A large-interval phased array antenna based on hybrid interleaved feed network

Abstract

The application discloses a large-interval phased array antenna based on a hybrid interleaved feed network, comprising: a hybrid interleaved feed network based on a double-line transmission line structure, comprising N radio frequency channel ports and M radiation unit ports; each channel port corresponds to multiple radiation units; each radiation unit port corresponds to two dipole arms, the two dipole arms are arranged on the top layer and the bottom layer of a single-layer substrate respectively, and the directions of the two dipole arms are opposite; the phase difference of 0 or 180 is realized by adjusting the directions of the two dipole arms; the amplitude of excitation is controlled by adjusting the width and / or length of the double-line transmission line between the two radiation unit ports. When the channel port is excited, the excitation from the radiation unit of the hybrid interleaved feed network is the sampling of a sinc function. The application can realize the approximate sinc function electric field distribution when a single channel is excited by the hybrid interleaved feed network, and then the top flat active directional diagram is obtained, and can be widely applied to the technical field of antennas.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a large-pitch phased array antenna based on a hybrid interleaved feed network. Background Technology

[0002] To suppress grating lobes in the visible space, existing large-pitch phased array antennas (with a pitch often greater than or equal to 1λ0) mainly employ methods such as radiating aperture interlacing and feeding network interlacing.

[0003] Aperture Interleaving: For aperture interleaved antennas, the RF channel typically corresponds one-to-one with the radiating element. To suppress grating lobes, special consideration must be given to the design of the radiating elements so that the radiating aperture portions overlap between elements, resulting in a flat-top active element radiation pattern. In the first existing literature, multi-layered disks are placed as directors on a stepped circular waveguide to produce a flat-top radiation pattern. The corresponding large-pitch phased array antenna with an x-direction spacing of 1.14λ0 and a y-direction spacing of 0.9872λ0 has a scanning range of ±20° along the x-direction, with grating lobe levels less than -11dB and -12dB in the Ka and C bands, respectively. However, these designs require very high profiles. Leaky-wave antennas with loaded lenses are used to realize large-pitch phased array antennas with a spacing of 2λ0, achieving a scanning capability of up to ±20° and a sidelobe level less than -13.0dB. However, the disadvantage of this design is its high profile, requiring additional mechanical movement structures to ensure scanning performance. In the existing second literature, a periodic leaky structure was designed using nails to expand and control the radiation aperture, achieving a flat-top radiation pattern. However, this was limited by the very narrow operating bandwidth exhibited by the periodic structure.

[0004] Interleaved Feed Networks: Interleaved feed network antennas achieve the effect of interleaved radiating apertures through feed network design, generally resulting in a lower profile. For interleaved feed network antennas, one RF channel often corresponds to multiple radiating elements, so the number of channels is often less than the number of radiating elements. Specifically, interleaved feed network antennas map fewer RF channels onto more radiating elements through the feed network, with the most important aspect being adjusting the mapping relationship to distribute radiated energy. In the existing third literature, an interleaved feed network is composed of fixed / variable gain amplifiers, power dividers, and attenuators, with a spacing of approximately 1.1λ0 between RF channels, achieving a ±25° scan range and a sidelobe level less than -18dB. This method results in a complex antenna structure and high cost due to the extensive use of active components. To overcome these challenges, the existing fourth literature employs different types of power dividers to implement an interleaved feed network. This large-pitch phased array antenna has a spacing of 2λ0, achieving a ±14° scan range. However, it has a high grating lobe level of approximately -1dB.

[0005] In summary, existing technical solutions have the following problems: 1) Existing designs for radiating aperture interleaved antennas are relatively complex and have high profiles, making integration with RF front-end circuits difficult. 2) Existing designs for feed network interleaved antennas require a large number of active components, resulting in higher costs and making implementation in the millimeter-wave band difficult. Summary of the Invention

[0006] In order to at least partially solve one of the technical problems existing in the prior art, the present invention aims to provide a large-pitch phased array antenna based on a hybrid interleaved feed network.

