Broadband tight coupling polarization conversion transmission and reflection integrated array antenna unit

Abstract

The invention provides a broadband tight coupling polarization conversion transmission and reflection integrated array antenna unit. An array is formed by periodically arranging a plurality of antenna units integrating transmission and reflection structures; the transmission structure comprises a cross-shaped dual-polarization receiving dipole antenna and a single-polarization radiation dipole antenna, a middle floor and a phase shift line are arranged between the two antennas, and a receiving layer and a transmitting layer of the transmission structure are formed through parallel double-line connection; the reflection structure is composed of a dipole antenna orthogonal to the receiving direction of the transmission structure, and reflection is completed through parallel double-wire grounding. The middle three layers of floors and the phase shift lines respectively form transmission and reflection band-shaped phase transmission lines, the lengths of the phase shift lines are adjusted according to different positions of each unit in the array, and spherical electromagnetic waves are converted into planar electromagnetic waves. The broadband bidirectional beam communication antenna has the advantages of broadband, low cost, bidirectional beam transmission and the like, and can be used for broadband bidirectional beam communication antennas.

Description

Technical Field

[0001] The present invention belongs to the technical field of antennas in wireless communication systems, and particularly relates to a broadband tightly coupled polarization conversion transmission-reflection integrated array antenna element. Background Art

[0002] High-gain antennas can provide enhanced signal strength for the reception and transmission of wireless signals in application scenarios such as satellite communication, radar detection, and deep space communication, and have important application values. With the rapid development of wireless communication systems, the performance requirements for high-gain antennas are becoming more and more diverse. For example, in order to meet the requirement of the platform for electronic devices to cover different operating frequency bands, a high-gain antenna is required to have the ability to operate in a wide frequency band; in order to meet the requirement of a high-resolution radar detection system to achieve real-time tracking of targets, a high-gain antenna is required to have the ability of beam scanning; in order to meet the measurement of along-track and cross-track velocities in an interferometric synthetic aperture radar system, a high-gain antenna is required to have functions such as the ability of bidirectional radiation beams. Among them, reflectarray antennas and transmitarray antennas are different from traditional high-gain antennas such as phased array antennas, and have advantages such as simple feed networks, low energy loss, and low processing difficulty, and have broad application prospects in various fields.

[0003] The reflectarray and transmitarray antenna arrays are arranged by a certain number of antenna elements, and the electromagnetic waves radiated by the feed source are phase-controlled by the discrete elements to focus the spherical waves into plane waves with a specific beam direction, thereby achieving high-gain characteristics. Due to the use of space feeding, the design and use of complex feed networks are effectively avoided, and the energy consumption is reduced. However, as a new type of high-gain antenna, the reflectarray and transmitarray antennas have problems of single radiation function and limited operating frequency band, which restrict their applications in directions such as navigation and satellite communication. Therefore, the research on the bidirectional beam radiation of this antenna is of great significance.

[0004] A tightly coupled antenna structure is an antenna structure that improves the impedance matching, gain, radiation pattern and other characteristics of the antenna by closely arranging antenna elements, causing strong mutual coupling between the antenna elements, and compensating for the strong inductive effect caused by the ground plane through the coupling capacitance between the elements. Tightly coupled antennas have a wide range of applications in communication and radar systems. For example, they can provide high gain and narrow beamwidth, improving the stability and transmission rate of communication links; they can achieve multi-band operation, supporting various communication standards such as 4G and 5G; they can provide high-resolution imaging capabilities, enhancing the accuracy of target detection and tracking; in radio navigation systems, they can improve the accuracy and reliability of positioning, etc. However, the design of tightly coupled structures still faces multiple challenges. The strong mutual coupling effect between antenna elements may lead to unstable antenna performance, requiring precise electromagnetic simulation and optimization. At the same time, due to the small distance between antenna elements, the size of tightly coupled antennas is often limited, affecting the radiation efficiency and bandwidth of the antenna. Moreover, tightly coupled antennas require higher-precision processes during processing and integration to ensure the precise alignment and connection between antenna elements. Summary of the Invention

[0005] In order to overcome the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a broadband tightly coupled polarization conversion transmission-reflection integrated array antenna element, which uses a tightly coupled structure to broaden the antenna bandwidth and integrate the transmission and reflection antennas, so as to solve the constraints of narrow bandwidth and single function of high-gain antennas, and thus realize the wide application of high-gain antennas in various fields.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A broadband tightly coupled polarization conversion transmission-reflection integrated array antenna element, comprising a dual-polarized dipole, a reflection phase shifter line, a transmission phase shifter line and a single-polarized dipole;

[0008] The reflection phase shifter line is connected to the x-polarization direction transmission unit of the dual-polarized dipole, and the transmission phase shifter line is simultaneously connected to the y-polarization direction transmission unit of the dual-polarized dipole and the x-polarization direction transmission unit of the single-polarized dipole, forming a receive-transmit-transmit structure; the dual-polarized dipole receives y- and x-polarized electromagnetic waves and reflects the y-polarized electromagnetic waves, and the single-polarized dipole radiates x-polarized electromagnetic waves.

