CN107579344A - Millimeter-wave substrate-integrated waveguide dual circularly polarized low-sidelobe common-aperture array antenna - Google Patents

Abstract

The present invention provides a kind of millimeter-wave substrate integrated waveguide double-circle polarization Sidelobe Shared aperture array antenna, stacks gradually from top to bottom：First metal copper clad layers, first medium layer, the second metal copper clad layers, second dielectric layer, the 3rd metal copper clad layers；The present invention is orthogonal by two spaces caused by 90 ° of couplers and the long array antenna of Shared aperture parallel-plate based on substrate integration wave-guide, phase differs 90 ° of line polarization wave, work(is not waited to divide carry out of the feeding network to its each linear polarization from directional diagram one-dimensional H faces Sidelobe figuration by substrate integration wave-guide respectively, by circular polarisation Pattern synthesis principle, realize the Sidelobe in two normal surfaces of double-circle polarization directional diagram, using one-dimensional figuration technology while two orthogonal plane Sidelobes of double-circle polarization are realized, simplify feeding network and realize difficulty, this antenna realizes that Sidelobe double-circle polarization Shared aperture generates using substrate integration wave-guide parallel-plate long gap formation formula, with easy processing, the characteristics of low section and high integration.

Description

Millimeter-wave substrate-integrated waveguide dual circularly polarized low-sidelobe common-aperture array antenna

technical field

The invention belongs to the technical field of moving target communication antennas, and more specifically relates to a millimeter-wave substrate-integrated waveguide double-circular polarization low-sidelobe common-aperture array antenna.

Background technique

The new generation of antennas must meet the characteristics of miniaturization and low profile, and must have strong anti-interference ability and high channel capacity. Compared with metal waveguides, substrate-integrated waveguides have the characteristics of high integration, low profile, low loss, and easy processing. For the design of planar circuits and array antennas in the millimeter-wave frequency band, substrate-integrated waveguides are a good choice.

On the one hand, circularly polarized antennas have been widely used in the fields of satellite communication, ship-borne, airborne, missile-borne and other moving target communications due to their strong anti-interference ability and ability to accept electromagnetic waves in any polarization state. On the other hand, most of the noise power received by the antenna comes from the sidelobe area of the antenna pattern, and an antenna with low sidelobe level plays a vital role in wireless communication applications. Therefore, an antenna with both circular polarization and low sidelobe characteristics will greatly improve the anti-interference ability of the antenna and the signal-to-noise ratio of the received signal, which will have a crucial impact on the quality of the subsequent signal processing of the communication system. . At present, there are generally two ways to design circularly polarized low-sidelobe array antennas: one is to add a circular polarizer to the online-polarized low-sidelobe antenna. This design method will increase the size of the antenna and cannot Simultaneously realize the characteristics of left-handed circular polarization and right-handed circular polarization; the second is to design an orthogonal feed network that satisfies low sidelobe characteristics, such as the traditional slot array or patch array antenna, but most of the current circular polarization is achieved in a certain Low sidelobe of a surface, literature A.B.Smolders and H.J.Visser, "Low side-lobe circularly-polarized phased arrays using a random sequential rotation technique," IEEE Trans.AntennasPropag.,vol.62,no.12,pp.6476–6481 ,Dec.2014. Using random sequence rotation technique to achieve low sidelobes in two orthogonal planes of circular polarization pattern through microstrip patch, but it is very difficult to achieve dual circular polarization. This is because the millimeter-wave wavelength is shorter, and its two-dimensional feed network will be extremely complex.

Contents of the invention

In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a millimeter-wave substrate-integrated waveguide dual-circularly polarized low-sidelobe common-aperture array antenna.

