Low-profile CTS flat-plate array antenna

Abstract

A low-profile CTS flat-plate array antenna includes a radiating layer, a mode switching layer and a feed network layer which are sequentially arrayed from top to bottom. The mode switching layer comprises a first metal plate and a mode switching cavity array arranged on an upper surface of the first metal plate and comprising 2.sup.2n mode switching cavities arrayed in 2.sup.n rows and 2.sup.n columns, wherein n is an integer greater than or equal to 1. Each mode switching cavity includes a first rectangular cavity, a second rectangular cavity, a third rectangular cavity, a fourth rectangular cavity and a fifth rectangular cavity which are sequentially connected from left to right. The 2.sup.n mode switching cavities located in each row are sequentially connected end to end.

Claims

1. A low-profile CTS flat-plate array antenna, comprising a radiating layer, a mode switching layer and a feed network layer which are sequentially arrayed from top to bottom, wherein the mode switching layer comprises a first metal plate and a mode switching cavity array arranged on an upper surface of the first metal plate, the mode switching cavity array comprises 2.sup.2n mode switching cavities which are arrayed in 2.sup.n rows and 2.sup.n columns, n is an integer greater than or equal to 1, and the 2.sup.n mode switching cavities located in each row are sequentially connected end to end; each said mode switching cavity comprises a first rectangular cavity, a second rectangular cavity, a third rectangular cavity, a fourth rectangular cavity and a fifth rectangular cavity which are sequentially connected from left to right, wherein the first rectangular cavity, the second rectangular cavity, the third rectangular cavity, the fourth rectangular cavity and the fifth rectangular cavity have long edges in a row direction of the mode switching cavity array and wide edges in a column direction of the mode switching cavity array; with a center of the first rectangular cavity as a baseline, a center of the second rectangular cavity deviates forwards relative to the center of the first rectangular cavity; a front long edge of the second rectangular cavity extends beyond a front long edge of the first rectangular cavity, a center of the third rectangular cavity and the center of the first rectangular cavity are located on a same line and are parallel to the long edges of the first rectangular cavity, the fourth rectangular cavity and the second rectangular cavity are symmetrical with respect to the center of the third rectangular cavity, and the fifth rectangular cavity and the first rectangular cavity are symmetrical with respect to the center of the third rectangular cavity; the first rectangular cavity, the second rectangular cavity, the third rectangular cavity, the fourth rectangular cavity and the fifth rectangular cavity are formed by rectangular grooves formed in the upper surface of the first metal plate, heights of the first rectangular cavity, the second rectangular cavity, the third rectangular cavity, the fourth rectangular cavity and the fifth rectangular cavity are equal and are smaller than a height of the first metal plate; a width of the first rectangular cavity is smaller than that of the third rectangular cavity, a width of the third rectangular cavity is smaller than that of the second rectangular cavity, a width of the second rectangular cavity is smaller than half of a wavelength, a width of the fifth rectangular cavity is equal to that of the first rectangular cavity, and a width of the fourth rectangular cavity is equal to that of the second rectangular cavity; a lower surface of the first metal plate is provided with 2.sup.2n input ports which are arrayed in 2.sup.2n rows and 2.sup.2n columns, formed by rectangular grooves formed in the lower surface of the first metal plate and vertically communicated with the 2.sup.2n mode switching cavities in a one-to-one correspondence manner; as for each said input port and the mode switching cavity correspondingly communicated with the input port, a vertical central axis of the input port overlaps a vertical central axis of the third rectangular cavity of the mode switching cavity, long edges of the input port are parallel to the long edges of the third rectangular cavity and are shorter than the long edges of the third rectangular cavity, and wide edges of the input port are parallel to the wide edges of the third rectangular cavity and are narrower than the wide edges of the third rectangular cavity; a center distance between the input port in the k.sup.th row and the j.sup.th column and the input port in the k.sup.th row and the (j+1).sup.th column ranges from 0.8 time of the wavelength to 1.2 times of the wavelength, and the center distance between the input port in the k.sup.th row and the j.sup.th column and the input port in the (k+1).sup.th row and the j.sup.th column ranges from 0.8 time of the wavelength to 1.2 times of the wavelength, wherein k=1, 2, 3, . . . , and 2.sup.n, and j=1, 2, 3, . . . , and 2.sup.n.

