High-isolation double-frequency common-caliber miniaturized phased-array antenna

Abstract

The invention relates to the technical field of antennas, in particular to a high-isolation double-frequency common-caliber miniaturized phased-array antenna which comprises a high-frequency-band linear polarization end-fire metal patch array structure, a low-frequency-band linear polarization end-fire metal patch array structure, a public metal reflection floor and a single-layer dielectric substrate. Radiation structures of the high-frequency-band linear polarization end-fire metal patch array structure and the low-frequency-band linear polarization end-fire metal patch array structure are formed by improved dipoles of microstrip balun feed with out-of-band rejection, so that linear polarization is achieved, and then the dipoles are fed through the improved microstrip balun with out-of-band radiation rejection. The suppression on high frequency is further deepened and the decoupling bandwidth is expanded; in addition, a decoupling structure is added between the adjacent common-frequency antennas to improve the isolation and radiation capability between the adjacent common-frequency antenna units, high isolation and wide beam coverage of the dual-frequency common-aperture phased-array antenna can be realized, the performance of the antenna is improved, and the dual-frequency common-aperture phased-array antenna is simple in process and low in cost.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a high-isolation dual-frequency common-aperture miniaturized phased array antenna. Background Art

[0002] Phased array antennas play an important role in radar systems. As radar systems develop from single functions to multi-function integration, the performance requirements for wide-angle scanning and dual-frequency (multi-frequency) multiplexing of phased array antennas are also very urgent. As an emerging development direction of phased array antennas, common aperture technology has the advantage of integrating multi-band and multi-polarization antennas in the same compact radiation aperture through structural multiplexing. It has a wide range of application value in radar systems. However, it puts forward higher requirements for compactly arranged common aperture phased array antennas, especially requiring high isolation between dual-frequency antennas and strong interference suppression capabilities to meet the requirements of dual-frequency antennas working simultaneously after common aperture. Secondly, the beam of the common aperture phased array antenna is required to cover as large a range as possible.

[0003] At present, common methods for suppressing the isolation between dual-frequency antennas include loading frequency selective surfaces between dual-frequency antenna layers, cascading filters at the antenna feed end, and utilizing the cutoff frequency characteristics of waveguides to achieve high isolation between dual-frequency antennas. However, the above methods face problems in large-angle scanning, low insertion loss, and low-cost applications. Summary of the invention

[0004] The purpose of the present invention is to provide a high-isolation dual-frequency co-aperture miniaturized phased array antenna, aiming to solve the problems faced in designing existing co-aperture phased array antennas for radar systems, such as difficult array topology layout, severe coupling between the same frequency and different frequencies, and limited scanning range.

[0005] To achieve the above object, the present invention provides a high-isolation dual-frequency co-aperture miniaturized phased array antenna, comprising a high-frequency linear polarization end-fire metal patch array structure, a low-frequency linear polarization end-fire metal patch array structure, a common metal reflection floor and a single-layer dielectric substrate;

[0006] The high-frequency linear polarization end-fire metal patch array structure and the low-frequency linear polarization end-fire metal patch array structure are located above the common metal reflection floor and are respectively attached to the common metal reflection floor. The thickness of the common metal reflection floor is 1 mm. The high-frequency linear polarization end-fire metal patch array structure and the low-frequency linear polarization end-fire metal patch array structure are periodically alternately arranged along the X-axis direction of the common metal reflection floor. The high-frequency linear polarization end-fire metal patch array structure and the low-frequency linear polarization end-fire metal patch array structure are respectively arranged in a repeated periodic manner along the Y-axis direction.

[0007] Among them, there are 4 low-frequency band linear polarization end-fire metal patch array structures and 4 high-frequency band linear polarization end-fire metal patch array structures, and the 4 low-frequency band linear polarization end-fire metal patch array structures and the 4 high-frequency band linear polarization end-fire metal patch array structures are alternately repeated in the X-axis direction, and the spacing between adjacent low-frequency band linear polarization end-fire metal patch array structures and high-frequency band linear polarization end-fire metal patch array structures is 27.5 mm.

[0008] Among them, each of the low-frequency band linear polarization end-fire metal patch array structures is composed of 4 radiating units, the 4 radiating units are periodically repeated along the Y-axis direction, and the spacing between every two radiating units is 75 mm; each of the high-frequency band linear polarization end-fire metal patch array structures is also composed of 4 radiating units, the 4 radiating units are periodically repeated along the Y-axis direction, and the spacing between every two radiating units is 45 mm.

