A continuously-scannable dual linearly-polarized leaky-wave antenna

Abstract

The application discloses a continuously scanning dual linear polarized leaky-wave antenna, which comprises a lower layer feed waveguide and an upper layer radiation array, and the two layers are connected through a dielectric screw. The feed waveguide is located at the lower layer of the dual linear polarized leaky-wave antenna, and comprises a microstrip impedance transformation structure, a high-dispersion half-mode dielectric substrate integrated waveguide (HSIW), an impedance transition structure between the two, and a row of metalized through holes penetrating through the lower layer dielectric plate. The radiation array is located at the upper layer of the dual linear polarized leaky-wave antenna, and is composed of a row of periodic metal strips, which are uniformly and spacedly arranged on the upper layer dielectric plate, and the metal strips are located at the edge position of the rectangular groove. The application achieves the purpose of fast scanning of the antenna beam, avoids the energy loss caused by lumped components, and can realize the continuous scanning of the beam in two polarization states.

Description

Technical Field

[0001] This invention belongs to the field of microwave antennas, specifically relating to a continuously scanning dual-line polarized leaky wave antenna. Background Technology

[0002] The antenna module is located at the radio frequency terminal of the wireless communication system. As a device for transmitting and receiving radio signals, it is a key node in the entire wireless communication system and determines the performance of the entire communication system.

[0003] Leaky wave antennas are a classic type of beam-scanning antenna. By controlling the energy leakage rate (i.e., the loss constant), they can achieve a narrow beam with high directivity and high gain. Furthermore, based on the traveling wave principle, the main beam of a leaky wave antenna can scan the radiation space as the frequency changes (referred to as "frequency scanning"), which is beneficial for increasing the coverage of radio signals and improving the frequency space reuse rate.

[0004] Compared to the widely used phased array antennas, leaky wave antennas do not require complex feeding networks and large, expensive transceiver components, significantly reducing the cost, design complexity, and weight of antenna modules. Due to their unique advantages, leaky wave antennas can serve as an alternative solution to phased array antenna systems in scenarios with specific requirements regarding cost budget, size, weight, and carrier shape.

[0005] Periodic leaky-wave antennas can achieve beam scanning from back to front, but they inherently suffer from an open stopband. Without specific intervention, the impedance in the normal band is often severely mismatched, leading to a beam scanning dead zone in the normal region. The beam coverage is divided into forward and backward regions, ultimately preventing continuous beam scanning. The study of dual-polarization and multi-polarization performance is also a hot topic in the field of leaky-wave antennas. Traditional designs change the antenna's polarization performance by loading lumped components, i.e., electrically controlled reconfigurable polarization antennas. However, the introduction of numerous components increases the structural complexity (DC bias circuit) and additional losses (losses generated by components) of such multi-polarization antennas. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a dual-polarized continuous scanning leaky-wave antenna, solving the deficiencies of existing leaky-wave antennas. It overcomes the open-stopband problem, widens the coverage area, and enables continuous beam scanning. The mutually perpendicular linear polarization characteristics can be switched by mechanical rotation, avoiding additional energy loss. This invention features high directivity, wide coverage, and dual polarization, and also has the advantages of simple design, compact structure, and low cost. It can be applied to modern wireless communication systems and is a feasible solution to improve the capacity of communication systems by utilizing polarization multiplexing technology (dual polarization) and spatial multiplexing technology (multi-beam).

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A continuously scanning dual-polarized leaky antenna includes a lower feed waveguide and an upper radiating array, which are connected by dielectric screws.

[0009] The feed waveguide is located below the dual-polarized drain wave of the antenna and includes a microstrip impedance transformation structure, a high-dispersion half-mode dielectric substrate integrated waveguide (HSIW), an impedance transition structure between the two, and a row of metallized vias penetrating the lower dielectric substrate, for a total of 11 through-dielectric plates.

[0010] The microstrip impedance transformation structure is a quarter-wavelength microstrip impedance converter that can realize impedance conversion between the RF connector and the high-dispersion HSIW, and can convert the TEM wave (transverse electromagnetic wave) excited by the RF connector into a TE10 mode electromagnetic wave that can be transmitted in the HSIW.

