Dual-frequency filtering planar lens antenna applied to satellite communication

Abstract

The invention provides a dual-frequency filtering planar lens antenna applied to satellite communication, which comprises a lens array, the lens array is composed of a plurality of lens units, each lens unit comprises a first substrate, a second substrate, a third substrate and a fourth substrate which are sequentially arranged from top to bottom, the upper surface of the first substrate is provided with a radiation patch of the dual-frequency filtering antenna, and the upper surface of the second substrate is provided with a radiation patch of the dual-frequency filtering antenna. A broadband magnetoelectric dipole is arranged on the fourth substrate, a snakelike strip line is arranged on the upper surface of the third substrate, and one end of the snakelike strip line is connected with a feed end metalized through hole of a radiation patch of the dual-frequency filtering antenna through a first vertical feed probe. And the other end of the snakelike strip line is connected with a feed arm of the broadband magnetoelectric dipole through a second vertical feed probe. The dual-band filtering antenna has the advantages that dual-band filtering and beam forming functions are achieved through the radiation patches of the dual-band filtering antenna, radiation zero points are generated on the two sides of two passbands, meanwhile, a high roll-off coefficient is kept through the snakelike strip line structure, and therefore the defects of traditional design are overcome.

Description

Technical Field

[0001] This invention relates to the technical fields of electronic devices and radio frequency antennas, and in particular to a dual-frequency filtered planar lens antenna for satellite communication. Background Technology

[0002] With the explosive growth of low-Earth orbit satellite communications, problems such as spectrum scarcity, increased co-channel interference, and limited satellite payload space have become increasingly prominent. A low-profile dual-band filtered planar lens can effectively improve satellite communication performance. The high-gain beamforming of the lens antenna can enhance link stability and reduce transmit power requirements; dual-band filtering can alleviate spectrum congestion and support multi-band collaborative operation such as X / Ku; the low profile provided by the planar lens can adapt to the stringent space constraints of satellites.

[0003] There are two main technical approaches to traditional filter lens antennas: one is to use a split design method, which separates the lens part from the filter components, resulting in a large overall size and high profile of the filter lens; the other is to scale the FSS (Frequency Selective Surface) unit to obtain different phase compensations. This method results in a small overlap in the working range of different units, uneven gain, and a weak filtering effect.

[0004] Currently, no filter lens has dual-frequency functionality because using two different units can easily cause crosstalk and result in low aperture efficiency. Using a single unit requires at least four transmission zeros and the entire unit operates over a wide frequency range. Summary of the Invention

[0005] To address the problems in the prior art, this invention provides a dual-frequency filtered planar lens antenna for satellite communication, comprising a lens array composed of multiple lens units. Each lens unit includes a first substrate, a second substrate, a third substrate, and a fourth substrate arranged sequentially from top to bottom. A radiating patch for the dual-frequency filtered antenna is disposed on the upper surface of the first substrate. A broadband magnetoelectric dipole is disposed on the fourth substrate. A serpentine strip is disposed on the upper surface of the third substrate. One end of the serpentine strip is connected to the metallized via of the feed end of the radiating patch of the dual-frequency filtered antenna via a first vertical feed probe, and the other end of the serpentine strip is connected to the feed arm of the broadband magnetoelectric dipole via a second vertical feed probe.

[0006] As a further improvement of the present invention, the radiating patch includes a first U-shaped radiating patch as an inner radiating unit and a second U-shaped radiating patch as an outer radiating unit. The first U-shaped radiating patch is disposed within the U-shaped groove of the second U-shaped radiating patch. The width of each of the two side arms of the first U-shaped radiating patch and the second U-shaped radiating patch is greater than the width of their respective bottom connecting sections, and the widths of their two side arms are equal. Rectangular notches are symmetrically provided on the inner sides of the two side arms of the second U-shaped radiating patch, and a first elongated radiating patch is disposed between the two notches. The two ends of the elongated radiating patch are respectively close to the two notches. The first U-shaped radiating patch has a slot at both ends that maintains a gap with the edge of the notch, and the width of the strip-shaped radiating patch is less than the length of the notch. The feed point is located at the end of the slot of the first U-shaped radiating patch, and a second strip-shaped radiating patch extends from the center of the feed point into the slot. The second strip-shaped radiating patch and the first strip-shaped radiating patch are orthogonally connected at a center point to form a cross-shaped structure. A third strip-shaped radiating patch is symmetrically arranged on both sides of the feed point, and the ends of each third strip-shaped radiating patch are close to the left and right arms of the second U-shaped radiating patch, respectively, and maintain a set gap between them.

