WO2022217558A1

WO2022217558A1 - Broadband dual-frequency dual-circular-polarization reflective array antenna with independently controllable wave beams

Info

Publication number: WO2022217558A1
Application number: PCT/CN2021/087607
Authority: WO
Inventors: 蒋之浩; 童宣锋; 洪伟
Original assignee: 东南大学; 网络通信与安全紫金山实验室
Priority date: 2021-04-13
Filing date: 2021-04-15
Publication date: 2022-10-20
Also published as: CN113078477A; CN113078477B

Abstract

The present invention relates to the field of electronic devices in a wireless communication system. Disclosed is a broadband dual-frequency dual-circular-polarization reflective array antenna with independently controllable wave beams, the reflective array antenna comprising a dual-band broadband circularly polarized feed source and a planar reflective array, wherein the dual-band broadband circularly polarized feed source is placed near a focal plane of the planar reflective array; the planar reflective array comprises low-frequency and high-frequency dual-circular-polarization phase shift units which are in a common-aperture periodic staggered arrangement; and each of the dual-circular-polarization phase shift units comprises a circular patch layer, a metal ground layer etched with an I-shaped slot, a layer of two microstrip lines having different lengths, a metal floor plate layer, etc. By means of the present invention, dynamic phases are combined with rotation phases, such that left-handed phases and right-handed phases are independently controlled simultaneously in a K band and a Ka band, and open cross-shaped slot processing and forms such as a microstrip line slot-coupled patch are used, thereby ensuring the ultimate dual-band broadband characteristics of a reflective array antenna. The reflective array antenna has the advantages of a low profile, easy machining, easy integration, low costs, etc., and has important application prospects in the fields of satellite communications, etc.

Description

Broadband dual-frequency dual-circularly polarized reflectarray antenna with independently steerable beams

technical field

The invention belongs to the field of electronic devices of wireless communication systems, and in particular relates to a broadband dual-frequency dual-circularly polarized reflection array antenna with independently controllable beams.

Background technique

At present, the normal operation of space probes usually relies on satellite communication. The commonly used satellite communication frequency bands include bands such as C, K and Ka. Both K-band and Ka-band belong to a specific radio frequency range. K-band refers to radio waves with frequencies in the range of 18-26.5GHz, and Ka-band refers to radio waves with frequencies in the range of 26.5-40GHz. In order to meet the requirements of long-distance stable communication, it is usually necessary to use high-gain circularly polarized antennas at both the transmitter and receiver of the communication, such as phased array antennas, reflector antennas, and so on.

The phased array antenna achieves high gain characteristics by exciting each unit in the phased array through a complex feed network or a receiving/transmitting module, and its disadvantages lie in higher feed network loss and higher cost; It is based on the quasi-optical principle. The spherical wave emitted by the feed is irradiated on the reflective surface and then reflected to form a high-gain plane wave. The disadvantage is that the paraboloid is difficult to accurately process in the millimeter wave frequency band.

In order to overcome the shortcomings of phased arrays and reflector antennas, planar reflector array antennas came into being. Its planar structure, light weight, low cost, low profile and low loss have made it widely used in mobile communications, satellite communications and other fields. more and more attention. Based on the sub-wavelength arrangement of phase-shifting elements of different frequencies and different structures on the reflectarray, multi-frequency and multi-polarization reflectarray antennas have been realized. Dual-frequency dual-circularly polarized beam independently steerable reflectarray antennas are even rarer. The existing dual-frequency dual-circularly polarized reflectarray antennas are divided into two categories, one is based on the multi-functional layer, the upper layer is a dual-frequency linear circular polarization converter, and the lower layer is a dual-frequency linearly polarized reflectarray antenna. The disadvantage is that there are many functional layers, complex structure, high profile and narrow bandwidth; the other type is based on circuit implementation, and an orthogonal coupler is loaded under the dual-frequency radiator of common aperture to realize dual-frequency dual-circularly polarized reflection array. The disadvantage of the antenna is that the bandwidth is narrow and the frequency of the dual frequency is relatively small.

SUMMARY OF THE INVENTION

Technical purpose: In order to meet the high gain requirements for antennas in applications such as mobile communication and satellite communication, the present invention provides a broadband dual-frequency dual-circularly polarized reflection array with independently controllable beams. The reflection array antenna has a low profile, is easy to process, etc. Structural advantages, and can provide dual-frequency dual-circular polarization, broadband, high gain, low axial ratio, small gain jitter, and independently controllable circularly polarized beams.

