a transmission line,
• whereby said first array has an omnidirectional radiation pattern at said first frequency band and said second array has an omnidirectional radiation pattern at said second frequency band.

A dual band, omnidirectional antenna system comprising:

• a dual band, omnidirectional antenna including;
• a first array having a plurality of linearly arranged first elements with a first frequency band and a first feed structure connecting said first elements, said first array being substantially in a first plane,
• a second array having a plurality of linearly arranged second elements with a second frequency band and a second feed structure connecting said second elements, said second array being aligned with said first array and substantially in a second plane that is parallel to and spaced a selected first distance from said first plane, and
• a third array having a plurality of linearly arranged parasitic third elements, said third array being aligned with said second array .and substantially in a third plane that is parallel to and spaced, opposite said first plane, a selected second distance from said second plane, and
• a diplexer connected to said first and second feed structures, and
• a radome having an elongated, cylindrical radome tube, an upper end cap attached over an upper end of said tube, and a lower end cap attached over a lower end of said tube, said radome being sized and shaped to fit over said antenna with said diplexer at said lower end cap, said radome including a connector connected to said diplexer and extending through said lower end cap to provide common connection of said first and second arrays to a transmission line,
• whereby said first array has an omnidirectional radiation pattern at said first frequency band and said second array has an omnidirectional radiation pattern at said second frequency band.