[0007] As a further improvement of the present invention, the upper surface of the fourth substrate is covered with copper foil, and four square radiating patches of the same size are symmetrically arranged along the center line on the lower surface of the fourth substrate, two on each side, and the feed arm is provided at the center line; each square radiating patch is provided with three blind vias, and the square radiating patch is connected to the copper foil through the blind vias.

[0008] As a further improvement of the present invention, the serpentine strip is composed of at least one U-shaped radial patch, wherein the first U-shaped radial patch includes a first connecting segment, a second connecting segment, and a third connecting segment connected in sequence, and the length L of the third connecting segment of each lens unit is... V They are all different to control the phase of the electromagnetic waves; the length L of the third connecting segment V Adjustable, used to control the total length of the serpentine strip.

[0009] As a further improvement of the present invention, the lens units are distributed in a mirror-symmetrical manner along the center line of the lens array, and the feed ends of the two columns of lens units on both sides of the center line are arranged opposite to each other. In the remaining columns of lens units, the feed end direction of each column of lens units is the same as the feed end direction of its adjacent lens unit closer to the center line.

[0010] As a further improvement of the present invention, the first substrate, the second substrate, the third substrate, and the fourth substrate are bonded together in sequence from top to bottom, and the edges of each substrate are aligned.

[0011] As a further improvement of the present invention, a Rogers 4450F adhesive layer with a thickness of 0.1 mm is disposed on the lower surface of the first substrate, the second substrate, and the third substrate; the thicknesses of the first substrate, the second substrate, the third substrate, and the fourth substrate are 0.481 mm, 0.354 mm, 0.354 mm, and 2.8 mm, respectively; the fourth substrate is made of F4BTM350 material with a relative permittivity of 3.5, and the first substrate, the second substrate, and the third substrate are made of F4BTM220 material with a relative permittivity of 2.2.

[0012] As a further improvement of the present invention, the dual-frequency filtering planar lens also includes a bracket, on which the lens array is mounted, and a mounting interface is provided for supporting and positioning a coaxial-to-WR75 waveguide converter.

[0013] As a further improvement of the present invention, the bracket is a resin bracket.

[0014] As a further improvement of the present invention, the total length of the serpentine strip is between 0.1 mm and 2 mm, and the width of the serpentine strip is 1.1 mm.

[0015] The beneficial effects of the present invention are as follows: 1. The present invention achieves dual-band filtering and beamforming functions through a patch radiator (radiating patch of a dual-band filter antenna) with a specific structure, and generates radiation nulls on both sides of the two passbands. By introducing a serpentine stripline structure, a high roll-off coefficient is maintained on the one hand, and phase compensation is provided by the serpentine stripline structure to maintain the planar structure and reduce the lens profile, thereby overcoming the shortcomings of traditional designs. Attached Figure Description

[0016] Figure 1 This is an overall structural diagram of the lens unit of the present invention;

[0017] Figure 2 This is a plan view of the first substrate layer of the present invention;

[0018] Figure 3 This is a diagram of the serpentine strip structure of the present invention;

[0019] Figure 4 This is a plan view of the fourth substrate layer of the present invention;

[0020] Figure 5 This is an overall structural diagram of the lens of the present invention;

[0021] Figure 6 The dual-frequency filtering planar lens unit of this invention is in different L V |S under parameters 11 |and|S 21 |Image;

[0022] Figure 7 The present invention relates to a dual-frequency filtering plane lens with different L values ​​at different angles. V Transmission phase relationship diagram;

[0023] Figure 8 shows the S-values ​​of the unit of the dual-frequency filtering plane lens of the present invention under different incident angles. 21 Figure; (8a) E plane; (8b) H plane;

[0024] Figure 9 This is a gain diagram of the dual-frequency filtering planar lens array of the present invention;

[0025] Figure descriptions: 1-First substrate, 2-Second substrate, 3-Third substrate, 4-Fourth substrate, 5-First vertical feed probe, 6-Second vertical feed probe, 7-First U-shaped radiating patch, 8-Second U-shaped radiating patch, 9-First elongated radiating patch, 10-Feed point, 11-Second elongated radiating patch, 12-Third elongated radiating patch, 13-Square radiating patch, 14-Feed arm, 15-Blind hole post, 16-Serpentine strip, 17-First connecting segment, 18-Second connecting segment, 19-Third connecting segment, 20-Waveport, 21-Support, 22-Lens array; Detailed Implementation

