A broadband beam splitter based on unidirectional mode

Abstract

The present invention provides a broadband beam splitter, relating to the technical field of beam splitters. The broadband beam splitter provided by the present invention comprises: an input waveguide, a first output waveguide, and a second output waveguide; a first ferrite plate in the first output waveguide and a second ferrite plate in the second output waveguide are respectively located in magnetic field environments of equal size and opposite directions. The broadband beam splitter provided by the present invention utilizes the anti-backscattering and high transmission efficiency characteristics of a unidirectional mode to improve the low transmission efficiency caused by mode matching problems at the junction. The broadband beam splitter provided by the present invention has strong anti-interference capabilities, strong electromagnetic wave transmission anti-interference capabilities, high transmission efficiency, a large operating frequency bandwidth, and an adjustable beam splitting ratio and operating 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] Microwave power beam splitters are key components in integrated information systems. They distribute input microwave signals to multiple output ports in a specific ratio while ensuring impedance matching and isolation between the output ports. Consequently, they are widely used in intelligent integrated electronics, including modern radar, WeChat communications, and chips. However, traditional microwave power beam splitters suffer from low overall transmission efficiency due to complex mode matching and backscattering at the interface. Their splitting ratio and bandwidth are limited by structural parameters and operating frequency.

[0003] Currently, mainstream beam splitter structures include Y- and T-type beam splitters based on photonic crystals, multi-port architectures (such as two-port, three-port, or extended types), and designs utilizing directional coupling and multimode interference principles. However, these beam splitters all have significant performance shortcomings. For example, photonic crystal-based beam splitters are susceptible to lattice defects, resulting in reduced transmission efficiency, while directional coupling devices struggle to achieve broadband response due to their phase sensitivity. Multimode interference beam splitters are limited in their ability to control the splitting ratio and lack flexibility. Therefore, a solution to address these issues is urgently needed. Summary of the Invention

[0004] The purpose of the present invention is to provide a broadband beam splitter, which utilizes 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 electromagnetic wave transmission anti-interference ability, high transmission efficiency, large operating frequency bandwidth and adjustable splitting ratio and operating frequency band.

[0005] The present invention provides a broadband beam splitter, comprising: an input waveguide formed by 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 formed by the first metal plate, the first ferrite plate, the second dielectric channel, and a third metal plate along a second direction; and a second output waveguide formed by the second metal plate, the second ferrite plate, the third dielectric channel, and the 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 near the center of an opening side of the first dielectric channel; the first ferrite plate and the second ferrite plate are respectively located in magnetic field environments of equal magnitude and opposite directions; and the first direction and the second direction are perpendicular to each other.

[0006] The present invention provides a broadband beam splitter. In a magnetic field environment, the structural design of the first ferrite plate, the second ferrite plate, and the beam splitter can open a bandgap that does not support bulk modes but supports unidirectional modes. The input waveguide and the first and second output waveguides share a bandgap and support unidirectional electromagnetic waves that are transmitted in only one direction without reflection. In addition, a current excitation source provided in the first dielectric channel can excite unidirectional electromagnetic waves, without reflection at the beam splitter boundary, and the electromagnetic waves can flow to the first and second output waveguides at different splitting ratios.

[0007] Optionally, along the second direction, a width ratio of the second medium channel to the third medium 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 size of 536G-1072G.

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

[0010] Optionally, along the first direction, the width of the first metal flat plate and the second metal flat plate is 6 mm.

[0011] Optionally, the material of the first ferrite plate and the second ferrite plate is yttrium iron garnet, and the characteristic circular 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 air medium, and the dielectric constant of the air medium is 1.

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

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

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

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

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

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

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

[0020] Optionally, it also 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 adhered 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 medium channel, the second medium channel, and the third medium channel; the first direction, the second direction, and the third direction are perpendicular to each other.

[0021] Compared with the prior art, the broadband beam splitter provided by the present invention has at least one of the following beneficial technical effects:

[0022] 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 electromagnetic wave transmission anti-interference ability, large operating frequency bandwidth, adjustable splitting ratio, and adjustable operating frequency band in the microwave field. It has important application prospects in intelligent integrated electronic information devices such as modern radar and satellite communications;

[0023] 2. The broadband beam splitter provided by the present invention transmits in only one direction without reflection in the frequency range of 4.5 GHz to 7 GHz when the magnetic field strength is 715 G, in the frequency range of 4 GHz to 6.5 GHz when the magnetic field strength is 536 G, and in the frequency range of 5.5 GHz to 8 GHz when the magnetic field strength is 1072 G.

