CN112134013A - A Broadband Dual-Polarized Phased Array Antenna Based on Dielectric Integrated Cavity - Google Patents

Abstract

The invention discloses a broadband dual-polarization phased array antenna based on a dielectric integrated cavity, which relates to the field of wireless communication technology, the field of radar technology, and in particular to the field of phased array antennas for grid-shaped cavity in communication systems . The antenna layout of the invention is simple and compact, and the grid-shaped cavity layout enables the phased array antenna to have high consistency of two polarizations, excellent radiation performance, and good port isolation; the feeding structure is simple, thereby avoiding complex feeding networks. . The structure of the dielectric integrated cavity further reduces the weight of the antenna, and enables the radiation aperture of the entire antenna to be fabricated using the PCB process, which is easy to process and assemble, and facilitates direct integration with the RF front-end.

Description

A Broadband Dual-Polarized Phased Array Antenna Based on Dielectric Integrated Cavity

technical field

The invention relates to the technical field of wireless communication, the technical field of radar, and in particular to the field of phased array antennas used for grid-shaped cavities in communication systems.

Background technique

In the past few decades, broadband dual-polarized phased array antennas have received increasing attention in the military and commercial fields, and are widely used in systems such as multi-function radar, weather monitoring, and aviation control, especially military carrier platforms for high-performance multi- The need for functional (surveillance, identification, target tracking) radar systems has prompted the rapid development of broadband dual-polarized phased array antennas. In the context of this application, broadband, dual polarization, low profile, and light weight are the main design criteria for the antenna. Antennas with broadband characteristics are beneficial to the radar system to achieve multi-task and multi-target cooperative work; dual-polarization characteristics are beneficial to realize polarization multiplexing and polarization agility, and improve the anti-interference ability and sensitivity of the system. Therefore, it is very beneficial to realize broadband and dual polarization under a single antenna array aperture. In the traditional broadband dual-polarization phased array antenna design method, firstly, in order to avoid grating lobes in the scanning space, the size of the antenna element must meet the condition of no grating lobes. Design difficulty. Secondly, since a single dual-polarized phased array element has two orthogonally arranged polarization ports, the two polarization ports need to work independently to avoid mutual interference as much as possible, so the improvement of polarization isolation is also due to dual-polarization phase control. important issues to be considered in the design of array antennas. Finally, when the size of the small array element satisfies the condition of no grating lobes, the mutual coupling between the array elements will be very strong, which seriously affects the scanning performance of the array element. Even if the antenna array unit has good broadband impedance matching at the side-fire angle, in the case of large-angle scanning, the array elements often have serious impedance mismatch due to the change of the mutual coupling pattern between the array elements. How to suppress the array elements Mutual coupling has always been one of the main challenges in the design of traditional phased array antennas.

In recent years, the new idea of using the coupling between antenna elements to realize broadband phased array antennas has attracted extensive attention and in-depth research by relevant scholars in the field of international antennas. The theoretical basis of this idea is the continuous current surface theory proposed by Professor Wheeler in 1965. Professor Wheeler stated in the paper entitled "Simple Relations Derived from a Phased-Array Antenna Made of an Infinite Current Sheet" in the journal IEEE Transactions on Antennas and Propagation. This theory is explained in detail.

In 2003, Professor B. Munk of Ohio State University first proposed a new type of broadband phased array using coupling between antenna elements in the US Patent No. 6512487 "Wideband Phased Array Antenna and Associated Methods". array. Its characteristic is that coupling capacitors are added between the dipole units, and the strong mutual coupling effect between the units is used to form a continuous current, which overcomes the limitation of the mutual coupling effect on the antenna bandwidth and scanning angle. In practical applications, the feed network of the dual-polarized strongly coupled dipole phased array antenna needs to be carefully designed to avoid cross-polarization radiation and polarization isolation degradation caused by the feed network. In addition, in order to avoid common mode resonance caused by unbalanced feeding of dipoles, shorting probes or other complex suppression measures are usually required. Therefore, the structure of the feed network of the dual-polarized strongly coupled dipole array is complex, which increases the size, profile and cost of the entire antenna system.

