An X, K u , and K-band omni-directional antenna with dielectric loading is disclosed. It comprises a conductor with a loading dielectric resonator and a ground plane. Broad frequency coverage from 7.5 to 26 GHz includes uniform azimuthal coverage from +10 to +70 degrees. The antenna can be used generally in microwave communications including Digital Radio Frequency Tags (DRaFTs) communicating with airborne and satellite platforms.
1. A dielectrically loaded omnidirectional broadband antenna comprising:
a ground plane;
a conductor element wire having a length of 0.387 inch measured from said ground plane to distal end of said conductor element wire and a diameter of 0.050 inch; and
a dielectric resonator having an outer diameter of 0.290 inch, an inner diameter of 0.102 inch, and height of 0.151 inch, whereby said antenna is loaded, and whereby voltage standing wave ratio (VSWR) of said antenna throughout entire range between frequencies of 6 GHz and 26 GHz is between 1.0 and 2.5.
2. The antenna of claim 1 , wherein radiation is in the X, Ku, and K-bands, whereby radiation pattern azimuthal uniformity between +10 and +70 degrees from an axis of said azimuthal uniformity is between +2 dBi to +7 dBi at 7 GHz, −5 dBi to +7 dBi at 9 GHz, −8 dBi to +7 dBi at 15 GHz, and 0 dBi to +7 dBi at 18 GHz, wherein said axis of said azimuthal uniformity is taken to lie along said antenna's axis of symmetry.
3. The antenna of claim 2 , wherein resonant frequency is between entire range of 7.5 GHz and 26 GHz.
4. The antenna of claim 1 , wherein said dielectric resonator is proximate said ground plane.
5. The antenna of claim 1 , wherein said dielectric resonator is in contact with said ground plane.
6. The antenna of claim 1 , wherein said dielectric resonator is a toroid with rectangular cross section of about 99.5 percent pure alumina.
7. The antenna of claim 1 , wherein the relative dielectric constant ∈ r of said dielectric resonator is about 9.7.
8. The antenna of claim 1 , wherein said length of said conductor measured from said ground plane to distal end of said conductor element wire is 0.387 inch.
9. The antenna of claim 1 , wherein said ground plane comprises a copper disk.
10. The antenna of claim 1 , wherein said ground plane diameter is six inches.
11. The antenna of claim 1 , wherein the radiation polarization is about vertical.
12. The antenna of claim 1 , wherein the radiation pattern provides transmit and receive reciprocity.
13. The antenna of claim 1 , wherein the radiation pattern is substantially omnidirectional in the plane of said ground plane.
14. The antenna of claim 1 , wherein the radiation pattern azimuth coverage is uniform between about plus ten and about plus seventy degrees from an axis of azimuthal uniformity, wherein said axis of said azimuthal uniformity is taken to lie along said antenna's axis of symmetry.
15. A dielectrically loaded omnidirectional microwave antenna comprising:
a ground plane;
a conductor element free-standing wire having a length of 0.387 inch measured from said ground plane to distal end of said conductor element free-standing wire and a diameter of 0.050 inch; and
a dielectric resonator having an outer diameter of 0.290 inch, an inner diameter of 0.102 inch and height of 0.151 inch; whereby said antenna is loaded, and whereby voltage standing wave ratio (VSWR) of said antenna throughout entire range between frequencies of 6 GHz and 26 GHz is between 1.0 and 2.5.
16. A microwave frequency tag comprising:
at least one broadband microwave antenna comprising:
a ground plane;
a conductor element wire having a length of 0.387 inch measured from said ground plane to distal end of said conductor element wire and a diameter of 0.050 inch;
a dielectric resonator having an outer diameter of 0.290 inch, an inner diameter of 0.102 inch, and height of 0.151 inch, whereby said antenna is loaded, whereby voltage standing wave ratio (VSWR) of said antenna throughout entire range between frequencies of 6 GHz and 26 GHz is between 1.0 and 2.5; and
circuitry in electrical communication with said antenna whereby said microwave frequency tag communicates with a transceiver.
17. The microwave frequency tag of claim 16 , wherein said tag is associated with personnel.
18. The microwave frequency tag of claim 16 , wherein said tag is associated with vehicles.
19. The microwave frequency tag of claim 16 , wherein said tag is a digital radio frequency tag (DRaFT) communicating with airspaceborne radar.
20. The microwave frequency tag of claim 16 , comprising: two said antennas in close proximity wherein there is less than 1 dB of gain pattern variation in azimuth.