[0007] The technical solution adopted in this invention is:

[0008] A large-pitch phased array antenna based on a hybrid interleaved feed network includes:

[0009] A hybrid interleaved feed network based on a dual-line transmission line structure is disposed on a single-layer substrate and includes N RF channel ports and M radiation unit ports; wherein each channel port corresponds to multiple radiation units to achieve RF channel radiation aperture interleaving, where N < M;

[0010] The RF channel port is used to connect to the balun converter, and the radiating unit port is used to connect to the dipole. Each radiating unit port corresponds to two oscillating arms, which are connected to a transmission line. The two oscillating arms are respectively disposed on the top and bottom layers of the single-layer substrate, and the two oscillating arms are in opposite directions. By adjusting the direction of the two oscillating arms, a phase difference of 0° or 180° can be achieved. The amplitude of the excitation can be controlled by adjusting the width and / or length of the bilinear transmission line between the two radiating unit ports.

[0011] When a channel port is excited, the excitation from the radiating element of the hybrid interleaved feed network is a sample of the sinc function.

[0012] Furthermore, the large-pitch phased array antenna also includes multiple directors and a metal reflector to improve the antenna gain and suppress radiation back lobes;

[0013] The director is positioned above the oscillator arm; the reflector is perpendicular to the monolayer substrate and located at the RF channel port, and a channel for the transmission line is provided between the reflector and the monolayer substrate.

[0014] Furthermore, the hybrid interleaved feed network includes 5 radio frequency channel ports and 16 radiating element ports. The distance between two adjacent radio frequency channel ports is 1λ0, and the distance between two adjacent radiating element ports is 1 / 3λ0, where λ0 is the operating frequency band of the antenna.

[0015] Furthermore, the hybrid interleaved feed network includes 5 radio frequency channel ports and 21 radiating element ports. The distance between two adjacent radio frequency channel ports is 1.5λ0, and the distance between two adjacent radiating element ports is 3 / 8λ0, where λ0 is the operating frequency band of the antenna.

[0016] Furthermore, the balun converter is used to convert between two types of transmission lines, namely two-line transmission lines and microstrip lines, through a substrate-integrated waveguide.

[0017] Furthermore, the balun converter is connected to an external SMA connector.

[0018] The beneficial effects of this invention are: when a single channel is excited by a hybrid interleaved feeding network, the invention can achieve an approximate sinc function electric field distribution, thereby obtaining an active radiation pattern with a flat top; the low scan gain roll-off ensures that the entire antenna retains a low sidelobe level. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following description is provided with accompanying drawings of the relevant technical solutions in the embodiments of the present invention or the prior art. It should be understood that the accompanying drawings described below are only for the purpose of clearly illustrating some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a three-dimensional view of the phased array antenna with a 1λ0 channel spacing in an embodiment of the present invention;

[0021] Figure 2 This is a front view of the phased array antenna with a 1λ0 channel spacing in an embodiment of the present invention;

[0022] Figure 3 These are detailed diagrams of the first and second parts of the phased array antenna with a 1λ0 channel spacing in an embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram of the hybrid interleaving network (i.e., hybrid interleaving feed network) of a phased array antenna with a 1λ0 channel spacing in an embodiment of the present invention; where CP represents the radio frequency channel port and EP represents the radiating element port;

[0024] Figure 5 This is a schematic diagram of the balun converter in an embodiment of the present invention;

[0025] Figure 6 This is a three-dimensional view of a phased array antenna with a channel spacing of 1.5λ0 in an embodiment of the present invention;

[0026] Figure 7This is a front view of a phased array antenna with a channel spacing of 1.5λ0 in an embodiment of the present invention;

[0027] Figure 8 These are detailed diagrams of the first and second parts of the phased array antenna with a 1.5λ0 channel spacing in an embodiment of the present invention.