Technical scheme: In order to realize the above-mentioned technical purpose, the present invention adopts the following technical scheme:

A broadband dual-frequency dual circularly polarized reflection array antenna with independently controllable beams is characterized in that: it comprises a dual-band broadband circularly polarized feed source and a plane reflection array arranged oppositely, and the plane reflection array includes a plurality of periodic common apertures. K-band dual-circular polarization phase shift units and Ka-band dual-circular polarization phase-shift units are staggered; the K-band dual-circular polarization phase-shift units and Ka-band dual-circular polarization phase-shift units both include four layers of metal Floor;

In the K-band dual circular polarization phase shift unit, the four metal layers from top to bottom are the first circular metal patch etched with a cross-shaped slit in the center, and the first metal floor etched with an orthogonal I-shaped slit. , Two first microstrip transmission lines and first metal base plates with different lengths located on the same metal layer; wherein the ends of the two first microstrip transmission lines are provided with first metallized vias, and the first metallized vias are connected to the first metal floor;

In the Ka-band dual-circular polarization phase shift unit, the four metal layers from top to bottom are the second circular metal patch and the second metal floor etched with the orthogonal I-shaped slit, which are located on the same metal layer. a second microstrip transmission line with different segment lengths and a second metal base plate; the ends of the two segments of the second microstrip transmission line are provided with second metallized vias, and the second metallized vias are connected to the second metal floor;

The first circular metal patch and the second circular metal patch are both disposed toward the dual-band broadband circularly polarized feed source.

Specifically, the dual-band broadband circularly polarized feed includes a K-band broadband circularly polarized feed and a Ka-band broadband circularly polarized feed, and the K-band broadband circularly polarized feed is placed near the focal plane of the planar reflection array, The vertical distance from the plane reflection array is F1, and the diameter of the plane reflection array is D, where 0.6≤F1/D≤1.5;

The Ka-band broadband circularly polarized feed is placed near the focal plane of the planar reflection array, and the vertical distance from the planar reflection array is F2, where 0.6≤F2/D≤1.5.

Specifically, the K-band dual-circular polarization phase-shift units and the Ka-band dual-circular-polarization phase-shift units are periodically staggered with a common aperture, and the K-band dual-circular-polarization phase-shift units are two-dimensionally arranged periodically at On the vertices of the square grid whose side length is the K-band period length, the Ka-band dual-circular polarization phase-shifting elements are periodically arranged in two dimensions at the center of the square grid whose side length is the K-band period length or 1.5 Ka-band period lengths. On the point, the Ka-band period length of the K-band dual circularly polarized phase shift unit is 0.3 to 0.5 K-band wavelengths, and the Ka-band cycle length of the Ka-band dual circularly polarized phase shift unit is 0.5 to 0.7 Ka-band wavelengths.

Specifically, the K-band dual circular polarization phase shift unit includes a K-band first metal layer, a K-band second metal layer, a K-band third metal layer, and a K-band fourth metal layer; the K-band first metal layer A first substrate layer is arranged between the K-band second metal layer and the K-band second metal layer, a second substrate layer is arranged between the K-band second metal layer and the K-band third metal layer, and the K-band third metal layer and the K-band third metal layer are arranged. An air layer is arranged between the fourth metal layers of the wave band, and a first adhesive layer is arranged between the first substrate layer and the second substrate layer;

The Ka-band dual circular polarization phase shift unit includes a Ka-band first metal layer, a Ka-band second metal layer, a Ka-band third metal layer and a Ka-band fourth metal layer; the Ka-band first metal layer and the Ka-band A first substrate layer is arranged between the second metal layer, a second substrate layer is arranged between the Ka-band second metal layer and the Ka-band third metal layer, and the Ka-band third metal layer and the Ka-band fourth metal layer An air layer is arranged in the middle, and a first adhesive layer is arranged between the first substrate layer and the second substrate layer.

Specifically, the shape of the K-band first metal layer and the Ka-band first metal layer is any one of a circle, a ring, a "cross" shape or a polygon, and the polygon includes a triangle, a quadrangle, and the like.

Specifically, the gap on the first circular metal patch of the K-band dual circular polarization phase shift unit is in the middle of the patch, or at the edge of the patch, and the shape is a "cross" shape, a "meter" shape or no gap. .

Specifically, the shape of the gap on the first metal floor and the second metal floor is any one of a "one" shape, an "I" shape, a "cross" shape, a "Z" shape or an oval shape.

Specifically, the first microstrip transmission line or the second microstrip transmission line is in the form of an open-circuit microstrip line, a short-circuit microstrip line, an open-circuit stripline, a short-circuit stripline, a substrate-integrated waveguide, or a substrate-integrated coaxial line any of the lines.

Specifically, the length difference between the two first microstrip transmission lines in the K-band dual circular polarization phase shift unit is a quarter of the K-band wavelength, and the reflection phase difference is 180°;

The length difference between the two second microstrip transmission lines in the Ka-band dual-circular polarization phase shift unit is a quarter of the Ka-band wavelength, and the reflection phase difference is 180°.

Specifically, according to the different lengths of the first microstrip transmission lines in each K-band dual-circularly polarized phase shift unit, the K-band dual-circularly polarized phase-shift unit in the planar reflector is named K-band dual-circularly polarized phase-shift unit From 1 to K-band dual-circular polarization phase shift unit 8, the reflection phase difference corresponding to the adjacent K-band dual-circular polarization phase-shift unit is 22.5°; the eight K-band dual-circular polarization phase-shift units with continuous phase difference are rotated as a whole. processing to form a total of 64 states of K-band right-hand circular polarization 3 bits × left-hand circular polarization 3 bits;

According to the different lengths of the second microstrip transmission lines in each Ka-band dual-circular polarization phase shift unit, the Ka-band dual-circular polarization phase-shift units in the planar reflector are named as Ka-band dual-circular polarization phase-shift units 1 to Ka-band Double circular polarization phase shift unit eight, the reflection phase difference corresponding to the adjacent Ka band double circular polarization phase shift unit is 22.5°; The Ka-band has 3 bits of right-hand circular polarization and 3 bits of left-hand circular polarization, a total of 64 states.