[0011] The impedance transition structure achieves impedance matching between the microstrip impedance transformation structure and the high-dispersion HSIW by tapering the depth of the corrugated groove.

[0012] The high-dispersion HSIW is formed by etching subwavelength periodic grooves along the opening edge on one side of the HSIW's longitudinal direction.

[0013] The high-dispersion HSIW possesses both bandpass and high-dispersion characteristics. The inherent high-pass characteristic of the SIW, combined with the low-pass characteristic generated by the subwavelength periodic groove, results in a bandpass characteristic, which significantly increases its dispersion. The high-dispersion feed waveguide facilitates the realization of leaky-wave antennas with high-speed beam scanning.

[0014] The periodic metal pillars, uniformly spaced and loaded onto the HSIW, can suppress the open-band stoppage phenomenon. By optimizing the position of the metal pillars, the open-band stoppage phenomenon can be eliminated in both vertical and horizontal polarization operating states.

[0015] The radiating array, located on the upper layer of the dual-polarized leaky antenna, consists of a column of 12 periodic metal strips evenly spaced on the upper dielectric substrate. The metal strips are positioned at the edges of rectangular grooves. The excitation signal is gradually coupled to these metal strips via a feed waveguide and then radiated into free space. The antenna polarization performance is altered by mechanically rotating the metal strips by 90°: when the metal strips are placed horizontally, the antenna radiates horizontally polarized waves; when the metal strips are placed vertically, the antenna radiates vertically polarized waves.

[0016] The rectangular groove has little impact on the electromagnetic performance of the antenna. Its function is to mechanically position the metal strip and ensure that the metal strip reaches a horizontal or vertical position when rotating.

[0017] The upper and lower dielectric plates are separated by dielectric supports; dielectric screws pass through the dielectric supports and fix the lower and upper dielectric plates.

[0018] The beneficial effects of this invention are as follows:

[0019] (1) By introducing a subwavelength periodic groove, a feed waveguide structure with high dispersion characteristics is designed, thereby achieving the purpose of fast antenna beam scanning.

[0020] (2) This invention has dual polarization characteristics, which can generate two mutually perpendicular linear polarizations, and is achieved by mechanically rotating the radiation structure to switch them. Compared with other electrically controlled polarized reconfigurable leaky antennas, it avoids the energy loss caused by lumped components.

[0021] (3) The present invention overcomes the problem of open stopband, expands the coverage range, and can achieve continuous beam scanning in both polarization states.

[0022] (4) The present invention has the advantages of simple design, compact structure and low cost. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the beam-reconfigurable leaky antenna described in the embodiment;

[0024] Figure 2 This is a side view schematic diagram of the beam-reconfigurable leaky-wave antenna described in the embodiment;

[0025] Figure 3 This is a schematic diagram of the feed waveguide (lower dielectric substrate 1) of the beam-reconfigurable leaky wave antenna described in the embodiment.

[0026] Figure 4 This is a schematic diagram of the radiating array (upper dielectric substrate 2) of the beam-reconfigurable leaky wave antenna described in the embodiment;

[0027] Figure 5 This is a schematic diagram of the dielectric screw of the beam-reconfigurable leaky antenna described in the embodiment;

[0028] Figure 6 This is a schematic diagram of the periodic rectangular groove and metal strip of the beam-reconfigurable leaky-wave antenna described in the embodiment;

[0029] Figure 7 This is a schematic diagram of the radiation element current distribution of the beam-reconfigurable leaky antenna described in the embodiment.

[0030] Figure 8 This is a schematic diagram of the S-parameter curves of the beam-reconfigurable leaky-wave antenna described in the embodiment.

[0031] Figure 9The radiation pattern of the beam-reconfigurable leaky antenna described in the embodiment is shown when the metal strip is placed horizontally (along the Y-axis).

[0032] Figure 10 The radiation pattern of the beam-reconfigurable leaky antenna when the metal strip is placed vertically (along the X-axis direction) as described in the embodiment.

