A phased array film antenna with a correction function of a slot coupled feed

Abstract

The application relates to a slot-coupled phased array film antenna with a correction function, and belongs to the field of phased array technology antennas. The phased array film antenna is composed of a patch film layer, a slot film layer, a feed film layer and a radio frequency connector, and the improvement lies in that the phased array film antenna further comprises a correction structure; the correction structure comprises a coupling line, a correction line, a correction through hole, a grounding line and a correction radio frequency connector. The coupling line is arranged in a straight line on the patch film layer and penetrates between two rows of microstrip patches. The correction line and the correction through hole are arranged on the slot film layer and correspond to the upper and lower internal ends of the coupling line. The correction line and the grounding line are arranged on the feed film layer and correspond to the upper and lower coupling slots. The correction through hole and the grounding line are connected through a metal wire. The inner and outer conductors of the correction radio frequency connector are respectively connected with the correction line and the connector. The correction structure realizes random phase error correction adjustment of a feed system of the phased array film antenna.

Description

Technical Field

[0001] This invention belongs to the field of phased array antenna technology, specifically relating to a slot-coupled fed phased array thin-film antenna with correction function. Background Technology

[0002] Thin-film antennas can be used to realize lightweight, deployable antennas with high gain and large aperture, and have important applications in fields such as Earth communication, Earth observation, land remote sensing, deep space exploration and communication. Such lightweight antennas are significant for reducing weight and cost.

[0003] A typical implementation uses a microstrip patch antenna structure, where the antenna is divided into several layers, such as a patch layer, a slot layer, a feed layer, and a reflective layer, each printed on a different thin film, and then assembled using a support structure. Depending on the specific application, this structure can be extended to more complex structures by adding patch layers and reflective layers.

[0004] In phased array antenna systems, due to the processing and installation tolerances of various feeder components, component replacement, and the influence of ambient temperature, phased array antenna feeding systems exhibit considerable random phase errors. Active component failure and operational instability degrade antenna performance. To maintain antenna performance, the system must possess amplitude and phase monitoring and correction capabilities. If these errors are not corrected, they will severely disrupt the antenna pattern characteristics, causing a decrease in antenna gain, deterioration of sidelobe levels, and worsening of beam pointing accuracy.

[0005] Common calibration methods for phased array antennas can be divided into internal calibration and external calibration. External calibration is performed using an anechoic chamber probe and auxiliary antennas. Its advantages are small equipment size and the ability to correct antenna inconsistencies. Its disadvantages are lower calibration accuracy and susceptibility to external influences. Internal calibration introduces a calibration network between the antenna and the RF components. Its advantages are high calibration accuracy, but its disadvantages are a large equipment size. To achieve reliable calibration, internal calibration is often used, embedding the transmission port of the calibration network between the antenna and the active components, transmitting or receiving coupled energy at the coupling port. If the calibration network cannot be designed using the antenna system's inherent structure, additional volume and weight will be introduced.

[0006] For non-thin-film multilayer phased array antennas, a transmission line can be added to the antenna input port as a coupling line, and several coupling lines can be connected to form a correction network. However, in the context of thin-film antennas, the implementation of the correction network presents significant challenges. First, thin-film antennas prioritize lightweight design and have strict weight requirements; the correction network should be implemented on existing multilayer thin films, rather than adding additional thin films or microstrip boards. Second, to achieve energy distribution and combining within the antenna array, various feeding networks exist in the feed layer. The layout of the feeding network, to some extent, limits the space of the correction network, requiring it to be as compact as possible. Existing literature does not mention thin-film antenna schemes integrating correction networks. Summary of the Invention

[0007] To achieve the embedding of a lightweight correction network structure on a thin-film antenna, this invention provides a slot-coupled fed phased array thin-film antenna with correction function.

[0008] A slot-coupled feed phased array thin-film antenna with correction function includes a phased array thin-film antenna composed of a patch thin-film layer 1, a slot thin-film layer 3, a feed thin-film layer 7 and an RF connector 8.

[0009] An upper foam layer 2 is provided between the patch film layer 1 and the slot film layer 3, and a lower foam layer 6 is provided between the slot film layer 3 and the power supply film layer 7.

