Broadband beam splitter

Abstract

The invention provides a broadband beam splitter, and relates to the technical field of beam splitters. The broadband beam splitter provided by the invention comprises an input waveguide, a first output waveguide and a second output waveguide, and the first ferrite flat plate in the first output waveguide and the second ferrite flat plate in the second output waveguide are respectively positioned in magnetic field environments with the same size and opposite directions. According to the broadband beam splitter provided by the invention, by utilizing the characteristics of backscattering resistance and high transmission efficiency of a one-way mode, the problem of low transmission efficiency caused by a mode matching problem at a junction can be improved; the high-frequency beam splitter has the advantages of strong anti-interference capability, strong electromagnetic wave transmission anti-interference capability, high transmission efficiency, large working frequency bandwidth and adjustable beam splitting proportion and working frequency band.

Description

Technical Field

[0001] The present invention relates to the technical field of beam splitters, and in particular to a broadband beam splitter. Background Art

[0002] The microwave power splitter is one of the key components of integrated information systems. It is used to direct the input microwave signal to multiple output ports according to a specific ratio, and at the same time can ensure the impedance matching and isolation performance between multiple output ports. Therefore, it is widely used in modern radar, microwave communication, chips and other intelligent integrated electronic fields. However, due to the complex mode matching and backscattering effects at the junction, traditional microwave power splitters generally have the problem of low total transmission efficiency, and their splitting ratio and bandwidth are limited by structural parameters and operating frequencies.

[0003] Currently, the mainstream beam splitter structures include Y-type and T-type beam splitters based on photonic crystals, multi-port architectures (such as two-port, three-port or extended types), and types designed using the principles of directional coupling and multimode interference. However, these beam splitters all have obvious shortcomings in performance. For example, the beam splitter based on photonic crystals is easily affected by lattice defects, resulting in a decrease in transmission efficiency, while the directional coupling device is difficult to achieve a broadband response due to phase sensitivity, and the multimode interference type beam splitter is limited in the adjustment of the splitting ratio and is not flexible enough. Therefore, there is an urgent need to provide a solution to improve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a broadband beam splitter, which can utilize the anti-backscattering and high transmission efficiency characteristics of the unidirectional mode to improve the low transmission efficiency problem caused by mode matching problems at the junction, and has strong anti-interference ability, strong anti-interference ability for electromagnetic wave transmission, high transmission efficiency, large operating frequency bandwidth, adjustable splitting ratio and operating frequency band.

[0005] A broadband beam splitter provided by the present invention includes: an input waveguide composed of a first metal plate, a first ferrite plate, a first dielectric channel, a second ferrite plate and a second metal plate along a first direction; a first output waveguide composed of a first metal plate, a first ferrite plate, a second dielectric channel and a third metal plate along a second direction; a second output waveguide composed of a second metal plate, a second ferrite plate, a third dielectric channel and a third metal plate along the second direction; the first dielectric channel, the second dielectric channel and the third dielectric channel are interconnected to form a T-shaped branch, and a current excitation source is provided at the center of the first dielectric channel near the opening side; the first ferrite plate and the second ferrite plate are respectively located in magnetic field environments with the same size and opposite directions; the first direction is perpendicular to the second direction.

[0006] A broadband beam splitter provided by the present invention, in a magnetic field environment, the structural design of the first ferrite plate, the second ferrite plate and the beam splitter can open the bandgaps that do not support the bulk mode and support the unidirectional mode, and the input waveguide shares a bandgap with the first output waveguide and the second output waveguide and supports unidirectional electromagnetic waves that can only be transmitted in one direction and have no reflection; in addition, a current excitation source arranged in the first dielectric channel can excite unidirectionally transmitted electromagnetic waves, there is no reflection at the boundary of the beam splitter, and the electromagnetic waves can flow to the first output waveguide and the second output waveguide with different beam splitting ratios.

[0007] Optionally, along the second direction, the width ratio of the second dielectric channel to the third dielectric channel is 6:(0.1 - 25).

[0008] Optionally, the first ferrite and the second ferrite are in a magnetic field environment with a magnetic field strength of 536 G - 1072 G.

[0009] Optionally, along the first direction, the widths of the first ferrite plate and the second ferrite plate are 4 mm - 8 mm.

[0010] Optionally, along the first direction, the widths of the first metal plate and the second metal plate are 6 mm.

