Patent EA-001583-B1 (EA)
Title: A planar dual-frequency arrey antenna
Inventor: LEVI SHEM-TOV
IPC: H01Q5/42
Filed: 1996-07-04
Abstract: 1. A planar antenna assembly (1, 90, 100) for receiving and transmitting electromagnetic radiation in two frequency bands, said planar antenna assembly comprising, in a layered formation, a first (2, 20) top planar array antenna unit operating in a low frequency band and a second (6, 30) bottom planar array antenna unit operating in a high frequency band,  said first planar array antenna unit comprising a dielectric plate (24, 96, 110), planar array of patches and a feed array; each feed being coupled to a respective one of said patches; each patch being resonant to frequencies in said low frequency band and transparent to frequencies in said high frequency band; said second planar array antenna unit comprising a dielectric plate (34, 99) a ground plane (35), a planar array of patches and a feed array, wherein each feed of being coupled to a respective one of said patches, characterized in that said first planar array antenna unit comprising a ground plane (25, 97) reflecting frequences being in said low frequency band , and transparent to frequencies in said high frequency band. 2. The planar antenna assembly according to claim 1, wherein said second planar array antenna unit comprises a planar array of patches and said feed array being disposed on the front face of said dielectric plate with each feed of said feed array being electrically coupled to a respective one patch of said patches and ground plane (35, 45) being disposed on said rear face of said first dielectric plate. 3. The planar antenna assembly according to claim2, wherein said second planar array antenna unit further comprising a second dielectric plate (46) and a second planar array, said second planar array of patches being disposed on the front face of said second dielectric plate (46), said rear face of said second dielectric plate facing the front face of said first dielectric plate (44) and each patch of said first planar array of patches being substantially aligned with a respective one patch of said patches of said second planar array of patches (47). 4. The planar antenna assembly according to claim 1, wherein said second planar array antenna unit comprises second dielectric plate (56), said first planar array of patches (51) being disposed on the front face of said first dielectric plate (54) and said feed array being disposed on the rear face of said first dielectric plate with each feed (52) of said feed array being electromagnetically coupled to a respective one patch (51) of said patches of said first planar array of patches, said ground plane (55) being disposed on said rear face of said second dielectric plate (56), and the front face of said second dielectric plate facing the rear face of said first dielectric face. 5. The planar antenna assembly according to claim 1, wherein said second planar array antenna unit comprises a second dielectric plate (75), said first planar array of patches (71) being disposed on the front face of said first dielectric plate (74), said ground plane (76) being disposed on said rear face of said first dielectric plate (74), said ground plane having a plurality of apertures, the front face of said second dielectric plate facing the rear face of said first dielectric face and said feed array being disposed on the rear face of said second dielectric plate (75) with each feed of said feed array (72) being electromagnetically coupled to a respective one of said patches (71) of said first planar array of patches via a respective one of said apertures (77) in said ground plane, said apertures being resonant to frequencies in said high frequency band. 6. The planar antenna assembly according to claim 4 or 5, wherein said second planar array antenna unit further comprises a third dielectric plate (57, 78) and a second planar array of patches, said planar array of patches being disposed on the front face of said third dielectric plate, said rear face of said third dielectric plate facing the front face of said first dielectric plate (54, 74) and each patch of said second planar array of patches (58, 79) being substantially aligned with a respective one of said patches of said first planar array of patches (51, 71). 7. The planar antenna assembly according to any of claims 1 to 6, wherein said first planar array (20) antenna unit is a planar arrey of patches and a feed array being disposed on the front face of said dielectric plate, with each feed of said feed array (22, 42) being electrically coupled to a respective one of said patches of said first planar array of patches and a ground plane being disposed on said rear face of said first dielectric plate. 8. The planar antenna assembly according to claim 7, wherein said first planar array antenna unit further comprises a second dielectric plate (46) and a second planar array of patches, said second planar array of patches (47) being disposed on the front face of said second dielectric plate, the rear face of said second dielectric plate facing the front face of said first dielectric plate (44) and patches of the second planar array of patches (47) being substantially aligned with respective to patches (41) of said planar array of patches. 