[0010] Two rows of microstrip patches 12 are evenly distributed on the top surface of the patch film layer 1;

[0011] Corresponding to the two rows of microstrip patches 12, two rows of antenna slots 31 are evenly distributed on the top surface of the slot film layer 3;

[0012] Corresponding to the two rows of microstrip patches 12, the bottom surface of the feeding thin film layer 7 is evenly provided with feeding structures, and the bottom surface of the feeding thin film layer 7 is also provided with a T-shaped grounding wire 72.

[0013] It also includes correction structures;

[0014] The calibration structure includes a coupling line 11, a set of calibration slots, a set of calibration through holes, a calibration line 73, a grounding line 74 and a calibration RF connector 9; the set of calibration slots consists of three parallel calibration slots (33), and the set of calibration through holes consists of three calibration through holes (34);

[0015] The coupling line 11 is arranged in a straight line on the top surface of the patch film layer 1 and passes through the space between two adjacent rows of microstrip patches 12; the antenna end 111 of the coupling line 11 is located at one edge of the patch film layer 1, and the inner end 112 of the coupling line 11 is located on the other side of the patch film layer 1.

[0016] The set of correction seams is provided on the gap film layer 3, and the set of correction seams corresponds vertically to the inner end 112 of the coupling line 11, and the three correction seams 33 are perpendicular to the coupling line 11; a set of correction through holes is opened on the gap film layer 3 outside the set of correction seams.

[0017] The correction line 73 is disposed on the bottom surface of the feed thin film layer 7. The correction line 73 is parallel to the coupling line 11 and is located below the inner end of the coupling line 11. The correction line 73 and the grounding line 74 are on a straight line, and there is a gap between the correction line 73 and the grounding line 74.

[0018] A set of correction seams enables energy transmission between coupling line 11 and correction line 73;

[0019] The outer conductor of the calibration RF connector 9 is connected to the calibration connection through hole 742 of the grounding wire 74, and the inner conductor of the calibration RF connector 9 is connected to the grounding terminal 734 of the calibration wire 73.

[0020] The correction structure enables random phase error correction and adjustment of the feed system of the phased array thin-film antenna.

[0021] Further technical solutions are as follows:

[0022] The spacing between adjacent correction seams 33 in the set of correction seams 33 is equal.

[0023] One end of the calibration line 73 opposite to the microstrip patch 12 is the inner end, which is a small fan-shaped end 731. The other end of the calibration line 73 opposite to the grounding line 74 is the outer end, which is provided with a terminal 734. Calibration branch lines 733 are provided on both sides of the outer end. A pair of calibration fan-shaped pieces 732 are provided radially on the calibration line 73 between the inner and outer ends. The grounding line 74 is provided with three connectors, one end of which is connected in parallel, and the other end of which is provided with a connecting ring 741. The terminal 734 of the calibration line 73 corresponds to the parallel connection of the three connectors of the grounding line 74. The three calibration through holes 34 on the slot film layer 3 and the annular holes of the corresponding connecting rings 741 on the bottom surface of the feed film layer 7 are connected by calibration metal wires 5.

[0024] The correction spur line 733 is an L-shaped line.

[0025] The phased array thin-film antenna array consists of two or more rows of phased array thin-film antennas arranged in parallel along the direction perpendicular to the coupling line; it includes two or more coupling lines 11, two or more correction lines 73, ground line 74 and correction RF connector 9; the correction structure connects two or more correction lines 73 in parallel through a power divider network 735 and connects them to a ground terminal 734.

[0026] The beneficial technical effects of this invention are reflected in the following aspects:

[0027] 1. This invention adds a correction network structure to the structure of a typical phased array thin-film antenna, achieving an integrated design without adding extra thin films, dielectrics, support structures, or loads. By employing the same three-layer thin-film framework as the antenna elements, the correction network can be parasitic on the antenna array. Using the same feeding principle as the antenna elements, coupling lines, correction slots, and correction lines are designed in the patch thin-film layer, slot thin-film layer, and feed thin-film layer, respectively, enabling microwave signal transmission between the three thin films. A correction RF connector is connected to one side of the correction line, forming the external microwave signal interface. The coupling line is inserted into the antenna array, and the coupling amount can be controlled by adjusting the width of the coupling line and the distance between the coupling line and the microstrip patch. When the coupling amount is appropriate, its strength meets the correction requirements without affecting the antenna performance. This achieves an integrated design of the antenna and correction network structure and function.

