Electric control wave beam scanning circular polarization reflective array antenna

Abstract

The invention relates to the technical field of antennas, in particular to an electrically controlled beam scanning circularly polarized reflective array antenna. Comprising a plurality of reflective array units which are arranged in equal rows and equal columns to form a reflective array structure; a horn antenna is arranged above the reflective array structure; the reflective array unit is square and sequentially comprises a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer and a third metal layer from top to bottom. According to the invention, 1-bit phase compensation can be realized only by integrating a single PIN diode in the unit. Compared with the prior art, the economic cost of the electrically controlled beam scanning reflective array antenna is effectively reduced. In addition, the antenna also has the advantages of good oblique incidence performance, circular polarization radiation and wide-angle scanning.

Description

Technical Field

[0001] The invention relates to the technical field of antennas, and in particular to an electrically controlled beam scanning circularly polarized reflectarray antenna. Background Art

[0002] With the rapid development of radar communication and satellite detection technology, the demand for high-gain beam scanning antennas is increasing, aiming to achieve fast and wide-area signal coverage. Phased array antennas can achieve flexible beam scanning, but their complex feeding network and high manufacturing cost severely limit their application in some fields. As an air-fed system, reflectarray antennas combine the advantages of reflector antennas and phased array antennas, effectively simplifying the antenna structure and reducing production costs. At present, the means to achieve beam scanning of reflectarray antennas mainly include mechanical rotation units, liquid metal injection technology, integrated active devices, etc. Among them, compared with mechanical scanning, electronic scanning technology has the ability to scan quickly without mechanical rotation, and has become a hot topic in industry research in recent years. The polarization characteristics of electromagnetic waves also affect the performance of communication systems. Compared with linearly polarized antennas, circularly polarized antennas show stronger anti-interference ability, anti-multipath effect and adaptability to different polarizations. In view of the above discussion, the research on electronically controlled beam scanning circularly polarized reflectarray antennas is of great significance.

[0003] In the field of beam electronic scanning of reflector arrays, traditional 1-bit phase compensation technology usually relies on integrating two PIN diodes inside the unit, and controlling the on-off state of the PIN diodes to achieve 180° phase switching of the reflector array unit, thereby adjusting the beam direction. However, this design mode means that a considerable number of PIN diodes need to be configured on the array surface, which brings high economic costs and circuit complexity. Summary of the invention

[0004] The present invention discloses an electrically controlled beam scanning circularly polarized reflector array antenna, comprising a plurality of reflector array units, wherein the plurality of reflector array units are arranged in equal rows and columns to form a reflector array structure;

[0005] A horn antenna is disposed above the reflective array structure;

[0006] The reflective array unit is square, and includes, from top to bottom, a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, and a third metal layer; the upper end of the first metalized via is connected to the first metal layer, and the lower end passes through the first dielectric layer, the second metal layer, and the second dielectric layer in sequence to be connected to the third metal layer; the upper end of the second metalized via is connected to the first metal layer, and the lower end passes through the first dielectric layer to be connected to the second metal layer.

[0007] Furthermore, the horn antenna has a rotationally symmetrical truncated cone geometric structure, and a metal spiral wire is embedded in the center of the horn antenna.

[0008] Further, the first metal layer includes a circular ring with two cracks, and the two cracks are respectively located on the upper side and the right side of the circular ring;

[0009] A PIN diode is arranged in the upper crack, and a high impedance line is symmetrically arranged on the upper right side and the upper left side of the ring.

[0010] Furthermore, the upper surface of the second metal layer completely covers the lower surface of the first dielectric layer, and the lower surface of the second metal layer completely covers the upper surface of the second dielectric layer.

[0011] Furthermore, the third metal layer completely covers the lower surface of the second dielectric layer, including multiple DC feeders and a fan-shaped branch; the multiple DC feeders are arranged in parallel at the horizontal center line of the third metal layer, and the fan-shaped branch is located at the upper right corner of the DC feeder.

[0012] Furthermore, one end of the second metallized via is connected to one of the high impedance lines, and the lower end is connected to the second metal layer; the upper end of the first metallized via is connected to another high impedance line of the first metal layer, and the lower end is connected to the DC feeder line of the third metal layer.

[0013] Further, the height h1 of the first dielectric substrate is 4 mm, and the height h2 of the second dielectric substrate is 2 mm;

[0014] The width of the crack g1 on the right side of the ring is 0.5 mm, and the width of the crack g2 on the left side of the ring is 0.4 mm;

[0015] The inner diameter r1 of the ring is 3.6 mm, and the outer diameter r2 of the ring is 5.6 mm;

[0016] The upper surfaces of the first dielectric layer and the second dielectric layer are both square, and the side length p is 12 mm.

[0017] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0018] The present invention can realize 1-bit phase compensation by integrating only a single PIN diode in the unit. Compared with the prior art, the present invention effectively reduces the economic cost of the electrically controlled beam scanning reflector array antenna. In addition, the present invention also has the advantages of good oblique incidence performance, circular polarization radiation, and wide-angle scanning.