Beneficial effect: Compared with the prior art, the present invention provides a high-gain beam independently controllable broadband dual-frequency dual-circularly polarized reflect array antenna, and its advantages are:

(1) Combined with the dynamic phase change and the rotational phase change, the simultaneous independent control of the left-handed phase and the right-handed phase is realized in both the K-band and the Ka-band, that is, the dual-frequency dual-circularly polarized beam is independently controllable.

(2) The dual-frequency characteristic is realized by using the K-band dual-circular polarization phase-shift unit and the Ka-band dual-circular-polarization phase-shift unit with a common aperture and periodic staggered arrangement. The patch adopts the method of opening a "cross"-shaped gap, which reduces the size of the K-band circular patch, improves the isolation between the K-band and the Ka-band, and ensures the accurate phase shift of the K-band and the Ka-band. Spend.

(3) Both the K-band dual-circular polarization phase-shift unit and the Ka-band dual-circular polarization phase-shift unit are in the form of microstrip line slot-coupled patches. Both the circularly polarized phase shift unit and the Ka-band dual circularly polarized phase shift unit have broadband characteristics; in addition, by changing the length of the microstrip line and the size of the gap on the metal floor at the same time, a broadband phase shift response is achieved, ensuring that The final dual-band broadband characteristics of the reflectarray antenna, including gain and axial ratio broadband characteristics.

(4) The proposed reflectarray antenna only uses a single functional layer, which has the advantages of low profile, easy processing, easy integration and low cost. The cross section of the reflectarray is only _0.28λK , where λK represents the _K -band free space wavelength, which is the same as Compared with the existing dual-function layer reflectarray antenna, the profile is reduced by nearly 80% and has a wider bandwidth.

Description of drawings

1 is a three-dimensional schematic diagram of a beam independently controllable broadband dual-frequency dual circularly polarized reflectarray antenna proposed by the present invention;

Figure 2 is a three-dimensional schematic diagram of a K-band dual circularly polarized phase shift unit;

3 is a three-dimensional schematic diagram of a Ka-band dual circularly polarized phase shift unit;

Among them, 1-K-band broadband circularly polarized feed, 2-Ka-band broadband circularly polarized feed, 3-planar reflection array, 4-K-band dual circularly polarized phase shift unit, 5-Ka-band dual circularly polarized Phase shift unit;

3a-first substrate layer, 3b-second substrate layer, 3c-first adhesive layer;

4a-the first circular metal patch, 4b-the first metal floor, 4c-the first microstrip transmission line, 4d-the first metallized via hole, 4e-the first metal bottom plate;

5a- the second circular metal patch, 5b- the second metal floor, 5c- the second microstrip transmission line, 5d- the second metallized via hole, 5e- the second metal bottom plate;

Figure 4 shows the reflection coefficient amplitudes and reflection phases corresponding to the K-band and Ka-band dual-circular polarization phase shift units 1 to 8 respectively, Figure 4a corresponds to the K-band, and Figure 4b corresponds to the Ka-band;

Figure 5 shows the distribution diagram of the reflection phase in 64 states of right-hand circular polarization 3 bits × left-hand circular polarization 3 bits formed after the K-band and Ka-band dual-circular polarization phase shift units are rotated at different angles from one to eight. Figure 5a corresponds to the K-band reflection phase, and Figure 5b corresponds to the Ka-band reflection phase;

Figure 6 shows the simulated right-hand circular polarization and left-hand circular polarization normalization when the beam independently steerable broadband dual-frequency dual circularly polarized reflectarray antenna is excited by the K-band right circularly polarized feed horn antenna Radiation pattern, Figure 6a corresponds to the xz plane at 19GHz, Figure 6b corresponds to the yz plane at 19GHz, Figure 6c corresponds to the xz plane at 20GHz, Figure 6d corresponds to the yz plane at 20GHz, Figure 6e corresponds to the xz plane at 21GHz, and Figure 6f corresponds to the yz plane at 21GHz noodle;

Figure 7 shows the simulated right-hand circular polarization and left-hand circular polarization normalized radiation when the beam independently steerable broadband dual-frequency dual circularly polarized reflectarray antenna is excited by the K-band left-circularly polarized feed horn antenna Figure 7a corresponds to the xz plane at 19GHz, Figure 7b corresponds to the yz plane at 19GHz, Figure 7c corresponds to the xz plane at 20GHz, Figure 7d corresponds to the yz plane at 20GHz, Figure 7e corresponds to the xz plane at 21GHz, and Figure 7f corresponds to the yz plane at 21GHz ;

Fig. 8 shows the simulated gain and axial ratio with frequency when the beam independently controllable broadband dual-frequency dual circularly polarized reflectarray antenna is excited by the K-band right-handed/left-handed circularly polarized feed horn antenna. 8a corresponds to the gain, and Fig. 8b corresponds to the axial ratio.