[0009] In one embodiment, the dual-polarized dipole is disposed on the first dielectric substrate, the single-polarized dipole is disposed on the second dielectric substrate, the reflection phase shift line and the transmission phase shift line are disposed on the dielectric substrate layer, the first dielectric substrate, the dielectric substrate layer, and the second dielectric substrate are arranged from top to bottom, and a first cross-shaped plug is disposed between the first dielectric substrate and the dielectric substrate layer to connect the transmission unit of the dual-polarized dipole to the reflection phase shift line and the transmission phase shift line; a second cross-shaped plug is disposed between the dielectric substrate layer and the second dielectric substrate to connect the transmission unit of the single-polarized dipole to the transmission phase shift line.

[0010] In one embodiment, the dielectric substrate layer is composed of four stacked dielectric substrates, and is respectively combined with two phase shift lines to form a stripline structure. There is an upper ground plane above the first dielectric substrate, and a metal reflection phase shift line is disposed below the first dielectric substrate or above the second dielectric substrate. There is an intermediate ground plane below the second dielectric substrate or above the third dielectric substrate, and a transmission phase shift line is disposed below the third dielectric substrate or above the fourth dielectric substrate. There is a lower ground plane below the fourth dielectric substrate.

[0011] In one embodiment, chamfering is performed at the bending positions of both the reflection phase shift line and the transmission phase shift line.

[0012] In one embodiment, the terminal of the reflection phase shift line is open-circuited, and the phase of the reflection mode is regulated by adjusting the length of the bending region; both ends of the transmission phase shift line are respectively connected to the transmission units of the dual-polarized dipole and the single-polarized dipole, and the phase of the transmission mode is regulated by adjusting the length of the bending region.

[0013] In one embodiment, the dual-polarized dipole includes a dual-polarized dipole metal patch disposed on the upper side of the first dielectric substrate and a first circular metal patch disposed on the lower side; the single-polarized dipole includes a second circular metal patch disposed on the upper side of the second dielectric substrate and a single-polarized dipole metal patch disposed on the lower side.

[0014] The dual-polarized dipole metal patch receives incident waves in the x and y polarization directions, and the circular metal patch at the connection between the dipole arms is coupled to the first circular metal patch.

[0015] The single-polarized dipole metal patch receives incident waves in the y polarization direction and radiates x-polarized waves, and the circular metal patch at the connection between the dipole arms is coupled to the second circular metal patch.

[0016] In one embodiment, both the first cross-shaped plug and the second cross-shaped plug include a first plug and a second plug. The first plug is a vertical plate along the x polarization direction, and the second plug is a vertical plate along the y polarization direction.

[0017] Both the first and second plates of the first cross-shaped plate are provided with double-sided parallel transmission lines. One side of the double-sided parallel transmission line of the first plate is connected to the reflection phase shift line, and the other side is grounded. One side of the double-sided parallel transmission line of the second plate is connected to the transmission phase shift line, and the other side is grounded;

[0018] The first plate of the second cross-shaped plate is provided with a double-sided parallel transmission line. One side of the double-sided parallel transmission line is connected to the transmission phase shift line, and the other side is grounded.

[0019] In one embodiment, the first and / or second plates of the first cross-shaped plate are provided with double-sided coupled short-circuit transmission lines. The double-sided coupled short-circuit transmission lines of the first cross-shaped plate ground the first circular metal patch;

[0020] The first and / or second plates of the second cross-shaped plate are provided with double-sided coupled short-circuit transmission lines. The double-sided coupled short-circuit transmission lines of the second cross-shaped plate ground the second circular metal patch.

[0021] In one embodiment, after the x-polarized electromagnetic wave passes through the double-sided parallel transmission line on the first plate of the first cross-shaped plate, it passes through the reflection phase shift line, and after the phase compensation is completed by adjusting the length of the bent part of the reflection phase shift line, it is reflected, that is, the reflected x-polarized electromagnetic wave.

[0022] In one embodiment, after the y-polarized electromagnetic wave passes through the double-sided parallel transmission line on the second plate of the first cross-shaped plate, it passes through the transmission phase shift line, and after the phase compensation is completed by adjusting the length of the bent part of the transmission phase shift line, it is connected to the double-sided parallel transmission line on the second cross-shaped plate and radiated through the single-polarized dipole metal patch, that is, the y-polarized electromagnetic wave is radiated into the x-polarized electromagnetic wave after polarization conversion.

[0023] In one embodiment, the antenna unit realizes the phase regulation by changing the lengths of the bent regions of the reflection phase shift line and the transmission phase shift line. The reflection phase is above -2 dB, the transmission phase is above -3 dB, the phase parameter satisfies 360°, and the working bandwidth of the antenna with a stable radiation pattern is 3 times the frequency, that is, 5 - 15 GHz.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] First, the present invention innovatively combines transmission and reflection in the same aperture, overcomes the shortcoming of the single radiation direction of a single transmission array or reflection array antenna, broadens the application scenario of the array, and improves the flexibility of array application.

[0026] Second, the present invention innovatively performs selective polarization conversion, that is, the transmission structure receives the y-polarized electromagnetic wave and radiates the x-polarized electromagnetic wave by receiving the single-polarized dipole radiation through the dual-polarized dipole, so that the polarization of the transmission and reflection structures is unified, and the radiation efficiency of the antenna is increased.

