Global navigation satellite system antenna with a hollow core

An antenna comprising:

• a conductive cylindrical tube having:
• a longitudinal axis;
• an inner surface having a first inner diameter;
• and
• an outer surface having a first outer diameter;
• a ground plane, wherein:
• the ground plane comprises a first annulus having:
• a first circular inner periphery having a second inner diameter;
• and
• a first circular outer periphery having a second outer diameter;
• the ground plane is orthogonal to the longitudinal axis;
• and
• the first circular inner periphery is electrically connected to the outer surface;
• a low-frequency radiator, wherein:
• the low-frequency radiator comprises a second annulus having:
• a second circular inner periphery having a third inner diameter;
• and
• a second circular outer periphery having a third outer diameter;
• the low-frequency radiator is orthogonal to the longitudinal axis;
• the second circular inner periphery is electrically connected to the outer surface;
• the low-frequency radiator is spaced apart from the ground plane;
• and
• a low-frequency radiating gap is configured between the second circular outer periphery and the ground plane;
• a high-frequency radiator, wherein:
• the high-frequency radiator comprises a third annulus having:
• a third circular inner periphery having a fourth inner diameter;
• and
• a third circular outer periphery having a fourth outer diameter;
• the high-frequency radiator is orthogonal to the longitudinal axis;
• the high-frequency radiator is spaced apart from the low-frequency radiator such that the low-frequency radiator is disposed between the high-frequency radiator and the ground plane;
• the third circular outer periphery is electrically connected to the low-frequency radiator;
• and
• a high-frequency radiating gap is configured between the third circular inner periphery and the outer surface;
• and
• a set of high-frequency capacitive elements, wherein:
• the set of high-frequency capacitive elements is spaced apart from the high-frequency radiator;
• each high-frequency capacitive element in the set of high-frequency capacitive elements has a first end and a second end;
• and
• the first end of each high-frequency capacitive element is electrically connected to the outer surface.