Figure 9 shows the simulated right-hand circular polarization and left-hand circular polarization normalization when the beam independently steerable broadband dual-frequency dual circularly polarized reflectarray antenna is excited by the Ka-band right-handed circularly polarized feed horn antenna Radiation pattern, Figure 9a corresponds to the xz plane at 29GHz, Figure 9b corresponds to the yz plane at 29GHz, Figure 9c corresponds to the xz plane at 30GHz, Figure 9d corresponds to the yz plane at 30GHz, Figure 9e corresponds to the xz plane at 31GHz, and Figure 9f corresponds to the yz plane at 31GHz noodle;

Figure 10 shows the simulated right-hand circular polarization and left-hand circular polarization normalized radiation when the beam independently controllable broadband dual-frequency dual circularly polarized reflectarray antenna is excited by the Ka-band left-circularly polarized feed horn antenna Figure 10a corresponds to the xz plane at 29GHz, Figure 10b corresponds to the yz plane at 29GHz, Figure 10c corresponds to the xz plane at 30GHz, Figure 10d corresponds to the yz plane at 30GHz, Figure 10e corresponds to the xz plane at 31GHz, and Figure 10f corresponds to the yz plane at 31GHz ;

Figure 11 shows the simulated gain and axial ratio versus frequency curve when the beam independently controllable broadband dual-frequency dual circularly polarized reflectarray antenna is excited by the Ka-band right-handed/left-handed circularly polarized feed horn antenna. 11a corresponds to the gain, and Fig. 11b corresponds to the axial ratio.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings

As shown in FIG. 1 , the present invention proposes a broadband dual-frequency dual circularly polarized reflectarray antenna with independently controllable beams. The reflectarray antenna includes a K-band broadband circularly polarized feed 1 and a Ka-band broadband circularly polarized feed. 2 and a planar reflector 3. Both the K-band broadband circularly polarized feed 1 and the Ka-band broadband circularly polarized feed 2 are placed near the focal plane of the planar reflection array 3 . The diameter of the plane reflection array 3 is D, which is set to 180mm here, the vertical distance between the K-band broadband circularly polarized feed 1 and the plane reflection array 3 is F1, and the value of F1/D is between 1 and 1.5, which is set here. is 1.2; the vertical distance between the Ka-band broadband circularly polarized feed 2 and the planar reflection array 3 is F2, and the value of F2/D is between 1 and 1.5, which is set to 1.3 here.

As shown in FIG. 1 , the planar reflection array 3 is composed of a K-band dual circularly polarized phase shift unit 4 and a Ka-band dual circularly polarized phase shift unit 5 . The K-band dual-circularly polarized phase shift units 4 and the Ka-band dual-circularly polarized phase-shift units 5 are periodically staggered with a common aperture on the plane reflector 3 , wherein the K-band dual-circularly polarized phase shift units 4 are two-dimensional periodic Arranged on the vertices of a square grid whose side length is the K-band period length, the Ka-band dual-circular polarization phase shift units 5 are periodically arranged in two dimensions on the side length of the K-band period length or 1.5 Ka-band period lengths. On the center point of the square grid of The period is 0.5 to 0.7 Ka-band wavelengths, and is set to 0.6 Ka-band wavelengths here.

As shown in Figure 2, the K-band dual circular polarization phase shift unit 4 is composed of four metal layers, two substrate layers and one adhesive layer; the first metal layer of the K-band is etched with a "cross" shape in the center. The first circular metal patch 4a of the slot, the second metal layer of the K-band is a first metal floor 4b etched with an orthogonal "I"-shaped slot, and the third metal layer of the K-band is two first microstrips with different lengths In the transmission line 4c, the ends of the two microstrip transmission lines are provided with first metallized vias 4d to connect to the K-band first metal floor 4b, and the K-band fourth metal layer is the first metal floor 4e.

A first substrate layer 3a is arranged between the K-band first metal layer and the K-band second metal layer, and a second substrate layer 3b is arranged between the K-band second metal layer and the K-band third metal layer. An air layer is arranged between the third metal layer in the band and the fourth metal layer in the K band, and a first adhesive layer 3c is arranged between the first substrate 3a and the second substrate layer 3b.

