A 1-bit encoded wideband wide-angle scanning reflective array antenna

Abstract

This invention belongs to the field of antenna engineering technology, specifically providing a 1-bit encoded wide-bandwidth angle-scanning reflective array antenna to achieve high-speed, low-cost beam scanning with wide-bandwidth angle-scanning characteristics. This invention employs a wide-bandwidth horn feed and dipole antenna elements. The element structure uses a phase delay line with short-circuited terminations to control the phase, which not only provides wide-bandwidth characteristics but also minimizes inter-element coupling and mutual influence, suppressing resonance. Furthermore, the DC control structure is simple, significantly reducing the number of electronic control components and lowering the complexity of the electronic control method. In summary, this invention utilizes a stripline transmission line to achieve wide-bandwidth, low-loss linear phase shift and employs 1-bit encoding for high-speed, low-cost array phase electrical modulation to achieve wide-bandwidth angle-scanning, offering advantages such as simple structure and convenient electronic control.

Description

Technical Field

[0001] This invention belongs to the field of antenna engineering technology and relates to a low-cost reconfigurable reflective array antenna that can achieve wide bandwidth angle scanning characteristics, specifically providing a 1-bit encoded wide bandwidth angle scanning reflective array antenna. Background Technology

[0002] Array antennas are widely used in satellite communications, MIMO, radar imaging, and other fields. Wide bandwidth and wide-angle scanning are core requirements and indicators for array antennas. Wide bandwidth means higher communication throughput and transmission rate, while wide angle means a larger spatial detection range. However, early array antennas used mechanical scanning, which was extremely inefficient due to its large aperture, bulk, and weight, making it unsuitable for real-time radar imaging and communication systems. Meanwhile, phased array antennas with high-speed electronic scanning characteristics were prohibitively expensive. Therefore, achieving high-speed, low-cost beam scanning has become a core requirement for array antennas. In recent years, coded and reconfigurable reflective array antennas have emerged as important candidate solutions.

[0003] In terms of broadband operation, common methods for bandwidth expansion of reflective array antennas mainly involve using multiple resonant structures within a single element, such as the multilayer patch in the paper "Broadband design of three-layer printed reflectarrays" and the single-layer structure in the paper "Millimeter-wave single-layer wideband high-gain reflectarray antenna with ability of spatial dispersion compensation". However, this approach increases the profile and loss and disrupts angular stability for multilayer structures, while limiting the upper limit of bandwidth expansion for single-layer structures. Another approach is to design phased array antenna elements with broadband operation capabilities, controlling the time delay / phase shift through time / phase delay lines that are short-circuited or open-circuited at the termination. Currently, the only structure capable of ultra-wideband operation is the antenna element based on the time delay line, such as the ultra-wideband tightly coupled dipole reflectarray element in the paper "An ultra-wideband tightly coupled dipole reflectarray antenna". Theoretically, the antenna bandwidth is the operating bandwidth, but in practical applications, the nonlinear phase curve caused by transmission line resonance limits the ultra-wideband operation capability of this antenna element.

[0004] In terms of wide-angle beam scanning, traditional beam scanning methods for reflective array antennas mainly include mechanical scanning, multiple feed sources, and dual-focus. Currently, the most commonly used method for achieving fast wide-angle electrical scanning of reflective array antennas is reconfigurable technology. This involves using devices such as PIN diodes and microwave switches to control the reflection states of array elements, encoding the elements, and using an FPGA board to control the array surface states, thus achieving different scanning states. For example, the 1-bit encoding in the literature "A high aperture efficiency 1-bit reconfigurable reflectarray antenna with extremely low power consumption" and the 2-bit encoding in the literature "Design of a 2-bit dual-polarized reconfigurable reflectarray with high aperture efficiency" correspond to two and four sets of reflection phase states, respectively.