In the Chinese patent with the application number CN201610945580.0 "A Phased Array Antenna Based on Connection Cavity", a broadband phased array antenna designed based on the continuous current surface theory is proposed, which uses a microstrip feeder to excite the connection cavity body to form continuous equivalent magnetic current radiation, which effectively increases the working bandwidth of the antenna. However, this antenna needs to open a long slot on its metal floor to form a connection cavity, and the antenna radiation aperture cannot be made entirely by the PCB process, which is inconvenient to directly integrate with the RF front-end.

SUMMARY OF THE INVENTION

Aiming at the problems existing in the prior art, the present invention provides a design that avoids complex feeding networks, the radiation aperture can be made entirely by the PCB process, is easy to integrate, convenient to process and assemble, and has wideband, low profile, high polarization isolation, low Dual-polarized phased array antenna with cross-polarization ratio and excellent scanning performance characteristics.

In order to achieve the above purpose, the present invention adopts the following technical scheme: a broadband dual-polarized phased array antenna based on a dielectric integrated cavity, the phased array antenna includes, from bottom to top, a lower dielectric substrate 101 and a middle dielectric substrate 102 , the upper dielectric substrate 103;

A plurality of metal patches 109 are arranged in an array on the upper surface of the lower dielectric substrate 101, and a circle of metallized vias 110 are arranged around the inner edge of the metal patches 109. The upper end of the metallized vias 110 is connected to the lower dielectric substrate 101 The upper surface of the metal patch 109 is flush with the lower surface of the lower dielectric substrate 101; the metal patch 109 is provided with two coaxial joint inner cores 108: the vertical polarization coaxial joint inner core and the horizontal polarization coaxial joint inner core core, the upper end of the inner core 108 of the coaxial connector is flush with the upper surface of the middle-layer dielectric substrate 102, and the lower end protrudes from the lower-layer dielectric substrate 101, and is connected to the external equipment of the broadband dual-polarized phased array antenna, the inner core of the coaxial connector 108 is not in contact with the metal patch 109;

The upper surface of the middle-layer dielectric substrate 102 is provided with a plurality of elongated vertically polarized microstrip feeders 106 and elongated horizontally polarized microstrip feeders 105; one end of each vertically polarized microstrip feeder 106 is connected to a vertical The upper end of the inner core of the polarized coaxial joint, the other end of the vertically polarized microstrip feed line 106 extends to the corresponding top of the adjacent metal patch 109 in the vertical direction; one end of each horizontally polarized microstrip feed line 105 is connected to a corresponding one The upper end of the inner core of the horizontally polarized coaxial joint, the other end of the horizontally polarized microstrip feed line 105 extends to the corresponding top of the adjacent metal patch 109 along the horizontal direction;

The upper surface of the upper dielectric substrate 103 is provided with a mesh metal patch 107. The mesh metal patch 107 includes multiple rows of patches in the vertical direction and multiple rows of patches in the horizontal direction. Including multiple sets of metal strips, each set of metal strips is not in contact, and each set of metal strips includes three parallel identical metal strips; the two ends of the three metal strips in each set are respectively located in two adjacent pieces A set of metal strips are provided above the corresponding tops of the metal patches 109, and on the corresponding tops of all adjacent metal patches 109;

A dielectric integrated cavity 104 is formed between the metallized vias 110 of the adjacent metal patches 109 of the lower dielectric substrate 101, and a cross-shaped dielectric integrated cavity 104 and the four adjacent metal patches 109 are formed. The three-layer structure corresponding to the cross-shaped dielectric integrated cavity 104 constitutes a basic antenna unit.