In order to realize the foregoing invention object, the technical scheme of the present invention is as follows:

A millimeter-wave substrate integrated waveguide dual-circularly polarized low-sidelobe common-aperture array antenna is stacked sequentially from top to bottom: the first metal copper-clad layer, the first dielectric layer, the second metal copper-clad layer, and the second dielectric layer , the third metal clad copper layer;

On the first metal copper clad layer, 14-16 double long slot units of the same size are etched in the vertical and horizontal directions to form a common-aperture slot antenna array; , the second metal copper clad layer together constitute the substrate integrated waveguide parallel plate waveguide in two directions; the 16 coupling slots etched on the vertical and horizontal edges of the second metal copper clad layer are connected with the 15 vertical and horizontal columns inside the first dielectric layer The through-metallized hole with a distance of 2.1 mm, the first metal copper-clad layer, and the second metal-clad copper layer together constitute the substrate integrated waveguide interlayer coupling structure; the through-metallized hole of the second dielectric layer and the second metal copper-clad layer , The third metal copper clad layer together form two identical 1-16 unequal power distribution networks and a 90° coupler; the edge of the third metal copper clad layer is etched with two coupling apertures, which are used by the standard rectangular waveguide WR-10 is used as a feeding window; the coupler includes 4 ports, which are input port, isolation port, coupling port and directional port. The power distribution network ranging from 1 to 16, in which the output amplitude of the coupled port and the directional port are equal, and the output phase of the coupled port lags by 90°.

In order to overcome the difficulties in the design of dual circularly polarized low-sidelobe antennas, the present invention firstly proposes a substrate-integrated waveguide common-aperture dual-polarized array antenna with orthogonal polarization, and uses a 90° coupler in the feed network at the same time , to generate left-handed circularly polarized waves (LHCP) and right-handed circularly polarized waves (RHCP). In order to avoid using the complex two-dimensional shaping method, a special one-dimensional shaping method is adopted, which can realize sidelobe level suppression on two orthogonal planes of the circularly polarized array antenna.

As a preferred method, the selected substrate is Taconic TLY-5, the thickness is 0.508mm, the thickness of the copper foil on the dielectric layer is 0.018mm, the distance between adjacent antenna units on the common aperture array is 2.31mm, and one antenna unit is 33mm long and 0.15mm wide. mm, two long gaps 0.63mm apart.

As a preferred manner, the size of the coupling gaps on the second metal copper-clad layer is 1.4 mm×0.5 mm, and the position is 1.45 mm from the center of the terminal metal via hole.

As a preferred method, the unequal power distribution network is left-right symmetrical, the branch width w1 of the second-level unequal power distributor branch is 1.64mm, w2 is 1.45mm, and the center tuning hole offset is 0.15mm; the third-level unequal power distribution The branch widths w1 of the device branches are 1.86mm and 1.85mm respectively, w2 are 1.68mm and 1.68mm respectively, and the center tuning hole offsets are respectively 0.21mm and 0.21mm; are 1.85mm, 1.64mm, 1.54mm, 1.54mm, w2 are 1.68mm, 1.3mm, 1.4mm, 1.46mm respectively, and the center tuning hole offsets are 0.3mm, 0.3mm, 0.3mm, 0mm respectively.

The beneficial effects of the present invention are: the technical solution of the present invention is to combine the two spatially orthogonal, linearly polarized waves with a phase difference of 90° generated by the 90° coupler based on the substrate integrated waveguide and the common-aperture parallel plate long slot array antenna , through the substrate-integrated waveguide unequal power sub-feeding network, the one-dimensional H-plane low-side lobe shaping of each linear polarization self-direction pattern is carried out, and the circular polarization pattern synthesis principle is used to realize dual circular polarization. Low sidelobes in two orthogonal planes of the pattern. The use of one-dimensional shaping technology greatly simplifies the difficulty of implementing the feed network while achieving low sidelobes in two orthogonal planes of dual circular polarization. The antenna adopts the form of a substrate-integrated waveguide parallel plate long slot array to realize low-side lobe double-circular polarization common-aperture generation, and has the characteristics of easy processing, low profile and high integration.

Description of drawings

Figure 1 is an overall schematic diagram of a millimeter-wave substrate-integrated waveguide dual-circularly polarized low-sidelobe common-aperture array antenna.

Figure 2 is a structural diagram of a millimeter wave substrate integrated waveguide parallel plate waveguide dual circular polarization low side lobe common aperture antenna array.