[0028] Figure 9 This is a schematic diagram of the hybrid interleaved network (i.e., hybrid interleaved feed network) of a phased array antenna with a channel spacing of 1.5λ0 in an embodiment of the present invention; where CP represents the radio frequency channel port and EP represents the radiating element port;

[0029] Figure 10 This is the active element radiation pattern of the phased array antenna with a 1λ0 channel spacing in this embodiment of the invention when the middle port is excited at 9.8GHz;

[0030] Figure 11 This is the active element radiation pattern of the phased array antenna with a 1λ0 channel spacing in this embodiment of the invention when the middle port is excited at 10GHz;

[0031] Figure 12 This is the active element pattern of a phased array antenna with a 1λ0 channel spacing in an embodiment of the present invention when the middle port is excited at 10.2GHz;

[0032] Figure 13 This is a schematic diagram of the scanning performance of a phased array antenna with a 1λ0 channel spacing at 9.8GHz in an embodiment of the present invention;

[0033] Figure 14 This is a schematic diagram of the scanning performance of a phased array antenna with a 1λ0 channel spacing at 10GHz in an embodiment of the present invention;

[0034] Figure 15 This is a schematic diagram of the scanning performance of a phased array antenna with a 1λ0 channel spacing at 10.2 GHz in an embodiment of the present invention;

[0035] Figure 16 This is the active element radiation pattern of a phased array antenna with a 1.5λ0 channel spacing in an embodiment of the present invention when the middle port is excited at 9.8GHz;

[0036] Figure 17 This is the active element radiation pattern of a phased array antenna with a channel spacing of 1.5λ0 in an embodiment of the present invention when the middle port is excited at 10GHz;

[0037] Figure 18 This is the active element radiation pattern of a phased array antenna with a channel spacing of 1.5λ0 in an embodiment of the present invention when the middle port is excited at 10.2GHz;

[0038] Figure 19This is a schematic diagram of the scanning performance of a phased array antenna with a channel spacing of 1.5λ0 in an embodiment of the present invention at 9.8GHz;

[0039] Figure 20 This is a schematic diagram of the scanning performance of a phased array antenna with a channel spacing of 1.5λ0 in an embodiment of the present invention at 10GHz;

[0040] Figure 21 This is a schematic diagram of the scanning performance of a phased array antenna with a channel spacing of 1.5λ0 in an embodiment of the present invention at 10.2GHz. Detailed Implementation

[0041] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The step numbers in the following embodiments are set only for ease of explanation, and there is no limitation on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0042] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0043] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0044] Furthermore, in the description of this invention, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0045] In the description of this invention, unless otherwise explicitly defined, terms such as "setting," "installing," and "connecting" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0046] like Figure 1 As shown, this embodiment provides a large-pitch phased array antenna based on a hybrid interleaved feed network, including:

[0047] A hybrid interleaved feed network based on a dual-line transmission line structure is disposed on a single-layer substrate and includes N RF channel ports and M radiation unit ports; wherein each channel port corresponds to multiple radiation units to achieve RF channel radiation aperture interleaving, where N < M;

[0048] The radio frequency channel port is used to connect to the balun converter, and the radiating unit port is used to connect to the dipole. Each radiating unit port corresponds to two oscillator arms, which are respectively disposed on the top and bottom layers of the single-layer substrate, and the two oscillator arms are in opposite directions. By adjusting the direction of the two oscillator arms, a phase difference of 0° or 180° can be achieved. The amplitude of the excitation can be controlled by adjusting the width and / or length of the bi-line transmission line between the two radiating unit ports.

[0049] When a channel port is excited, the excitation from the radiating element of the hybrid interleaved feed network is a sample of the sinc function.

[0050] The above-mentioned large-pitch phased array antenna will be explained in detail below with reference to the accompanying drawings and specific embodiments.

[0051] Example 1

[0052] See Figure 1 In this embodiment, a hybrid interleaved feed network was used to design a phased array antenna with a radio frequency channel spacing of 1λ0 to verify the feasibility of the design.

[0053] (1) Hybrid interleaved feeder network

[0054] According to antenna array theory, the radiation pattern is equal to the product of the channel pattern and the array factor pattern. Given the channel spacing and the excitation amplitude and phase, the array factor can be determined. Therefore, to suppress grating lobes outside the scanning region, large-spacing phased array antennas require a flat-top pattern, corresponding to an aperture field distribution with a sinc function.

[0055] To meet this requirement, this embodiment proposes a simple and compact hybrid interleaved power supply network. It can be simplified to... Figure 2The diagram illustrates a hybrid cascaded feeding scheme of N channel ports and M radiating elements. Each channel corresponds to multiple radiating elements, enabling RF channel radiation aperture interleaving. For each channel, the signal from the channel port is evenly distributed by the central T-junction. Then, transmission line segments with different characteristic impedances and lengths are cascaded after the T-junction, each corresponding to an output port (called a radiating element port) connected to a radiating element.