Further, the height of the metallized via hole 110 is 0.02-0.2 λ _low , λ _low is the free space wavelength at the low frequency end, and the gap width between adjacent metal patches 109 is 0.02-0.2 λ _low ; the lower dielectric substrate 101 A dielectric integrated cavity 104 is formed between the metallized vias 110 of adjacent metal patches 109, and the direction between adjacent metal patches 109 is the width direction of the dielectric integrated cavity 104; The centerlines in the width direction of the dielectric integrated cavity 104 are separated by _{0.02-0.2λlow} ; the lengths of the horizontally polarized microstrip feeder 105 and the vertically polarized microstrip feeder 106 are _{0.05-0.4λlow} ; the relative dielectric of the upper dielectric substrate 103 The constant is between 1 and 3.5, and the thickness is 0.01 to 0.1λ _low ; the upper dielectric substrate 103 is directly covered on the middle layer dielectric substrate 102 or placed at a position less than 0.1λ _low from the upper surface of the middle layer dielectric substrate 102; a single metal The strips have a length of 0.1 to _0.4λlow and a width of 0.005 to _0.1λlow .

Further, the vertically polarized microstrip feed line 106 and the horizontally polarized microstrip feed line 105 have exactly the same shape, and are long strips with wide ends at both ends and narrow in the middle, and the width of the feed end is narrower than that of the coupling end.

Further, the metal patch 109 is a square or quasi-square; the quasi-square structure is that each side of the square is divided into three sections protruding outward, and the included angle between each section is greater than 160° and less than 180°.

Further, the broadband dual-polarized phased array antenna is in the shape of a flat plate or a plane arc.

The beneficial effects of the invention are as follows: the antenna layout is simple and compact, and the grid-shaped cavity layout enables the phased array antenna to have high consistency of two polarizations, excellent radiation performance, and good port isolation; complex feed network. The structure of the dielectric integrated cavity further reduces the weight of the antenna, and enables the radiation aperture of the entire antenna to be fabricated using the PCB process, which is easy to process and assemble, and facilitates direct integration with the RF front-end.

Description of drawings

FIG. 1 is an exploded schematic diagram of the structure of a planar broadband dual-polarized phased array antenna based on a dielectric integrated cavity in Embodiment 1. As shown in FIG.

Figure 2 is a multi-view of a basic antenna unit, wherein (a) is a schematic diagram of the upper surface of the upper dielectric substrate, (b) is a side cross-sectional view, (c) is a schematic diagram of the upper surface of the middle dielectric substrate, and (d) is the lower dielectric substrate Schematic diagram of the upper surface of the substrate.

3 is a schematic structural diagram of the broadband dual-polarized phased array antenna of the present invention when it is in the shape of a flat plate arc, wherein (a) is a three-dimensional diagram of a flat plate arc array, (b) is a plan view of the flat plate arc array, and (c) is a flat plate arc Front view of the shape array.

FIG. 4 is a schematic diagram when the metal patch on the upper surface of the lower dielectric substrate is square.

FIG. 5 is a schematic diagram when the metal patch on the upper surface of the lower dielectric substrate is quasi-square.

FIG. 6 is a diagram showing the simulation result of the active voltage standing wave ratio according to Embodiment 1 of the present invention.

FIG. 7 is a diagram showing a simulation result of port isolation according to Embodiment 1 of the present invention.

FIG. 8 is a diagram showing a simulation result of an active voltage standing wave ratio according to Embodiment 2 of the present invention.

FIG. 9 is a simulation result diagram of an active voltage standing wave ratio according to Embodiment 3 of the present invention.

Detailed ways

Example 1

The flat panel array form of broadband dual-polarized phased array antenna based on a dielectric integrated cavity in this embodiment is divided into three layers as shown in FIG. The middle-layer dielectric substrate 102 of the horizontally polarized microstrip feeder 105 and the vertically polarized microstrip feeder 106, the upper-layer dielectric substrate 103 printed with the mesh metal patch 107; the thickness of the lower-layer dielectric substrate 101 is 3 mm, and the relative permittivity is 3 , the metal patch 109 and metallized vias 110 arranged periodically in the dielectric substrate form a grid-shaped dielectric integrated cavity 104 with a depth of 3 mm and a width of 5 mm; the relative dielectric constant of the intermediate dielectric substrate 102 is 2.2 and the thickness is 0.25 mm. , the upper surface of which is printed with a horizontally polarized microstrip feeder 105 and a vertically polarized microstrip feeder 106; the relative dielectric constant of the upper dielectric substrate 103 is 2.2, the thickness is 2.5 mm, and the upper surface is printed with a mesh metal patch 107; two The inner core 108 of the coaxial joint passes through the lower dielectric substrate 101 and the middle dielectric substrate 102 and is connected to the horizontally polarized microstrip feeder 105 and the vertically polarized microstrip feeder 106, respectively, and feeds; the midpoint of the adjacent metal patch 109 The distance between them is 12.5mm; the size of each metal strip in the mesh metal patch is 7mm × 0.7 mm, and the spacing between the metal strips in the same direction is 2 mm; the working frequency band of this embodiment is 7.5-12.5 GHz, the array height is 0.24 times the high-frequency 12.5 GHz free-space wavelength, and features a low profile.