Figure 3 is the feed network of the millimeter wave substrate integrated waveguide parallel plate waveguide dual circular polarization low side lobe common aperture antenna.

Figure 4 is an ideal circularly polarized low-sidelobe common-aperture point source array model.

Fig. 5 is a partial enlarged view of the tree-like unequal power dividing network.

Figure 6 shows the simulation and test results of 94GHz left-handed circular polarization and right-handed circular polarization with low sidelobes, where Figure 6(a) is left-handed circular polarization and Figure 6(b) is right-handed circular polarization.

Fig. 7 is the simulation and test results of axial ratio of left-handed circular polarization and right-handed circular polarization, in which Fig. 7(a) is left-handed circular polarization, and Fig. 7(b) is right-handed circular polarization.

Among them, 1 is the first metal copper clad layer, 2 is the first dielectric layer, 3 is the second metal copper clad layer, 4 is the second dielectric layer, 5 is the third metal copper clad layer, 11 is the double long slot unit, 21 is the through metallization hole set around the edge of the first dielectric layer, 22 is the through metallization hole inside the first dielectric layer, 31 is the coupling gap, 41 is the through metallization hole of the second dielectric layer; 42 is the second level 43 and 44 are the branches of the third-level unequal power divider, 45-48 are the branches of the fourth-level unequal power divider, 51 is the first coupling aperture, and 52 is the second coupling aperture.

detailed description

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

As shown in Figure 1, a millimeter-wave substrate integrated waveguide dual-circularly polarized low-sidelobe common-aperture array antenna is stacked sequentially from top to bottom: the first metal copper-clad layer 1, the first dielectric layer 2, the second metal Copper clad layer 3, second dielectric layer 4, third metal copper clad layer 5;

On the first metal copper clad layer 1, 14-16 double slit units 11 of the same size are respectively etched in the vertical and horizontal directions. As shown in FIG. ×15 long-slot unit antennas form a common-aperture slot antenna array; in order to increase the radiation capability, each unit is composed of two long slots. The through metallization holes 21 set around the edge of the first dielectric layer 2 together with the first metal copper clad layer 1 and the second metal copper clad layer 3 form a substrate integrated waveguide parallel plate waveguide in two directions; the second metal copper clad layer The 16 coupling slots 31 etched on the vertical and horizontal edges of 3 are respectively 15 vertical and horizontal columns inside the first dielectric layer with a distance of 2.1 mm through metallized holes 22, the first metal copper clad layer 1, and the second metal copper clad layer 3 together form the substrate integrated waveguide interlayer coupling structure; the through metallization hole 41 of the second dielectric layer 4 together with the second metal copper clad layer 3 and the third metal copper clad layer 5 form two identical 1 to 16 different Equal power distribution network and a 90° coupler; two coupling apertures 51, 52 are etched on the edge of the third metal copper clad layer 5, which are used as feeding windows by WR-10 of the standard rectangular waveguide; the coupler includes 4 The two ports are respectively input port, isolation port, coupling port and directional port. The structure of the coupler is completely centrosymmetric. The directional port outputs are equal in magnitude, and the coupled port outputs are phase lagged by 90°.

In order to overcome the difficulties in the design of dual circularly polarized low-sidelobe antennas, the present invention firstly proposes a substrate-integrated waveguide common-aperture dual-polarized array antenna with orthogonal polarization, and uses a 90° coupler in the feed network at the same time , to generate left-handed circularly polarized waves (LHCP) and right-handed circularly polarized waves (RHCP). In order to avoid using the complex two-dimensional shaping method, a special one-dimensional shaping method is adopted, which can realize sidelobe level suppression on two orthogonal planes of the circularly polarized array antenna.

Specifically, the unequal power distribution network is left-right symmetrical, the branch width w1 of the branch 42 of the second stage unequal power divider is 1.64mm, w2 is 1.45mm, and the offset of the central tuning hole is 0.15mm; the third stage unequal power distribution The branch widths w1 of device branches 43 and 44 are 1.86mm and 1.85mm respectively, w2 are 1.68mm and 1.68mm respectively, and the center tuning hole offsets are 0.21mm and 0.21mm respectively; 48 branch widths w1 are 1.85mm, 1.64mm, 1.54mm, 1.54mm, w2 are 1.68mm, 1.3mm, 1.4mm, 1.46mm respectively, and the center tuning hole offsets are 0.3mm, 0.3mm, 0.3mm, 0mm.