[0028] 2. This invention improves the matching performance of the calibration network through the design of the patch layer coupling line, the slot layer slot structure, and the feed layer transmission structure. During antenna calibration, a standing wave ratio of no more than 2.1 and a coupling degree of approximately -35dB are achieved within a 7% bandwidth.

[0029] 3. The correction network structure technology of this invention can be extended to antenna arrays of various sizes through the power divider network. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the phased array thin-film antenna structure of the present invention.

[0031] Figure 2 for Figure 1 Exploded view.

[0032] Figure 3 for Figure 1 A bottom view.

[0033] Figure 4 This is a schematic diagram of the patch film layer structure.

[0034] Figure 5 for Figure 4 Enlarged image.

[0035] Figure 6 This is a schematic diagram of the gap film layer structure.

[0036] Figure 7 This is a schematic diagram of the top view of the feeding thin film layer.

[0037] Figure 8 This is a schematic diagram of the antenna feed line structure.

[0038] Figure 9 This is a schematic diagram of the correction line.

[0039] Figure 10 for Figure 9 A magnified view of a portion of the image.

[0040] Figure 11 This is a coupling diagram for Example 1.

[0041] Figure 12 The standing wave diagram for Example 1 is shown below; (a) calibrated RF connector port; (b) RF connector end.

[0042] Figure 13 This is the orientation diagram of Example 1.

[0043] Figure 14 This is a schematic diagram of the structure of Example 2.

[0044] Figure 15 This is a bottom view of Example 2.

[0045] Figure 16 This is a schematic diagram of a power distribution network.

[0046] Figure 17 This is a coupling diagram of Example 2.

[0047] Figure 18 The standing wave diagram for Example 2 is shown below; (a) calibrated RF connector port and (b) RF connector end.

[0048] Figure 19 This is the orientation diagram for Example 2.

[0049] Figure 20 This is a schematic diagram of the structure of Example 3.

[0050] The numbers in the diagram above are: 1. Patch film layer; 2. Upper foam layer; 3. Slot film layer; 4. Antenna wire; 5. Correction wire; 6. Lower foam layer; 7. Feed film layer; 8. RF connector; 9. Correction RF connector; 11. Coupler line; 111. Antenna end; 112. Internal end; 12. Microstrip patch; 31. Antenna slot; 32. Antenna through-hole; 33. Correction slot; 34. Correction through-hole; 71. Antenna feed line; 711. Antenna feed line stub; 72. T-type grounding wire; 721. Grounding ring; 722. Connector through-hole; 73. Correction line; 731. Small sector end; 732. Correction sector piece; 733. Correction stub line; 734. Terminal; 735. Power divider network; 74. Grounding wire; 741. Terminal ring; 742. Correction connection through-hole. Detailed Implementation

[0051] The present invention will be further described below with reference to the accompanying drawings and embodiments. Example 1

[0052] See Figure 1 and Figure 2A slot-coupled feed phased array thin-film antenna with correction function includes a patch thin-film layer 1, a slot thin-film layer 3, a feed thin-film layer 7, an RF connector 8, and a correction structure.

[0053] See Figure 2 An upper foam layer 2 is provided between the patch film layer 1 and the slot film layer 3, and a lower foam layer 6 is provided between the slot film layer 3 and the power supply film layer 7.

[0054] See Figure 4 Two rows of microstrip patches 12 are evenly distributed on the top surface of the patch film layer 1. The microstrip patches 12 are rectangular.

[0055] See Figure 6 Corresponding vertically to the two rows of microstrip patches 12, two rows of antenna slots 31 and antenna through holes 32 are evenly distributed on the top surface of the slot film layer 3; see also Figure 2 , Figure 6 and Figure 8 The antenna through-hole 32 and the corresponding grounding ring 721 on the bottom surface of the feed film layer 7 are connected by the antenna wire 4. Corresponding to the two rows of microstrip patches 12, the bottom surface of the feed film layer 7 is evenly provided with antenna feed structures and T-shaped grounding wires 72.