2. The low-profile CTS flat-plate array antenna according to claim 1, wherein the feed network layer comprises a second metal plate, 4.sup.n H-type single ridge waveguide power dividers and a first E-plane waveguide power divider, the 4.sup.n H-type single ridge waveguide power dividers and the first E-plane waveguide power divider are arranged on the second metal plate, and n is an integer greater than or equal to 1; each said H-type single ridge waveguide power divider has an input terminal and four output terminals; the 4.sup.n H-type single ridge waveguide power dividers are evenly distributed in k rows and k columns to form a first-stage feed network array, wherein k={square root over (4.sup.n)}; starting from a first row and a first column, the H-type single ridge waveguide power dividers in every two rows and every two columns form a first-stage H-type single ridge waveguide power dividing network unit of the first-stage feed network array, the first-stage feed network array comprises 4.sup.n1 said first-stage H-type single ridge waveguide power dividing network units, input terminals of the four H-type single ridge waveguide power dividers in each said first-stage H-type single ridge waveguide power dividing network unit are connected through an H-type single ridge waveguide power divider; a second-stage feed network array including j rows and j columns is formed by the H-type single ridge waveguide power dividers used for connecting the input terminals of the four H-type single ridge waveguide power dividers in each of the 4.sup.n1 first-stage H-type single ridge waveguide power dividing network unit, wherein j={square root over (4.sup.n1)}; starting from the first row and the first column, the H-type single ridge waveguide power dividers in every two rows and every two columns form a second-stage H-type single ridge waveguide power dividing network unit of the second-stage feed network array, the second-stage feed network array comprises 4.sup.n2 said second-stage H-type single ridge waveguide power dividing network units, and the input terminals of the four H-type single ridge waveguide power dividers in each said second-stage H-type single ridge waveguide power dividing network unit are connected through an H-type single ridge waveguide power divider; in this way, an (n1).sup.th-stage H-type single ridge waveguide power dividing network unit including only four of said H-type single ridge waveguide power dividers is formed, wherein the input terminals of the four H-type single ridge waveguide power dividers of the (n1).sup.th-stage H-type single ridge waveguide power dividing network unit are connected through an H-type single ridge waveguide power divider, two output terminals of the first E-plane waveguide power divider are connected with the input terminal of one of the four H-type single ridge waveguide power dividers in the (n1).sup.th-stage H-type single ridge waveguide power dividing network unit, and an input terminal of the first E-plane waveguide power divider is an input terminal of the low-profile CTS flat-plate array antenna; the four output terminals of each of the four H-type single ridge waveguide power divider in the first-stage feed network array are provided with a single ridge waveguide-rectangular waveguide converter.