In Figure 3, the excitation signal is fed from one port of the coupling aperture 51 or 52 (corresponding to right-handed circular polarization and left-handed circular polarization respectively), while the other port is connected to a matching load, and passes through the metal waveguide to the substrate-integrated waveguide. The transition structure couples energy into the substrate integrated waveguide; then the signal is divided into two signals with equal amplitude and 90° phase difference through a 90° coupling bridge, and these two signals are simultaneously fed into the spatially orthogonal 1-16 The phase balance unequal power division network; then the energy in the second dielectric layer 4 is fed into the first dielectric layer 2 by etching the coupling gap in the second metal copper clad layer 3; at this time in the first dielectric layer 2 There will be 16 horizontal TE ₁₀ waves and 16 vertical TE ₁₀ waves. Through mode synthesis, the TE10 waves will be synthesized into two mutually orthogonal quasi-TEM waves transmitted in parallel plate waveguides; the last two orthogonal The quasi-TEM waves with equal amplitude and 90° phase difference feed the polarized common-aperture long-slot planar antenna, and finally form circularly polarized waves.

Circular polarization low sidelobe principle: As shown in Figure 4, an ideal point source antenna array with an array size of N×N is used to illustrate the design process of a circular polarization low sidelobe common-aperture array antenna. Arrays 1# and 2# are horizontal linearly polarized and vertically linearly polarized array antennas respectively, each column in array 1# and each row in array 2# can be considered as a long slot unit in the panel array antenna, and array 3# is 1# and 2# polarized co-aperture array antennas. Let the normalized electric field pattern of array 1# be The normalized electric field pattern of array 2# is The pattern F ₁ (θ,90°) of array 1# has low sidelobe characteristics in the yoz plane, but the pattern F ₁ (θ,0°) in the xoz plane does not have low sidelobe characteristics; array 2# has low sidelobe characteristics in the xoz plane The in-plane pattern F ₂ (θ, 0°) has low sidelobe characteristics, and the in-plane pattern F ₂ (θ, 90°) does not have low sidelobe characteristics. This is consistent with the characteristics of the flat panel slot antenna, and the power pattern functions of arrays 1#~3# can be written as (1)~(3).

It can be known from formula (3) that the pattern function of circular polarization array 3# is composed of arrays 1# and 2#, so the shape of arrays 1# and 2# can be reasonably designed to obtain the desired shape of circular polarization pattern. For example, in the horizontal plane, ie , let ε ₁ =ε ₂ , since the current amplitude of array 1# in the x direction is a uniform aperture distribution, then D ₁ (θ,0°) does not have low sidelobe characteristics, and the current amplitude of array 2# in the x direction By designing the unequal power dividing network, D ₂ (θ,0°) has low sidelobe characteristics, and then the circularly polarized D ₃ (θ,0°) synthesized by the two has certain low sidelobe effects. same in The plane can also achieve low sidelobe characteristics by this method. Therefore, the low sidelobe characteristics of circularly polarized antennas in all planes can be realized only by designing a plane with low sidelobe for the linearly polarized array.

The operating frequency of this embodiment is 94 GHz, and the selected substrate is Taconic TLY-5 with a thickness of 0.508 mm and a copper foil on the medium with a thickness of 0.018 mm. The distance between adjacent antenna units on the common-aperture array is 2.31 mm, and one antenna unit is composed of two long slots with a length of 33 mm, a width of 0.15 mm, and a distance of 0.63 mm. The substrate-integrated waveguide unequal power division network is shown in Figure 5. By adjusting the branch width of each power division level and the position of the central tuning hole, ports A to P can be output in phase and with unequal amplitude. Refer to Table 1 for the design parameter values. Finally, Realize -25dB Taylor distribution with port A-P current normalized amplitudes of 0.25, 0.35, 0.4, 0.5, 0.56, 0.67, 0.91, 1, 1, 0.91, 0.67, 0.56, 0.5, 0.4, 0.35 and 0.25. In order to achieve good matching between layers, the size of the coupling gap 31 on the second metal copper-clad layer 3 is 1.45mm×0.5mm, and the position is 1.45mm according to the center of the terminal metal through hole. Finally, the 90° coupling bridge is combined to finally solve the problem of the difficulty in realizing low sidelobes in two orthogonal planes of traditional dual circular polarization.