The K-band dual circular polarization phase shift unit 4 is divided into K-band dual circular polarization phase shift unit 1 to unit 8 according to the state naming of the eight K-band third metal layers 4c two microstrip lines with different lengths. The reflection phase difference between the two microstrip transmission lines of different lengths of the third metal layer 4c of the K-band dual circular polarization phase shift unit 1 to unit 8 is 180°, which ensures that each K-band dual circular polarization phase shift unit 4 Both can receive right-handed/left-handed circularly polarized waves emitted by the feed, and reflect right-handed/left-handed circularly polarized waves of the same handedness. The phase difference of the microstrip lines corresponding to the adjacent K-band dual-circular polarization phase shift units is 22.5°, that is, the phase difference between the K-band dual-circular polarization phase-shift unit 1 and the K-band dual-circular polarization phase-shift unit 2 is 22.5° , the phase difference between the K-band dual-circular polarization phase shift unit 2 and the K-band dual-circular polarization phase shift unit 3 is 22.5°, and so on. Rotate the K-band dual-circular polarization phase shift unit 1 to unit 8 as a whole, and finally form a total of 64 states of K-band right-hand circular polarization 3 bits × left-hand circular polarization 3 bits. Figure a in Figure 4 corresponds to the eight phase shift units in the K-band. Each phase-shift unit is essentially a K-band dual circularly polarized phase-shift unit. The difference is that these eight units have microstrip lines on the third metal layer. The difference in length is 22.5° out of phase between adjacent units, and the rest are the same. The design of the eight units is determined according to the precision of the circular polarization phase regulation by the reflectance array. Rotating each of these eight units by different angles will form a total of 64 states of 3-bit left-hand circular polarization × 3-bit right-hand circular polarization in the K-band. One of the corresponding 64 states is placed at this position according to the phase regulation required for left-hand circular polarization and right-hand circular polarization in the K-band on the reflection front. In the present invention, the set circular polarization control precision is 3 bits, which corresponds to the linear polarization control precision of 4 bits, that is, the phase difference between adjacent units is 22.5°. If the set circular polarization control precision is n(n≥ 1) bits, the corresponding linear polarization control precision is (n+1) bits.

When the K-band right-handed/left-handed broadband circularly polarized horn feed 1 is excited, the two orthogonal linearly polarized components of the radiated right-handed/left-handed circularly polarized waves are radiated by the K-band dual circularly polarized phase shift unit 4 The first circular metal patch 4a is received, and is coupled to the first microstrip transmission line 4c through an orthogonal "I"-shaped slot, and returns after passing through the first metallized via 4d at the end of the microstrip line. ”-shaped slot is coupled to the first circular metal patch 4a and radiates outward. Since the lengths of the two first microstrip transmission lines 4c are different in length by a quarter wavelength, that is, the reflection phases of the two orthogonal linear polarization components are different by 180°, the reflected waves are still circular poles with the same rotation direction as the incident polarization. change. By rotating the K-band dual-circular polarization phase shift unit 1 to unit 8 with different microstrip line lengths, a total of 64 states of 3-bit right-handed circular polarization × 3-bit left-handed circular polarization can be realized, which satisfies the requirements for right-handed/left-handed circular polarization. Independent control of polarized beams.

As shown in Figure 3, the Ka-band dual circular polarization phase shift unit 5 is composed of four metal layers, two substrate layers and one adhesive layer; the first metal layer of the Ka-band is the second circular metal patch 5a, the second metal layer of the Ka-band is a second metal floor 5b etched with orthogonal "I"-shaped slits, and the third metal layer of the Ka-band is two second microstrip transmission lines 5c of different lengths. The end is provided with a second metallized via 5d connected to the Ka-band second metal layer, and the Ka-band fourth metal layer is the second metal base plate 5e.

A first substrate layer 3a is arranged between the first metal layer of Ka-band and the second metal layer of Ka-band, a second substrate layer 3b is arranged between the second metal layer of Ka-band and the third metal layer of Ka-band, An air layer is arranged between the third metal layer in the band and the fourth metal layer in the Ka band, and a first adhesive layer 3c is arranged between the first substrate 3a and the second substrate layer 3b.

Similarly, the Ka-band dual-circular polarization phase shift unit 5 is divided into Ka-band dual-circular polarization phase-shift unit 1 to unit 8 according to the state naming of eight kinds of Ka-band third metal layer 5c microstrip lines with different lengths. The reflection phase difference between the two microstrip transmission lines with different lengths of the third metal layer 5c of Ka-band dual-circular polarization phase shift units 1 to 8 is 180°, which ensures that each Ka-band dual-circular polarization phase shift unit 5 Both can receive right-handed/left-handed circularly polarized waves emitted by the feed, and reflect right-handed/left-handed circularly polarized waves of the same handedness. The phase difference of the microstrip lines corresponding to the adjacent Ka-band dual-circular polarization phase shift units is 22.5°, that is, the phase difference between Ka-band dual-circular polarization phase-shift unit 1 and Ka-band dual-circular polarization phase-shift unit 2 is 22.5° , the phase difference between Ka-band dual-circular polarization phase-shift element 2 and Ka-band dual-circular polarization phase-shift element 3 is 22.5°, and so on. The Ka-band dual circular polarization phase shift unit 1 to unit 8 are rotated as a whole, and finally a total of 64 states of Ka-band right-hand circular polarization 3 bits × left-hand circular polarization 3 bits are formed. Figure b in Figure 4 corresponds to the eight phase shift units in the Ka-band. Each phase-shift unit is essentially a Ka-band double circularly polarized phase shift unit. The difference is that these eight units have microstrip lines on the third metal layer. The difference in length is 22.5° out of phase between adjacent units, and the rest are the same. Rotating each of these eight units by different angles forms a total of 64 states of Ka-band 3-bit left-hand circular polarization × 3-bit right-hand circular polarization. One of the corresponding 64 states is placed in this position according to the phase regulation required for the left-handed circular polarization and the right-handed circular polarization of the Ka-band on the reflection front.