[0056] See Figure 7 The antenna feeding structure includes two antenna feed line groups, which correspond vertically to two rows of microstrip patches 12. Each antenna feed line group consists of several antenna feed line elements evenly distributed on a straight line. Each antenna feed line element consists of an antenna feed line 71 and a T-shaped grounding line 72 on a straight line.

[0057] See Figure 8 The T-shaped grounding wire 72 has three connectors, one end of which is connected in parallel, and the other end of each connector is provided with a grounding ring 721. Connector through holes 722 are provided on the T-shaped grounding wire 72 between adjacent parallel connectors. Antenna feed line 71 opposite to the T-shaped grounding wire 72 has antenna feed line branches 711 connected to both sides of one end.

[0058] The RF connector 8 is located below the feed film layer 7, with its inner conductor connected to the antenna feed line 71 and its outer conductor connected to the T-shaped ground wire 72.

[0059] The calibration structure includes a coupling line 11, a calibration line 73, a grounding line 74, a set of calibration slots, a set of calibration vias, and a calibration RF connector 9. The set of calibration slots consists of three calibration slots 33, and the set of calibration vias consists of three calibration vias 34.

[0060] See Figure 4 The coupling line 11 is straight, located on the top surface of the patch film layer 1, and runs through the space between two adjacent rows of microstrip patches 12. (See also...) Figure 5 The antenna end 111 of the coupling line 11 is located at one edge of the patch film layer 1, and the inner end 112 of the coupling line 11 is located on the other side of the patch film layer 1.

[0061] See Figure 6 A set of correction seams is formed in the slit film layer 3. The spacing between adjacent correction seams 33 in the set is equal, and the three correction seams 33 are perpendicular to the coupling line 11. Three correction through holes 34 are formed on the slit film layer 3 outside the set of correction seams. See also Figure 2 A set of correction seams corresponds vertically to the inner end 112 of the coupling line 11.

[0062] See Figure 7 The correction line 73 is disposed on the bottom surface of the feeding thin film layer 7, and is parallel and corresponding to the coupling line 11 vertically, with the correction line 73 located below the inner end of the coupling line 11; the correction line 73 and the ground line 74 are on a straight line, and a gap is provided between the correction line 73 and the ground line 74. See Figure 2 Above the correction line 73 is a set of correction seams on the slit film layer 3; the set of correction seams enables the transmission of energy between the coupling line 11 and the correction line 73; the three correction through holes 34 and the corresponding ring holes of the wiring ring 741 are connected by the correction metal wire 5.

[0063] See Figure 9 One end of the calibration line 73 opposite to the microstrip patch 12 is the inner end, which is a small fan-shaped end 731. The other end of the calibration line 73 opposite to the ground wire 74 is the outer end, which has a terminal 734. Calibration spur lines 733, which are L-shaped, are located on both sides of the outer end. A pair of calibration fan-shaped plates 732 are radially arranged on the calibration line 73 between its inner and outer ends. (See also...) Figure 10 The grounding wire 74 has three connectors, one end of which is connected in parallel, and the other end of each connector has a connecting ring 741. The connecting end 734 of the correction wire 73 corresponds to the parallel connection of the three connectors of the grounding wire 74; the three correction through holes 34 on the slot film layer 3 and the corresponding ring holes of the connecting rings 741 on the bottom surface of the feed film layer 7 are connected by correction metal wires 5.

[0064] A calibration connector through hole 742 is provided on the grounding wire 74 between adjacent parallel connector ends.

[0065] See Figure 9 The outer conductor of the calibration RF connector 9 is connected to the calibration connection through hole 742 of the ground wire 74, and the inner conductor of the calibration RF connector 9 is connected to the ground terminal 734 of the calibration line 73.