[0005] Based on this, the present invention provides a 1-bit encoded wide-bandwidth angle-scanning reflective array antenna, which enables high-speed, low-cost beam scanning and has wide-bandwidth angle-scanning characteristics. Summary of the Invention

[0006] The purpose of this invention is to provide a 1-bit encoded wide-bandwidth angle-scanning reflective array antenna, which adopts a wide-bandwidth horn feed and dipole antenna elements, uses a stripline transmission line to achieve wide-bandwidth, low-loss linear phase shift, and uses 1-bit stripline transmission line encoding for high-speed, low-cost array phase electrical modulation to achieve wide-bandwidth angle-scanning. It has the advantages of simple structure and convenient electrical control.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A wide-bandwidth scanning reflective array antenna with 1-bit encoding is composed of several unit structures arranged in an array. Each unit structure consists of a radiating layer, a phase modulation layer, and an electronic control structure.

[0009] The radiating layer includes: a first PCB board 1, a surface mount dipole 11, a power supply probe 12, and a short-circuit probe 13; the phase-shifting layer includes: a second PCB board 2, a first short-circuit pin 21, a second short-circuit pin 22, an upper ground 23, a third PCB board 3, a first DC probe 31, a second DC probe 32, a ground DC probe 33, a phase shift line 34, a high-resistance ground line 35, and a lower ground 36; the electrical control structure includes: a first PIN diode 341, a second PIN diode 342, a ground line 37, and a DC control line 38;

[0010] A surface mount dipole is disposed on the upper surface of the first PCB board, including two symmetrical dipole arms; a power supply probe 12 passes through the first PCB board 1 and the second PCB board 2 and connects one dipole arm to the phase shift line 34; a short circuit probe 13 passes through the first PCB board 1 and connects the other dipole arm to the upper ground 23.

[0011] The upper ground 23 is located on the upper surface of the second PCB board 2 and on the lower surface of the first PCB board 1; the phase shift line 34 and the high-resistance ground line 35 are both located on the upper surface of the third PCB board 3 and on the lower surface of the second PCB board 2; the lower ground 36 is located on the lower surface of the third PCB board 3.

[0012] Phase shift line 34 includes a long phase shift line and a short phase shift line. The beginnings of the long phase shift line and the short phase shift line are connected and are connected to the feed probe 12. The ends of the long phase shift line and the short phase shift line are respectively connected to the second DC probe 32 and the first DC probe 31. The second DC probe 32 and the first DC probe 31 pass through the third PCB board 3. One end of the high-resistance grounding line 35 is connected to the beginnings of the long phase shift line and the short phase shift line, and the other end is connected to the grounding DC probe 33. The grounding DC probe 33 passes through the third PCB board 3. The first short-circuit pin 21 and the second short-circuit pin 22 are respectively set at the ends of the short phase shift line and the long phase shift line. After passing through the second PCB board 2 and the third PCB board 3, they are connected to the upper ground 23 and the lower ground 36.

[0013] The first PIN diode 341 is loaded in the short phase shift line, and the positive direction is from the end to the beginning of the short phase shift line; the second PIN diode 342 is loaded in the long phase shift line, and the positive direction is from the beginning to the end of the long phase shift line; the grounding DC probe 33 is connected to the DC ground through the grounding wire 37, and the first DC probe 31 and the second DC probe 32 are connected to the DC control signal through the DC control line 38.

[0014] Furthermore, when the first DC probe 31 and the second DC probe 32 are connected to a negative voltage, the second PIN diode 342 is turned on and the first PIN diode 341 is turned off. At this time, the long phase shift line is short-circuited, and the unit structure is encoded as encoding state "1". When the first DC probe 31 and the second DC probe 32 are connected to a positive voltage, the second PIN diode 342 is turned off and the first PIN diode 341 is turned on. At this time, the short phase shift line is short-circuited, and the unit structure is encoded as encoding state "0". This achieves 1-bit encoding.

[0015] Furthermore, the feed source for the reflector array antenna is a horn antenna.

[0016] Furthermore, the surface mount dipole is a butterfly-shaped dipole and is positioned along the centerline of the upper surface of the first PCB board.

[0017] Furthermore, both the long phase shift line and the short phase shift line adopt a strip transmission line with a disk structure at both the beginning and the end.

[0018] Furthermore, a circular isolation strip is opened on the upper ground 23 corresponding to the power supply probe 12.

