CN110233334A - The horizontal polarization leaky-wave antenna of mirror image Medium Wave Guide is integrated based on substrate - Google Patents

Abstract

The present invention provides a kind of horizontal polarization leaky-wave antenna that mirror image Medium Wave Guide is integrated based on substrate, including feeder line structure, irradiation structure, and feed structure, the feeder line structure of antenna with being followed successively by feeder line lower metal from the bottom up, feeder line dielectric layer, irradiation structure includes multiple radiating elements, radiating element is the metal strip shape patch for being tightly attached to central transmission band part upper surface, feed structure is from the bottom up successively comprising feed structure lower metal, feed structure dielectric layer, upper layer metal, the present invention combines corresponding radiating element that can realize miniaturization under the premise of guaranteeing that leaky-wave antenna is efficient using SIIG feeder line；The present invention is applied in array figuration with SIIG feeder line combination radiating element, and the high efficiency and miniaturization of antenna can be realized while guaranteeing figuration effect.

Description

Horizontally polarized leaky-wave antenna based on substrate-integrated image dielectric waveguide

technical field

The invention belongs to the technical field of leaky wave antennas, relates to SIIG technology and antenna miniaturization technology, and specifically relates to a horizontally polarized leaky wave antenna based on a substrate-integrated image dielectric waveguide.

Background technique

The leaky wave antenna is an antenna that radiates into space by generating energy leakage in the longitudinal direction of the waveguide structure. It can be divided into continuous leaky wave antenna and periodic leaky wave antenna in form. The periodic leaky wave antenna is composed of a uniform guided wave structure with periodic loading, and radiates energy outward through surface loading. This antenna has the characteristics of low profile, commonality with metal planes and beam scanning by changing frequency. Compared with the uniform leaky wave antenna, the periodic leaky wave antenna usually has better directionality, larger scanning range and more flexible design scheme, and is more suitable for beamforming. For periodic leaky wave antennas, the element spacing is determined by the beam pointing and the waveguide wavelength of the feeder. For the leaky wave antenna, under the condition that the beam pointing is determined, the element spacing is proportional to the working wavelength. Currently common feeders include microstrip lines, coplanar waveguides, and substrate integrated waveguides (The substrate integrated waveguide, SIW). The distance between elements of the wave antenna is large, and a sufficient number of elements is required to ensure the radiation efficiency of the antenna, which makes it difficult to miniaturize the antenna. At the same time, in the shaping design of the array, enough elements are also needed to achieve a good shaping effect, which further increases the difficulty of the miniaturization design of the leaky-wave antenna with beam-forming capability. For example, the literature "Y.Geng, J.Wang, Y.Li, Zheng Li, M. Chen and Z.Zhang, "High-efficiency leaky-wave antenna array with sidelobe suppression and multibeam generation", IEEEAntennas Wireless Propag. Lett., In vol 16, pp.2787-2790, 2017", the SIW is used as the feeder, and a horizontal slot is opened on its top as the radiation unit. By changing the length of the slot, the radiation capability of the unit is adjusted to realize beamforming. Under the condition that its sidelobe level is -20.8dB and its efficiency is 85.9%, its electrical length is 8.5 free space wavelengths, which is difficult to meet the miniaturization requirement.

In order to solve this problem, the present invention proposes to use the substrate integrated image guide (SIIG) as the feeder to load the leaky wave antenna of the horizontally polarized metal patch unit. Since SIIG is usually processed with a high dielectric constant substrate, its waveguide wavelength is small, so the unit spacing is small; at the same time, the radiation unit used has a strong radiation ability, and the unit spacing can be further reduced to half of the original through phase compensation .

SIIG-based leaky wave array antennas such as the literature "A.Patrovsky and K.Wu, "Substrate Integrated Image Guide Array Antenna for the Upper Millimeter-Wave Spectrum", IEEE Transactions on Antennas and Propagation, vol.55, no.11, pp. 2994-3001, 2007" and the literature "YJCheng, YXGuo and XY Bao, et al., "Millimeter-Wave LowTemperature Co-Fired Ceramic Leaky-Wave Antenna and Array Based on the Substrate Integrated Image Guide Technology", IEEE Trans.Antennas Propag. ,vol.62, no.2, pp.669-676, 2014", they all use metal patches as radiation elements to radiate vertically polarized waves, these element forms cannot be designed for phase compensation, and the array does not perform beamforming and miniaturized design. Literature "MengTian Mu, Yu Jian Cheng, "Low sidelobe level short leaky-wave antenna based onsingle-layer PCB-based substrate integrated image guide", IEEE AntennasWirel.Propag.Lett., vol.17, no.8, pp.2787 In -2790,2018", the SIIG leaky wave antenna was shaped and miniaturized. However, its unit radiates vertically polarized waves and cannot perform phase compensation. Another example is the literature "N.tDolatsha and J.Hesselbarth, Millimeter-wave antenna array fed by an insulated image guide operating in higher-order mode", IEEE Trans.Antennas Propag., vol.61, no.6, pp.3369–3373, 2013", using SIIG high-order mode to excite the dipole array to radiate horizontally polarized waves. Due to the use of high-order mode, Compared with other feeder forms, its unit spacing is not significantly reduced, so miniaturization cannot be achieved.