[0019] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings of the present invention are as follows.

[0021] Figure 1 Side view of the electronically steered beam scanning circularly polarized reflectarray antenna;

[0022] Figure 2 The top view and bottom view of the electronically steered beam scanning circularly polarized reflectarray antenna;

[0023] Figure 3 It is a hierarchical structure diagram of the reflective array unit;

[0024] Figure 4 It is a top view of the reflect array unit;

[0025] Figure 5 This is a bottom view of the reflective array unit;

[0026] Figure 6 The reflection coefficient curve and phase response curve of the reflect array unit to the circularly polarized vertical incident wave when the PIN diode is turned off;

[0027] Figure 7 It is the reflection coefficient curve and phase response curve of the reflect array unit to the circularly polarized vertical incident wave when the PIN diode is turned on;

[0028] Figure 8 is the reflection coefficient curve of the reflect array unit for the circularly polarized oblique incident wave when the PIN diode is turned off;

[0029] Fig. 9 It is the reflection coefficient curve of the reflect array unit for the circularly polarized oblique incident wave when the PIN diode is turned on;

[0030] Fig.10 A simulation diagram of beam scanning results according to an embodiment of the present invention;

[0031] Fig.11 It is a simulation diagram of the gain and axial ratio changing with frequency when the beam pointing is θ=25° in an embodiment of the present invention;

[0032] Among them: 1-first dielectric layer, 2-second dielectric layer, 3-circular ring, 4-PIN diode, 5-high impedance line, 5-1-second metallized via, 5-2-first metallized via, 6-second metal layer, 7-fan-shaped branch. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0034] An electrically controlled beam scanning circularly polarized reflectarray antenna, such as Figure 1 and Figure 2 As shown, it includes a reflective array structure and a horn antenna system. Figure 3 As shown in Figure 1, the reflective array structure adopts a layered structure design. Figure 4 and Figure 5 As shown, it includes a plurality of reflective array units, and the plurality of reflective array units are arranged in equal rows and columns to form a reflective array structure; a horn antenna is arranged above the reflective array structure; the reflective array unit is square, and includes, from top to bottom, a first metal layer, a first dielectric layer 1, a second metal layer 6, a second dielectric layer 2 and a third metal layer; the upper end of the first metalized via 5-1 is connected to the first metal layer, and the lower end passes through the first dielectric layer 1, the second metal layer 6 and the second dielectric layer 2 in sequence to be connected to the third metal layer; the upper end of the second metalized via 5-2 is connected to the first metal layer, and the lower end passes through the first dielectric layer 1 to be connected to the second metal layer 6.

[0035] The horn antenna is a rotationally symmetrical truncated cone geometric structure, and a metal spiral wire is embedded in the center of the horn antenna.

[0036] The first metal layer includes a ring 3 with two cracks, and the two cracks are respectively located on the upper side and the right side of the ring 3;

[0037] A PIN diode 4 is arranged in the upper crack 3 , and a high impedance line 5 is symmetrically arranged on the upper right side and the upper left side of the ring 3 .

[0038] The upper surface of the second metal layer 6 completely covers the lower surface of the first dielectric layer 1 , and the lower surface of the second metal layer 6 completely covers the upper surface of the second dielectric layer 2 .

[0039] The third metal layer completely covers the lower surface of the second dielectric layer 2, and includes multiple DC feeders and a fan-shaped branch 7; the multiple DC feeders are arranged in parallel at the horizontal center line of the third metal layer, and the fan-shaped branch 7 is located at the upper right corner of the DC feeder.

[0040] One end of the second metallized via 5 - 2 is connected to one of the high impedance lines 5 , and the lower end is connected to the second metal layer 6 ; the upper end of the first metallized via 5 - 1 is connected to another high impedance line 5 of the first metal layer, and the lower end is connected to the DC feeder of the third metal layer 6 .

[0041] simulation:

[0042] In this embodiment, the reflective array is composed of 16×16 units. Figure 4 shown.

[0043] The parameter dimensions of the circular polarization reflect array unit are shown in the following table:

[0044]

[0045] The first metal layer is mainly composed of the following three parts: a metal ring with a crack, a symmetrically placed high impedance line, and a PIN diode connecting the metal patches on both sides. When the diode is turned off, it is equivalent to a 5.2ohm resistor, a 0.15nH inductor, and a 0.025pF capacitor in series; when the diode is turned on, it is equivalent to a 5.2ohm resistor and a 0.15nH inductor in series. Figure 5 As shown, the third metal layer includes a DC feed line and a fan-shaped branch. By applying different bias voltages on the DC feed line, the on-off state of the PIN diode can be accurately controlled.