3. The low-profile CTS flat-plate array antenna according to claim 2, wherein each said single ridge waveguide-rectangular waveguide converter comprises a first rectangular metal block, a sixth rectangular cavity is formed in the first rectangular metal block, a first E-plane step and a first H-plane step are arranged in the sixth rectangular cavity, the first E-plane step is rectangular, a height of the first E-plane step is smaller than that of the sixth rectangular cavity, a lower end face of the first E-plane step is attached to a lower end face of the sixth rectangular cavity, a front end face of the first E-plane step is attached to a front end face of the sixth rectangular cavity, a rear end face of the first E-plane step is attached to a rear end face of the sixth rectangular cavity, a left end face of the first E-plane step is attached to a left end face of the sixth rectangular cavity, a rear end face of the first H-plane step is attached to the rear end face of the sixth rectangular cavity, a right end face of the first H-plane step is attached to a right end face of the sixth rectangular cavity, a lower end face of the first H-plane step is attached to the lower end face of the sixth rectangular cavity, a height of the first H-plane step is equal to that of the sixth rectangular cavity, a rectangular waveguide output port communicated with the sixth rectangular cavity is formed in an upper surface of the first rectangular metal block, a single ridge waveguide input port is formed in a front end face of the first rectangular metal block and communicated with the sixth rectangular cavity, a height of the single ridge waveguide input port is equal to that of the sixth rectangular cavity, a bottom surface of the single ridge waveguide input port and a bottom surface of the sixth rectangular cavity are located on a same plane, a left end face of the single ridge waveguide input port is flush with a right end face of the first E-plane step, and a right end face of the single ridge waveguide input port is flush with the right end face of the sixth rectangular cavity; a first ridge step extending onto the bottom surface of the sixth rectangular cavity is arranged on the bottom surface of the single ridge waveguide input port and comprises a first rectangular ridge and a second rectangular ridge which are sequentially connected, a height of the first rectangular ridge is greater than that of the second rectangular bridge and is smaller than that of the sixth rectangular cavity, a front end face of the first rectangular ridge is flush with a front end face of the single ridge waveguide input port, a rear end face of the first rectangular ridge is flush with a rear end face of the single ridge waveguide input port, the rear end face of the first rectangular ridge is attached to a front end face of the second rectangular ridge, a left end face of the first rectangular ridge is flush with a left end face of the second rectangular ridge, a right end face of the first rectangular ridge is flush with a right end face of the second rectangular ridge, a distance from the left end face of the first rectangular ridge to the right end face of the first E-plane step is equal to a distance from the right end face of the first rectangular ridge to the right end face of the sixth rectangular cavity, a rear end face of the second rectangular ridge is spaced from the first H-plane step by a certain distance, and the right end face of the first rectangular ridge is flush with a left end face of the first H-plane step.

4. The low-profile CTS flat-plate array antenna according to claim 1, wherein the radiating layer comprises a first radiating unit and a second radiating unit, the first radiating unit comprises a third metal plate and 2.sup.n second E-plane waveguide power dividers arranged on the third metal plate, the 2.sup.n second E-plane waveguide power dividers are arrayed in 2.sup.n rows and in 1 column, each said second E-plane waveguide power divider has an input terminal and two output terminals, distances between the second E-plane waveguide power dividers in every two adjacent rows are equal, the input terminal of the second E-plane waveguide power divider in the h.sup.th row is communicated with 2.sup.n mode switching cavities in the h.sup.th row, and a center line of the input terminal of the second E-plane waveguide power divider in the h.sup.th row in the row direction and center lines of the 2.sup.n mode switching cavities in the h.sup.th row in the row direction are located on a same plane which is perpendicular to the third metal plate, wherein h=1, 2, 3, . . . , 2.sup.n; the second radiating unit comprises a fourth metal plate and 2.sup.n+1 E-plane step horns arranged on the fourth metal plate, wherein the 2.sup.n+1 E-plane step horns are arrayed in 2.sup.n+1 rows and in 1 column, each said E-plane step horn has an input terminal and an output terminal, distances between the E-plane step horns in every two adjacent rows are equal, and output terminals of the 2.sup.n+1 E-plane step horns are communicated with the two output terminals of each of the 2.sup.n second E-plane waveguide power dividers in a one-to-one correspondence manner.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an exploded view of a low-profile CTS flat-plate array antenna of the invention;

(2) FIG. 2 is a partial sectional view of the low-profile CTS flat-plate array antenna of the invention;

(3) FIG. 3 is a top view of a mode switching layer of the low-profile CTS flat-plate array antenna of the invention;

(4) FIG. 4 is a structural view of a mode switching cavity of the low-profile CTS flat-plate array antenna of the invention;

(5) FIG. 5 is a bottom view of the mode switching layer of the low-profile CTS flat-plate array antenna of the invention;

(6) FIG. 6 is a top view of a feed network layer of the low-profile CTS flat-plate array antenna of the invention;

(7) FIG. 7 is a perspective view of a single ridge waveguide-rectangular waveguide converter of the low-profile CTS flat-plate array antenna of the invention; and

(8) FIG. 8 is an exploded view of the single ridge waveguide-rectangular waveguide converter of the low-profile CTS flat-plate array antenna of the invention.