[0027] Thirdly, the present invention innovatively combines a tightly coupled dipole antenna with a transmissive and reflective array, resulting in strong mutual coupling between antenna elements. The strong inductive effect caused by the ground plane is compensated by the coupling capacitance between the elements, thereby improving the characteristics of the antenna such as impedance matching, gain, and radiation pattern. At the same time, the disadvantage of the narrow bandwidth of the transmissive and reflective array antenna is improved, and the operating bandwidth of the antenna is broadened to three times the frequency, that is, 5 - 15 GHz. Description of the Drawings

[0028] Figure 1 is the overall structure diagram of the unit structure of the present invention;

[0029] Figure 2 is the structure diagram of the patch of the tightly coupled dipole antenna of the present invention. Among them, (a) is the top view of the dual-polarized dipole metal patch, and (b) is the bottom view of the single-polarized dipole metal patch;

[0030] Figure 3 is the left view of the present invention;

[0031] Figure 4 is the front view of the cross-shaped insertion board in the middle upper layer;

[0032] Figure 5 is the detailed structure diagram of the intermediate dielectric layer of the present invention;

[0033] Figure 6 is the top view of the phase shift line structure of the present invention. Among them, (a) is the reflection phase shift line structure, and (b) is the transmission phase shift line structure;

[0034] Figure 7 is the reflection and transmission coefficient diagram of the present invention. Among them, (a) is the reflection coefficient and reflection phase curve diagram, and (b) is the transmission coefficient and transmission phase curve diagram;

[0035] Figure 8 is the top view of the model after arranging the units of the present invention;

[0036] Figure 9 is the reflection radiation pattern at the 9 GHz frequency point after arranging the units of the present invention. Among them, (a) is the 9 GHz reflection E-plane radiation pattern, and (b) is the 9 GHz reflection H-plane radiation pattern;

[0037] Figure 10 is the transmission radiation pattern at the 9 GHz frequency point after arranging the units of the present invention. Among them, (a) is the 9 GHz transmission E-plane radiation pattern, and (b) is the 9 GHz transmission H-plane radiation pattern;

[0038] Figure 11This is the reflection pattern of the present invention at the 12 GHz frequency point after arranging the units. Among them, (a) is the 12 GHz reflection E-plane pattern, and (b) is the 12 GHz reflection H-plane pattern;

[0039] Figure 12 This is the transmission pattern of the present invention at the 12 GHz frequency point after arranging the units. Among them, (a) is the 12 GHz transmission E-plane pattern, and (b) is the 12 GHz transmission H-plane pattern;

[0040] Figure 13 This is the reflection pattern of the present invention at the 15 GHz frequency point after arranging the units. Among them, (a) is the 15 GHz reflection E-plane pattern, and (b) is the 15 GHz reflection H-plane pattern;

[0041] Figure 14 This is the transmission pattern of the present invention at the 15 GHz frequency point after arranging the units. Among them, (a) is the 15 GHz transmission E-plane pattern, and (b) is the 15 GHz transmission H-plane pattern.

[0042] Figure 15 This is the schematic diagram of the reflection and transmission gains of the array antenna of the present invention.

[0043] In the figure: 1. The first dielectric plate; 2. The second cross-shaped insertion plate; 3. The dielectric substrate layer; 4. The second cross-shaped insertion plate; 5. The second dielectric substrate; 101. The dual-polarized dipole metal patch; 102. The first circular metal patch; 201. The double-sided parallel transmission line; 202. The double-sided coupled short-circuit transmission line; 31. The first layer of dielectric substrate; 32. The second layer of dielectric substrate; 33. The third layer of dielectric substrate; 34. The fourth layer of dielectric substrate; 301. The upper floor; 302. The reflection phase-shifting line; 303. The transmission phase-shifting line; 304. The middle floor; 305. The lower floor; 501. The second circular metal patch; 502. The single-polarized dipole metal patch. Detailed implementation mode

[0044] The following further details the implementation mode of the present invention in conjunction with the drawings and embodiments.

[0045] Refer to Figure 1 to further elaborate on the overall structure of the tightly coupled polarization conversion transmission and reflection integrated unit of the present invention.

[0046] The present invention mainly includes several functional parts such as a dual-polarized dipole, a reflection phase-shifting line 302, a transmission phase-shifting line 303, and a single-polarized dipole. Among them, the x-polarization direction transmission unit of the dual-polarized dipole is connected to the reflection phase-shifting line 302, and the y-polarization direction transmission unit and the x-polarization direction transmission unit of the single-polarized dipole are simultaneously connected to the transmission phase-shifting line 303 to form a complete receiving-transmitting-emitting structure. The dual-polarized dipole receives y- and x-polarized electromagnetic waves and reflects the y-polarized electromagnetic wave, while the single-polarized dipole radiates the x-polarized electromagnetic wave.

[0047] According to the above structure, the present invention can selectively perform polarization conversion. By receiving the radiation of the single-polarized dipole through the dual-polarized dipole, the transmission structure receives the y-polarized electromagnetic wave and radiates the x-polarized electromagnetic wave, and the reflection structure receives and reflects the x-polarized electromagnetic wave, so that the polarization of the transmission and reflection structures is unified, increasing the antenna radiation efficiency. Moreover, through the above design, the present invention combines transmission and reflection on the same aperture, overcoming the drawback of the single radiation direction of a single transmission array or reflection array antenna.