[0046] Only a single PIN diode is integrated in each reflective array unit. The reflected wave phase is regulated by controlling the on-off state of the PIN diode to achieve 1-bit phase compensation. The simulation results refer to Figure 6 The PIN diode off state Off is recorded as state 1, and the PIN diode on state On is recorded as state 2. When the circularly polarized wave is incident vertically on the unit, both state 1 and state 2 show a high reflection coefficient. In the frequency band of 6.0 to 7.7 GHz, the reflection coefficient is maintained above 0.8. For details, please refer to Figure 6 These two states can achieve a 180° reflection phase difference within a wide bandwidth, which fully meets the technical requirements of 1-bit phase compensation. For specific phase curves, please refer to Figure 7 This design not only simplifies the unit structure, but also ensures the accuracy and efficiency of phase control within the required frequency band.

[0047] Reference Figure 8 and Fig. 9 For the oblique incidence case, the circularly polarized reflectarray unit proposed in the present invention exhibits good stability in both states. At the center frequency of 7 GHz, the reflection coefficients corresponding to the two states are both higher than 0.8 at different incident angles.

[0048] The core of this embodiment is to control the beam pointing by controlling the on-off state of the PIN diodes in the 16×16 units. Its electronic scanning performance is as follows: Fig.10 As shown. On the observation plane, with 7 GHz as the observation frequency, several typical beams are selected, and the main lobe directions are 0°, 10°, 20°, 30°, 40°, and 50°. As can be seen from the figure, the present invention can effectively realize the beam convergence and wide-angle scanning functions, and the scanning loss is low.

[0049] Reference Fig.11Taking the scanning angle θ=25° as an example, the peak gain of the circularly polarized reflectarray antenna of the present invention at 7GHz can reach 16.1dBic, the aperture efficiency at this time is 16.2%, and the 3dB gain bandwidth is about 13.8%, about 6.75-7.75GHz. In the frequency range of 6.75-7.25GHz, the axial ratio is kept below 3dB, showing good circular polarization performance.

[0050] In summary, for the proposed electrically controlled beam scanning circularly polarized reflectarray antenna, only a single PIN diode needs to be integrated in each unit to achieve 1-bit phase compensation, thereby realizing beam electronic scanning. Compared with the prior art, the present invention reduces the number of required PIN diodes to half of the original, significantly reducing the manufacturing cost while maintaining good performance. After simulation, the reflectarray unit has good oblique incidence performance, and the circularly polarized reflectarray antenna has the characteristics of wide-angle scanning, beam convergence, and low scanning loss.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An electrically controlled beam scanning circularly polarized reflectarray antenna, characterized in that: It comprises a plurality of reflective array units, wherein the plurality of reflective array units are arranged in equal rows and columns to form a reflective array structure; A horn antenna is disposed above the reflective array structure; The reflective array unit is square, and includes, from top to bottom, a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, and a third metal layer; the upper end of the first metalized via is connected to the first metal layer, and the lower end passes through the first dielectric layer, the second metal layer, and the second dielectric layer in sequence to be connected to the third metal layer; the upper end of the second metalized via is connected to the first metal layer, and the lower end passes through the first dielectric layer to be connected to the second metal layer.

2. The electrically controlled beam scanning circularly polarized reflectarray antenna according to claim 1, characterized in that: The horn antenna is a rotationally symmetrical truncated cone geometric structure, and a metal spiral wire is embedded in the center of the horn antenna.

3. The electrically controlled beam scanning circularly polarized reflectarray antenna according to claim 1, characterized in that: The first metal layer comprises a circular ring with two cracks, wherein the two cracks are respectively located on the upper side and the right side of the circular ring; A PIN diode is arranged in the upper crack, and a high impedance line is symmetrically arranged on the upper right side and the upper left side of the ring.

4. The electrically controlled beam scanning circularly polarized reflectarray antenna according to claim 4, characterized in that: The upper surface of the second metal layer completely covers the lower surface of the first dielectric layer, and the lower surface of the second metal layer completely covers the upper surface of the second dielectric layer.

5. The electrically controlled beam scanning circularly polarized reflectarray antenna according to claim 5, characterized in that: The third metal layer completely covers the lower surface of the second dielectric layer and includes multiple DC feeders and a fan-shaped branch; the multiple DC feeders are arranged in parallel at the horizontal center line of the third metal layer, and the fan-shaped branch is located at the upper right corner of the DC feeder.

6. The electrically controlled beam scanning circularly polarized reflectarray antenna according to claim 5, characterized in that: One end of the second metallized via is connected to one of the high impedance lines, and the lower end is connected to the second metal layer; the upper end of the first metallized via is connected to another high impedance line of the first metal layer, and the lower end is connected to the DC feeder line of the third metal layer.

7. The electrically controlled beam scanning circularly polarized reflectarray antenna according to claim 6, characterized in that: The height h1 of the first dielectric substrate is 4 mm, and the height h2 of the second dielectric substrate is 2 mm; The width of the crack g1 on the right side of the ring is 0.5 mm, and the width of the crack g2 on the left side of the ring is 0.4 mm; The inner diameter r1 of the ring is 3.6 mm, and the outer diameter r2 of the ring is 5.6 mm; The upper surfaces of the first dielectric layer and the second dielectric layer are both square, and the side length p is 12 mm.

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