[0019] Furthermore, circular isolation strips are respectively opened on the lower ground 36 corresponding to the first DC probe 31, the second DC probe 32, and the grounding DC probe 33.

[0020] Furthermore, the long phase shift lines are arranged perpendicularly to the short phase shift lines.

[0021] Based on the above technical solution, the beneficial effects of the present invention are as follows:

[0022] This invention provides a 1-bit encoded wide-bandwidth angle-scanning reflective array antenna with X-band (8~12GHz) wide-bandwidth angle-scanning capability, capable of beam scanning within a ±60° conical range, exhibiting superior performance in wide-bandwidth angle-scanning. The unit structure employs a phase delay line with short-circuited terminals to control the phase, which not only possesses broadband characteristics but also minimizes inter-element coupling and mutual influence, suppressing resonance. Furthermore, the unit structure and DC control structure are simple, significantly reducing the number of electronic control devices and lowering the complexity of the electronic control method. Attached Figure Description

[0023] Figure 1 This is a perspective view of the array surface of the 1-bit encoded wide bandwidth scanning reflective array antenna in this invention.

[0024] Figure 2 This is a three-dimensional schematic diagram of the unit structure of the 1-bit encoded wide bandwidth scanning reflective array antenna in this invention.

[0025] Figure 3 This is a schematic diagram of the unit structure of the 1-bit encoded wide bandwidth angle scanning reflective array antenna in this invention. Figure 3 (a) is the upper surface of the first PCB board. Figure 3 (b) is the upper surface of the second PCB board. Figure 3 (c) represents the upper surface of the third PCB board. Figure 3 The middle (d) is the lower surface of the third PCB board.

[0026] Figure 4 The figure shows the simulation results of the reflection coefficient of the reflective array antenna feed and the periodic dipole antenna element under 50Ω excitation in this invention.

[0027] Figure 5 The simulation results of the reflection amplitude of the reflective array antenna element in state "0" and state "1" in this invention are shown.

[0028] Figure 6 The simulation results of the reflection phase of the reflective array antenna element in this invention under state "0" and state "1" are shown in the figure.

[0029] Figure 7 This is a schematic diagram of the encoding of the 1-bit encoded wide bandwidth angle scanning reflective array antenna in this invention when side-firing at 10GHz.

[0030] Figure 8 This is a schematic diagram of the encoding of the 1-bit encoded wide-bandwidth angle scanning reflective array antenna in this invention when scanning to 30 degrees in the H plane at 10 GHz.

[0031] Figure 9 This is the far-field radiation pattern of the scanning surface of the 1-bit encoded wide-bandwidth angle scanning reflector antenna in this invention during 10GHz E-plane beam scanning.

[0032] Figure 10 This is the far-field radiation pattern of the scanning surface of the 1-bit encoded wide-bandwidth angle scanning reflector antenna in this invention during 10GHz H-plane beam scanning.

[0033] Figure 11 This is the far-field radiation pattern of the scanning plane of the 1-bit encoded wide-bandwidth angle scanning reflector antenna in this invention during 12GHz E-plane beam scanning.

[0034] Figure 12 This is the far-field radiation pattern of the scanning plane of the 1-bit encoded wide-bandwidth angle scanning reflector antenna in this invention during 12GHz H-plane beam scanning.

[0035] In the above figures: 1 is the first PCB board, 11 is the surface mount dipole, 12 is the power supply probe, and 13 is the short-circuit probe; 2 is the second PCB board, 21 is the first short-circuit pin, 22 is the second short-circuit pin, and 23 is the upper ground; 3 is the third PCB board, 31 is the first DC probe, 32 is the second DC probe, 33 is the ground DC probe, 34 is the phase shift line, 35 is the high-resistance ground line, 36 is the lower ground, 37 is the ground line, 38 is the DC control line, 341 is the first PIN diode, and 342 is the second PIN diode. Detailed Implementation

[0036] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0037] This embodiment provides a 1-bit encoded wide-bandwidth angle-scanning reflective array antenna, the array plane perspective view of which is shown below. Figure 1 As shown, the array size is 16×16, the feed is a horn antenna, the distance between the horn aperture surface and the upper layer of the array surface is 75mm, and the element size is 12.5×12.5mm. 2 The operating frequency is 8~12GHz.