[0048] To support and specifically implement the above overall functional parts, from top to bottom, the present invention adopts a five-layer structure including a first dielectric substrate 1, a first cross-shaped insert 2, a dielectric substrate layer 3, a second cross-shaped insert 4, and a second dielectric substrate 5. The dual-polarized dipole of the present invention is arranged on the first dielectric substrate 1, the single-polarized dipole is arranged on the second dielectric substrate 5, and the reflection phase-shifting line 302 and the transmission phase-shifting line 303 are arranged on the dielectric substrate layer 3. The first cross-shaped insert 2 is orthogonally and vertically placed and supported between the first dielectric substrate 1 and the dielectric substrate layer 3. The second cross-shaped insert 4 is also orthogonally and vertically placed and supported between the dielectric substrate layer 3 and the second dielectric substrate 5. The first cross-shaped insert 2 and the second cross-shaped insert 4 are both mechanical support parts and can also be used as the connection parts between the corresponding transmission units and the phase-shifting lines, and both include a first insert and a second insert. Both the first insert and the second insert are vertical plates. In the present invention, it is defined that the first insert is along the x-polarization direction and the second insert is along the y-polarization direction. It should be noted that in the present invention, when described as "orthogonal", it preferably refers to "orthogonal" along the x-polarization direction and the y-polarization direction respectively.

[0049] The dielectric substrate layer 3 of the present invention adopts a stacked structure of four dielectric substrates, which are respectively combined with two phase-shifting lines, namely the reflection phase-shifting line 302 and the transmission phase-shifting line 303, to form a stripline structure. Specifically, above the first dielectric substrate 31 is the upper floor 301, and above the lower or second dielectric substrate 32 is provided with a metal reflection phase-shifting line 302. Below the second dielectric substrate 32 or above the third dielectric substrate 33 is the intermediate floor 304, and above the third dielectric substrate 33 or above the fourth dielectric substrate 34 is provided with a transmission phase-shifting line 303. Below the fourth dielectric substrate 34 is the lower floor 305. The lower part of the first cross-plate 2 is connected to the upper floor 301, and the upper part of the second cross-plate 4 is connected to the lower floor 305. It should be noted that in the present invention, when described as "provided", its meaning includes processes such as printing and etching.

[0050] Exemplarily, in the present invention, the material of the first dielectric substrate 1 is Rogers 4003, with a relative dielectric constant ε r = 3.55 and a thickness of 0.254 mm. The material of the two dielectric substrates (i.e., the first plate and the second plate) of the first cross-plate 2 is F4BM233, with a relative dielectric constant ε r = 2.33 and a thickness of 0.254 mm. The material of each dielectric substrate of the dielectric substrate layer 3 is F4BM217, with a relative dielectric constant ε r = 2.17 and a thickness of 0.381 mm. The material and thickness of the second cross-plate 4 are the same as those of the first cross-plate 2, and the material and thickness of the second dielectric substrate 5 are the same as those of the first dielectric substrate 1.

[0051] Refer to Figure 2 、 3 Figures 4, 5 and 6 for a further detailed description of the overall structure of the metal patch of the present invention.

[0052] As Figure 2 shown, the dual-polarized dipole of the present invention includes a dual-polarized dipole metal patch 101 provided on the upper side of the first dielectric substrate 1. As shown in Fig. 2(a), this structure is formed by two dipole antennas with lengths nearly half a wavelength in two orthogonal directions in a cross shape, which can receive incident electromagnetic waves from two orthogonal polarization directions of x polarization and y polarization. The unit length P = 7.5 mm. Among them, a circular metal patch is used as a coupling capacitor at the junction of the antenna dipole arms, and the diameter D1 of the circular metal patch = 1.2 mm. The single-polarized dipole of the present invention includes a single-polarized dipole metal patch 502 provided on the upper side of the second dielectric substrate 5. As shown in Fig. 2(b), this structure is composed of a dipole arm in the x direction and a coupling circular metal patch, which is a dipole in the x direction, can receive incident waves in the y polarization direction, and radiate x polarization waves. Among them, a circular metal patch is used as a coupling capacitor at the junction of the antenna dipole arms.

[0053] The dual-polarized dipole of the present invention may further include a first circular metal patch 102 disposed on the lower side of the first dielectric substrate 1, and the single-polarized dipole may further include a second circular metal patch 501 disposed on the lower side of the second dielectric substrate 5. As Figure 3 and Figure 4 shown, the circular metal patch of the dual-polarized dipole metal patch 101 and the first circular metal patch 102 are coupled through a dielectric laminate to form a coupling capacitor to cancel the reactance brought by the upper floor 301 of the dielectric substrate layer 3, thereby optimizing the impedance matching of the antenna structure and increasing the operating bandwidth of the antenna. Correspondingly, the circular metal patch at the connection between the dipole arms of the single-polarized dipole metal patch 502 is coupled to the second circular metal patch 501. The diameter D2 of the first circular metal patch 102 is 1.8 mm, and at the same time, the first circular metal patch 102 is grounded, thereby eliminating the common-mode resonance generated by the tightly coupled dipole structure and enabling the antenna unit to have a wider operating bandwidth. The second circular metal patch 501 has the same structure as the first circular metal patch 102.