It can be found that it is difficult for existing schemes to use SIW and other transmission lines as leaky-wave antenna feeders to meet the requirements of beamforming, miniaturization, and high efficiency at the same time for leaky-wave array antennas; Array shaping and miniaturization design of polarized radiation leaky wave antenna.

Contents of the invention

The purpose of the present invention is to solve the problem that it is difficult to realize beamforming, miniaturization and high efficiency at the same time based on the leaky wave antenna, and propose a horizontally polarized leaky wave antenna array based on the SIIG structure, combined with the short wavelength of the SIIG waveguide and the phase of the radiation unit The compensation feature ensures high efficiency and miniaturization of the antenna while performing beamforming.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A horizontally polarized leaky-wave antenna based on a substrate-integrated image dielectric waveguide, including a feeder structure 1, a radiation structure 2 and a feeder structure 3,

The feeder structure 1 of the antenna includes, from bottom to top, the metal ground 12 of the lower layer of the feeder, and the feeder dielectric layer 11, wherein the feeder dielectric layer 11 is symmetrically arranged with two air hole areas 112 left and right along the central axis, and between the two air hole areas 112 Be the central transmission belt 111;

The radiation structure 2 includes a plurality of radiation units. The radiation unit is a metal strip-shaped patch 21 close to the upper surface of the central transmission belt part 111. The metal strip-shaped patches 21 are arranged along the electromagnetic wave propagation direction of the central transmission belt. The angle between the strip patch 21 and the central axis 113 of the conveyor belt is not 0 degrees or 90 degrees, and the inclination directions of two adjacent metal strip patches 21 are opposite, and the midpoint of each metal strip patch is at On the central axis 113 of the transmission belt, the distance between two adjacent metal strip-shaped patches 21 on the central axis 113 of the transmission belt is equal, and the feeder structure 1 and the radiation structure 2 constitute the radiation part of the antenna;

The feed structure 3 includes the lower metal ground 33 of the feed structure, the dielectric layer 32 of the feed structure, and the upper metal 31 in order from bottom to top. On the layer 32, there is a metallized through hole 321 penetrating through the feeding medium at the position corresponding to the bottom circular groove 331, and the top layer circular groove 311 is opened on the upper layer metal 31 corresponding to the position of the bottom circular groove 331, and the metal through the feeding medium The through hole 321, the circular groove 311 on the top layer, and the circular groove 331 on the bottom layer coincide with the three circle centers, and run through the SIW transition structure metallized through hole of the three layers of the lower metal ground 33 of the feed structure, the feed structure dielectric layer 32, and the upper metal 31 34 are arranged as a SIW transition structure, the metallized through-hole 321 penetrating through the feed medium, the top circular groove 311 and the bottom circular groove 331 are all located inside the SIW transition structure, and the coaxial probe is inserted into the metallized through-hole through the feed medium. In the hole 321, the part where the coaxial probe protrudes from the dielectric layer 32 of the feed structure is covered by the metal cavity 35; at the intersection of the SIW transition structure and the feed line structure, a gradual deformation groove 312 is opened on the central axis of the upper metal layer 31, and the gradual change The groove 312 gradually widens along the direction from the feed structure 3 to the feed line structure 1, so as to achieve impedance matching with the feed line structure 1; at the end of the upper layer metal 31, a plurality of medium layers penetrating the feed structure and the lower layer of the feed structure are arranged laterally In the metallized through hole 36 of the metal ground, the central axis of the feeder structure coincides with the central axis of the feeder structure.

As an optimal method, in the direction perpendicular to the propagation direction of the electromagnetic wave of the feeder line, multiple radiation parts are arranged side by side, and the original one-dimensional linear array is expanded into a two-dimensional array, and then two-dimensional shaping is performed; the formed two-dimensional array The feeder structure shares the feeder dielectric layer 11 and the feeder lower layer metal ground 12 .