[0033] Figure 11 The gain curve of the beam-reconfigurable leaky antenna described in the embodiment;

[0034] Figure 12 The efficiency curve of the beam-reconfigurable leaky antenna described in the embodiment;

[0035] In the figure: 1-lower dielectric substrate, 11-microstrip impedance conversion structure, 12-impedance transition structure, 13-high dispersion half-mode waveguide, 14-metallized via, 2-upper dielectric substrate, 21-radiating metal strip array, 22-rectangular groove, 23-dielectric screw, 31-dielectric support, 32-dielectric screw. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of this application provided below with reference to the accompanying drawings is not intended to limit the scope of protection of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The present invention will be further described below with reference to the accompanying drawings.

[0037] A schematic diagram of the beam-reconfigurable leaky antenna described in this embodiment is shown below. Figure 1 As shown, the side view is as follows Figure 2 As shown, the present invention mainly consists of two parts: an antenna feed waveguide and an antenna radiating array. The feed waveguide is located in the lower layer of the dual-polarized leaky antenna and includes a microstrip impedance transformation structure 11, a high-dispersion half-mode dielectric substrate integrated waveguide HSIW 13, an impedance transition structure 12 between the two, and a row of metallized vias 14 penetrating the lower dielectric substrate 1.

[0038] The radiation array is located on the upper layer of the dual-polarized leaky antenna and consists of a column of periodic metal strips 21, which are evenly spaced on the upper dielectric substrate 2. The metal strips 21 are located at the edge of the rectangular groove 22.

[0039] The antenna feed waveguide is implemented on the lower dielectric substrate 1, as follows: Figure 3 As shown. The antenna radiating array is completed on the upper dielectric substrate 2, as follows. Figure 4 As shown in the diagram, the two dielectric substrates are separated by dielectric support pillars 31. Dielectric screws 32 penetrate dielectric substrate 1 and dielectric substrate 2, fixing the lower dielectric substrate 1 and the upper dielectric substrate 2, ultimately forming the structure shown in the diagram. Figure 1 The antenna shown in the schematic diagram. The top and side views of the dielectric screw 32 are as follows. Figure 5 As shown, the left figure is a top view of the dielectric screw, and the right figure is a side view of the dielectric screw. Both the lower dielectric plate 1 and the upper dielectric plate 2 are made of dielectric materials with a relative permittivity of 2.65 and a dielectric loss tangent of 0.0007.

[0040] Furthermore, the two microstrip impedance conversion structures 11 can be connected to external RF connectors, with one end connected to the excitation signal and the other end connected to a 50Ω matching load.

[0041] The microstrip impedance transformation structure 11 is a quarter-wavelength microstrip impedance converter that can realize impedance conversion between the RF connector and the high-dispersion HSIW, and can convert the TEM wave (transverse electromagnetic wave) excited by the RF connector into a TE10 mode electromagnetic wave that can be transmitted in the HSIW.

[0042] When transmitting the TE10 mode, the two narrow metal walls of the substrate integrated waveguide (SIW) can be considered equivalent to electric walls, and the central longitudinal section can be considered equivalent to a magnetic wall. Therefore, the HSIW, which is half the size of the SIW, can also transmit the TE10 mode, with the narrow metal walls considered equivalent to electric walls and the open narrow walls considered equivalent to magnetic walls. That is, compared to the SIW, the size of the HSIW is only half that of the SIW without affecting the dominant mode field distribution.

[0043] Furthermore, the bottom of the lower dielectric substrate 1 is covered with metal, and the metallized through-hole 14 penetrates the lower dielectric substrate 1.

[0044] The 11 metallized vias 14 are evenly spaced on the HSIW13 to suppress open-circuit stopband phenomenon.

[0045] Furthermore, the high-dispersion HSIW13 features subwavelength periodic grooves etched along the opening edge on one side of the HSIW longitudinal direction. These periodic rectangular grooves and metal strips are, for example... Figure 6 As shown, the left image is a top view, and the right image is a side view. Periodic rectangular grooves 22 are engraved on the upper dielectric plate 2, and periodic metal strips 21 are placed on the rectangular grooves 22 and fixed by dielectric screws 23. The metal strips 21 can be manually rotated to distribute horizontally or vertically.

[0046] Furthermore, such as Figure 7As shown, the periodic radiation unit has horizontal polarization current and vertical polarization current respectively, indicating that the vertical and horizontal linear polarization can be switched by manually rotating the metal strip.