[0066] The phased array thin-film antenna in this embodiment 1 is an antenna element that scans one dimension along the X-axis. In the transmit calibration state, an external transmitting device feeds a microwave signal to the RF connector 8. This microwave signal is sequentially transmitted to the antenna feed line 71, antenna slot 31, microstrip patch 12, coupling line 11, a set of calibration slots, calibration line 73, and calibration RF connector 9. Finally, the external receiving device receives the microwave signal at the calibration RF connector 9. By comparing the amplitude and phase with a single signal, the random amplitude and phase errors of the RF channel corresponding to the RF connector 8 are corrected.

[0067] In the receiving calibration state, the external transmitting device feeds microwave signals to each calibration RF connector 9. These microwave signals are sequentially transmitted to the calibration line 73, a set of calibration slots, the coupling line 11, the microstrip patch 12, the antenna slot 31, the antenna feed line 71, and the RF connector 8. Finally, the external receiving device receives the microwave signal at the calibration RF connector 9. By comparing the amplitude and phase with a single signal, the random amplitude and phase errors of the RF channel corresponding to the RF connector 8 are corrected.

[0068] In the receiving state, the microwave signal from space passes sequentially through the microstrip patch 12, the antenna slot 31, the antenna feed line 71, and the RF connector 8 to reach the external receiving device.

[0069] In the transmission state, microwave signals from external transmitting equipment are radiated into space sequentially through RF connector 8, antenna feed line 71, antenna slot 31, and microstrip patch 12.

[0070] See Figure 11 In this embodiment 1, the coupling is between -22.5dB and -45dB within the operating frequency band of approximately 7% of the relative bandwidth.

[0071] See Figure 12 In (a) of this embodiment 1, the corrected port VSWR is better than 2.1 within an operating frequency band of approximately 7% relative bandwidth; see also Figure 12 In (b) of this embodiment, the antenna port VSWR is better than 1.6 within the operating frequency band of approximately 7% relative bandwidth.

[0072] See Figure 13 The intermediate frequency radiation pattern of this embodiment 1 has a gain of approximately 20dB. Example 2

[0073] See Figure 14 The phased array thin-film antenna array consists of four phased array thin-film antennas of Embodiment 1 arranged side by side along a direction perpendicular to the coupling line. This antenna array enables two-dimensional scanning.

[0074] See Figure 14 Eight rows of microstrip patches 12 and four coupling lines 11 are evenly distributed on the top surface of the patch film layer 1. The microstrip patches 12 are rectangular patches.

[0075] See Figure 15 On the bottom surface of the power feeding thin film layer 7, there are four correction lines 73 and one grounding line 74 corresponding to the inner end 112 of the coupling line 11 on the patch thin film layer 1.

[0076] The calibration structure includes four coupling lines 11, four calibration lines 73, one grounding line 74, four sets of calibration seams, and a calibration RF connector 9. See also... Figure 16 The four correction lines 73 are connected in parallel to a ground terminal 734 through the power divider network 735.

[0077] The other structures are the same as in Example 1.

[0078] During receiver calibration, the microwave signal travels from the external device, sequentially through the calibration RF connector 9, calibration line 73, power divider network 735, four sets of calibration slots, and coupling line 11 to the antenna array. During transmitter calibration, the microwave signal travels from the microstrip patch 12, sequentially through the coupling line 11, four sets of calibration slots, calibration line 73, power divider network 735, and calibration RF connector 9 to the external device; thus correcting the random amplitude and phase errors of the antenna array in Embodiment 2.

[0079] See Figure 17 In this embodiment 2, the antenna array operates within a frequency band with a relative bandwidth of approximately 3.6%, and the coupling is between -30dB and -45dB.

[0080] See Figure 18 In this embodiment 2, the antenna array has a corrected port VSWR better than 2.0 within a working frequency band with a relative bandwidth of about 3.6%; and an antenna port VSWR better than 1.8 within a working frequency band with a relative bandwidth of about 3.6%.

[0081] See Figure 19 The intermediate frequency radiation pattern of the antenna array in this embodiment 2 has a gain of approximately 26dB. Example 3

[0082] This third embodiment is a variation of the antenna element in embodiment 1. See also... Figure 20 The microstrip patch 12 is a circular patch, and the other structures are the same as in Example 1.