[0054] As Figure 3 and Figure 4 shown, both the first plugboard and the second plugboard of the first cross plugboard 2 are provided with double-sided parallel transmission lines 201 on both sides. The double-sided parallel transmission lines 201 are divided into a connection transmission line side and a ground side by the plugboard thickness. Among them, one side of the double-sided parallel transmission line 201 on the first plugboard is connected to the reflection phase shift line 302, and the other side is grounded. For example, it can be connected to the upper floor 301 to achieve grounding. Further, it can be grounded by extending to the floor part outside the pad through an arc curve. One side of the double-sided parallel transmission line 201 of the second plugboard is connected to the transmission phase shift line 303, and the other side is grounded. For example, it can be connected to the upper floor 301 to achieve grounding. Different from this, the second cross plugboard 4 is only provided with double-sided parallel transmission lines 201 on the first plugboard, and the second plugboard does not need to be provided. One side of its double-sided parallel transmission line 201 is connected to the transmission phase shift line 303, and the other side is grounded. For example, it can be connected to the lower floor 305 to achieve grounding.

[0055] The transmission phase shift line 303 of the present invention connects the double-sided parallel transmission lines 201 of the first cross plugboard 2 and the second cross plugboard 4 to form a "receive-transmit-transmit" structure, and adjusts the phase of the transmission mode by adjusting the length of the bent area. To reduce the mismatch loss, the reflection phase shift line 302 and the transmission phase shift line 303 are both chamfered at the bent part.

[0056] Furthermore, the present invention also provides a double-sided coupled short-circuit transmission line 202 on the first plugboard and / or the second plugboard of the first cross-shaped plugboard 2. The double-sided coupled short-circuit transmission line 202 of the first cross-shaped plugboard 2 grounds the first circular metal patch 102, for example, it can be connected to the upper floor 301 to achieve grounding. Further, the structures on both sides of the coupled short-circuit transmission line 202 are the same. The upper end is connected to the first circular metal patch 102 of the first dielectric substrate 1, and the lower end is grounded along the plugboard groove to cancel the common-mode resonance generated by the tightly coupled structure.

[0057] Correspondingly, a double-sided coupled short-circuit transmission line 202 is provided on the first plugboard and / or the second plugboard of the second cross-shaped plugboard 4. The double-sided coupled short-circuit transmission line 202 of the second cross-shaped plugboard 4 grounds the second circular metal patch 501, for example, it can be connected to the lower floor 305 to achieve grounding.

[0058] With the above structure, the first circular metal patch 102 is grounded through the double-sided coupled short-circuit transmission line 202 on the first cross-shaped plugboard 2, and the dual-polarized dipole metal patch 101 is fed through the double-sided parallel transmission line 201 on the first cross-shaped plugboard 2. The two ends above the double-sided parallel transmission line 201 are respectively connected to the two ends of the dipole antenna. The side connected to the reflection phase-shifting line is located inside the plugboard, with the same width up and down, and is connected to the reflection phase-shifting line 302 through the metal posts in the dielectric substrate layer 3. The side connected to the floor is located outside the plugboard, and is etched in an asymptotically linear shape with a narrower upper part and a wider lower part. The width of the lower end is greater than the diameter of the metal post pad so as to be connected to the upper floor 301, forming a complete loop with the tightly coupled antenna structure and the inner transmission line side. Among them, the widths w2 of the double-sided parallel transmission line 201 and the coupled short-circuit transmission line 202 are 0.2 mm.

[0059] Furthermore, the present invention designs grooves with a certain width at the upper position of the first plugboard and the lower position of the second plugboard to achieve the insertion of the substrates. To improve the processing accuracy, the present invention reserves a width of 0.1 mm at the interface where the first dielectric substrate 1 is inserted into the first cross-shaped plugboard 2, avoiding short circuits while ensuring the precise connection between the transmission line and the antenna structure. Among them, the overall height h1 of the unit is 10.248 mm, and the height h3 of the cross-shaped plugboard is 4.108 mm.

[0060] As Figure 5 shown, the dielectric substrate layer 3 composed of four stacked dielectric substrates of the present invention includes an upper floor 301, a first dielectric substrate 31, a reflection phase-shifting line 302, a second dielectric substrate 32, an intermediate floor 304, a third dielectric substrate 33, a transmission phase-shifting line 303, a fourth dielectric substrate 34, and a lower floor 305. Among them, the reflection and transmission phase-shifting lines, the floors, and the dielectric substrates form two-layer stripline structures. As Figure 6As shown in (a) and (b) thereof, both the reflection phase shift line 302 and the transmission phase shift line 303 are bent line structures. The reflection phase shift line 302 is connected to the transmission unit of the dual-polarized dipole, and both ends of the transmission phase shift line 303 are respectively connected to the transmission units of the dual-polarized dipole and the single-polarized dipole.

[0061] Furthermore, for the reflection phase shift line 302, the pad metal column penetrates through the first dielectric substrate 31 and is connected to the parallel transmission line on one side of the inner side of the first cross-shaped insert 2. The pad diameter D3 = 0.6 mm, and the line width w1 = 0.2 mm. The length L of the bent part of the reflection phase shift line 302 R is adjusted according to the different unit positions. After the current in the x-polarization direction passes through the double-sided parallel transmission line 201 on the first insert of the first cross-shaped insert 2, it passes through the metal column and finally returns along the original path after passing through the reflection phase shift line 302 with an open end. Among them, L R determines the length of the current passing path, resulting in a path difference between different units, and then a phase difference, which can compensate the phase of the units at different positions in the array, convert the spherical wave radiated by the feed into a plane wave for reflection, that is, reflect the x-polarized electromagnetic wave. Among them, L R has a length range of 0.5 - 6.5 mm.