[0024] 3. The broadband beam splitter provided by the present invention can control the output power ratio between the first output waveguide and the second output waveguide by adjusting the width of the second medium channel and the third medium channel in the second direction;

[0025] 4. The broadband beam splitter provided by the present invention can achieve adjustable working frequency band under a specific beam splitting ratio by adjusting the magnetic field size of the magnetic field environment in which the first ferrite plate and the second ferrite plate are located. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the overall structure of a broadband beam splitter provided by the present invention;

[0027] Figure 2 A schematic diagram of the two-dimensional structure of a broadband beam splitter provided by the present invention;

[0028] Figure 3 A structural diagram of the input waveguide, first output waveguide, and second output waveguide of a broadband beam splitter provided by the present invention, as well as a theoretical dispersion diagram of electromagnetic wave transmission;

[0029] Figure 4 A broadband beam splitting transmission spectrum 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;

[0030] Figure 5 A curve diagram showing a change in the splitting ratio of a broadband beam splitter provided by the present invention when the width of the third medium channel is adjusted;

[0031] Figure 6 The broadband beam splitting transmission spectrum of a broadband beam splitter provided by the present invention when the magnetic field intensity is 715G and the beam splitting ratios are 67:33 and 75:25;

[0032] Figure 7 The broadband beam splitting transmission spectra of a broadband beam splitter provided by the present invention are respectively shown when the magnetic field strength is 536G, 1027G, and the beam splitting ratio is 67:33, and 75:25.

[0033] Description of reference numerals:

[0034] 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 DESCRIPTION

[0035] In order to make the purpose, 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. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs.

[0036] See also Figure 1 An embodiment of the present invention provides a broadband beam splitter with a structural design based on a unidirectional mode, including: an input waveguide, which is 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, which is composed of the first metal plate 1, the first ferrite plate 4, the second dielectric channel 7 and the third metal plate 3 along a second direction; and a second output waveguide, which is composed of the second metal plate 2, the second ferrite plate 5, the third dielectric channel 8 and the third metal plate 3 along the second direction.

[0037] In practice, 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 and third dielectric channels 7 and 8, while the other end serves as the input. The other end of the second dielectric channel 7 serves as the first output, and the other end of the third dielectric channel 8 serves as the second output. Furthermore, the medium in the T-shaped branch is air, with a dielectric constant of 1. A current excitation source 9 is located near the center of the opening of the first dielectric channel 6 in the T-shaped beam splitter. This current excitation source 9 is capable of stimulating unidirectional electromagnetic waves.

[0038] In practice, the first ferrite plate 4 and the second ferrite plate 5 are each located in a magnetic field environment of equal magnitude and opposite direction. Specifically, by applying two magnetic fields in opposite directions, the first ferrite plate 4 and the second ferrite plate 5 are magnetized, respectively, thereby generating non-reciprocal unidirectional transmission, thereby creating a bandgap that supports a unidirectional transmission mode that only transmits in one direction without backreflection. Specifically, the first direction and the second direction are perpendicular to each other, and the direction of the magnetic field applied to the first ferrite plate 4 and the second ferrite plate 5 is the third direction. The first, second, and third directions are all perpendicular to each other.

[0039] In some embodiments, the material of the first ferrite plate 4 and the second ferrite plate 5 is yttrium iron garnet, and the characteristic circular frequency of the yttrium iron garnet is 2π×5×10 9rad / s, and a relative dielectric constant of 15. Furthermore, the first ferrite plate 4 and the second ferrite plate 5 are placed in a magnetic field environment of 536G-1072G, and along the first direction, the width of the first ferrite plate 4 and the second ferrite plate 5 is 4mm-8mm. In practice, by adjusting the magnetic field, the operating frequency band of the broadband beam splitter can be adjusted at a specific splitting ratio.

[0040] In practice, the broadband beam splitter further includes a first magnetic sheet and a second magnetic sheet arranged along a third direction, with the first magnetic sheet and the second magnetic sheet respectively attached to opposite sides of the second metal plate. Furthermore, the projections of the first and second magnetic sheets 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 medium channel 6, the second medium channel 7, and the third medium channel 8. Specifically, the first and second magnetic sheets can be ferromagnetic sheets.

[0041] In some embodiments, the first metal plate 1, the second metal plate 2, and the third metal plate 3 are made of copper, and the width of the first metal plate 1 and the second metal plate 2 along the first direction is 6 mm. Furthermore, 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 practice, by adjusting the width ratio of the second dielectric channel 7 to the third dielectric channel 8, the output power ratio between the first output waveguide and the second output waveguide can be adjusted. Furthermore, by fixing the width ratio of the second dielectric channel 7 to the third dielectric channel 8, wideband wave transmission can be achieved at a specific splitting ratio.