As a preferred method, the width of the central transmission belt is 6mm, and the perforated areas on both sides have air hole areas formed by 5 rows of non-metallized holes. The diameter of the non-metallized holes is 1.8mm, and the period is 2mm. Each non-metallized hole and The two upper and lower non-metallized holes adjacent to the right side are arranged in an equilateral triangle.

As a preferred manner, the radiation structure 2 includes 28 units, the unit pitch is 4 mm, the width is 1.6 mm, and the length is 5.7 mm.

As a preferred manner, each radiating unit includes two parallel metal strips.

The working principle of the present invention is as follows:

For the radiating unit, suppose the radiation electric fields of two adjacent units are E ₁ and E ₂ , the inclination angles are α ₁ and α ₂ , and the free space wavenumber is k ₀ , then the superposition of the radiation electric field at the angle θ of the pattern can be expressed as For formula (1):

When the phase difference between the two (-Δθ+π) is guaranteed to be within a certain range between 0 and π (not 0 or π), in the θ direction, the electric field of the horizontally polarized wave The maximum is the sum of the two field strengths; and the vertically polarized electric field E _{θ is} the smallest, which is the difference between the two field strengths. This conclusion also applies to arrays composed of units of this form. The angle at which the sum of the radiation fields is the largest is the beam pointing of the array, so for this array antenna, its beam pointing θ ₀ can be expressed as formula (2):

For an ordinary periodic leaky wave antenna that radiates -1 harmonic, its beam pointing to θ ₀ can be expressed as formula (3):

The difference between formula (2) and formula (3) can be understood as that for the horizontally polarized unit proposed by the present invention, the inclination directions of two adjacent units are opposite, which is equivalent to introducing phase compensation with a magnitude of π. Therefore, for this kind of unit, under the condition that the beam points to a certain point, the distance between the units is half of the original one.

At the same time, combined with the characteristics of SIIG that has a short waveguide wavelength and strong radiation due to discontinuity disturbance, this antenna has a small spacing between elements and strong radiation ability, which can ensure the high efficiency of the leaky wave antenna and has the advantage of miniaturization, and Suitable for beamforming applications.

In summary, the beneficial effects of the present invention are:

1. The present invention proposes a horizontally polarized radiation unit based on the SIIG structure, which has strong radiation capability and phase compensation characteristics;

2. The present invention adopts the SIIG feeder combined with the corresponding radiation unit to realize miniaturization under the premise of ensuring the high efficiency of the leaky wave antenna;

3. In the present invention, the SIIG feeder combined with the radiation unit is applied to array forming, which can realize high efficiency and miniaturization of the antenna while ensuring the forming effect.

Description of drawings

Fig. 1 is an overall structural diagram of Embodiment 1 of the present invention.

Fig. 2 is a top view of the feeder structure in Embodiment 1 of the present invention.

Fig. 3 is a side view of the feeder structure in Embodiment 1 of the present invention.

Fig. 4 is a structural diagram of the radiation unit in Embodiment 1 of the present invention.

Fig. 5 is a side view of the feeding structure of Embodiment 1 of the present invention.

Fig. 6 is a top view of the feeding structure of Embodiment 1 of the present invention.

Fig. 7 is a bottom view of the feeding structure of Embodiment 1 of the present invention.

Fig. 8 is a structural diagram of a radiation unit in Embodiment 2 of the present invention.

Fig. 9 is a structure diagram of multiple radiation parts in Embodiment 3 of the present invention.

1 is the feeder structure, 2 is the radiation structure, 21 is the metal strip patch, 3 is the feeder structure, 12 is the metal ground of the lower layer of the feeder, 11 is the feeder dielectric layer, 111 is the central transmission belt, 112 is the air hole area, 113 is the central axis of the transmission belt, 31 is the upper metal, 311 is the top circular groove, 312 is the gradual deformation groove, 32 is the medium layer of the feeding structure, 321 is the metallized through hole penetrating through the feeding medium, and 33 is the lower layer of the feeding structure The metal ground, 331 is the bottom circular groove, 34 is the metallized through hole of the SIW transition structure, 35 is the metal cavity, and 36 is the metallized through hole penetrating through the medium layer of the feed structure and the metal ground of the lower layer of the feed structure.

Detailed ways

The present invention will be further elaborated below in conjunction with the accompanying drawings and embodiments.