[0038] like Figure 2 and Figure 3As shown, the unit structure consists of a radiation layer, a phase modulation layer, and an electrical control structure; wherein:

[0039] The radiating layer includes: a first PCB board 1, a patch dipole 11, a power supply probe 12, and a short-circuit probe 13; the first PCB board has a thickness of 4.5 mm and a dielectric constant of 2.2; the patch dipole is a butterfly-shaped dipole disposed on the upper surface of the first PCB board 1, including two symmetrical dipole arms with a total length of 12 mm and a width that gradually changes from 0.8 mm to 3 mm, with a 1.5 mm diameter disk structure on the narrow side; the power supply probe 12 is a metallized via that passes through the first PCB board 1 and the second PCB board 2, with a diameter of 1 mm, and the power supply probe 12 connects the right dipole arm to the phase shift line 34; the short-circuit probe 13 is a metallized via that passes through the first PCB board 1, with a diameter of 1 mm, and the short-circuit probe 13 connects the left dipole arm to the upper ground 23;

[0040] The phase-shifting layer includes: a second PCB board 2, a first short-circuit pin 21, a second short-circuit pin 22, an upper ground 23, a third PCB board 3, a first DC probe 31, a second DC probe 32, a ground DC probe 33, a phase-shifting line 34, a high-resistance grounding line 35, and a lower ground 36. The second PCB board 2 has a thickness of 0.5mm and a dielectric constant of 3.5. The third PCB board 3 has a thickness of 1.5mm and a dielectric constant of 3.5. The upper ground 23 is located on the upper surface of the second PCB board 2 and on the lower surface of the first PCB board 1. A circular isolation strip is formed on the upper ground 23 corresponding to the feed probe 12 to prevent the feed probe 12 from short-circuiting with the upper ground 23. The diameter of the circular isolation strip is 2.4mm. The phase-shifting line 34 and the high-resistance grounding line 35 are both located on the upper surface of the third PCB board 3 and on the lower surface of the second PCB board 2. The phase-shifting line 34 includes a long phase-shifting line and a short phase-shifting line with lengths of 6mm and 2mm, respectively. mm; Both the long and short phase shift lines adopt strip transmission lines with disk structures at both the beginning and end. The line width of the strip transmission line is 0.9 mm, and the diameters of the disk structures at the beginning and end are 1.5 mm and 1 mm, respectively. The beginnings of the long and short phase shift lines are connected, that is, they share the beginning disk structure and are connected to the feed probe 12. The ends of the long and short phase shift lines are respectively connected to the second DC probe 32 and the first DC probe 31. The second DC probe 32 and the first DC probe 31 are metallized vias passing through the third PCB board 3, and their diameters are both 0.6 mm. One end of the high-resistance grounding wire 35 is connected to the beginning of the long and short phase shift lines, and the other end is connected to the grounding DC probe 33. The line width of the high-resistance grounding wire 35 is 0.2 mm, and the grounding... DC probe 33 is a metallized via that passes through the third PCB board 3, and its diameter is also 0.6mm. The lower ground 36 is set on the lower surface of the third PCB board 3. The lower ground 36 has circular isolation strips corresponding to the first DC probe 31, the second DC probe 32, and the ground DC probe 33. The diameter of each circular isolation strip is 1mm, which is used to prevent the first DC probe 31, the second DC probe 32, and the ground DC probe 33 from being short-circuited with the lower ground 36. The first short-circuit pin 21 and the second short-circuit pin 22 are respectively set at the end of the short phase shift line and the long phase shift line. Both of them pass through the metallized vias of the second PCB board 2 and the third PCB board 3, and connect the upper ground 23 and the lower ground 36. The diameter of the first short-circuit pin 21 and the second short-circuit pin 22 is 0.6mm.