Claims

1. A slot-coupled fed phased array thin-film antenna with correction function, comprising a phased array thin-film antenna consisting of a patch thin-film layer (1), a slot thin-film layer (3), a feed thin-film layer (7) and an RF connector (8); An upper foam layer (2) is provided between the patch film layer (1) and the slot film layer (3), and a lower foam layer (6) is provided between the slot film layer (3) and the power supply film layer (7). Two rows of microstrip patches (12) are evenly distributed on the top surface of the patch film layer (1). Corresponding to the two rows of microstrip patches (12) above and below, two rows of antenna slots (31) are evenly distributed on the top surface of the slot film layer (3). Corresponding to the two rows of microstrip patches (12) above and below, the bottom surface of the feeding thin film layer (7) is provided with feeding structures and a T-shaped grounding wire (72). Its features are: It also includes correction structures; The calibration structure includes a coupling line (11), a set of calibration slots, a set of calibration through holes, a calibration line (73), a grounding line (74), and a calibration RF connector (9); the set of calibration slots consists of three parallel calibration slots (33), and the set of calibration through holes consists of three calibration through holes (34); The coupling line (11) is straight and is located on the top surface of the patch film layer (1), and runs through the space between two adjacent rows of microstrip patches (12); the antenna end (111) of the coupling line (11) is located at one edge of the patch film layer (1), and the inner end (112) of the coupling line (11) is located on the other side of the patch film layer (1); The set of correction seams is provided on the gap film layer (3), and the set of correction seams corresponds vertically to the inner end (112) of the coupling line (11), and the three correction seams (33) are perpendicular to the coupling line (11); a set of correction through holes is opened on the gap film layer (3) outside the set of correction seams; The correction line (73) is disposed on the bottom surface of the feed thin film layer (7). The correction line (73) is parallel to the coupling line (11) and is located below the inner end of the coupling line (11). The correction line (73) and the grounding line (74) are on a straight line, and there is a gap between the correction line (73) and the grounding line (74). A set of correction seams enables the transmission of energy between the coupling line (11) and the correction line (73); The outer conductor of the calibration RF connector (9) is connected to the calibration connection through hole (742) of the ground wire (74), and the inner conductor of the calibration RF connector (9) is connected to the terminal (734) of the calibration wire (73). The correction structure enables random phase error correction and adjustment of the feed system of the phased array thin-film antenna.

2. The slot-coupled fed phased array thin-film antenna with correction function according to claim 1, characterized in that: The spacing between adjacent correction joints (33) in the set of correction joints (33) is equal.

3. The slot-coupled fed phased array thin-film antenna with correction function according to claim 1, characterized in that: One end of the calibration line (73) opposite to the microstrip patch (12) is the inner end, which is a small fan-shaped end (731). The other end of the calibration line (73) opposite to the grounding line (74) is the outer end. The end of the outer end is provided with a terminal (734), and calibration branch lines (733) are provided on both sides of the outer end. A pair of calibration fan-shaped pieces (732) are provided radially between the inner and outer ends of the calibration line (73). The grounding line (74) is provided with three connectors. One end of the three connectors is connected in parallel, and the other end of the three connectors is provided with a connecting ring (741). The terminal (734) of the calibration line (73) corresponds to the parallel connection of the three connectors of the grounding line (74). The three calibration through holes (34) on the slot film layer (3) and the ring holes of the connecting rings (741) on the bottom surface of the corresponding feed film layer (7) are connected by calibration wires (5).

4. The slot-coupled fed phased array thin-film antenna with correction function according to claim 3, characterized in that: The correction branch line (733) is an L-shaped line.

5. A phased array thin-film antenna array based on a slot-coupled feed phased array thin-film antenna with correction function according to any one of claims 1-4, characterized in that: The phased array thin-film antenna array consists of two or more rows of phased array thin-film antennas arranged in parallel along the direction perpendicular to the coupling line; including two or more coupling lines (11), two or more correction lines (73), ground line (74) and correction RF connector (9); the correction structure connects two or more correction lines (73) in parallel through a power divider network (735) and connects them to a terminal (734).

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