9. The planar antenna assembly according to any of claims 1 to 6, wherein said first planar array antenna unit further comprises a second dielectric plate (56), the first planar array of patches (51) being disposed on the front face of the first dielectric plate (54), said feed array being disposed on the rear face of the first dielectric plate with each feed of said feed array (52) being electromagnetically coupled to a respective one patch (51) of said patches of said first planar array of patches, said ground plane (55) being disposed on the rear face of the second dielectric plate (56), and the front face of said second dielectric plate (56) facing the rear face of said first dielectric plate (54). 10. The planar antenna assembly according to any of claims 1 to 6, wherein said first planar array antenna unit further comprises a second dielectric plate (75), the first planar array of patches (71) being disposed on the front face of the first dielectric plate (74), and the ground plane (76) being disposed on the rear face of the first dielectric plate (74), besides said ground plane having a plurality of apertures (77), the front face of said second dielectric plate (75) facing the rear face of said first dielectric plate (74) and said feed array being disposed on the rear face of said second dielectric plate with each feed of said feed array (72) being electromagnetically coupled to a respective one of said patches (71) of said first planar array of patches via a respective one of said apertures (77) in said ground plane, said apertures being resonant to frequencies in said high frequency band. 11. The planar antenna assembly according to claim 9 or 10, wherein said first planar array antenna unit further comprises a third dielectric plate (78) and a second planar array of patches, said second planar array of patches being disposed on the front face of the third dielectric plate (78), and the rear face of the third dielectric plate facing the front face of the first dielectric plate (74), and each patch of said second planar array of patches (79) being substantially aligned with a respective one patch of said patches (71) of said first planar array of patches. 12. The planar antenna assembly according to any of claims 1 to 6, wherein said first planar array antenna unit further comprises a second dielectric plate (98), the planar array of patches (91) being disposed on the front face of the first dielectric plate (96), and said ground plane (97) being disposed on the rear face of said first dielectric plate (96), said first dielectric plate being spaced from said second dielectric plate so as to form an antenna chamber, said feed array being disposed on the rear face of said second dielectric plate (98) with each feed (92) of said feed array being electrically coupled to a respective one of said patches (91) of said first planar array of patches by a plurality of feed probes (95) and said second planar antenna unit being located within said antenna chamber. 13. The planar antenna assembly according to claim 12, wherein said first planar array antenna unit further comprises a third dielectric plate (110) and a second planar array of patches, said second planar array of patches being disposed on the front face of the third dielectric plate, and the rear face of the third dielectric plate facing the front face of the first dielectric plate112and each patch of said second planar array of patches (112) being substantially aligned with a respective one patch of said patches (91) of said first planar array of patches. 14. The planar antenna assembly according to any one of claims 7 to 11, wherein said first and second planar antenna units are separated by a dielectric plate (4) with front and rear faces, said front and rear faces of said dielectric plate facing said first and second planar antenna units respectively. 15. The planar antenna assembly according to either of claims 112 or 13, wherein said second planar antenna unit is located within said antenna chamber, with a dielectric plate interposed between said second antenna unit and said ground plane of said first antenna unit. 16. The planar antenna assembly according to any of the preceding claims, wherein said first planar array antenna unit is designed for the reception and transmission of circularly polarized electromagnetic radiation and is characterized in that: said at least one array of patches of said first planar array antenna unit is grouped into 2.times.2 patch subarrays (220, 260, 290, 300) having each in clockwise or counter-clockwise sequence first, second, third and fourth (222, 262, 292, 91) subarray members; said feeds of said feed array of said first planar array antenna unit are grouped into 2.times.2 feed subarrays having each in clockwise or counter