[0062] Similar to the reflection phase shift line 302, the pad metal column below the transmission phase shift line 303 penetrates through the first dielectric substrate 31, the second dielectric substrate 32, and the third dielectric substrate 33 and is connected to the parallel transmission line on one side of the inner side of the first cross-shaped insert 2. The pad metal column above penetrates through the fourth dielectric substrate 34 and is connected to the parallel transmission line on one side of the inner side of the second cross-shaped insert 4. After the current in the y-polarization direction passes through the double-sided parallel transmission line 201 on the second insert of the first cross-shaped insert 2, it passes through the metal column, passes through the transmission phase shift line 303, and is transmitted to the lower metal column and the double-sided parallel transmission line 201 of the second cross-shaped insert 4, and radiates x-polarized electromagnetic waves after polarization rotation by the single-polarized dipole metal patch 502, that is, the y-polarized electromagnetic wave radiates x-polarized electromagnetic waves after polarization conversion. Furthermore, the length L of the bent part L will be adjusted according to the different unit positions, change the current passing path length to form a phase difference for phase compensation, so that the array antenna composed of units finally radiates a plane wave.

[0063] All the parameter values involved in the unit are shown in Table 1:

[0064] Table 1

[0065] Parameter P h1 h2 h3 h4 Dimension (mm) 7.5 10.248 0.254 4.108 0.381 Parameter D1 D2 D3 w1 w2 Dimension (mm) 1.2 1.8 0.6 0.2 0.2

[0066] Wherein, P is the side length of the antenna element, h1 is the thickness of the antenna element, h2 is the board thickness of the first dielectric substrate 1, the first plug board, the second plug board, and the second dielectric substrate 5, h3 is the plug board height of the first cross plug board 2 and the second cross plug board 4. h4 is the board thickness of each dielectric substrate in the dielectric substrate layer 3. D1 is the diameter of the circular metal patch at the connection between the dipole arms of the dual-polarized dipole and the single-polarized dipole. D2 is the diameter of the lower circular metal patch 102 and the upper circular metal patch 501, D3 is the diameter of the pad, w1 is the line width of the reflection phase shift line 302 and the transmission phase shift line 303, and w2 is the line width of the double-sided coupled short-circuit transmission line 202.

[0067] According to the above structure, the present invention has the advantages of broadband, simultaneous transmission and reflection, and high gain. It can be used in the 5-15 GHz band. Within the working band, it realizes the function of combining the transmission and reflection linear polarization states into the same state and aperture, and is suitable for broadband two-way beam communication antennas.

[0068] The following further illustrates the technical effects of the present invention in combination with simulation experiments:

[0069] The reflection coefficient and the reflection phase change curve diagram obtained by modeling and simulating the present invention using the commercial simulation software HFSS2022R1 when L L varies with different lengths in the range of 0.5-6.5 mm, and the transmission coefficient and the transmission phase change diagram when L L varies with different lengths in the range of 0.5-6.5 mm are as Figure 7 shown. Figure 7 In (a), it is the reflection coefficient and reflection phase curve diagram. Among them, the abscissa is the frequency value, the unit is GHz, the left ordinate is the amplitude of the reflection coefficient, the unit is dB, and the right ordinate is the phase of the reflection coefficient, the unit is deg. The four curves in the figure respectively correspond to L R = 0.5, 2.5, 4.5, 6.5 mm. In the four states, the reflection coefficient is greater than -1 dB in the 5-17.5 GHz frequency band, and the phase change exceeds 360°, which can provide sufficient phase compensation space, and the phase curves are approximately parallel to each other, verifying the broadband characteristics of the unit reflection state. Figure 7 In (b), it is the transmission coefficient and transmission phase curve diagram. Among them, the abscissa is the frequency value, the unit is GHz, the left ordinate is the amplitude of the transmission coefficient, the unit is dB, and the right ordinate is the phase of the transmission coefficient, the unit is deg. The four curves in the figure respectively correspond to L L = 0.5, 2.5, 4.5, 6.5 mm. The transmission coefficient is greater than -3 dB in the 5-15.5 GHz frequency band, and the phase change exceeds 360°. The curves are approximately parallel to each other, that is, the unit has broadband characteristics in the transmission state.

[0070] The array modeling and simulation of the present invention are carried out using the commercial simulation software HFSS 2022R1, as Figure 8 shown. Further, the phase compensation principle and method for constructing an array of antenna elements are described. For transmissive and reflective array antennas, whether accurate phase compensation can be performed for the spatial path difference caused by the air-feed form is the key to affecting the focusing performance of the array antenna. Next, the phase compensation calculation method for the transmissive array surface is described. First, the antenna element is usually regarded as being in the far field of the feed source. Therefore, the electromagnetic wave reaching any element from the feed source can be regarded as a plane wave. According to optical theory, the required phase compensation φ S of the array surface is proportional to the distance from the element to the phase center of the feed source, and its mathematical expression is:

[0071] φ S =-k 0 d i (1)

[0072] where k 0 is the propagation constant of the electromagnetic wave in vacuum, and d i is the distance from any element on the transmissive array surface to the phase center of the feed source. If the focusing beam direction of the array antenna is then according to the array antenna theory, a phase gradient needs to be provided for the phase distribution of the array surface:

[0073]

[0074] where (x i , y i ) is the coordinate of the i-th element in the antenna array surface. From the above formula, it can be seen that for a transmissive or reflective array antenna with a specific beam pointing, the required phase distribution corresponding to each element on the array surface is:

[0075]

[0076] where ψ 0 is the phase constant, which is usually used to optimize the phase of the transmissive array surface and does not change the beam pointing of the antenna.