Example 1

A horizontally polarized leaky-wave antenna based on a substrate-integrated image dielectric waveguide, including a feeder structure 1, a radiation structure 2 and a feeder structure 3,

The feeder structure 1 of the antenna includes, from bottom to top, the metal ground 12 of the lower layer of the feeder, and the feeder dielectric layer 11, wherein the feeder dielectric layer 11 is symmetrically arranged with two air hole areas 112 left and right along the central axis, and between the two air hole areas 112 Be the central transmission belt 111;

The radiation structure 2 includes a plurality of radiation units. The radiation unit is a metal strip-shaped patch 21 close to the upper surface of the central transmission belt part 111. The metal strip-shaped patches 21 are arranged along the electromagnetic wave propagation direction of the central transmission belt. The angle between the strip patch 21 and the central axis 113 of the conveyor belt is not 0 degrees or 90 degrees, and the inclination directions of two adjacent metal strip patches 21 are opposite, and the midpoint of each metal strip patch is at On the central axis 113 of the transmission belt, the distance between two adjacent metal strip-shaped patches 21 on the central axis 113 of the transmission belt is equal, and the feeder structure 1 and the radiation structure 2 constitute the radiation part of the antenna;

The feed structure 3 includes the lower metal ground 33 of the feed structure, the dielectric layer 32 of the feed structure, and the upper metal 31 in order from bottom to top. On the layer 32, there is a metallized through hole 321 penetrating through the feeding medium at the position corresponding to the bottom circular groove 331, and the top layer circular groove 311 is opened on the upper layer metal 31 corresponding to the position of the bottom circular groove 331, and the metal through the feeding medium The through hole 321, the circular groove 311 on the top layer, and the circular groove 331 on the bottom layer coincide with the three circle centers, and run through the SIW transition structure metallized through hole of the three layers of the lower metal ground 33 of the feed structure, the feed structure dielectric layer 32, and the upper metal 31 34 are arranged as a SIW transition structure, the metallized through-hole 321 penetrating through the feed medium, the top circular groove 311 and the bottom circular groove 331 are all located inside the SIW transition structure, and the coaxial probe is inserted into the metallized through-hole through the feed medium. In the hole 321, the part where the coaxial probe protrudes from the dielectric layer 32 of the feed structure is covered by the metal cavity 35; at the intersection of the SIW transition structure and the feed line structure, a gradual deformation groove 312 is opened on the central axis of the upper metal layer 31, and the gradual change The groove 312 gradually widens along the direction from the feed structure 3 to the feed line structure 1, so as to achieve impedance matching with the feed line structure 1; at the end of the upper layer metal 31, a plurality of medium layers penetrating the feed structure and the lower layer of the feed structure are arranged laterally The vias 36 are metallized to suppress energy leakage. The central axis of the feeder structure coincides with the central axis of the feed structure.

This embodiment provides a SIIG-based horizontally polarized low-sidelobe leaky-wave antenna, the structure of which is shown in FIG. 1 , including a feeder structure 1 , a radiation structure 2 and a feeder structure 3 . In this implementation example, the antenna array has a length of 124 mm, works in the Ku band, has a center frequency of 13.6 GHz, an electrical length of 4.9λ ₀ , and a beam pointing of 110°. The radiation ability is controlled by changing the tilt angle of each unit, so as to achieve low sidelobe shaping.

In this embodiment, the top view and side view of the feeder structure of the antenna are shown in Fig. 2 and Fig. 3 respectively, and from bottom to top are the lower metal ground 12 and the dielectric layer 11, wherein the dielectric layer can be divided into a central transmission belt 111 The air hole area 112 is arranged on both sides. The dielectric substrate has a relative permittivity of 10.9, a thickness of 2.54 mm, and a metal thickness of 0.5 oz. The width of the central transmission belt is 6mm, and there are 5 rows of non-metallized holes in the perforated area on both sides. The diameter of the non-metallized holes is 1.8mm, and the period is 2mm. The adjacent upper and lower non-metallized holes are arranged in an equilateral triangle. The radiation structure 2 contains 28 units, the unit spacing is 4mm, the width is 1.6mm, and the length is 5.7mm. The radiation ability is adjusted by changing the inclination angle to form the shape. The adjacent units are designed with phase compensation, and the inclination direction is opposite. The unit structure is shown in Figure 4.

Example 2

As shown in FIG. 8 , the difference between this embodiment and Embodiment 1 is that each radiation unit includes two parallel metal strips.

Example 3

As shown in Figure 9, the difference between this embodiment and Embodiment 1 is that in the direction perpendicular to the propagation direction of the feeder electromagnetic wave, multiple radiation parts are arranged side by side, and the original one-dimensional line array is expanded into a two-dimensional plane array. Then two-dimensional shaping is carried out; the feeder structure of the formed two-dimensional array shares the feeder medium layer 11 and the metal ground 12 of the lower layer of the feeder. The feed structure is combined with the change of the power distribution network.

