Planar end fire antenna for wideband low form factor applications
An end-fire antenna for wideband low form factor applications includes a first metal layer, a second metal layer, and a dielectric layer disposed between the first and second metal layers. An open cavity formed in the dielectric layer that is filled with air, the cavity defined by a pair of sidewalls that extend from an aperture of the cavity to a rear wall of the cavity, where the depth of the aperture is defined between the aperture and the rear wall. The cavity is formed by selecting the width of the aperture of the cavity and the depth of the cavity such that the antenna achieves the same gain during operation irrespective of a variation in the thickness of the antenna.
1. An end-fire antenna comprising:
a first metal layer;
a second metal layer;
a dielectric layer disposed between the first and second metal layers; and
an open cavity formed in the dielectric layer filled with air, the cavity defined by a pair of sidewalls that extend from an aperture of the cavity to a rear wall of the cavity, a depth of the cavity defined between the aperture and the rear wall, the side walls extending at an angle such that the cavity has a tapered shape defined by a taper angle between the side walls.
2. The end-fire antenna of claim 1 wherein a width of the aperture is greater than a width of the rear wall.
3. The end-fire antenna of claim 2 wherein the taper angle is between about 0 and 15 degrees.
4. The end-fire antenna of claim 3 wherein the taper angle is about 11 degrees.
5. The end-fire antenna of claim 1 wherein the cavity is rectangular and the sidewalls are generally parallel to each other.
6. The end-fire antenna of claim 1 wherein the antenna has a thickness of between about 100 microns and about 1 mm.
7. The end-fire antenna of claim 6 wherein the antenna has a thickness of between about 200 microns and about 400 microns.
8. The end-fire antenna of claim 7 wherein the antenna has a width of about 5 mm and a length of about 2.5 mm.
9. An antenna structure comprising:
an array of a plurality of end-fire antennas, each antenna having a first metal layer, a second metal layer, a dielectric layer disposed between the first and second metal layers, and an open cavity formed in the dielectric layer filled with air, the cavity defined by a pair of sidewalls that extend from an aperture of the cavity to a rear wall of the cavity, a depth of the cavity defined between the aperture and the rear wall.
10. Then antenna structure of claim 9 , wherein the plurality of end-fire antennas are arranged in a single row.
11. The antenna structure of claim 9 wherein the plurality of end-fire antennas are arranged in a plurality of rows and columns such that at least one of the antennas is stacked on another of the antennas.
12. The antenna structure of claim 11 wherein the array is a 2×2 array of antennas.
13. The antenna structure of claim 9 wherein the side walls extend at an angle and a width of the aperture is greater than a width of the rear wall, such that the cavity has a tapered shape defined by a taper angle between the side walls.
14. The antenna structure of claim 13 wherein the taper angle is between about 0 and 15 degrees.
15. A radiofrequency module comprising:
a printed circuit board; and
an end-fire antenna connected to the printed circuit board, the end-fire antenna defined by a dielectric layer disposed between a pair of metal layers and an open cavity formed in the dielectric layer filled with air, the cavity defined by a pair of sidewalls that extend from an aperture of the cavity to a rear wall of the cavity, a depth of the cavity defined between the aperture and the rear wall.
16. The radiofrequency module of claim 15 wherein the side walls extend at an angle and a width of the aperture is greater than a width of the rear wall, such that the cavity has a tapered shape defined by a taper angle between the side walls.
17. The radiofrequency module of claim 16 wherein the taper angle is between about 0 and 15 degrees.
18. The radiofrequency module of claim 17 wherein the taper angle is about 11 degrees.
19. The radiofrequency module of claim 15 wherein the cavity is rectangular and the sidewalls are generally parallel to each other.
20. The end-fire antenna of claim 15 wherein the antenna has a thickness of between about 100 microns and about 1 mm.
21. The radiofrequency module of claim 20 wherein the antenna has a thickness of between about 200 microns and about 400 microns.
22. The radiofrequency module of claim 15 wherein the antenna has a width of about 5 mm and a length of about 2.5 mm.
23. A wireless mobile device comprising:
an end-fire antenna defined by a dielectric layer disposed between a pair of metal layers and an open cavity formed in the dielectric layer filled with air, the cavity defined by a pair of sidewalls that extend from an aperture of the cavity to a rear wall of the cavity, a depth of the cavity defined between the aperture and the rear wall.
24. The wireless mobile device of claim 23 wherein the side walls extend at an angle and a width of the aperture is greater than a width of the rear wall, such that the cavity has a tapered shape defined by a taper angle between the side walls.
25. The wireless mobile device of claim 24 wherein the taper angle is between about 0 and 15 degrees.
26. The wireless mobile device of claim 25 wherein the taper angle is about 11 degrees.
27. The wireless mobile device of claim 23 wherein the cavity is rectangular and the sidewalls are generally parallel to each other.
28. The end-fire antenna of claim 23 wherein the antenna has a thickness of between about 100 microns and about 1 mm.
29. The wireless mobile device of claim 28 wherein the antenna has a thickness of between about 200 microns and about 400 microns.
30. The wireless mobile device of claim 23 wherein the antenna has a width of about 5 mm and a length of about 2.5 mm.