FIG. 2 is a schematic diagram of a basic antenna unit after the broadband dual-polarization phased array antenna of the present invention is divided into units, which is convenient for observing the positional relationship between the elements of each layer. Figure (a) is a schematic diagram of the upper surface of the upper dielectric substrate 103 of the basic antenna unit, Figure (b) is a side cross-sectional view of the basic antenna unit, Figure (c) is a schematic diagram of the upper surface of the middle layer dielectric substrate 102 of the basic antenna unit, Figure (d) It is a schematic diagram of the upper surface of the lower dielectric substrate 101 of the basic antenna unit; it can be seen that the metal strip is directly above the dielectric integrated cavity 104; the horizontally polarized microstrip feeder 105 and the vertically polarized microstrip feeder 106 span the adjacent Two metal patches 109 .

FIG. 3 is a schematic structural diagram of the broadband dual-polarized phased array antenna of the present invention when it is in the shape of a flat plate arc. Figure (a) is a three-dimensional view of the flat plate arc array, Figure (b) is a top view of the flat plate arc array, and Figure (c) is a front view of the flat plate arc array.

FIG. 4 is a schematic diagram when the metal patch on the upper surface of the lower dielectric substrate is square.

FIG. 5 is a schematic diagram when the metal patch on the upper surface of the lower dielectric substrate is quasi-square. The square-like structure is to divide each side of the square into three protruding sections, and the included angle between each section is greater than 160° and less than 180°.

FIG. 6 shows the simulation results of the variation of the active voltage standing wave ratio of the horizontally polarized port with the frequency of the array unit in the embodiment 1 under different scanning angles. It can be seen that in the scanning range of ±60°, the impedance bandwidth of the active VSWR less than 2 is greater than 50%. Due to the symmetry of the array element structure, the simulation results of the scanning performance of the polarization of the element have good consistency.

FIG. 7 shows the simulation results of the variation of the port isolation with the frequency of the array unit in Example 1 under different scanning angles. It can be seen from this that the isolation of the two orthogonally polarized ports in the array unit is less than -20dB within the ±60° scanning range. It can be seen from the above simulation results that the array unit in this embodiment realizes the broadband and dual polarization characteristics of the phased array antenna.

Example 2

This embodiment is based on a dielectric integrated cavity in the form of a flat panel array of broadband dual-polarized phased array antennas, which is divided into three layers as shown in FIG. The middle layer dielectric substrate 102 of the polarized microstrip feeder 105 and the vertically polarized microstrip feeder 106, the upper layer dielectric substrate 103 printed with the mesh metal patch 107; the thickness of the lower layer dielectric substrate 101 is 3.5mm, and the relative dielectric constant is 2.2 , the metal patch 109 and metallized vias 110 arranged periodically in the dielectric substrate form a grid-shaped dielectric integrated cavity 104 with a depth of 3.5 mm and a width from 4 mm to 5 mm; the relative permittivity of the intermediate dielectric substrate 102 2.2, the thickness is 0.127mm, and the horizontally polarized microstrip feeder 105 and the vertically polarized microstrip feeder 106 are printed on the upper surface; the relative permittivity of the upper dielectric substrate 103 is 2.2, the thickness is 2.5mm, and the upper surface is printed with mesh metal stickers sheet 107; two coaxial joint inner cores 108 pass through the lower dielectric substrate 101 and the middle dielectric substrate 102 and are respectively connected to the horizontally polarized microstrip feeder 105 and the vertically polarized microstrip feeder 106, and feed; metal patch 109 is a quasi-square, and the quasi-square structure is that each side of the square is divided into three sections protruding outward, and the included angle between each section is 160°; the distance between the midpoints of adjacent metal patches 109 is 12.5mm ; The size of each metal strip in the mesh metal patch is 7.5 mm × 0.6 mm, and the spacing between the metal strips in the same direction is 2 mm; the working frequency band of this embodiment is 7.2-12.7 GHz, and the array height is high It is 0.26 times the free-space wavelength of 12.7 GHz, and has the characteristics of low profile.