[0026] like Figure 1 , 5 As shown, this invention discloses a dual-frequency filtering planar lens for satellite communication, including a lens array 22 composed of multiple lens units. Each lens unit includes a first substrate 1, a second substrate 2, a third substrate 3, and a fourth substrate 4 arranged sequentially from top to bottom. A radiating patch for a dual-frequency filtering antenna is disposed on the upper surface of the first substrate 1. A broadband magnetoelectric dipole is disposed on the fourth substrate 4. A serpentine stripline 16 is disposed on the upper surface of the third substrate 3. One end of the serpentine stripline 16 is connected to the metallized through-hole of the feed end of the radiating patch of the dual-frequency filtering antenna through a first vertical feed probe 5. The other end of the serpentine stripline 16 is connected to the feed arm 14 of the broadband magnetoelectric dipole through a second vertical feed probe 6.

[0027] like Figure 2As shown, the radiating patch of the dual-band filter antenna adopts a double U-shaped nested structure, including a first U-shaped radiating patch 7 as the inner radiating unit and a second U-shaped radiating patch 8 as the outer radiating unit. The first U-shaped radiating patch 7 is disposed within the U-shaped groove of the second U-shaped radiating patch 8. The width of the two side arms of the first U-shaped radiating patch 7 and the second U-shaped radiating patch 8 is greater than the width of their respective bottom connecting sections, and the widths of their two side arms are equal. Rectangular notches are symmetrically arranged on the inner sides of the two side arms of the second U-shaped radiating patch 8, and a first elongated strip radiating patch 9 is disposed between the two notches. The two ends of the elongated strip radiating patch 9 are respectively close to the two... The notch has gaps at both ends and the edge of the notch, and the width of the elongated radiating patch 9 is less than the length of the notch; the feed point (10) is set at the end of the opening groove of the first U-shaped radiating patch 7, and a second elongated radiating patch 11 is set from the center of the feed point 10 into the opening groove; the second elongated radiating patch 11 and the first elongated radiating patch 9 are orthogonally connected at a center point to form a cross-shaped structure; a third elongated radiating patch 12 is symmetrically arranged on both sides of the feed point 10, and the ends of each third elongated radiating patch 12 are close to the left arm and right arm of the second U-shaped radiating patch 8, respectively, and maintain a set gap with them.

[0028] like Figure 4 As shown, the upper surface of the fourth substrate 4 is covered with copper foil, and four square radiating patches 13 of the same size are symmetrically arranged along the center line on the lower surface of the fourth substrate 4, two on each side, and a feed arm 14 is provided at the center line; each square radiating patch 13 is provided with three blind vias 15, and the square radiating patch 13 is connected to the copper foil through the blind vias 15.

[0029] like Figure 3 As shown, the serpentine strip 16 is composed of at least one U-shaped radial patch, wherein the first U-shaped radial patch includes a first connecting segment 17, a second connecting segment 18, and a third connecting segment 19 connected in sequence, and the length L of the third connecting segment 19 of each lens unit is... V The segments are different from each other to control the phase of the electromagnetic waves. The length L of the third connecting segment 19 is... V It is the key variable that determines the total length of the serpentine strip, and is adjusted by adjusting L. V The overall length can be effectively adjusted. Each lens unit has a filtering and transmission function, but the Lv parameter of each lens unit is different, so the phase delay is different. When the electromagnetic wave comes out from the wave port 20, the phase compensation obtained after passing through each unit is different, so that the spherical wave becomes a plane wave. The phase of the transmitted electromagnetic wave is basically consistent. According to the principle of wave interference, the electric field superposition is maximized at this time, and the antenna gain is the highest. The serpentine stripline of this invention is composed of four U-shaped radiating patches connected in sequence. The first connecting segment 7 of the first U-shaped radiating patch is connected to the radiating patch of the dual-frequency filtering antenna, and the tail end of the fourth U-shaped radiating patch is connected to the broadband magnetoelectric dipole.