[0056] When a channel port is excited, the excitation from the radiating element of the hybrid interleaved feed network is a sample of a sinc function, specifically, the phase should be 0° or 180°. The excitation amplitude and phase of the radiating element can be controlled by adjusting the characteristic impedance and length of different TL segments. Therefore, a near-sinc function aperture field distribution can be generated, resulting in a top-flat pattern in the far field. In this way, a phased array antenna with low scan gain variation and low grating lobes can be realized.

[0057] (2) Phased array antenna with 1λ0 channel spacing

[0058] This phased array antenna consists of 16 radiating elements with an element spacing of d = 1 / 3λ0. It is fed by 5 radio frequency channels with a channel spacing of 1λ0. The antenna operates in the 9.8-10.2 GHz frequency band. The overall structure is as follows: Figure 1 and Figure 2 As shown.

[0059] The antenna uses a single-layer Rogers 4003 substrate with a thickness of 0.508 mm, and it mainly consists of three parts: 1) a dipole radiating element with a director; 2) a hybrid interleaved network based on a two-line transmission line; and 3) a balun converter that converts the two-line transmission line into a microstrip line.

[0060] Part 1: The basic radiating element of the antenna is a dipole printed on a substrate. There is a vibrating arm on each of the top and bottom sides of the substrate. The 0° / 180° phase can be controlled by adjusting the direction of the two vibrating arms. In addition, multiple directors and a reflector are used to improve the antenna gain and suppress the radiation back lobe.

[0061] Part Two: Hybrid Interleaved Networks Composed of Two-Line Transmission Lines, such as Figure 4 As shown, it has 5 RF channel ports (connecting to the balun converter) and 16 radiating element ports (connecting to the dipole). The length between two adjacent radiating element ports is approximately 1 / 2λ. g (λ g(Wavelength), corresponding to a 180° phase difference. When an RF channel port is excited, the electric field on the port connected to the radiating element is ideally a sample of the sinc function (corresponding to the formation of a flat-topped active radiation pattern in the far-field region). Therefore, it is necessary to adjust the amplitude and phase (0° or 180°) of the radiating element ports on the interleaved network. Specifically, on the one hand, the 0° or 180° phase difference is controlled by flipping the oscillator arm connected to the radiating element port. On the other hand, the amplitude of the excitation is controlled by adjusting the width and length of the two-wire transmission line between the two radiating element ports, such as... Figure 3 As shown.

[0062] Part Three: To connect the two-wire transmission line and the microstrip line, a balun converter is needed. This converter actually achieves the conversion between the two transmission lines through a substrate-integrated waveguide, such as... Figure 5 As shown.

[0063] See Figure 10-12 , Figure 10-12 For the active element radiation patterns of a phased array antenna with a channel spacing of 1λ0 at different frequencies when the middle port is excited, see [reference]. Figure 13-15 , Figure 13-15 A schematic diagram of the scanning performance of a phased array antenna with a channel spacing of 1λ0 at different frequencies.

[0064] Example 2

[0065] See Figure 6 In this embodiment, a hybrid interleaved feed network was used to design a phased array antenna with a radio frequency channel spacing of 1.5λ0 to verify the feasibility of the design.

[0066] This phased array antenna consists of 21 radiating elements with an element spacing of d = 3 / 8λ0. It is fed by 5 radio frequency channels with a channel spacing of 1.5λ0. The antenna operates in the 9.8-10.2 GHz frequency band. The overall structure is as follows: Figure 6 and Figure 7 As shown.

[0067] The phased array antenna with a channel spacing of 1.5λ0 has the same structure as the phased array antenna with a channel spacing of 1λ0 in Embodiment 1. The main difference is the hybrid interleaved network constructed based on two-wire transmission lines in the second part. After the channel spacing is increased from 1λ0 to 1.5λ0, the resulting hybrid interleaved network is as follows: Figure 9 As shown, it has 5 RF channel ports (connecting to the balun converter) and 21 radiating element ports (connecting to the dipole). When one channel is excited, to obtain the electric field distribution of the sinc function, the amplitude and phase of the radiating element are controlled in the same way as the phased array antenna with a 1λ0 channel spacing, as shown. Figure 8 As shown.

