Broadband tapered monopole antenna
A broadband tapered monopole antenna includes a counterpoise that is oriented horizontally and a planar radiator that is oriented vertically. The planar radiator is bounded by a curved edge extending between first and second vertices, a first edge adjacent to the curved edge, a second edge adjacent to the first edge, and a third edge adjacent to both the second edge and the curved edge. The first edge extends vertically between the second vertex and a third vertex. The second edge extends horizontally between the third vertex and a fourth vertex. The third edge extends vertically between the fourth vertex and the first vertex. A gap width between the curved edge and the planar counterpoise increases monotonically between a minimum gap width at the first vertex and a maximum gap width at the second vertex. The planar radiator has a maximum height that is greater than the maximum gap width.
1 . A broadband tapered monopole antenna, comprising:
a planar counterpoise; and a planar radiator oriented perpendicularly to the planar counterpoise, the planar radiator being bounded by: a curved edge extending between a first vertex and a second vertex, a gap width between the curved edge and the planar counterpoise increasing monotonically between a minimum gap width at the first vertex and a maximum gap width at the second vertex; a first edge extending at least partially between the second vertex and a third vertex, the third vertex having a perpendicular distance to the planar counterpoise that is greater than the maximum gap width; a second edge extending at least partially between the third vertex and a fourth vertex; a third edge extending at least partially between the fourth vertex and a fifth vertex, the fifth vertex having a perpendicular distance to the planar counterpoise that is greater than the minimum gap width, the fourth vertex having a perpendicular distance to the planar counterpoise that is greater than the perpendicular distance to the planar counterpoise of the fifth vertex; and a fourth edge extending at least partially between the fifth vertex and the first vertex; wherein: the planar radiator has a maximum height that is greater than the maximum gap width, the maximum height establishing a fundamental resonant frequency, the planar radiator cooperating with the planar counterpoise to resonantly radiate at the fundamental resonant frequency; the minimum gap width establishes a highest tapered-slot frequency and the maximum gap width establishes a lowest tapered-slot frequency, the planar radiator cooperating with the planar counterpoise to non-resonantly radiate at frequencies between the highest tapered-slot frequency and the lowest tapered-slot frequency; and the lowest tapered-slot frequency is greater than the fundamental resonant frequency.
2 . The broadband tapered monopole antenna of claim 1 , wherein:
the planar radiator cooperates with the planar counterpoise to create a resonance that is centered at the fundamental resonant frequency, the resonance extending between a lower monopole frequency and an upper monopole frequency; and
the lowest tapered-slot frequency is greater than the upper monopole frequency.
3 . The broadband tapered monopole antenna of claim 1 , wherein:
the planar radiator lies in a radiator plane; and
the planar radiator, along the entirety of the curved, first, second, third, and fourth edges, is bounded by a dielectric material in the radiator plane.
4 . The broadband tapered monopole antenna of claim 1 , the fifth vertex having a location such that the third edge and the fourth edge form a single straight line.
5 . The broadband tapered monopole antenna of claim 1 , the perpendicular distance to the planar counterpoise of the fifth vertex being equal to the maximum gap width.
6 . The broadband tapered monopole antenna of claim 1 , wherein:
the planar radiator comprises an upper radiator section bounded by the first edge, the second edge, the third edge, and an internal edge extending between the fifth vertex and the second vertex; and
the broadband tapered monopole antenna further comprises a resistive layer covering at least part of the upper radiator section.
7 . The broadband tapered monopole antenna of claim 6 , the resistive layer fully covering the upper radiator section.
8 . The broadband tapered monopole antenna of claim 6 , the resistive layer only covering said at least part of the upper radiator section.
9 . The broadband tapered monopole antenna of claim 1 , further comprising a dielectric substrate, the planar radiator being located on a face of the substrate.
10 . The broadband tapered monopole antenna of claim 1 , the planar radiator comprising electrically conductive material.
11 . The broadband tapered monopole antenna of claim 10 , the electrically conductive material comprising metal.
12 . The broadband tapered monopole antenna of claim 11 , the metal comprising copper, silver, gold, nickel, tin, or any combination thereof.
13 . The broadband tapered monopole antenna of claim 1 , the second edge being straight.
14 . The broadband tapered monopole antenna of claim 1 , wherein: the perpendicular distance to the planar counterpoise of the third vertex is equal to the perpendicular distance to the planar counterpoise of the fourth vertex such that the second edge is parallel to the planar counterpoise.
15 . The broadband tapered monopole antenna of claim 1 , the first edge being straight.
16 . The broadband tapered monopole antenna of claim 15 , the first edge being oriented perpendicularly to the planar counterpoise.
17 . The broadband tapered monopole antenna of claim 15 , the first edge being oriented non-perpendicularly to the planar counterpoise.
18 . The broadband tapered monopole antenna of claim 1 , the third edge being straight.
19 . The broadband tapered monopole antenna of claim 18 , the third edge being oriented perpendicularly to the planar counterpoise.
20 . The broadband tapered monopole antenna of claim 18 , the third edge being oriented non-perpendicularly to the planar counterpoise.
21 . The broadband tapered monopole antenna of claim 1 , the first and second edges form, at the third vertex, an inside angle of the planar radiator that is greater than ninety degrees.
22 . The broadband tapered monopole antenna of claim 1 , the second and third edges form, at the fourth vertex, an inside angle of the planar radiator that is greater than ninety degrees.