FIG. 8 shows the simulation results of the variation of the active voltage standing wave ratio of the horizontally polarized port with the frequency of the array unit in the embodiment 2 under different scanning angles. It can be seen that the impedance bandwidth with an active VSWR less than 2 is greater than 55% in the ±60° scanning range. The metal patches 109 in this embodiment are quasi-square, and the periodically arranged metal patches 109 and metallized vias 110 form a grid-type dielectric integrated cavity 104 with a gradient width. Better impedance matching bandwidth.

Example 3

The broadband dual-polarized phased array antenna based on the dielectric integrated cavity of this embodiment is in the form of a planar arc array; as shown in FIG. , the middle-layer dielectric substrate 102 printed with the horizontally polarized microstrip feeder 105 and the vertically polarized microstrip feeder 106, the upper-layer dielectric substrate 103 printed with the mesh metal patch 107; the thickness of the lower-layer dielectric substrate 101 is 3 mm, which is relatively The constant is 3. Periodically arranged metal patches 109 and metallized vias 110 are used in the dielectric substrate to form a grid-shaped dielectric integrated cavity 104 with a depth of 3 mm and a width of 4.8 mm; the relative permittivity of the intermediate dielectric substrate 102 is 2.2 , the thickness is 0.25mm, and the horizontally polarized microstrip feeder 105 and the vertically polarized microstrip feeder 106 are printed on the upper surface; the relative permittivity of the upper dielectric substrate 103 is 2.2, the thickness is 3mm, and the upper surface is printed with a mesh metal patch 107 Two coaxial joint inner cores 108 pass through the lower dielectric substrate 101 and the middle dielectric substrate 102 and are respectively connected to the horizontally polarized microstrip feeder 105 and the vertically polarized microstrip feeder 106, and feed; the overall planar arc array The structure is a semi-circle, the diameter of the inner circle of the circle is 100mm, and the diameter of the outer circle is 111.5mm; the working frequency band of this embodiment is 7.6-12.6GHz, and the thickness of the array section is 0.24 of the free space wavelength of the high frequency 12.6 GHz. times, with low profile characteristics.

FIG. 9 shows the simulation results of the variation of the active voltage standing wave ratio of the horizontally polarized port with the frequency of the planar arc-shaped array unit in Embodiment 3 under different scanning angles. It can be seen that the impedance bandwidth with an active VSWR less than 2 is greater than 50% in the ±60° scanning range. It can be seen from the above simulation results that the array unit in this embodiment can still achieve the broadband and wide-angle scanning characteristics of the phased array antenna under conformal conditions.

Claims (5)

1. A broadband dual-polarization phased-array antenna based on a dielectric integrated cavity body comprises the following components in sequence from bottom to top: a lower dielectric substrate (101), an intermediate dielectric substrate (102), and an upper dielectric substrate (103);

the metal-clad plate is characterized in that a plurality of metal patches (109) are arranged on the upper surface of the lower-layer dielectric substrate (101) at intervals, a circle of metalized through holes (110) are formed around the inner edge of each metal patch (109), the upper ends of the metalized through holes (110) are flush with the upper surface of the lower-layer dielectric substrate (101), and the lower ends of the metalized through holes are flush with the lower surface of the lower-layer dielectric substrate (101); two coaxial connector inner cores (108) are arranged in the metal patch (109): the upper end of the inner core (108) of the coaxial connector is flush with the upper surface of the middle-layer medium substrate (102), the lower end of the inner core (108) of the coaxial connector extends out of the lower-layer medium substrate (101) and is connected with external equipment of the broadband dual-polarized phased-array antenna, and the inner core (108) of the coaxial connector is not in contact with the metal patch (109);