[0047] Furthermore, such as Figure 8 The diagram shows the S-parameters of the antenna of this invention, demonstrating good impedance matching performance in the 10.2-14.4 GHz frequency band, achieving |S... 11 | Less than -10dB.

[0048] Furthermore, such as Figure 9 As shown, the radiation gain pattern of the linearly polarized leaky antenna in the yoz plane is displayed when the metal strip is placed horizontally. It is found that the frequency scanning characteristics of the radiation beam from -25° to 28° are achieved in this scanning plane.

[0049] Furthermore, such as Figure 10 As shown, the radiation gain pattern of the linearly polarized leaky antenna in the yoz plane is displayed when the metal strip is placed vertically. It is found that the frequency scanning characteristics of the radiation beam from -58° to 39° are achieved in this scanning plane.

[0050] Furthermore, such as Figure 11 The figure shows the gain curves of the linearly polarized leaky antenna in the 10-15 GHz range when the metal strip is placed horizontally and vertically. The figure shows that the maximum gain of the antenna is approximately 16.7 dB.

[0051] Furthermore, such as Figure 12 The figure shows the efficiency curves of the linearly polarized leaky antenna in the 10-15 GHz range when the metal strip is placed horizontally and vertically. It can be seen from the figure that the overall efficiency of the antenna is above 90% between approximately 11-14 GHz.

[0052] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A continuously-scannable dual linearly-polarized leaky-wave antenna, characterized by, It includes a lower-layer feed waveguide and an upper-layer radiation array, which are connected by a dielectric screw (32); The feed waveguide is located in the lower layer of the dual-polarized leaky antenna and includes a microstrip impedance transformation structure (11), a high dispersion half-mode dielectric substrate integrated waveguide (HSIW) (13), an impedance transition structure (12) between the two, and a row of metallized vias (14) penetrating the lower dielectric substrate (1). The radiation array is located on the upper layer of the dual-polarized leaky antenna and consists of a column of periodic metal strips (21) arranged at uniform intervals on the upper dielectric plate (2). The metal strips (21) are located at the edge of the rectangular groove (22). There are 12 rectangular grooves (22) engraved on the upper medium plate (2) to mechanically position the metal strip (21). The metal strip (21) is horizontally and vertically distributed by mechanically rotating the metal strip (21) by 90°. The metal strip (21) is fixed to the rectangular groove (22) by the medium screw (23).

2. The continuously scannable dual-linear polarized leaky antenna according to claim 1, characterized in that, The high-dispersion half-mode dielectric substrate integrated waveguide HSIW (13) is formed by etching a subwavelength periodic groove along the opening edge of one side of the high-dispersion half-mode dielectric substrate integrated waveguide HSIW. The high-dispersion half-mode dielectric substrate integrated waveguide HSIW (13) has bandpass characteristics and high dispersion characteristics.

3. The continuously-scannable dual linearly-polarized leaky-wave antenna of claim 2, wherein, The microstrip impedance transformation structure (11) is a quarter-wavelength microstrip impedance transformer that realizes impedance transformation between the RF connector and the high-dispersion half-mode dielectric substrate integrated waveguide HSIW (13), and converts the transverse electromagnetic wave TEM wave excited by the RF connector into a TE10 mode electromagnetic wave transmitted in the high-dispersion half-mode dielectric substrate integrated waveguide HSIW (13).

4. The continuously scannable dual-linear polarized leaky antenna according to claim 3, characterized in that, The impedance transition structure (12) achieves impedance matching between the microstrip impedance transformation structure (11) and the high dispersion half-mode dielectric substrate integrated waveguide (HSIW) (13) by tapering the depth of the corrugated groove.

5. The continuously-scannable dual linearly-polarized leaky-wave antenna of claim 4, wherein, The 11 metallized vias (14) are uniformly spaced on the high dispersion half-mode dielectric substrate integrated waveguide HSIW (13) to suppress the open-circuit stopband phenomenon.

6. The continuously-scannable dual linearly-polarized leaky-wave antenna according to any one of claims 1 to 5, characterized in that, The upper and lower dielectric plates are separated by a dielectric support (31); a dielectric screw (32) passes through the dielectric support (31) and the lower dielectric plate (1) and the upper dielectric plate (2) to fix the lower dielectric plate (1) and the upper dielectric plate (2).

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