DESCRIPTION OF THE EMBODIMENTS

(9) The invention is further expounded below with reference to the accompanying drawings and embodiments.

Embodiment

(10) As shown in the figures, a low-profile CTS flat-plate array antenna comprises a radiating layer, a mode switching layer and a feed network layer which are sequentially arrayed from top to bottom. The mode switching layer comprises a first metal plate 1 and a mode switching cavity array arranged on an upper surface of the first metal plate 1. The mode switching cavity array comprises 2.sup.2n mode switching cavities 2 which are arrayed in 2.sup.n rows and 2.sup.n columns, wherein n is an integer greater than or equal to 1, and the 2.sup.n mode switching cavities 2 located in each row are sequentially connected end to end. Each mode switching cavity 2 comprises a first rectangular cavity 3, a second rectangular cavity 4, a third rectangular cavity 5, a fourth rectangular cavity 6 and a fifth rectangular cavity 7 which are sequentially connected from left to right. The first rectangular cavity 3, the second rectangular cavity 4, the third rectangular cavity 5, the fourth rectangular cavity 6 and the fifth rectangular cavity 7 have long edges in a row direction of the mode switching cavity array and wide edges in the column direction of the mode switching cavity array. With a center of the first rectangular cavity 3 as a baseline, a center of the second rectangular cavity 4 deviates forwards relative to the center of the first rectangular cavity 3. A front long edge of the second rectangular cavity 4 extends beyond a front long edge of the first rectangular cavity 3, a center of the third rectangular cavity 5 and the center of the first rectangular cavity 3 are located on a same line and are parallel to the long edges of the first rectangular cavity 3, the fourth rectangular cavity 6 and the second rectangular cavity 4 are symmetrical with respect to the center of the third rectangular cavity 5, and the fifth rectangular cavity 7 and the first rectangular cavity 3 are symmetrical with respect to the center of the third rectangular cavity 5; the first rectangular cavity 3, the second rectangular cavity 4, the third rectangular cavity 5, the fourth rectangular cavity 6 and the fifth rectangular cavity 7 are formed by rectangular grooves formed in the upper surface of the first metal plate 1, heights of the first rectangular cavity 3, the second rectangular cavity 4, the third rectangular cavity 5, the fourth rectangular cavity 6 and the fifth rectangular cavity 7 are equal and are smaller than a height of the first metal plate 1. A width of the first rectangular cavity 3 is smaller than that of the third rectangular cavity 5, a width of the third rectangular cavity 5 is smaller than that of the second rectangular cavity 4, a width of the second rectangular cavity 4 is smaller than half of a wavelength, a width of the fifth rectangular cavity 7 is equal to that of the first rectangular cavity 3, and a width of the fourth rectangular cavity 6 is equal to that of the second rectangular cavity 4. A lower surface of the first metal plate 1 is provided with 2.sup.2n input ports 8 which are arrayed in 2.sup.2n rows and 2.sup.2n columns, formed by rectangular grooves formed in the lower surface of the first metal plate 1 and vertically communicated with the 2.sup.2n mode switching cavities 2 in a one-to-one correspondence manner. As for each input port 8 and the mode switching cavity 2 correspondingly communicated with the input port 8, a vertical central axis of the input port 8 overlaps a vertical central axis of the third rectangular cavity 5 in the mode switching cavity 2, long edges of the input port 8 are parallel to the long edges of the third rectangular cavities 5 and are shorter than the long edges of the third rectangular cavity 5, and wide edges of the input port 8 are parallel to the wide edges of the third rectangular cavity 5 and are narrower than the wide edges of the third rectangular cavity 5. A center distance between the input port 8 in the k.sup.th row and the j.sup.th column and the input port 8 in the k.sup.th row and the (j+1).sup.th column ranges from 0.8 time of the wavelength to 1.2 times of the wavelength, and the center distance between the input port 8 in the k.sup.th row and the j.sup.th column and the input port in the (k+1).sup.th row and the j.sup.th column ranges from 0.8 time of the wavelength to 1.2 times of the wavelength, wherein k=1, 2, 3, . . . , and 2.sup.n, and j=1, 2, 3, . . . , and 2.sup.n.