[0041] The electrical control structure includes: a first PIN diode 341, a second PIN diode 342, a grounding wire 37, and a DC control line 38; the first PIN diode 341 is loaded in the short phase shift line, and the positive direction is from the end to the beginning of the short phase shift line, with a gap opened in the short phase shift line corresponding to the first PIN diode 341; the second PIN diode 342 is loaded in the long phase shift line, and the positive direction is from the beginning to the end of the long phase shift line, with a gap opened in the long phase shift line corresponding to the second PIN diode 342; the grounding wire 37 is a wire connecting the grounding DC probe 33 to the DC ground, and the DC control line 38 is a wire connecting the first DC probe 31, the second DC probe 32, and the DC control signal.

[0042] Furthermore, when the first DC probe 31 and the second DC probe 32 are connected to a negative voltage, the second PIN diode 342 is turned on and the first PIN diode 341 is turned off. At this time, the long phase shift line is short-circuited, and the unit structure is encoded as encoding state "1". When the first DC probe 31 and the second DC probe 32 are connected to a positive voltage, the second PIN diode 342 is turned off and the first PIN diode 341 is turned on. At this time, the short phase shift line is short-circuited, and the unit structure is encoded as encoding state "0". This achieves 1-bit encoding.

[0043] Based on the above-mentioned wide bandwidth angle scanning reflective array antenna with 1-bit encoding, the beneficial effects of the present invention will be explained in detail below with reference to simulation tests.

[0044] like Figure 4 The figure shows the reflection coefficients of the horn antenna and the periodic dipole antenna under 50Ω excitation. As can be seen from the figure, both operate in the frequency range of 8~12GHz, and the reflection coefficients are basically below -10dB. Therefore, the horn antenna can be used as a broadband feed, and the dipole antenna can also be used as a broadband reflective antenna element when the terminal is totally reflected.

[0045] like Figure 5 and Figure 6 The figure shows the reflection amplitude and phase of two sets of coded states of a reflective array antenna element, derived from... Figure 5 It is evident that the reflective array antenna elements exhibit near total reflection in both coded states "1" and "0", resulting in low loss and high efficiency; Figure 6 It can be seen that the two sets of coded states are 180° out of phase at the center frequency of 10GHz, and about 40° out of phase at the side frequencies. The phase error is within an acceptable range and will not significantly affect the beam scanning performance.

[0046] like Figure 7 and Figure 8 The diagram shows the encoding schematics of the 1-bit encoded wide-bandwidth angle-scanning reflective array antenna in this embodiment when side-firing at 10GHz and scanning to 30° in the H-plane at 10GHz. The phase-shift line branch with the diode in the off state is hidden. Figure 7 and Figure 8Two sets of array encoding states are shown as an example.

[0047] like Figure 9 , Figure 10 , Figure 11 , Figure 12 The figures show the far-field radiation patterns of the scanning surface of the 1-bit encoded wide-angle scanning reflector antenna in this embodiment during 10GHz E-plane beam scanning, 10GHz H-plane beam scanning, 12GHz E-plane beam scanning, and 12GHz H-plane beam scanning. As can be seen from the figures, the encoded reflector antenna can achieve wide-angle beam scanning within a ±60° cone range.

[0048] In summary, this invention provides a 1-bit encoded wide-bandwidth angle-scanning reflective array antenna that achieves 1-bit phase encoding from 8 to 12 GHz. It enables rapid ±60° beam scanning in any cross section through array encoding control and achieves low-cost wide-bandwidth angle-scanning using a simple antenna structure and convenient electronic control.

[0049] The above description is merely a specific embodiment of the present invention. Any feature disclosed in this specification may be replaced by other equivalent or similar features unless otherwise specified. All disclosed features, or steps in all methods or processes, may be combined in any way except for mutually exclusive features and / or steps.