[0011] Optionally, the materials of the first ferrite plate and the second ferrite plate are yttrium iron garnet, and the characteristic angular frequency of the yttrium iron garnet is 2π × 5×10 9 rad / s and the relative dielectric constant is 15.

[0012] Optionally, the T-shaped branch is filled with an air medium, and the dielectric constant of the air medium is 1.

[0013] Optionally, the materials of the first metal plate and the second metal plate are copper.

[0014] Optionally, when the T-shaped branch is filled with an air medium, and along the second direction, the width of the second dielectric channel is 6 mm and the width of the third dielectric channel is 6 mm, the beam splitting ratio of the broadband beam splitter at the second dielectric channel and the third dielectric channel is 50:50.

[0015] Optionally, when the T-shaped branch is filled with an air medium, and along the second direction, the width of the second dielectric channel is 6 mm and the width of the third dielectric channel is 9.2 mm, the beam splitting ratio of the broadband beam splitter at the second dielectric channel and the third dielectric channel is 67:33.

[0016] Optionally, when the T-shaped branch is filled with an air medium, and the width of the second dielectric channel is 6 mm and the width of the third dielectric channel is 11.3 mm along the second direction, the beam splitting ratio of the broadband beam splitter at the second dielectric channel and the third dielectric channel is 75:25.

[0017] Optionally, when the magnitude of the magnetic field environment is 715 G, the operating frequency of the broadband beam splitter is 4.5 GHz - 7 GHz.

[0018] Optionally, when the magnitude of the magnetic field environment is 536 G, the operating frequency of the broadband beam splitter is 4 GHz - 6.5 GHz.

[0019] Optionally, when the magnitude of the magnetic field environment is 1072 G, the operating frequency of the broadband beam splitter is 5.5 GHz - 8 GHz.

[0020] Optionally, it further includes a first magnetic sheet and a second magnetic sheet arranged along the third direction, and the first magnetic sheet and the second magnetic sheet are respectively attached to both sides of the second metal plate; the projections of the first magnetic sheet and the second magnetic sheet along the third direction at least cover the first metal plate, the second metal plate, the third metal plate, the first ferrite plate, the second ferrite plate, the first dielectric channel, the second dielectric channel, and the third dielectric channel; the first direction, the second direction, and the third direction are perpendicular to each other in pairs.

[0021] The broadband beam splitter provided by the present invention has at least the following beneficial technical effects compared with the prior art: 1. The broadband beam splitter provided by the present invention based on the unidirectional mode has the advantages of strong anti-interference ability, high transmission efficiency, strong anti-interference ability for electromagnetic wave transmission, large working frequency bandwidth, adjustable beam splitting ratio, adjustable working frequency band, etc. in the microwave field, and has important application prospects in devices in modern radar, satellite communication and other intelligent integrated electronic information fields; 2. For the broadband beam splitter provided by the present invention, when the magnetic field strength is 715 G, within the frequency range of 4.5 GHz - 7 GHz, when the magnetic field strength is 536 G, within the frequency range of 4 GHz - 6.5 GHz, and when the magnetic field strength is 1072 G, within the frequency range of 5.5 GHz - 8 GHz, the input waveguide and the first output waveguide and the second output waveguide only transmit in one direction and have no reflection; 3. For the broadband beam splitter provided by the present invention, by adjusting the widths of the second dielectric channel and the third dielectric channel in the second direction, the output power ratio of the first output waveguide and the second output waveguide can be regulated; 4. For the broadband beam splitter provided by the present invention, by adjusting the magnetic field magnitude of the magnetic field environment where the first ferrite plate and the second ferrite plate are located, the adjustable working frequency band at a specific beam splitting ratio can be realized. Brief Description of the Drawings

[0022] Figure 1 FIG. 1 is a schematic diagram of the overall structure of a broadband beam splitter provided by the present invention; Figure 2 FIG. 2 is a schematic diagram of the two-dimensional structure of a broadband beam splitter provided by the present invention; Figure 3 FIG. 3 is a structural diagram of the input waveguide, the first output waveguide, and the second output waveguide of a broadband beam splitter provided by the present invention, as well as a theoretical dispersion diagram of electromagnetic wave transmission; Figure 4 FIG. 4 is a broadband beam splitting transmission spectrum diagram of a broadband beam splitter provided by the present invention when the beam splitting ratio between the first output waveguide and the second output waveguide is 50:50; Figure 5 FIG. 5 is a curve diagram of the change in the beam splitting ratio when the width of the third dielectric channel is adjusted for a broadband beam splitter provided by the present invention; Figure 6 FIG. 6 is a broadband beam splitting transmission spectrum diagram of a broadband beam splitter provided by the present invention when the magnetic field strength is 715 G and the beam splitting ratios are 67:33 and 75:25; Figure 7 FIG. 7 is a broadband beam splitting transmission spectrum diagram of a broadband beam splitter provided by the present invention when the magnetic field strengths are 536 G and 1027 G and the beam splitting ratios are 67:33 and 75:25, respectively.

