DUAL-POLARIZED DUAL-BAND BROAD BEAMWIDTH DIRECTIVE PATCH ANTENNA
An antenna architecture with a dual-band patch antenna structure having a broadened low-frequency beamwidth is disclosed. The dual band antenna structure comprises a high frequency patch antenna cavity stacked inline above a low frequency patch antenna cavity. An N-shaped metallic wall surrounds the low frequency patch antenna cavity and broadens the emission radiation beamwidth of the low frequency emission. As such, these dual band antenna structures can emit radiation with a beamwidth of approximately 90 degrees in the low frequency band of 700 MHz to 900 MHz as well as the high frequency band of 1.7 GHz to 2.2 GHz.
1 . An antenna radiating structure, comprising:
a first patch radiating element;
a second patch radiating element configured above and spaced apart from said first patch radiating element in a radiating direction; and
a metallic perimeter structure, configured around the edges of said first and second patch radiating elements, comprising at least first, second and third wall sections extending generally in the radiating direction and wherein at least two of the wall sections are angled relative to each other.
2 . The antenna radiating structure as set out in claim 1 , wherein said metallic perimeter structure is recessed from the top surface of said second patch radiating element.
3 . The antenna radiating structure as set out in claim 2 , wherein the third wall section extends further in the radiating direction than said first and second wall sections.
4 . The antenna radiating structure as set out in claim 1 , wherein said first wall section is configured with one end positioned in close proximity to said first patch radiating element and the other end extending in the radiating direction is oriented away from said first patch radiating element, wherein said second wall section is configured with one end coupled to the first wall section and the other end of said second wall section is oriented generally away from the radiating direction, and wherein said third wall section is configured with one end coupled to the second wall and the other end of said third section is oriented generally in the radiating direction.
5 . The antenna radiating structure as set out in claim 4 , wherein said metallic perimeter structure in cross section is approximately in the shape of the letter “N” to form a continuous N-shaped wall.
6 . The antenna radiating structure as set out in claim 1 , wherein said first patch radiating element has a planar surface with a surface normal perpendicular thereto and wherein at least one of the wall sections has a planar surface oriented at an angle of a few degrees relative to the surface normal of said first patch radiating element.
7 . The antenna radiating structure as set out in claim 6 , wherein said first and third wall sections each have a planar surface oriented at an angle of a few degrees relative to the surface normal of said first patch radiating element and oriented away from the first patch radiating element and wherein said second wall section has a planar surface oriented at an angle of a few degrees relative to the surface normal of said first patch radiating element and oriented toward the first patch radiating element.
8 . The antenna radiating structure as set out in claim 7 , wherein the planar surfaces of said first and second wall sections are substantially parallel.
9 . The antenna radiating structure as set out in claim 5 , wherein the N-shaped wall has four sides around the perimeter of the first patch radiating element, wherein the length of each side of the N-shaped wall measured in the direction parallel to the surface of the patch radiating element is approximately one half of the radiation emission wavelength.
10 . The antenna radiating structure as set out in claim 5 , further comprising a a metallic partial enclosure having a cavity containing the first and second patch radiating elements and wherein the height of the N-shaped wall in the radiating direction is in the range of approximately 0.5 to approximately 0.75 of the distance of said first patch radiating element above the bottom of said cavity.
11 . The antenna radiating structure as set out in claim 5 , wherein the radiation emission is in the range of approximately 700 MHz to approximately 900 MHz.
12 . An antenna radiating structure, comprising:
a low-frequency patch antenna structure;
a high-frequency patch antenna structure, wherein said high-frequency patch antenna structure is positioned above said low frequency patch antenna structure in a radiating direction; and
a metallic perimeter structure, configured around the edges of said low-frequency patch antenna structure, including one or more walls oriented at an angle to the radiating direction.
13 . The antenna radiating structure as set out in claim 12 , wherein said high-frequency patch antenna structure comprises:
a first high-frequency generally planar radiating element; and
a second high-frequency generally planar radiating element configured above and spaced apart from said first high-frequency generally planar radiating element in the radiating direction.
14 . The antenna radiating structure as set out in claim 13 , wherein said low-frequency patch antenna structure comprises:
a first low-frequency generally planar radiating element; and
a second low-frequency generally planar radiating element configured above and spaced apart from said first low-frequency generally planar radiating element in the radiating direction.
15 . The antenna radiating structure as set out in claim 14 , wherein said metallic perimeter structure is below the top surface of said second high-frequency generally planar radiating element.
16 . The antenna radiating structure as set out in claim 15 , wherein said metallic perimeter structure comprises at least first, second and third wall sections extending generally in the radiating direction and wherein at least two of the wall sections are angled relative to each other.
17 . The antenna radiating structure as set out in claim 16 , wherein said metallic perimeter is approximately in the shape of the letter “N” to form an N-shaped wall.
18 . The antenna radiating structure as set out in claim 14 , further comprising a metallic partial enclosure having a high-frequency cavity containing the first and second high-frequency generally planar radiating elements and a low-frequency cavity containing the first and second low-frequency generally planar radiating elements, wherein said high-frequency cavity extends partially into said low-frequency cavity.
19 . The antenna radiating structure as set out in claim 18 , wherein the radiation emission in the low-frequency band is in the range of approximately 700 MHz to approximately 900 MHz wherein the radiation emission in the high-frequency band is in the range of approximately 1.7 GHz to 2.2 GHz.
20 . An antenna array, comprising:
a ground plane;
first and second dual band antenna structures coupled to the ground plane, each comprising:
a low-frequency patch antenna structure;
a high-frequency patch antenna structure, wherein said high-frequency patch antenna structure is positioned above said low frequency patch antenna structure in a radiating direction; and
a metallic perimeter structure, configured around the edges of said low-frequency patch antenna structure, including one or more walls oriented at an angle to the radiating direction; and
a high band antenna structure configured on the ground plane between said first and second dual band antenna structures.