When the Ka-band right-handed/left-handed broadband circularly polarized horn feed 2 is excited, the two orthogonal linearly polarized components of the radiated right-handed/left-handed circularly polarized waves are radiated by the Ka-band dual circularly polarized phase shift unit 5 The circular metal patch 5a is received and coupled to the second microstrip transmission line 5c through an orthogonal "I" shaped slot, and returns after passing through the second metallized via 5d at the end of the microstrip line, through the orthogonal "I" The zigzag slot is coupled to the second circular metal patch 5a and radiates outward. Since the lengths of the two second microstrip transmission lines 5c differ by a quarter wavelength, that is, the reflection phases of the two orthogonal linear polarization components differ by 180°, the reflected waves are still circular poles with the same rotation direction as the incident polarization. change. By rotating the Ka-band dual-circular polarization phase shift unit 1 to unit 8 with different microstrip line lengths, a total of 64 states of 3-bit right-handed circular polarization × 3-bit left-handed circular polarization can be realized, which satisfies the requirements for right-handed/left-handed circular polarization. Independent control of polarized beams.

In the present invention, the plane reflection array is composed of K-band dual-circular polarization phase-shifting units and Ka-band dual-circular polarization phase-shifting units arranged in a staggered period with a common aperture, and the cross section is only 0.28λ _K . The K-band and Ka-band phase shift units are staggered with a common aperture period, in which the K-band phase shift unit period is 0.4 K-band wavelengths, and the Ka-band phase shift unit period is 0.6 Ka-band wavelengths. Both the K-band dual-circular polarization phase shift unit and the Ka-band dual-circular polarization phase-shift unit are in the form of microstrip line slot-coupled patches. Combined with the resonance generated by the slot and the resonance generated by the patch, the impedance bandwidth of the K-band phase shift unit up to 14.5%, and the impedance bandwidth of the Ka-band phase-shift unit reaches 15.7%. A "cross"-shaped gap is etched in the middle of the circular patch of the first metal layer of the K-band. The introduction of the "cross"-shaped gap reduces the size of the K-band circular patch and reduces the interaction between the K-band and the Ka-band. interference, and improve the dual-frequency working performance. For the K-band dual-circular polarization phase-shift unit and the Ka-band dual-circular polarization phase-shift unit, by changing the length of the microstrip line and the size of the gap on the metal floor at the same time, a broadband phase-shift response is achieved and dual-frequency reflection is guaranteed. The final broadband characteristics of the array antenna, including gain and axial ratio broadband characteristics.

According to the left-handed circular polarization and right-handed circular polarization phase required by the K/Ka-band subwavelength periodic arrangement of the corresponding units on the planar reflection array, the K/Ka-band dual-circular polarization phase shift unit 1 to unit 8 are rotated as a whole. , and finally form a total of 64 states of right-hand circularly polarized 3 bits × left-handed circularly polarized 3 bits, that is, the independent controllability of the K/Ka band dual circularly polarized beam is realized. Finally, the K-band right-handed circularly polarized wave points to θ=20°,

(θ refers to the pitch angle,

refers to the azimuth angle), its gain is 27.34dBic, the axial ratio is 0.54dB, and the efficiency is 36.27%; the K-band left-handed circularly polarized wave points to θ=20°,

The gain is 27.42dBic, the axial ratio is 0.41dB, and the efficiency is 36.93%; the 2dB gain bandwidth of the K-band right-handed/left-handed circular polarization is 15%; the bandwidth of the axial ratio less than 2dB is 20%. Ka-band right-handed circularly polarized wave points to θ=-10°,

The gain is 30.16dBic, the axial ratio is 0.81dB, and the efficiency is 31.4%; the Ka-band left-handed circularly polarized wave points to θ=-10°,

The gain is 30.31dBic, the axial ratio is 0.67dB, and the efficiency is 32.51%; the 2dB gain bandwidth of Ka-band right-handed/left-handed circular polarization is 11.7%; the bandwidth of the axial ratio less than 2dB is 10.8%.

The 64 states finally formed in the present invention are shown in Table 1.

Table 1

Unit 11 to Unit 88 in the first row of the table are the serial numbers of the 64 unit states, the former part in brackets in the second row refers to the double circular polarization phase shift unit 1 to unit 8, and the latter part refers to the angle of the overall rotation of the unit.

Figure 4 shows the reflection coefficient amplitudes and reflection phases corresponding to the K-band and Ka-band dual-circular polarization phase shift units 1 to 8 respectively. It can be seen that the reflection phase differences between the orthogonal linear polarizations of the same unit are all 180°, and the reflection phase difference between adjacent cells is 22.5°.

Fig. 5 shows the reflection phase of 64 states of right-hand circular polarization 3 bits × left-hand circular polarization 3 bits formed after the K-band and Ka-band dual circular polarization phase shift units 1 to 8 are rotated at different angles distribution map. It can be seen that these 64 states can provide independent phase shift control of right-handed and left-handed circularly polarized waves with a 3-bit, or 45°, phase shift accuracy.

Fig. 6 shows the simulated right-hand circular polarization sum in the xz plane and the yz plane when the beam independently steerable broadband dual-frequency dual circularly polarized reflectarray antenna is excited by the K-band right-hand circularly polarized feed horn antenna. Left-handed circularly polarized normalized radiation pattern. It can be seen that there is a right-handed circularly polarized wave pointing in the direction of 20° in the xz plane.