[0068] See Figure 16-18 , Figure 16-18 For the active element radiation patterns of a phased array antenna with a channel spacing of 1.5λ0 at different frequencies when the middle port is excited, see [reference]. Figure 19-21 , Figure 19-21 A schematic diagram of the scanning performance of a phased array antenna with a channel spacing of 1.5λ0 at different frequencies.

[0069] In summary, the two-pitch phased array antennas designed in this embodiment employ a simple and compact hybrid interleaved network. Exciting a single channel through this feeding network achieves an approximate sinc function electric field distribution, thereby obtaining an active radiation pattern with a flat top. This structure ensures both low scan gain roll-off and maintains a low sidelobe level for the entire antenna. Compared to similar designs, the proposed design has a more compact and simpler structure while maintaining competitive scanning performance. In general, this application has at least the following advantages and beneficial effects compared to the prior art:

[0070] (1) The hybrid interleaved feed network designed in this embodiment adjusts the amplitude and phase distribution of each radiating element to generate an active radiation pattern with a flat top, which suppresses the grating lobes that appear in the phased array antenna with large spacing RF channel, while ensuring that the phased array antenna achieves a small gain roll-off within the scanning range.

[0071] (2) The large-pitch phased array antenna in this embodiment is based on a hybrid feed interleaved network to achieve a simple and compact antenna structure.

[0072] In the foregoing description of this specification, references to terms such as "one embodiment," "another embodiment," or "some embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0073] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0074] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A large-pitch phased array antenna based on a hybrid interleaved feed network, characterized in that, include: A hybrid interleaved feed network based on a dual-line transmission line structure is disposed on a single-layer substrate and includes N radio frequency channel ports and M radiation unit ports. Each channel port corresponds to multiple radiating units to achieve radio frequency channel radiation aperture interleaving, N < M; The radio frequency channel port is used to connect to the balun converter, and the radiating unit port is used to connect to the dipole. Each radiating unit port corresponds to two oscillator arms, which are respectively disposed on the top and bottom layers of the single-layer substrate, and the two oscillator arms are in opposite directions. By adjusting the direction of the two oscillator arms, a phase difference of 0º or 180º can be achieved. The amplitude of the excitation can be controlled by adjusting the width and / or length of the bi-line transmission line between the two radiating unit ports. When a channel port is excited, the excitation from the radiating element of the hybrid interleaved feed network is a sample of the sinc function.

2. The large-pitch phased array antenna based on a hybrid interleaved feed network according to claim 1, characterized in that, The large-pitch phased array antenna also includes multiple directors and a reflector to improve the antenna gain and suppress radiation back lobes. The director is positioned above the oscillator arm; the reflector is perpendicular to the monolayer substrate and located at the RF channel port, and a channel for the transmission line is provided between the reflector and the monolayer substrate.

3. A large-pitch phased array antenna based on a hybrid interleaved feed network according to claim 1, characterized in that, The hybrid interleaved feed network includes 5 radio frequency channel ports and 16 radiating element ports, with a distance of 1 unit between adjacent radio frequency channel ports. λ 0, the distance between two adjacent radiating element ports is 1 / 3. λ 0, λ 0 represents the operating wavelength of the antenna.

4. A large-pitch phased array antenna based on a hybrid interleaved feed network according to claim 1, characterized in that, The hybrid interleaved feed network includes 5 RF channel ports and 21 radiating element ports, with a distance of 1.5 meters between adjacent RF channel ports. λ 0, the distance between two adjacent radiating element ports is 3 / 8. λ 0, λ 0 represents the operating wavelength of the antenna.

5. A large-pitch phased array antenna based on a hybrid interleaved feed network according to claim 1, characterized in that, The balun converter is used to convert between two types of transmission lines, namely two-line transmission lines and microstrip lines, through a substrate-integrated waveguide.

6. A large-pitch phased array antenna based on a hybrid interleaved feed network according to claim 1, characterized in that, The balun converter is connected to an external SMA connector.

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