As mentioned above, the above-mentioned embodiments are only illustrative to illustrate the principles and effects of the present invention, and are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention shall still be covered by the claims of the present invention.

Claims (5)

1. A horizontally polarized leaky-wave antenna based on substrate integrated image dielectric waveguide, characterized in that: comprise feeder structure (1), radiation structure (2) and feeder structure (3), The feeder structure (1) of the antenna is from bottom to top successively the metal ground (12) of the lower layer of the feeder, and the feeder dielectric layer (11), wherein the feeder dielectric layer (11) is symmetrically arranged with two air hole regions (112) along the central axis. ), between the two air hole areas (112) is the central transmission belt (111); The radiating structure (2) includes a plurality of radiating units, the radiating unit is a metal strip-shaped patch (21) close to the upper surface of the central transmission belt part (111), and the metal strip-shaped patch (21) is along the central transmission belt part (111). The direction of propagation of the electromagnetic wave is arranged, the angle between the metal strip patch (21) and the central axis of the transmission belt (113) is not 0 degrees or 90 degrees, and the inclination direction of two adjacent metal strip patches (21) On the contrary, the midpoint of each metal elongated patch is on the central axis (113) of the transmission belt, and the spacing between two adjacent metal elongated patches (21) on the central axis (113) of the transmission belt is equal, and the feeder The structure (1) and the radiation structure (2) constitute the radiation part of the antenna; The feed structure (3) sequentially includes the lower metal ground (33) of the feed structure, the medium layer (32) of the feed structure, and the upper metal (31) from bottom to top, and the lower metal ground (33) of the feed structure is opened The bottom circular groove (331), the metallized through hole (321) penetrating through the feed medium is arranged on the feeding structure medium layer (32) corresponding to the position of the bottom circular groove (331), and the upper layer metal (31) is connected with the bottom layer The top circular groove (311) is opened at the position corresponding to the circular groove (331), and the center of the metallized through hole (321) penetrating the feeding medium and the top circular groove (311) and the bottom circular groove (331) coincide The SIW transition structure metallized through holes (34) that run through the lower metal ground (33) of the feed structure, the dielectric layer (32) of the feed structure and the upper metal (31) are arranged to form a SIW transition structure, penetrating through the feed medium The metallized through hole (321), the top layer circular groove (311) and the bottom layer circular groove (331) are all located inside the SIW transition structure, and the coaxial probe is inserted into the metallized through hole (321) penetrating the feeding medium, The part of the coaxial probe protruding from the feed structure dielectric layer (32) is covered by the metal cavity (35); at the intersection of the SIW transition structure and the feeder structure, a gradual deformation groove ( 312), the tapered groove (312) gradually widens along the direction from the feed structure (3) to the feed line structure (1), so as to achieve impedance matching with the feed line structure (1); at the cut-off place of the upper metal (31), the lateral A plurality of metallized through holes (36) penetrating through the medium layer of the feed structure and the metal ground of the lower layer of the feed structure are arranged, and the central axis of the feed line structure coincides with the central axis of the feed structure. 2. The horizontally polarized leaky wave antenna based on substrate integrated image dielectric waveguide according to claim 1 is characterized in that: in the direction perpendicular to the feeder electromagnetic wave propagation direction, a plurality of radiation parts are arranged side by side, and the original The one-dimensional line array is expanded into a two-dimensional plane array, and then two-dimensionally shaped; the feeder structure of the formed two-dimensional plane array shares the feeder medium layer (11) and the metal ground (12) under the feeder line. 3. The horizontally polarized leaky-wave antenna based on substrate integrated image dielectric waveguide according to claim 1, characterized in that: the central transmission strip width is 6mm, and the perforated areas on both sides are respectively formed by 5 rows of non-metallized holes In the air hole area, the diameter of the non-metallized hole is 1.8mm, and the period is 2mm. Each non-metallized hole is arranged in an equilateral triangle with the upper and lower adjacent non-metallized holes on the right side. 4. the horizontally polarized leaky-wave antenna based on the substrate integrated image dielectric waveguide according to claim 1, is characterized in that: the radiation structure (2) comprises 28 units, the unit spacing is 4mm, the width is 1.6mm, and the length is 5.7mm. 5. The horizontally polarized leaky-wave antenna based on a substrate-integrated image dielectric waveguide according to claim 1, wherein each radiating unit comprises two parallel metal strips.