[0009] Among them, each radiating unit in the low-frequency linear polarization end-fire metal patch array structure and the high-frequency linear polarization end-fire metal patch array structure is composed of a miniaturized dipole fed by a microstrip balun with out-of-band suppression and a decoupling structure, wherein the low-frequency decoupling structure is arranged between two adjacent low-frequency miniaturized dipole units fed by a microstrip balun with out-of-band suppression, and the high-frequency decoupling structure is also located between the high-frequency miniaturized dipole units fed by a microstrip balun with out-of-band suppression, and the low-frequency inter-antenna decoupling structure and the high-frequency inter-antenna decoupling structure are respectively formed by cascading two open rings with different opening directions.

[0010] Among them, the miniaturized dipole fed by a microstrip balun with out-of-band suppression at a low frequency and the miniaturized dipole fed by a microstrip balun with out-of-band suppression at a high frequency are both composed of a horizontal dipole arm and a vertical dipole arm, and a gap is left between the horizontal dipole arm and the vertical dipole arm.

[0011] The horizontal metal arms and the vertical metal arms in the horizontal dipole arms and the vertical dipole arms are etched with rings of different sizes, and the horizontal metal arms and the vertical metal arms are symmetrically distributed.

[0012] Among them, each miniaturized dipole fed by a low-frequency microstrip balun with out-of-band suppression or a miniaturized dipole fed by a high-frequency microstrip balun with out-of-band suppression is respectively added with a pair of short-circuit branches on the basis of traditional microstrip balun feeding. The short-circuit branches provide out-of-band radiation suppression at high frequencies for the low-frequency microstrip balun and provide out-of-band radiation suppression at low frequencies for the high-frequency microstrip balun.

[0013] The present invention provides a high-isolation dual-frequency co-aperture miniaturized phased array antenna, comprising a high-frequency linear-polarization end-fire metal patch array structure, a low-frequency linear-polarization end-fire metal patch array structure, a common metal reflection floor and a single-layer dielectric substrate, wherein the radiation structures of the high-frequency linear-polarization end-fire metal patch array structure and the low-frequency linear-polarization end-fire metal patch array structure are both composed of dipoles fed by improved microstrip baluns with out-of-band suppression, thereby realizing linear polarization, and then the dipoles are fed by the improved microstrip balun with out-of-band radiation suppression, so as to further deepen the suppression of high frequencies and expand the decoupling bandwidth; in addition, the present invention adds a decoupling structure between adjacent same-frequency antennas to improve the isolation and radiation capability between adjacent same-frequency antenna units. The present invention can achieve high isolation and wide beam coverage of the dual-frequency co-aperture phased array antenna, improve the performance of the antenna, and at the same time, the process is simple and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a three-dimensional structural schematic diagram of a high-isolation dual-frequency common-aperture miniaturized phased array antenna of the present invention.

[0016] Figure 2 It is a schematic diagram of the main viewing angle of a high-isolation dual-frequency common-aperture miniaturized phased array antenna of the present invention.

[0017] Figure 3 It is a schematic diagram of the miniaturized dipole structure of the low-frequency microstrip balun feed with out-of-band suppression of the present invention.

[0018] Figure 4 It is a schematic diagram of the miniaturized dipole structure of the high frequency microstrip balun feed with out-of-band suppression of the present invention.

[0019] Figure 5 It is a schematic diagram of the miniaturized dipole surface current and beam expansion of the microstrip balun feed of the present invention.

[0020] Figure 6 The surface current vector distribution diagrams of the miniaturized dipole fed by the low-frequency microstrip balun of the present invention at low frequencies and high frequencies respectively.

[0021] Figure 7 These are the surface current vector distribution diagrams of the miniaturized dipole fed by the high-frequency microstrip balun of the present invention at low frequencies and high frequencies respectively.

[0022] Figure 8 The surface current vector distribution diagrams of the low-frequency microstrip balun with out-of-band radiation suppression at low frequencies and high frequencies respectively.

[0023] Fig. 9 The surface current vector distribution diagrams of the high-frequency microstrip balun with out-of-band radiation suppression at low frequencies and high frequencies respectively.

[0024] Fig.10 It is a comparison diagram of the surface current of the miniaturized dipole fed by adjacent low-frequency and high-frequency microstrip baluns of the present invention before and after the decoupling structure is loaded.

[0025] Fig.11 The present invention discloses a high-isolation dual-frequency common-aperture miniaturized phased array antenna with different frequency isolation between different antenna channels.