[0023] Description of the Reference Numerals: 1. First metal plate; 2. Second metal plate; 3. Third metal plate; 4. First ferrite plate; 5. Second ferrite plate; 6. First dielectric channel; 7. Second dielectric channel; 8. Third dielectric channel; 9. Current excitation source. Detailed Embodiments

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art in the field to which the present invention belongs.

[0025] Refer to Figure 1, an embodiment of the present invention provides a broadband beam splitter designed based on a unidirectional mode, including: an input waveguide composed of a first metal plate 1, a first ferrite plate 4, a first dielectric channel 6, a second ferrite plate 5, and a second metal plate 2 along a first direction; a first output waveguide composed of the first metal plate 1, the first ferrite plate 4, a second dielectric channel 7, and a third metal plate 3 along a second direction; and a second output waveguide composed of the second metal plate 2, the second ferrite plate 5, a third dielectric channel 8, and the third metal plate 3 along the second direction.

[0026] In fact, in the broadband beam splitter, the first dielectric channel 6, the second dielectric channel 7, and the third dielectric channel 8 are interconnected to form a T-shaped branch. Specifically, when the broadband beam splitter is in use, one end of the first dielectric channel 6 is connected to the second dielectric channel 7 and the third dielectric channel 8, and the other end serves as the input end, the other end of the second dielectric channel 7 serves as the first output end, and the other end of the third dielectric channel 8 serves as the second output end. In addition, the medium in the T-shaped branch is air with a dielectric constant of 1, and a current excitation source 9 is provided at the center of the first dielectric channel 6 near the opening side in the T-shaped beam splitting. The current excitation source 9 can excite an electromagnetic wave that propagates unidirectionally.

[0027] In fact, the first ferrite plate 4 and the second ferrite plate 5 are respectively located in magnetic field environments with the same size and opposite directions. Specifically, by applying two magnetic fields in opposite directions, the first ferrite plate 4 and the second ferrite plate 5 can be magnetized respectively, so as to generate non-reciprocal unidirectional transmission, which is used to open a bandgap that can support a unidirectional transmission mode that can only transmit unidirectionally in one direction and has no backward reflection. Specifically, the first direction and the second direction are perpendicular to each other, and the magnetic field directions applied on the first ferrite plate 4 and the second ferrite plate 5 are the third direction, and the first direction, the second direction, and the third direction are perpendicular to each other in pairs.

[0028] In some embodiments, the materials of the first ferrite plate 4 and the second ferrite plate 5 are yttrium iron garnet, and the characteristic angular frequency of the yttrium iron garnet is 2π × 5×10 9 rad / s, and the relative dielectric constant is 15. Further, the first ferrite plate 4 and the second ferrite plate 5 are in a magnetic field environment with a magnetic field magnitude of 536G - 1072G, and along the first direction, the widths of the first ferrite plate 4 and the second ferrite plate 5 are 4mm - 8mm. In fact, by adjusting the magnetic field magnitude, the operating frequency band of the broadband beam splitter can be adjusted at a specific beam splitting ratio.

[0029] In fact, the broadband beam splitter further includes a first magnetic sheet and a second magnetic sheet disposed along a third direction, and the first magnetic sheet and the second magnetic sheet are respectively attached to both sides of the second metal plate. At the same time, the projections of the first magnetic sheet and the second magnetic sheet along the third direction at least cover the first metal plate 1, the second metal plate 2, the third metal plate 3, the first ferrite plate 4, the second ferrite plate 5, the first dielectric channel 6, the second dielectric channel 7, and the third dielectric channel 8. Specifically, the first magnetic sheet and the second magnetic sheet can be made of ferromagnetic sheets.