(11) In this embodiment, the feed network layer comprises a second metal plate 9, 4.sup.n H-type single ridge waveguide power divider 10 and a first E-plane waveguide power divider 11. The 4.sup.n H-type single ridge waveguide power divider 10 and the first E-plane waveguide power divider 11 are arranged on the second metal plate 9, and n is an integer greater than or equal to 1. Each H-type single ridge waveguide power divider 10 has an input terminal and four output terminals. The 4.sup.n H-type single ridge waveguide power dividers 10 are evenly distributed in k rows and k columns to form a first-stage feed network array, wherein k={square root over (4.sup.n)}. Starting from a first row and a first column, the H-type single ridge waveguide power dividers 10 in every two rows and every two columns form a first-stage H-type single ridge waveguide power dividing network unit of the first-stage feed network array. The first-stage feed network array comprises 4.sup.n1 first-stage H-type single ridge waveguide power dividing network units. The input terminals of the four H-type single ridge waveguide power dividers 10 in each first-stage H-type single ridge waveguide power dividing network unit are connected through an H-type single ridge waveguide power divider. A second-stage feed network array including j rows and j columns is formed by the H-type single ridge waveguide power dividers used for connecting the input terminals of the four H-type single ridge waveguide power dividers 10 in each of the 4.sup.n1 first-stage H-type single ridge waveguide power dividing network units, wherein j={square root over (4.sup.n1)}. Starting from the first row and the first column, the H-type single ridge waveguide power dividers in every two rows and every two columns form a second-stage H-type single ridge waveguide power dividing network unit of the second-stage feed network array. The second-stage feed network array comprises 4.sup.n2 second-stage H-type single ridge waveguide power dividing network units. The input terminals of the four H-type single ridge waveguide power dividers in each second-stage H-type single ridge waveguide power dividing network unit are connected through an H-type single ridge waveguide power divider. In this way, an (n1).sup.th-stage H-type single ridge waveguide power dividing network unit including only four H-type single ridge waveguide power dividers is formed. The input terminals of the four H-type single ridge waveguide power dividers of the (n1).sup.th-stage H-type single ridge waveguide power dividing network unit are connected through an H-type single ridge waveguide power divider, two output terminals of the first E-plane waveguide power divider 11 are connected with the input terminal of one of the four H-type single ridge waveguide power dividers in the (n1).sup.th-stage H-type single ridge waveguide power dividing network unit, and an input terminal of the first E-plane waveguide power divider 11 is an input terminal of the low-profile CTS flat-plate array antenna. The four output terminals of each H-type single ridge waveguide power divider 10 in the first-stage feed network array are provided with a single ridge waveguide-rectangular waveguide converter 12.