Take the plane where the plane reflection array 2 is located as the xy plane, and the z axis is perpendicular to the xy plane.

Figure 7 shows the simulated right-handed circular polarization and left-handed circular polarization in the xz plane and yz plane when the beam independently steerable broadband dual-frequency dual circularly polarized reflectarray antenna is excited by the K-band left-handed circularly polarized feed horn antenna Circularly polarized normalized radiation pattern. It can be seen that there is a left-handed circularly polarized wave pointing in the direction of 20° in the yz plane.

Figure 8 shows the simulated gain and axial ratio versus frequency curves when the beam independently controllable broadband dual-frequency dual circularly polarized reflectarray antenna is excited by the K-band right-handed/left-handed circularly polarized feed horn antenna. It can be seen that the 2dB gain bandwidth of the K-band right-handed/left-handed circular polarization is both 15%; the bandwidth of the axial ratio less than 2dB is all 20%.

Fig. 9 shows the simulated right-hand circular polarization sum in the xz plane and the yz plane when the beam-independently steerable broadband dual-frequency dual circularly polarized reflectarray antenna is excited by the Ka-band right-handed circularly polarized feed horn antenna. Left-handed circularly polarized normalized radiation pattern. It can be seen that there is a right-handed circularly polarized wave pointing in the -10° direction in the yz plane.

Figure 10 shows the simulated right-hand circular polarization and left-hand circular polarization in the xz plane and yz plane when the beam independent controllable broadband dual-frequency dual circular polarization reflectarray antenna is excited by the Ka-band left-hand circularly polarized feed horn antenna Circularly polarized normalized radiation pattern. It can be seen that there is a left-handed circularly polarized wave pointing in the direction of -10° in the xz plane.

Figure 11 shows the simulated gain and axial ratio versus frequency curves of the beam independently steerable wideband dual-frequency dual circularly polarized reflectarray antenna excited by the Ka-band right-handed/left-handed circularly polarized feed horn antenna. It can be seen that the 2dB gain bandwidth of the Ka-band right-handed/left-handed circular polarization is both 11.7%; the bandwidth of the axial ratio less than 2dB is both 10.8%.

In summary, the present invention provides a beam-independently controllable broadband dual-frequency dual-circularly polarized reflectarray antenna capable of operating in the K and Ka bands. The reflectarray antenna has structural advantages such as low profile and easy processing. And can provide dual-frequency dual-circular polarization, wideband, high gain, low axial ratio, small gain jitter, circularly polarized beam independently controllable functions, and has important application prospects in the fields of mobile communication and satellite communication in the future.

The above is only the preferred embodiment of the present invention, it should be pointed out that: for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims

A broadband dual-frequency dual circularly polarized reflection array antenna with independently controllable beams, characterized in that it comprises a planar reflection array (3), and a K-band broadband circularly polarized feed source (1) disposed facing the planar reflection array (3). ) and a Ka-band broadband circularly polarized feed (2), and the planar reflection array (3) includes a plurality of K-band dual circularly polarized phase shift units (4) and Ka-band dual circular polarized elements that are periodically staggered with a common aperture A phase shift unit (5); the K-band dual-circular polarization phase-shift unit (4) and the Ka-band dual-circular polarization phase-shift unit (5) both include four metal layers;

In the K-band dual circularly polarized phase shift unit (4), the four metal layers from top to bottom are respectively a first circular metal patch (4a) with a cross-shaped slit etched in the center, and an orthogonal I-shaped slit etched in the center. a first metal floor (4b) of the slot, two first microstrip transmission lines (4c) with different lengths on the same metal layer, and a first metal bottom plate (4e); the ends of the two first microstrip transmission lines (4c) Each is provided with a first metallized via hole (4d), and the first metallized via hole (4d) is connected to the first metal floor (4b);

In the Ka-band dual-circular polarization phase shift unit (5), the four metal layers are respectively a second circular metal patch (5a) and a second metal floor (5a) etched with an orthogonal I-shaped slit from top to bottom. 5b), two second microstrip transmission lines (5c) and second metal base plates (5e) with different lengths are located on the same metal layer; a hole (5d), the second metallized via (5d) is connected to the second metal floor (5b);

The first circular metal patch (4a) and the second circular metal patch (5a) are both arranged towards the K-band broadband circularly polarized feed source (1) and the Ka-band broadband circularly polarized feed source (2).
The broadband dual-frequency dual circularly polarized reflectarray antenna with independently controllable beams according to claim 1, characterized in that: the K-band broadband circularly polarized feed (1) is placed at the focal point of the planar reflector (3). Near the plane, the vertical distance from the plane reflection array (3) is F1, and the diameter of the plane reflection array is D, where 0.6≤F1/D≤1.5;