[0030] In some embodiments, the materials of the first metal plate 1, the second metal plate 2, and the third metal plate 3 are copper, and the widths of the first metal plate 1 and the second metal plate 2 along the first direction are 6 mm. In addition, the width ratio of the second dielectric channel 7 to the third dielectric channel 8 along the second direction is 6:(0.1 - 25). In fact, by adjusting the width ratio of the second dielectric channel 7 to the third dielectric channel 8, the output power ratio of the first output waveguide and the second output waveguide can be adjusted. In addition, by fixing the width ratio of the second dielectric channel 7 to the third dielectric channel 8, large-bandwidth wave transmission under a specific beam splitting ratio can be achieved.

[0031] Specifically, referring to Figure 2 , along the first direction, the widths of the first ferrite plate 4 and the second ferrite plate 5 are h2, the width of the first dielectric channel 6 is h1, along the second direction, the widths of the first ferrite plate 4 and the second ferrite plate 5 are h3, the width of the second dielectric channel 7 is d1, and the width of the third dielectric channel 8 is d1. A magnetic field perpendicular to the paper surface and with an intensity of H is applied to the first ferrite plate 4, and a magnetic field perpendicular to the paper surface and with an intensity of H is applied to the second ferrite plate 5.

[0032] Referring to Figure 3 , in Figure 3 , (a) shows the two-dimensional structure diagram of the output waveguide, and in Figure 3 , (b) shows the output wave transmission dispersion diagram, where a magnetic field with a magnetic field intensity H of 715 G is applied to the first ferrite plate 4, the thickness d1 of the air medium in the second dielectric channel 7 is 6 mm, and the width h3 of the first ferrite plate 4 is 6 mm. Figure 3 In (b) of m -1.4ω m , that is, the bandwidth is 0.5ω m .

[0033] In Figure 3 , (c) shows the two-dimensional structure diagram of the input waveguide, and in Figure 3Among them, (c) shows the transmission dispersion diagram of the input wave. In this diagram, a magnetic field with a magnetic field intensity H of 715 G is applied to the first ferrite plate 4 and the second ferrite plate 5 in opposite directions. The thickness of the air dielectric layer in the first dielectric channel 6 is 6 mm, and the thickness d of the first ferrite plate 4 and the second ferrite plate 5 is 6 mm. Figure 3 In (d) among them, the red curve represents the odd mode, the blue curve represents the even mode, and the yellow shaded part represents the unidirectional region where the electromagnetic wave is transmitted forward. The theoretical range is 0.9ω m -1.4ω m That is, the bandwidth is 0.5ω m .

[0034] Based on Figure 3 , the transmission spectra of the first output waveguide and the second output waveguide and the total transmission spectrum as a function of frequency within the entire unidirectional range are shown as Figure 4 shown. It can be seen from Figure 4 that when the widths of the second dielectric channel 7 and the third dielectric channel 8 are both 6 mm, the broadband beam splitter has a symmetric up-down structure, behaves as an equal beam splitter, and the first output waveguide and the second output waveguide can achieve a 50:50 split within the entire unidirectional bandwidth of 0.5ω m , and the transmission efficiency is close to 100%. The operating frequency band range is 4.5 GHz - 7 GHz.

[0035] In some embodiments, an unequal beam splitting ratio can be achieved by breaking the structural symmetry. For example, on the basis of Figure 4 , while keeping other parameters unchanged and adjusting the width d2 of the third dielectric channel 8, different beam splitting ratios of the width beam splitter between the first output waveguide and the second output waveguide can be achieved, as shown in Figure 5 .

[0036] In some embodiments, on the basis of Figure 3 and Figure 5 , when the widths of the third dielectric channel 8 are adjusted to 9.2 mm and 11.3 mm, the broadband beam splitting transmission spectra are shown in (a) in Figure 6 and (b) in Figure 6 respectively. It can be seen from (a) in Figure 6 and (b) in Figure 6 that the first output waveguide and the second output waveguide can respectively achieve unidirectional bandwidths of 67:33 and 75:25, accounting for 70% and 66% of the entire bandwidth respectively.

[0037] In some embodiments, on the basis of Figure 6 , the magnetic field intensities of the first ferrite plate 4 and the second ferrite plate 5 are adjusted to 536 G and 1072 G, and the transmission spectra of the first output waveguide and the second output waveguide within the entire unidirectional range and the total transmission spectrum as a function of frequency are shown respectively as Figure 7in (a) of Figure 7 in (b) of Figure 7 in (c) of Figure 7 as shown in (d) of. From Figure 7 in (a) of Figure 7 in (b) of Figure 7 in (c) of Figure 7 in (d) of, it can be seen that when the width of the third medium channel 8 is 9.2 mm and 11.3 mm, the first output waveguide and the second output waveguide can still achieve unidirectional bandwidths of 67:33 and 75:25, accounting for 70% and 66% of the entire bandwidth respectively, and the transmission efficiency is also close to 100%, which is consistent with that when the magnetic field strength is 715 G. However, when the intensities are H = 536 G and H = 1072 G, the working frequency bands are 4.5 GHz - 7 GHz and 5.5 GHz - 8 GHz respectively, further indicating that the working frequency band can be regulated by changing the magnetic field.