[0030] The lens units are distributed symmetrically in a mirror image along the center line of the lens array. The feed ends of the two columns of lens units on both sides of the center line are arranged opposite each other. In the remaining columns of lens units, the feed end direction of each column of lens units is the same as the feed end direction of its adjacent lens unit closer to the center line.

[0031] The dual-frequency filter plane lens also includes a bracket 7. The lens array is mounted on the bracket 21. The bracket 21 is provided with a mounting interface 20 for supporting and positioning a coaxial to WR75 waveguide converter. The bracket 21 is a resin bracket, which serves to support and fix the focal length. The lens array is connected to the bracket 21 by screws.

[0032] This invention discloses a dual-frequency filtering planar lens for satellite communication. The top layer is a dual-frequency filtering antenna, and the bottom layer is a broadband magneto-electric dipole (ME-dipole). A serpentine strip is positioned between the ground planes of the two antennas. Except for the fourth substrate 4, which uses F4BTM350, all substrates use F4BTM220 material (relative permittivity 2.2). The first substrate 1, second substrate 2, and third substrate 3 each contain a 0.1mm thick Rogers 4450F adhesive layer. The total thicknesses of the first substrate 1, second substrate 2, third substrate, and fourth substrate are 0.481mm, 0.354mm, 0.354mm, and 2.8mm, respectively. The second substrate 2 has two through-holes. A first vertical feed probe 5 passes through one of the through-holes and connects to the radiating patch of the dual-frequency filtering antenna and the serpentine strip 16, respectively. A second first vertical feed probe 5 passes through the other through-hole and connects to the serpentine strip 16 and the broadband magneto-electric dipole, respectively. The second substrate 2 serves to separate the ground plane from the serpentine stripline. The feed line 14 of the bottom ME-dipole is positioned opposite to the feed point 10 of the top layer to create a distance between the two feed probes. Subsequently, a serpentine stripline 16 is inserted to connect the feed probes of the two antennas and provide variable phase delay.

[0033] Figure 6 The text gives different L values ​​under vertically incident waves. V |S under parameters 11 |and|S 21 |Result, L V See definition Figure 3 This controls the length of the serpentine band. Results show that the FSS unit has a maximum insertion loss of 1.05 dB in the passband and exhibits high selectivity and good out-of-band suppression. More importantly, from... Figure 6 As can be seen, as the length of the serpentine band 16 increases from 0.1 mm to 2 mm, the S of the FSS... 21| Maintain high consistency. After conversion, the phase difference corresponding to the length difference of the serpentine strip 16 is sufficient to meet the phase compensation requirements of different units in the lens array. This property is also conducive to achieving a short focal length of the lens, because the unit can compensate for a large phase difference, thereby reducing the overall size of the system. Figure 7 The image shows different L-shapes from different angles. V The transmission phase relationship is shown in the figure, where θ refers to the angle between the incident wave and the normal vector of the horizontal plane, and the same applies below. This indicates that the transmission phase of the FSS element maintains a stable linear relationship with the transmission line length under different incident angles and frequencies. Therefore, the phase delay of the element can be determined solely by the length of the strip at a specific frequency. Thus, the element possesses a variable transmission phase independent of its transmission frequency. Because of this characteristic, the phase delay introduced by the serpentine strip 16 can be calculated simply and accurately, simplifying the design process. For example... Figure 8(a) , 8(b) As shown, this lens unit maintains relatively stable transmission and filtering characteristics within a certain angle on both the E and H planes. Figure 9 As shown, the dual-band filtered planar lens antenna has flat gain in the 9.2-9.7 and 13-13.6 GHz operating frequency bands, a high roll-off coefficient in the transition band, and aperture efficiencies of 45% and 21% at the two frequency points, respectively. The out-of-band rejection is 12.5 dB and 15 dB, respectively.

[0034] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A dual-frequency filtered planar lens antenna for satellite communication, characterized in that: The system includes a lens array, which is composed of multiple lens units. Each lens unit includes a first substrate (1), a second substrate (2), a third substrate (3), and a fourth substrate (4) arranged sequentially from top to bottom. A radiating patch for a dual-frequency filter antenna is disposed on the upper surface of the first substrate (1). A broadband magnetoelectric dipole is disposed on the fourth substrate (4). A serpentine stripline (16) is disposed on the upper surface of the third substrate (3). One end of the serpentine stripline (16) is connected to the metallized through-hole of the feed end of the radiating patch of the dual-frequency filter antenna through a first vertical feed probe (5). The other end of the serpentine stripline (16) is connected to the feed arm (14) of the broadband magnetoelectric dipole through a second vertical feed probe (6).