[0026] Fig.12 The present invention discloses a high-isolation dual-frequency common-aperture miniaturized phased array antenna with same-frequency isolation between adjacent channels of high-frequency and low-frequency antennas.

[0027] Fig.13 It is a scanning pattern of a high-isolation dual-frequency common-aperture miniaturized phased array antenna of the present invention along the E / H plane at 1.65GHz, 13(a) is the scanning pattern along the E plane, and 13(b) is the scanning pattern along the H plane.

[0028] Fig.14 It is a scanning pattern of a high-isolation dual-frequency common-aperture miniaturized phased array antenna of the present invention along the E / H plane at 2.7 GHz, 14(a) is the scanning pattern along the E plane, and 14(b) is the scanning pattern along the H plane.

[0029] 101-high frequency band linear polarization end-fire metal patch array structure, 102-low frequency band linear polarization end-fire metal patch array structure, 103-common metal reflection floor, 104-single-layer dielectric substrate, 105-low frequency antenna decoupling structure, 106-high frequency antenna decoupling structure, 107-low frequency microstrip balun-fed miniaturized dipole with out-of-band suppression, 108-high frequency microstrip balun-fed miniaturized dipole with out-of-band suppression. DETAILED DESCRIPTION

[0030] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0031] See also Figures 1 to 4The present invention provides a high-isolation dual-frequency common-aperture miniaturized phased array antenna, a high-frequency linear polarization end-fire metal patch array structure 101, a low-frequency linear polarization end-fire metal patch array structure 102, a common metal reflection floor 103 and a single-layer dielectric substrate 104;

[0032] The high-frequency linear polarization end-fire metal patch array structure 101 and the low-frequency linear polarization end-fire metal patch array structure 102 are located above the common metal reflection floor 103 and are respectively attached to the common metal reflection floor 103. The thickness of the common metal reflection floor 103 is 1 mm. The high-frequency linear polarization end-fire metal patch array structure 101 and the low-frequency linear polarization end-fire metal patch array structure 102 are periodically alternately arranged along the X-axis direction of the common metal reflection floor 103. The high-frequency linear polarization end-fire metal patch array structure 101 and the low-frequency linear polarization end-fire metal patch array structure 102 are respectively repeatedly periodically arranged along the Y-axis direction.

[0033] The single-layer dielectric substrate 104 is a substrate for the high-frequency band linear-polarized end-fire metal patch array structure 101 and the low-frequency band linear-polarized end-fire metal patch array structure 102 .

[0034] There are four low-frequency linear polarization end-fire metal patch array structures 102 and four high-frequency linear polarization end-fire metal patch array structures 101. The four low-frequency linear polarization end-fire metal patch array structures 102 and the four high-frequency linear polarization end-fire metal patch array structures 101 appear alternately in the X-axis direction, and the spacing between adjacent low-frequency linear polarization end-fire metal patch array structures 102 and high-frequency linear polarization end-fire metal patch array structures 101 is 27.5 mm.

[0035] Each of the low-frequency linear polarization end-fire metal patch array structures 102 is composed of 4 radiating units, which are periodically repeated along the Y-axis direction, and the spacing between each two radiating units is 75 mm; each of the high-frequency linear polarization end-fire metal patch array structures 101 is also composed of 4 radiating units, which are periodically repeated along the Y-axis direction, and the spacing between each two radiating units is 45 mm.

[0036] Each radiating unit in the low-frequency linear polarization end-fire metal patch array structure 102 and the high-frequency linear polarization end-fire metal patch array structure 101 is composed of a miniaturized dipole fed by a microstrip balun with out-of-band suppression and a decoupling structure, wherein the low-frequency decoupling structure is arranged between two adjacent low-frequency miniaturized dipole 107 units fed by a microstrip balun with out-of-band suppression, and the high-frequency decoupling structure is also located between the high-frequency miniaturized dipole 108 units fed by a microstrip balun with out-of-band suppression, and the low-frequency inter-antenna decoupling structure 105 and the high-frequency inter-antenna decoupling structure 106 are respectively formed by cascading two open rings with different opening directions.

[0037] The miniaturized dipole 107 fed by a microstrip balun with out-of-band suppression at low frequency and the miniaturized dipole 108 fed by a microstrip balun with out-of-band suppression at high frequency are both composed of a horizontal dipole arm and a vertical dipole arm, and a gap is left between the horizontal dipole arm and the vertical dipole arm.

[0038] The horizontal metal arms and the vertical metal arms in the horizontal dipole arms and the vertical dipole arms are etched with rings of different sizes, and the horizontal metal arms and the vertical metal arms are symmetrically distributed.