(12) In this embodiment, each single ridge waveguide-rectangular waveguide converter 12 comprises a first rectangular metal block 13. A sixth rectangular cavity 14 is formed in the first rectangular metal block 13, a first E-plane step 15 and a first H-plane step 16 are arranged in the sixth rectangular cavity 14, the first E-plane step 15 is rectangular, a height of the first E-plane step 15 is smaller than that of the sixth rectangular cavity 14, a lower end face of the first E-plane step 15 is attached to a lower end face of the sixth rectangular cavity 14, a front end face of the first E-plane step 15 is attached to a front end face of the sixth rectangular cavity 14, a rear end face of the first E-plane step 15 is attached to a rear end face of the sixth rectangular cavity 14, a left end face of the first E-plane step 15 is attached to the front end face of the sixth rectangular cavity 14, a rear end face of the first H-plane step 16 is attached to the rear end face of the sixth rectangular cavity 14, a right end face of the first H-plane step 16 is attached to a right end face of the sixth rectangular cavity 14, a lower end face of the first H-plane step 16 is attached to the lower end face of the sixth rectangular cavity 14, a height of the first H-plane step 16 is equal to that of the sixth rectangular cavity 14, a rectangular waveguide output port 24 communicated with the sixth rectangular cavity 14 is formed in an upper surface of the first rectangular metal block 13, a single ridge waveguide input port 17 is formed in a front end face of the first rectangular metal block 13 and communicated with the sixth rectangular cavity 14, a height of the single ridge waveguide input port 17 is equal to that of the sixth rectangular cavity 14, a bottom surface of the single ridge waveguide input port 17 and a bottom surface of the sixth rectangular cavity 14 are located on a same plane, a left end face of the single ridge waveguide input port 17 is flush with a right end face of the first E-plane step 15, and a right end face of the single ridge waveguide input port 17 is flush with the right end face of the sixth rectangular cavity 14. A first ridge step extending onto the bottom surface of the sixth rectangular cavity 14 is arranged on the bottom surface of the single ridge waveguide input port 17 and comprises a first rectangular ridge 18 and a second rectangular ridge 19 which are sequentially connected, a height of the first rectangular ridge 18 is greater than that of the second rectangular bridge 19 and is smaller than that of the sixth rectangular cavity 14, a front end face of the first rectangular ridge 18 is flush with a front end face of the single ridge waveguide input port 17, a rear end face of the first rectangular ridge 18 is flush with a rear end face of the single ridge waveguide input port 17, the rear end face of the first rectangular ridge 18 is attached to a front end face of the second rectangular ridge 19, a left end face of the first rectangular ridge 18 is flush with a left end face of the second rectangular ridge 19, a right end face of the first rectangular ridge 18 is flush with a right end face of the second rectangular ridge 19, a distance from the left end face of the first rectangular ridge 18 to the right end face of the first E-plane step 15 is equal to a distance from the right end face of the first rectangular ridge 18 to the right end face of the sixth rectangular cavity 14, a rear end face of the second rectangular ridge 19 is spaced from the first H-plane step 16 by a certain distance, and the right end face of the first rectangular ridge 18 is flush with a left end face of the first H-plane step 16.

(13) In this embodiment, the radiating layer comprises a first radiating unit and a second radiating unit. The first radiating unit comprises a third metal plate 20 and 2.sup.n second E-plane waveguide power dividers 21 arranged on the third metal plate 20. The 2.sup.n second E-plane waveguide power dividers 21 are arrayed in 2.sup.n rows and in 1 column, each second E-plane waveguide power divider 21 has an input terminal and two output terminals, distances between the second E-plane waveguide power dividers 21 in every two adjacent rows are equal, the input terminal of the second E-plane waveguide power divider 21 in the h.sup.th row is communicated with the 2.sup.n mode switching cavities 2 in the h.sup.th row, and a center line of the input terminal of the second E-plane waveguide power divider 21 in the h.sup.th row in the row direction and center lines of the 2.sup.n mode switching cavities 2 in the h.sup.th row in the row direction are located on a same plane which is perpendicular to the third metal plate 20, wherein h=1, 2, 3, . . . , 2.sup.n. The second radiating unit comprises a fourth metal plate 22 and 2.sup.n+1 E-plane step horns 23 arranged on the fourth metal plate 22. The 2.sup.n+1 E-plane step horns 23 are arrayed in 2.sup.n+1 rows and in 1 column, each E-plane step horn 23 has an input terminal and an output terminal, distances between the E-plane step horns 23 in every two adjacent rows are equal, and output terminals of the 2.sup.n+1 E-plane step horns 23 are communicated with the two output terminals of each of the 2.sup.n second E-plane waveguide power dividers 21 in a one-to-one correspondence manner.

(14) In this embodiment, the H-type single ridge waveguide power dividers, the first E-plane waveguide power dividers 11, the second E-plane waveguide power dividers 21 and the E-plane step horns 23 are all mature products in corresponding technical fields.