2. The dual-frequency filtered planar lens antenna according to claim 1, characterized in that: The radiation patch includes a first U-shaped radiation patch (7) as an inner radiation unit and a second U-shaped radiation patch (8) as an outer radiation unit. The first U-shaped radiation patch (7) is disposed in the U-shaped groove of the second U-shaped radiation patch (8). The width of the two side arms of the first U-shaped radiation patch (7) and the second U-shaped radiation patch (8) is greater than the width of their respective bottom connecting sections, and the widths of their two side arms are equal. Rectangular notches are symmetrically provided on the inner sides of the two side arms of the second U-shaped radiation patch (8), and a first elongated radiation patch (9) is provided between the two notches. The two ends of the elongated radiation patch (9) are close to the two notches, and the two ends are close to the edges of the notches. The gap is such that the width of the elongated radiating patch (9) is less than the length of the notch; the feed point (10) is located at the end of the opening slot of the first U-shaped radiating patch (7), and a second elongated radiating patch (11) extends from the center of the feed point (10) into the opening slot; the second elongated radiating patch (11) and the first elongated radiating patch (9) are orthogonally connected at a center point to form a cross-shaped structure; a third elongated radiating patch (12) is symmetrically arranged on both sides of the feed point (10), and the ends of each third elongated radiating patch (12) are close to the left and right arms of the second U-shaped radiating patch (8) respectively, and a set gap is maintained between them.

3. The dual-frequency filtered planar lens antenna according to claim 1, characterized in that: The upper surface of the fourth substrate (4) is covered with copper foil, and four square radiating patches (13) of the same size are symmetrically arranged along the center line on the lower surface of the fourth substrate (4), two on each side, and the feed arm (14) is provided at the center line; each square radiating patch (13) is provided with three blind vias (15), and the square radiating patch (13) is connected to the copper foil through the blind vias (15).

4. The dual-frequency filtered planar lens antenna according to claim 1, characterized in that: The serpentine strip (16) is composed of at least one U-shaped radial patch, wherein the first U-shaped radial patch includes a first connecting segment (17), a second connecting segment (18), and a third connecting segment (19) connected in sequence, and the length L of the third connecting segment (19) of each lens unit is... V They are all different to control the phase of the electromagnetic wave; the length L of the third connecting segment (19) V Adjustable, used to control the total length of the serpentine strip (16).

5. The dual-frequency filtered planar lens antenna according to claim 1, characterized in that: The lens units are distributed in a mirror-symmetrical manner along the center line of the lens array. The feed ends of the two columns of lens units on both sides of the center line are arranged opposite each other. In the remaining columns of lens units, the feed end direction of each column of lens units is the same as the feed end direction of its adjacent lens unit closer to the center line.

6. The dual-frequency filtered planar lens antenna according to claim 1, characterized in that: The first substrate (1), the second substrate (2), the third substrate (3), and the fourth substrate (4) are bonded together from top to bottom, and the edges of each substrate are aligned.

7. The dual-frequency filtered planar lens antenna according to claim 6, characterized in that: A Rogers 4450F adhesive layer with a thickness of 0.1 mm is disposed on the lower surface of the first substrate (1), the second substrate (2), and the third substrate (3); the thicknesses of the first substrate (1), the second substrate (2), the third substrate (3), and the fourth substrate (4) are 0.481 mm, 0.354 mm, 0.354 mm, and 2.8 mm, respectively; the fourth substrate (4) is made of F4BTM350 material with a relative permittivity of 3.5, and the first substrate (1), the second substrate (2), and the third substrate (3) are made of F4BTM220 material with a relative permittivity of 2.

2.

8. The dual-frequency filtered planar lens antenna according to claim 1, characterized in that: The dual-frequency filter planar lens also includes a bracket (21), on which the lens array is mounted. The bracket (21) is provided with a mounting interface (20) for supporting and positioning a coaxial to WR75 waveguide converter.

9. The dual-frequency filtered planar lens antenna according to claim 8, characterized in that: The support (7) is a resin support.

10. The dual-frequency filtered planar lens antenna according to claim 4, characterized in that: The total length of the serpentine strip (16) is between 0.1 mm and 2 mm, and the width of the serpentine strip (16) is 1.1 mm.

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