[0077] To solve the problem of phase compensation for the array surface in a wide frequency band, the present invention uses the "equivalent distance delay" method: If the equivalent distance delay calculated for the element remains unchanged within a certain frequency band, then this distance delay can be used to compensate for the required spatial phase delay of the array surface and eliminate the influence of frequency. For a working bandwidth of three times the frequency and above, it is inaccurate to only use the unit phase delay data at a certain frequency point within the working frequency band to compensate for the required phase delay of the array surface throughout the entire frequency band. To eliminate the influence of frequency, the calculation formula for the spatial phase compensation of the antenna array surface is optimized and adjusted, and both sides of formula (3) are divided by k 0 to obtain:

[0078]

[0079] where k 0 is the propagation constant of electromagnetic waves in vacuum, and ψ 0 / k 0 represents any constant, which is only used to optimize the phase distribution of the array surface and does not affect the beam pointing of the transmissive array antenna, and can be ignored in the formula derivation. Let:

[0080] d(x i , y i ) = φ T (x i , y i ) / k 0 (5)

[0081] Then we have:

[0082]

[0083] where d(x i , y i ) is the required equivalent distance delay of the transmissive array element. According to formula (6), it can be seen that the required equivalent distance delay of the transmissive array antenna is only related to the relative positions of the feed antenna and the transmissive array element and the beam pointing of the array antenna, and is independent of frequency. When the designed array antenna element satisfies that the equivalent distance delay remains basically unchanged within the working frequency band, then this element can compensate for the different spatial phase delays required by the array surface within a wide frequency band.

[0084] The E-plane and H-plane radiation patterns of the array composed of the element arrangement of the present invention simulated by the commercial simulation software HFSS2022R1 are as shown in Figure 9 , Figure 10 , Figure 11 , Figure 12 , Figure 13 and Figure 14 , and the reflection and transmission gains of the array antenna are as shown in Figure 15 . Among them Figure 9 in (a) is the reflection E-plane radiation pattern at 9 GHz, and (b) is the reflection H-plane radiation pattern at 9 GHz; Figure 10 in (a) is the transmission E-plane radiation pattern at 9 GHz, and (b) is the transmission H-plane radiation pattern at 9 GHz; Figure 11 in (a) is the reflection E-plane radiation pattern at 12 GHz, and (b) is the reflection H-plane radiation pattern at 12 GHz; Figure 12 in (a) is the transmission E-plane radiation pattern at 12 GHz, and (b) is the transmission H-plane radiation pattern at 12 GHz; Figure 13 in (a) is the reflection E-plane radiation pattern at 15 GHz, and (b) is the reflection H-plane radiation pattern at 15 GHz; Figure 14Among them, (a) is the 15 GHz transmission E-plane pattern, and (b) is the 15 GHz transmission H-plane pattern. In the figure, the abscissa is the angle, with the unit of dB, and the ordinate is the normalized pattern, with the unit of dBi. As can be seen from the figure, the cross polarization and sidelobes are overall lower than -15 dB, and good pattern characteristics are exhibited within the frequency band range of 5 - 15 GHz. As Figure 15 shown, the antenna reflection gain varies between 10 - 19 dBi, and the transmission gain varies between 10 - 18 dBi.

[0085] The above simulation results show that, compared with the prior art, the present invention can have a wide operating frequency band under the conditions of simultaneous reflection and transmission, while maintaining the advantages of high gain of the reflection and transmission antennas.

[0086] The above has introduced in detail a broadband tightly coupled polarization conversion transmission and reflection integrated array antenna element provided by the present invention, and the principle and implementation manner of the present invention have been elaborated and realized by applying detailed structural design parameters. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that: for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A broadband tightly coupled polarization conversion transmission and reflection integrated array antenna unit, characterized in that: It includes a dual-polarization dipole, a reflection phase shift line (302), a transmission phase shift line (303) and a single-polarization dipole; The reflection phase shift line (302) is connected to the x-polarization direction transmission unit of the dual-polarization dipole, and the transmission phase shift line (303) is simultaneously connected to the y-polarization direction transmission unit of the dual-polarization dipole and the x-polarization direction transmission unit of the single-polarization dipole, forming a receiving-transmitting-emitting structure; the dual-polarization dipole receives y- and x-polarization electromagnetic waves and reflects y-polarization electromagnetic waves, and the single-polarization dipole radiates x-polarization electromagnetic waves.

2. The broadband tightly coupled polarization conversion transmission and reflection integrated array antenna unit according to claim 1 is characterized in that: The dual-polarization dipole is arranged on a first dielectric substrate (1), the single-polarization dipole is arranged on a second dielectric substrate (5), the reflection phase shift line (302) and the transmission phase shift line (303) are arranged on a dielectric substrate layer (3), the first dielectric substrate (1), the dielectric substrate layer (3) and the second dielectric substrate (5) are arranged from top to bottom, a first cross plug plate (2) is arranged between the first dielectric substrate (1) and the dielectric substrate layer (3) to connect the transmission unit of the dual-polarization dipole with the reflection phase shift line (302) and the transmission phase shift line (303); and a second cross plug plate (4) is arranged between the dielectric substrate layer (3) and the second dielectric substrate (5) to connect the transmission unit of the single-polarization dipole with the transmission phase shift line (303).