Table I

Design parameters of unequal power dividers at all levels

(Unit: MM)

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but 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 (4)

1. A kind of 1. millimeter-wave substrate integrated waveguide double-circle polarization Sidelobe Shared aperture array antenna, it is characterised in that：From top to bottom Stack gradually：First metal copper clad layers (1), first medium layer (2), the second metal copper clad layers (3), second dielectric layer (4), the 3rd Metal copper clad layers (5)；

   Direction respectively etches the double slit units (11) of 14-16 size identical in length and breadth in first metal copper clad layers (1), forms mouth altogether Footpath slot antenna array；What first medium layer (2) edge surrounding was set runs through plated through-hole (21) and the first metal copper clad layers (1), the second metal copper clad layers (3) form the substrate integration wave-guide parallel-plate waveguide on two directions together；Second metal copper clad layers (3) 16 respectively etched on the edge of direction in length and breadth couple gap (31) and each 15 row are apart in length and breadth inside first medium layer 2.1mm's forms the integrated ripple of substrate together through plated through-hole (22), the first metal copper clad layers (1), the second metal copper clad layers (3) Coupled structure between conducting shell；Second dielectric layer (4) is covered through plated through-hole (41) with the second metal copper clad layers (3), the 3rd metal Layers of copper (5) forms two identicals 1 and divides 16 unequal power to distribute network and 90 ° of couplers together；Third layer metal covers Layers of copper (5) edge etches two coupling bores (51,52), is used as feed window by the WR-10 of standard rectangular waveguide；The coupling Device includes 4 ports, respectively input port, isolated port, coupling port and oriented port, the complete center pair of coupler structure Claim, coupling port is connected two unequal power distribution networks of orthogonally located 1 point 16, wherein coupling port with oriented port respectively It is equal with oriented port output amplitude, and coupling port output phase lags 90 °.
2. 2. millimeter-wave substrate integrated waveguide double-circle polarization Sidelobe Shared aperture array antenna according to claim 1, it is special Sign is：The substrate of selection is Taconic TLY-5, thickness 0.508mm, and copper thickness is 0.018mm on dielectric layer, altogether mouth Adjacent antenna units on the array of footpath are at a distance of 2.31mm, and an antenna element is by long 33mm, wide 0.15mm, two at a distance of 0.63mm Root long gap forms.
3. 3. millimeter-wave substrate integrated waveguide double-circle polarization Sidelobe Shared aperture array antenna according to claim 1, it is special Sign is：The size in the coupling gap (31) in the second metal copper clad layers (3) is 1.4mm × 0.5mm, and position is according to end metal Through hole center is 1.45mm.
4. 4. millimeter-wave substrate integrated waveguide double-circle polarization Sidelobe Shared aperture array antenna according to claim 1, it is special Sign is：Unequal power distribution network is symmetrical, and the minor matters width w1 of second level unequal power divider minor matters (42) is 1.64mm, w2 1.45mm, center tuned window are biased to 0.15mm；The branch of third level unequal power divider minor matters (43,44) Byte wide w1 is respectively 1.86mm, 1.85mm, and w2 is respectively 1.68mm, 1.68mm, the biasing of center tuned window be respectively 0.21mm, 0.21mm；The minor matters width w1 of fourth stage unequal power divider minor matters (45-48) be respectively 1.85mm, 1.64mm, 1.54mm, 1.54mm, w2 are respectively 1.68mm, 1.3mm, 1.4mm, 1.46mm, the biasing of center tuned window be respectively 0.3mm, 0.3mm, 0.3mm、0mm。