[0038] Although the embodiments of the present invention have been described in detail above, it is obvious to those skilled in the art that various modifications and changes can be made to these embodiments. However, it should be understood that such modifications and changes are all within the scope and spirit of the present invention described in the claims. Moreover, the present invention described herein can have other embodiments and can be implemented or realized in various ways.

Claims

1. A broadband beam splitter, characterized in that, Comprising: An input waveguide composed of a first metal plate, a first ferrite plate, a first dielectric channel, a second ferrite plate, and a second metal plate along a first direction; A first output waveguide composed of a first metal plate, a first ferrite plate, a second dielectric channel, and a third metal plate along a second direction; a second output waveguide composed of a second metal plate, a second ferrite plate, a third dielectric channel, and a third metal plate along the second direction; the first dielectric channel, the second dielectric channel, and the third dielectric channel are interconnected to form a T-shaped branch, and a current excitation source is provided at the center of the first dielectric channel near the opening side; the first ferrite plate and the second ferrite plate are respectively located in magnetic field environments with the same size and opposite directions; the first direction and the second direction are perpendicular to each other.

2. The broadband beam splitter according to claim 1, wherein Along the second direction, the width ratio of the second dielectric channel to the third dielectric channel is 6:(0.1 - 25), the first ferrite and the second ferrite are in a magnetic field environment with a magnetic field magnitude of 536G - 1072G, along the first direction, the width of the first ferrite plate and the second ferrite plate is 4mm to 8mm, and along the first direction, the width of the first metal plate and the second metal plate is 6mm.

3. The broadband beam splitter according to claim 1, wherein The materials of the first ferrite plate and the second ferrite plate are yttrium iron garnet, and the characteristic angular frequency of the yttrium iron garnet is 2π × 5×10 9 rad / s, the relative dielectric constant is 15; and / or, the T-shaped branch is filled with an air medium, and the dielectric constant of the air medium is 1; and / or, the materials of the first metal plate and the second metal plate are copper.

4. The broadband beam splitter according to claim 1, characterized in that, When the T-shaped branch is filled with air medium, and the width of the second dielectric channel is 6mm and the width of the third dielectric channel is 6mm along the second direction, the beam splitting ratio of the broadband beam splitter at the second dielectric channel and the third dielectric channel is 50:

50.

5. The broadband beam splitter according to claim 1, wherein When the T-shaped branch is filled with air medium, and the width of the second dielectric channel is 6mm and the width of the third dielectric channel is 9.2mm along the second direction, the beam splitting ratio of the broadband beam splitter at the second dielectric channel and the third dielectric channel is 67:

33.

6. The broadband beam splitter according to claim 1, characterized in that, When the T-shaped branch is filled with air medium, and the width of the second dielectric channel is 6mm and the width of the third dielectric channel is 11.3mm along the second direction, the beam splitting ratio of the broadband beam splitter at the second dielectric channel and the third dielectric channel is 75:

25.

7. The broadband beam splitter according to claim 1, wherein, When the magnitude of the magnetic field environment is 715G, the operating frequency of the broadband beam splitter is 4.5GHz - 7GHz; when the magnitude of the magnetic field environment is 536G, the operating frequency of the broadband beam splitter is 4GHz - 6.5GHz; when the magnitude of the magnetic field environment is 1072G, the operating frequency of the broadband beam splitter is 5.5GHz - 8GHz.

8. The broadband beam splitter according to any one of claims 1 to 7, characterized in that It further includes a first magnetic sheet and a second magnetic sheet arranged along a third direction, and the first magnetic sheet and the second magnetic sheet are respectively attached to both sides of the second metal plate; the projections of the first magnetic sheet and the second magnetic sheet along the third direction at least cover the first metal plate, the second metal plate, the third metal plate, the first ferrite plate, the second ferrite plate, the first dielectric channel, the second dielectric channel, and the third dielectric channel; The first direction, the second direction, and the third direction are perpendicular to each other in pairs.

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