3. The broadband tightly coupled polarization conversion transmission and reflection integrated array antenna unit according to claim 2 is characterized in that: The dielectric substrate layer (3) is composed of four layers of dielectric substrates stacked together, which are respectively combined with two layers of phase shift lines to form a stripline structure, wherein an upper floor (301) is located above the first dielectric substrate, a metal reflection phase shift line (302) is arranged below or above the second dielectric substrate, an intermediate floor (304) is located below the second dielectric substrate or above the third dielectric substrate, a transmission phase shift line (303) is arranged below the third dielectric substrate or above the fourth dielectric substrate, and a lower floor (305) is located below the fourth dielectric substrate.

4. The broadband tightly coupled polarization conversion transmission and reflection integrated array antenna unit according to claim 1 is characterized in that: The reflection phase shift line (302) and the transmission phase shift line (303) are both subjected to angle cutting processing at the bending parts.

5. The broadband tightly coupled polarization conversion transmission and reflection integrated array antenna unit according to claim 1 or 2 or 3 or 4, characterized in that: The terminal of the reflection phase shift line (302) is open-circuited, and the phase of the reflection mode is regulated by adjusting the length of the bending region; the two ends of the transmission phase shift line (303) are respectively connected to the transmission units of the dual-polarization dipole and the single-polarization dipole, and the phase of the transmission mode is regulated by adjusting the length of the bending region.

6. The broadband tightly coupled polarization conversion transmission and reflection integrated array antenna unit according to claim 2, characterized in that: The dual-polarization dipole comprises a dual-polarization dipole metal patch (101) and a first circular metal patch (102) respectively arranged on the upper side of the first dielectric substrate (1) and on the lower side; the single-polarization dipole comprises a second circular metal patch (501) and a single-polarization dipole metal patch (502) respectively arranged on the upper side of the second dielectric substrate (5); The dual-polarized dipole metal patch (101) receives incident waves in the x and y polarization directions, and the circular metal patch at the connection between the dipole arms is coupled with the first circular metal patch (102); The single-polarized dipole metal patch (502) receives incident waves in the y-polarization direction and radiates x-polarized waves, and the circular metal patch at the connection between the dipole arms is coupled with the second circular metal patch (501).

7. The broadband tightly coupled polarization conversion transmission and reflection integrated array antenna unit according to claim 6, characterized in that: The first cross plug board (2) and the second cross plug board (4) both comprise a first plug board and a second plug board, the first plug board is a vertical board along the x-polarization direction, and the second plug board is a vertical board along the y-polarization direction; The first plug board and the second plug board of the first cross plug board (2) are both provided with double-sided parallel transmission lines (201), one side of the double-sided parallel transmission line (201) of the first plug board is connected to the reflection phase shift line (302), and the other side is grounded, and one side of the double-sided parallel transmission line (201) of the second plug board is connected to the transmission phase shift line (303), and the other side is grounded; A double-sided parallel transmission line (201) is arranged on the first plug board of the second cross plug board (4); one side of the double-sided parallel transmission line (201) is connected to the transmission phase shift line (303), and the other side is grounded.

8. The broadband tightly coupled polarization conversion transmission and reflection integrated array antenna unit according to claim 7, characterized in that: The first plugboard and / or the second plugboard of the first cross plugboard (2) is provided with a double-sided coupled short-circuit transmission line (202), and the double-sided coupled short-circuit transmission line (202) of the first cross plugboard (2) grounds the first circular metal patch (102); The first plugboard and / or the second plugboard of the second cross plugboard (4) is provided with a double-sided coupled short-circuited transmission line (202), and the double-sided coupled short-circuited transmission line (202) of the second cross plugboard (4) grounds the second circular metal patch (501).

9. The broadband tightly coupled polarization conversion transmission and reflection integrated array antenna unit according to claim 6 or 7, characterized in that: After the x-polarized electromagnetic wave passes through the double-sided parallel transmission line (201) on the first plug board of the first cross plug board (2), it passes through the reflection phase shift line (302), and is reflected after phase compensation is completed by adjusting the length of the bending part of the reflection phase shift line (302), that is, the x-polarized electromagnetic wave is reflected; After the y-polarized electromagnetic wave passes through the double-sided parallel transmission line (201) on the second plug board of the first cross plug board (2), it passes through the transmission phase shift line (303), and after phase compensation is completed by adjusting the length of the bending part of the transmission phase shift line (303), it is connected to the double-sided parallel transmission line (201) on the second cross plug board (4), and radiates through the single-polarized dipole metal patch (502), that is, the y-polarized electromagnetic wave radiates the x-polarized electromagnetic wave after polarization conversion.

10. The broadband tightly coupled polarization conversion transmission and reflection integrated array antenna unit according to claim 1, characterized in that: The antenna unit achieves phase control by changing the length of the bending area of ​​the reflection phase shift line (302) and the transmission phase shift line (303); the reflection phase is above -2dB, the transmission phase is above -3dB, the phase parameter satisfies 360°, and the antenna has a stable radiation pattern and an operating bandwidth of 3 times the frequency, i.e., 5-15GHz.

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