the upper surface of the middle layer medium substrate (102) is provided with a plurality of strip-shaped vertical polarization microstrip feeder lines (106) and strip-shaped horizontal polarization microstrip feeder lines (105); one end of each vertical polarization microstrip feeder line (106) is correspondingly connected with the upper end of a vertical polarization coaxial connector inner core, and the other end of each vertical polarization microstrip feeder line (106) extends to the corresponding upper part of the adjacent metal patch (109) along the vertical direction; one end of each horizontal polarization microstrip feeder line (105) is correspondingly connected with the upper end of one horizontal polarization coaxial joint inner core, and the other end of each horizontal polarization microstrip feeder line (105) extends to the corresponding upper part of the adjacent metal patch (109) along the horizontal direction;

the upper surface of the upper-layer dielectric substrate (103) is provided with a reticular metal patch (107), the reticular metal patch (107) comprises a plurality of columns of patches in the vertical direction and a plurality of rows of patches in the horizontal direction, each column or each row of patches comprises a plurality of groups of metal strips, each group of metal strips are not in contact with each other, and each group of metal strips comprises three parallel identical metal strips; two ends of each group of three metal strips are respectively positioned above two adjacent metal patches (109), and a group of metal strips is arranged above all adjacent metal patches (109);

a dielectric integrated cavity (104) is formed between the metalized through holes (110) of the adjacent metal patches (109) of the lower dielectric substrate (101), a cross-shaped dielectric integrated cavity (104) is formed between the adjacent four metal patches (109), and a three-layer structure corresponding to the cross-shaped dielectric integrated cavity (104) forms a basic antenna unit.

2. The broadband dual-polarized phased array antenna based on the dielectric integrated cavity as claimed in claim 1, wherein the height of the metalized via hole (110) is 0.02-0.2 λ_low，λ_lowThe wavelength of the free space at the low frequency end is 0.02-0.2 lambda of the gap width of the adjacent metal patches (109)_low(ii) a A dielectric integration cavity (104) is formed between the metalized via holes (110) of the adjacent metal patches (109) of the lower dielectric substrate (101), and the direction between the adjacent metal patches (109) is the width direction of the dielectric integration cavity (104); the distance between the axial line of the coaxial joint inner core (108) and the central line of the dielectric integration cavity (104) in the width direction is 0.02-0.2 lambda_low(ii) a The length of the horizontal polarization microstrip feed line (105) and the vertical polarization microstrip feed line (106) is 0.05-0.4 lambda_low(ii) a The upper dielectric substrate (103) has a relative dielectric constant of 1-3.5 and a thickness of 0.01-0.1 lambda_low(ii) a The upper medium substrate (103) is directly covered on the middle medium substrate (102) or is arranged at a distance less than 0.1 lambda from the upper surface of the middle medium substrate (102)_lowA position of height; the length of a single metal strip is 0.1-0.4 lambda_lowAnd a width of 0.005 to 0.1 lambda_low。

3. The broadband dual-polarized phased array antenna based on the dielectric integrated cavity as claimed in claim 1, wherein the vertically polarized microstrip feed line (106) and the horizontally polarized microstrip feed line (105) have the same shape, and are strip patches with two wide ends and a narrow middle, and the width of the feed end is narrower than that of the coupling end.

4. The broadband dual-polarized phased array antenna based on the dielectric integrated cavity as claimed in claim 1, wherein the metal patch (109) is square or square-like; the square-like structure is formed by dividing each side of a square into three sections protruding outwards, and the included angle between each section is larger than 160 degrees and smaller than 180 degrees.

5. The wideband dual-polarized phased array antenna based on a dielectric integrated cavity as claimed in claim 1, wherein said wideband dual-polarized phased array antenna is in a shape of a flat plate or a planar arc.

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