Claims

1. A 1-bit encoded wide-bandwidth angle-scanning reflective array antenna, composed of several unit structures arranged in an array, characterized in that, The unit structure consists of a radiation layer, a phase modulation layer, and an electrical control structure; The radiation layer includes: a first PCB board (1), a surface mount dipole (11), a power supply probe (12), and a short-circuit probe (13); the phase adjustment layer includes: a second PCB board (2), a first short-circuit pin (21), a second short-circuit pin (22), an upper ground (23), a third PCB board (3), a first DC probe (31), a second DC probe (32), a ground DC probe (33), a phase shift line (34), a high-resistance ground line (35), and a lower ground (36); the electrical control structure includes: a first PIN diode (341), a second PIN diode (342), a ground line (37), and a DC control line (38); A patch dipole (11) is disposed on the upper surface of the first PCB board (1) and includes two symmetrical dipole arms; a power supply probe (12) passes through the first PCB board (1) and the second PCB board (2) and connects one dipole arm to the phase shift line (34); a short circuit probe (13) passes through the first PCB board (1) and connects the other dipole arm to the upper ground (23). The upper ground (23) is located on the upper surface of the second PCB board (2) and on the lower surface of the first PCB board (1); the phase shift line (34) and the high-resistance ground line (35) are both located on the upper surface of the third PCB board (3) and on the lower surface of the second PCB board (2); the lower ground (36) is located on the lower surface of the third PCB board (3). The phase shift line (34) includes a long phase shift line and a short phase shift line. The beginnings of the long phase shift line and the short phase shift line are connected and are connected to the feed probe (12). The ends of the long phase shift line and the short phase shift line are respectively connected to the second DC probe (32) and the first DC probe (31). The second DC probe (32) and the first DC probe (31) pass through the third PCB board (3). One end of the high-resistance grounding line (35) is connected to the beginnings of the long phase shift line and the short phase shift line, and the other end is connected to the grounding DC probe (33). The grounding DC probe (33) passes through the third PCB board (3). The first short-circuit pin (21) and the second short-circuit pin (22) are respectively set at the ends of the short phase shift line and the long phase shift line. After passing through the second PCB board (2) and the third PCB board (3), they are connected to the upper ground (23) and the lower ground (36). The first PIN diode (341) is loaded in the short phase shift line, and the positive direction is from the end to the beginning of the short phase shift line; the second PIN diode (342) is loaded in the long phase shift line, and the positive direction is from the beginning to the end of the long phase shift line; the grounding DC probe (33) is connected to the DC ground through the grounding wire (37), and the first DC probe (31) and the second DC probe (32) are connected to the DC control signal through the DC control line (38).

2. The 1-bit encoded wide-bandwidth angle-scanning reflective array antenna according to claim 1, characterized in that, The feed source for the reflector array antenna is a horn antenna.

3. The 1-bit encoded wide-bandwidth angle-scanning reflective array antenna according to claim 1, characterized in that, When the first DC probe (31) and the second DC probe (32) are connected to negative voltage, the second PIN tube (342) is turned on and the first PIN tube (341) is turned off. At this time, the long phase shift line is short-circuited and the unit structure is encoded as encoding state "1". When the first DC probe (31) and the second DC probe (32) are connected to positive voltage, the second PIN tube (342) is turned off and the first PIN tube (341) is turned on. At this time, the short phase shift line is short-circuited and the unit structure is encoded as encoding state "0". Thus, 1-bit encoding is achieved.

4. The 1-bit encoded wide-bandwidth angle-scanning reflective array antenna according to claim 1, characterized in that, The surface mount dipole is a butterfly-shaped dipole and is positioned along the centerline of the upper surface of the first PCB board.

5. The 1-bit encoded wide-bandwidth angle-scanning reflective array antenna according to claim 1, characterized in that, Both long and short phase shift lines are strip transmission lines with a disk structure at both the beginning and end.

6. The 1-bit encoded wide-bandwidth angle-scanning reflective array antenna according to claim 1, characterized in that, A circular isolation strip is set up for the upper ground corresponding to the power supply probe.

7. The 1-bit encoded wide-bandwidth angle-scanning reflective array antenna according to claim 1, characterized in that, Circular isolation strips are respectively set for the first DC probe, the second DC probe, and the grounding DC probe on the lower layer.

8. The 1-bit encoded wide-bandwidth angle-scanning reflective array antenna according to claim 1, characterized in that, The long phase shift lines are arranged perpendicularly to the short phase shift lines.

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