[0039] In this embodiment, by bending the dipole arms of the miniaturized dipole 107 fed by a microstrip balun with out-of-band suppression at a low frequency and the miniaturized dipole 108 fed by a microstrip balun with out-of-band suppression at a high frequency, and then using capacitive coupling to extend the current path and generate a vertical current, thereby forming horizontal radiation, the miniaturization of the dipole antenna along the X-axis and the expansion of the beam width of the antenna unit can be effectively achieved; then, in order to effectively integrate the two dipole antennas working in different frequency bands to work in the same aperture plane, the two dipole antennas working in different frequency bands are miniaturized to different degrees, respectively, so that the antenna units of the two frequency bands can be arranged along the X-axis and the Y-axis with a half-wavelength unit spacing, which can avoid the appearance of grating lobes during large-angle beam scanning of the dual-frequency antenna, and further improve the beam scanning coverage of the dual-frequency antenna.

[0040] Secondly, not only the wide beam and miniaturization design of the dipole antenna is carried out, but also the horizontal and vertical radiating arms of the dipole antenna working in two frequency bands are etched with loops of different sizes to generate reverse currents at different frequencies, which can effectively suppress the induced currents generated by the different frequency antennas when they are working, thereby suppressing radiation and improving the isolation between different frequency antennas. In addition, in order to further improve the isolation between different frequency antennas, the improved microstrip feed balun with out-of-band suppression adds a pair of short-circuit branches on the basis of the traditional microstrip balun. Due to the addition of the short-circuit branches, the induced currents at different frequencies can be effectively suppressed, further deepening the isolation of different frequencies.

[0041] The low-frequency antenna decoupling structure 105 and the high-frequency antenna decoupling structure 106 are formed by mirror-connecting two open rings with different opening directions in a cascade manner. The cascading method can deepen the surface wave suppression between adjacent antennas by the open rings, improve the isolation between adjacent antennas, enhance the radiation and matching performance of the antennas, and realize the miniaturization of the decoupling structure and the expansion of the same-frequency decoupling bandwidth between antennas.

[0042] Furthermore, the horizontal metal arm of each miniaturized dipole fed by a microstrip balun with out-of-band suppression is formed by etching different rings, and a gap is left between the horizontal metal arm and the vertical parasitic metal arm, and a gap is also left between the vertical parasitic radiating arm and the common metal floor. These two gaps couple the energy of the horizontal radiating arm and the common metal floor to the vertical parasitic radiating arm, which can be used to increase the vertical current on the vertical parasitic radiating arm and widen the horizontal radiation. The capacitive component provided by the capacitive coupling arm can partially offset the inductive component between the antenna and the common reflection, and can also widen the working bandwidth of the antenna unit.

[0043] See also Figures 5 to 14 , the present invention further illustrates the antenna performance in conjunction with the performance parameter diagram.

[0044] In summary, compared with the prior art, the present invention has the following advantages and effects:

[0045] 1. The present invention places antenna units of different frequency bands on the same aperture plane. At the same time, in order to avoid grating lobes and radiation shielding when the two antenna arrays are performing large-angle scanning, the antenna units of the two frequency bands are miniaturized to varying degrees, and the unit spacing of the two antennas in the X-axis and Y-axis is within half a wavelength. Then, a coupling gap is left on the bent dipole antenna arm to achieve a longer vertical antenna arm. The vertical antenna arm couples energy not only from the horizontal antenna arm but also from the reflective floor. The vertical antenna arm couples more energy, the antenna unit achieves a wider beam width, and the high and low frequency antenna arrays achieve wide-angle beam coverage.

[0046] 2. The miniaturized dipole fed by the improved microstrip balun with out-of-band suppression of the present invention provides linear polarization. On the basis of realizing the miniaturization of the antenna and the wide beam radiation characteristics, out-of-band suppression of high frequency is generated by etching loops of different sizes on the horizontal antenna radiation metal arm and the vertical antenna radiation metal arm. Then, the dipole is fed by the improved microstrip balun with out-of-band radiation suppression to further deepen the suppression of high frequency and expand the decoupling bandwidth. By etching a hybrid out-of-band suppression method of loops of different sizes and a feeding balun with out-of-band radiation, the antenna array achieves broadband out-of-band decoupling and stronger out-of-band decoupling capability.