The Ka-band broadband circularly polarized feed (2) is placed near the focal plane of the planar reflection array (3), and the vertical distance from the planar reflection array is F2, where 0.6≤F2/D≤1.5.
The broadband dual-frequency dual-circularly polarized reflectarray antenna with independently controllable beams according to claim 1, characterized in that: the K-band dual-circularly polarized phase shift unit (4) and the Ka-band dual-circularly polarized phase shifter The units (5) are periodically staggered with a common aperture, wherein the K-band dual-circular polarization phase-shifting units (4) are periodically arranged in two dimensions on the vertices of a square grid whose side length is the K-band period length. The circularly polarized phase shift units (5) are periodically arranged in a two-dimensional manner on the center point of a square grid whose side length is the K-band period length or 1.5 Ka-band period lengths, and the K-band dual circularly polarized phase shift units (4) ) of the K-band cycle length is 0.3-0.5 K-band wavelengths, and the Ka-band cycle length of the Ka-band dual circular polarization phase shift unit (5) is 0.5-0.7 Ka-band wavelengths.
The broadband dual-frequency dual-circularly polarized reflectarray antenna with independently controllable beams according to claim 1, wherein the K-band dual-circularly polarized phase shift unit (4) comprises a K-band first metal layer, a K-band dual-circularly polarized phase shift unit (4) The second metal layer in the K-band, the third metal layer in the K-band and the fourth metal layer in the K-band; a first substrate layer (3a) is arranged between the first metal layer in the K-band and the second metal layer in the K-band, and the A second substrate layer (3b) is arranged between the second metal layer and the third K-band metal layer, an air layer is arranged between the K-band third metal layer and the K-band fourth metal layer, and the first substrate A first adhesive layer (3c) is arranged between the layer (3a) and the second substrate layer (3b);

The Ka-band dual circular polarization phase shift unit (5) includes a Ka-band first metal layer, a Ka-band second metal layer, a Ka-band third metal layer, and a Ka-band fourth metal layer; the first metal layer in the Ka-band A first substrate layer (3a) is arranged between the Ka-band second metal layer and the Ka-band second metal layer, and a second substrate layer (3b) is arranged between the Ka-band second metal layer and the Ka-band third metal layer. An air layer is arranged between the metal layer and the fourth metal layer of the Ka band, and a first adhesive layer (3c) is arranged between the first substrate layer (3a) and the second substrate layer (3b).
The beam-independently controllable broadband dual-frequency dual-circularly polarized reflectarray antenna according to claim 4, wherein the shape of the first metal layer of the K-band and the first metal layer of the Ka-band is a circle, a ring, " Any of a "cross" shape or a polygon.
The beam-independently controllable broadband dual-frequency dual-circularly polarized reflectarray antenna according to claim 1, characterized in that: the first circular metal patch ( The gap on 4a) is in the middle of the patch, or at the edge of the patch, and the shape is "cross" shape, "rice" shape or no gap.
The broadband dual-frequency dual-circularly polarized reflectarray antenna with independently controllable beams according to claim 1, characterized in that: the shape of the slits on the first metal floor (4b) and the second metal floor (5b) is " Any one of "one" shape, "g" shape, "cross" shape, "Z" shape or oval shape.
The broadband dual-frequency dual-circularly polarized reflectarray antenna with independently controllable beams according to claim 1, wherein the first microstrip transmission line (4c) or the second microstrip transmission line (5c) are in the form of both Any of an open microstrip line, a shorted microstrip line, an open stripline, a shorted stripline, a substrate-integrated waveguide, or a substrate-integrated coaxial line.
The broadband dual-frequency dual-circularly polarized reflectarray antenna with independently controllable beams according to claim 1, characterized in that: two first microstrip transmission lines in the K-band dual-circularly polarized phase shift unit (4) The length difference between (4c) is a quarter of the K-band wavelength, and the reflection phase difference is 180°;

The length difference between the two second microstrip transmission lines (5c) in the Ka-band dual circularly polarized phase shift unit (5) is a quarter of the Ka-band wavelength, and the reflection phase difference is 180°.
The broadband dual-frequency dual-circularly polarized reflectarray antenna with independently controllable beams according to claim 9, characterized in that: according to the different lengths of the first microstrip transmission lines in each K-band dual-circularly polarized phase shift unit (4) , the K-band dual circular polarization phase shift unit (4) in the planar reflection array (3) is named as K-band dual circular polarization phase shift unit 1 to K-band dual circular polarization phase shift unit 8, adjacent K-band dual circular polarization phase shift unit 8 The reflection phase difference corresponding to the circularly polarized phase shift unit is 22.5°; the eight K-band dual circularly polarized phase shift units with continuous phase differences are rotated as a whole to form a K-band right-handed circularly polarized 3 bits × left-handed circularly polarized 3 bits total 64 states;

According to the different lengths of the second microstrip transmission lines in each Ka-band dual-circular polarization phase shift unit (5), the Ka-band dual-circular polarization phase-shift unit (5) in the planar reflector (3) is named as Ka-band dual-circular polarization phase shift unit (5). From Circular Polarization Phase Shift Unit 1 to Ka-band Dual Circular Polarization Phase Shift Unit 8, the reflection phases corresponding to the adjacent Ka-band Dual Circular Polarization Phase Shift Units differ by 22.5°; The phase shift unit is rotated as a whole to form a total of 64 states of Ka-band right-hand circular polarization 3 bits × left-hand circular polarization 3 bits.