[0047] 3. In order to solve the strong coupling between adjacent antennas of the same frequency, the present invention adds a parasitic metal decoupling structure between the miniaturized dipoles fed by the adjacent high-frequency and low-frequency microstrip baluns with out-of-band suppression, respectively. Through the decoupling structure of a novel cascaded mirror structure, the miniaturization of the decoupling structure and the widening of the decoupling bandwidth between antennas of the same frequency are achieved, thereby reducing the coupling between adjacent antennas of the same frequency and improving the radiation capability of the antenna.

[0048] What is disclosed above is only one or more preferred embodiments of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of implementing the above embodiments and making equivalent changes according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A high-isolation dual-frequency common-aperture miniaturized phased array antenna, characterized in that: It includes a high-frequency linear polarization end-fire metal patch array structure, a low-frequency linear polarization end-fire metal patch array structure, a common metal reflection floor and a single-layer dielectric substrate; The high-frequency linear polarization end-fire metal patch array structure and the low-frequency linear polarization end-fire metal patch array structure are located above the common metal reflection floor and are respectively attached to the common metal reflection floor. The thickness of the common metal reflection floor is 1 mm. The high-frequency linear polarization end-fire metal patch array structure and the low-frequency linear polarization end-fire metal patch array structure are periodically alternately arranged along the X-axis direction of the common metal reflection floor. The high-frequency linear polarization end-fire metal patch array structure and the low-frequency linear polarization end-fire metal patch array structure are respectively arranged in a repeated periodic manner along the Y-axis direction.

2. The high-isolation dual-frequency common-aperture miniaturized phased array antenna according to claim 1, characterized in that: There are 4 low-frequency band linear polarization end-fire metal patch array structures and 4 high-frequency band linear polarization end-fire metal patch array structures. The 4 low-frequency band linear polarization end-fire metal patch array structures and the 4 high-frequency band linear polarization end-fire metal patch array structures are repeated alternately in the X-axis direction, and the spacing between adjacent low-frequency band linear polarization end-fire metal patch array structures and high-frequency band linear polarization end-fire metal patch array structures is 27.5 mm.

3. The high-isolation dual-frequency common-aperture miniaturized phased array antenna according to claim 2, characterized in that: Each of the low-frequency linear polarization end-fire metal patch array structures is composed of 4 radiating units, which are periodically repeated along the Y-axis direction, and the spacing between each two radiating units is 75 mm; each of the high-frequency linear polarization end-fire metal patch array structures is also composed of 4 radiating units, which are periodically repeated along the Y-axis direction, and the spacing between each two radiating units is 45 mm.

4. The high-isolation dual-frequency common-aperture miniaturized phased array antenna according to claim 3, characterized in that: Each radiating unit in the low-frequency linear polarization end-fire metal patch array structure and the high-frequency linear polarization end-fire metal patch array structure is composed of a miniaturized dipole fed by a microstrip balun with out-of-band suppression and a decoupling structure, wherein the low-frequency decoupling structure is arranged between two adjacent low-frequency miniaturized dipole units fed by a microstrip balun with out-of-band suppression, and the high-frequency decoupling structure is also located between the high-frequency miniaturized dipole units fed by a microstrip balun with out-of-band suppression, and the low-frequency inter-antenna decoupling structure and the high-frequency inter-antenna decoupling structure are respectively formed by cascading two open rings with different opening directions.

5. The high-isolation dual-frequency common-aperture miniaturized phased array antenna according to claim 4, characterized in that: The miniaturized dipole fed by a microstrip balun with out-of-band suppression at low frequency and the miniaturized dipole fed by a microstrip balun with out-of-band suppression at high frequency are both composed of a horizontal dipole arm and a vertical dipole arm, and a gap is left between the horizontal dipole arm and the vertical dipole arm.

6. The high-isolation dual-frequency common-aperture miniaturized phased array antenna according to claim 5, characterized in that: The horizontal metal arms and the vertical metal arms in the horizontal dipole arms and the vertical dipole arms are etched with rings of different sizes, and the horizontal metal arms and the vertical metal arms are symmetrically distributed.

7. The high-isolation dual-frequency common-aperture miniaturized phased array antenna according to claim 6, characterized in that: Each miniaturized dipole fed by a low-frequency microstrip balun with out-of-band suppression or a miniaturized dipole fed by a high-frequency microstrip balun with out-of-band suppression is respectively added with a pair of short-circuit branches on the basis of traditional microstrip balun feeding. The short-circuit branches provide out-of-band radiation suppression at high frequencies for the low-frequency microstrip balun and provide out-of-band radiation suppression at low frequencies for the high-frequency microstrip balun.

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