[0042] Specifically, see Figure 2 Along the first direction, the width of the first ferrite plate 4 and the second ferrite plate 5 is h2, and the width of the first dielectric channel 6 is h1. Along the second direction, the width of the first ferrite plate 4 and the second ferrite plate 5 is 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 with an outward strength of H perpendicular to the paper is applied to the first ferrite plate 4, and a magnetic field with an inward strength of H perpendicular to the paper is applied to the second ferrite plate 5.

[0043] See also Figure 3 ,exist Figure 3 (a) shows the two-dimensional structure of the output waveguide. Figure 3 (b) shows the output wave transmission dispersion diagram, where the first ferrite plate 4 applies a magnetic field with a magnetic field strength H of 715G, the thickness d1 of the air medium in the second dielectric channel 7 is 6mm, and the width h3 of the first ferrite plate 4 is 6mm. Figure 3 The red curve in (b) represents the transmission characteristics of the unidirectional output wave, and the yellow shaded area represents the unidirectional area of the forward transmission of the electromagnetic wave, which has a theoretical range of 0.9ω.m -1.4ω m , that is, the bandwidth is 0.5ω m .

[0044] exist Figure 3 (c) shows the two-dimensional structure of the input waveguide. Figure 3 (c) shows the transmission dispersion diagram of the input wave, where the first ferrite plate 4 and the second ferrite plate 5 apply magnetic fields with opposite directions and magnetic field strength H of 715G respectively. The thickness of the air dielectric layer in the first dielectric channel 6 is 6mm, and the thickness d of the first ferrite plate 4 and the second ferrite plate is 6mm. Figure 3 In (d), the red curve represents the odd mode, the blue curve represents the even mode, and the yellow shaded area represents the unidirectional region of forward electromagnetic wave transmission, with a theoretical range of 0.9ω m -1.4ω m , that is, the bandwidth is 0.5ω m .

[0045] exist Figure 3 Based on the transmission spectrum of the first output waveguide and the second output waveguide in the entire unidirectional range, the total transmission spectrum as a function of frequency is shown as follows: Figure 4 As shown. Figure 4 It can be seen that when the widths of the second medium channel 7 and the third medium channel 8 are both 6 mm, the broadband beam splitter is symmetrical in the upper and lower structures, and behaves as an evenly splitting beam splitter, and the first output waveguide and the second output waveguide can achieve a 50:50 0.5ω m The entire unidirectional bandwidth is within the range, and the transmission efficiency is close to 100%, and the operating frequency range is 4.5GHz-7GHz.

[0046] In some embodiments, an unequal splitting ratio can be achieved by breaking the structural symmetry, for example Figure 4 On the basis of keeping other parameters unchanged, adjusting the width d2 of the third medium channel 8 can achieve different splitting ratios of the width beam splitter in the first output waveguide and the second output waveguide, such as Figure 5 shown.

[0047] In some embodiments, Figure 3 and Figure 5 Based on the above, the broadband beam splitting transmission spectra when the width of the third medium channel 8 is adjusted to 9.2 mm and 11.3 mm are respectively as follows: Figure 6 (a) in Figure 6 As shown in (b) in the figure. Figure 6 (a) and Figure 6 As can be seen from (b), the first output waveguide and the second output waveguide can achieve unidirectional bandwidths of 67:33 and 75:25, respectively, accounting for 70% and 66% of the total bandwidth, respectively.

[0048] In some embodiments, Figure 6 Based on the above, the magnetic field strengths of the first ferrite plate 4 and the second ferrite plate 5 are adjusted to 536G and 1072G, respectively. The transmission spectra of the first output waveguide and the second output waveguide in the entire unidirectional range and the total transmission spectrum as a function of frequency are shown as follows: Figure 7 (a) in Figure 7 (b) Figure 7 (c) Figure 7 As shown in (d) in the figure. Figure 7 (a) in Figure 7 (b) Figure 7 (c) Figure 7 As can be seen from (d) in the figure, when the width of the third dielectric 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, respectively, accounting for 70% and 66% of the entire bandwidth, and the transmission efficiency is also close to 100%, which is consistent with the magnetic field strength of 715 G. However, the operating frequency bands when the strength is H = 536 G and H = 1072 G are 4.5 GHz-7 GHz and 5.5 GHz-8 GHz, respectively, further demonstrating that the operating frequency band can be controlled by changing the magnetic field.

[0049] While the embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations of these embodiments are possible. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as set forth in the claims. Furthermore, the invention described herein is susceptible to other embodiments and may be practiced or implemented in a variety of ways.

Claims

1. A broadband beam splitter based on a unidirectional mode, characterized in that: include: An input waveguide formed by 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 formed by a first metal plate, a first ferrite plate, a second dielectric channel and a third metal plate along the second direction; a second output waveguide formed by 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 and form a T-shaped branch, and a current excitation source is provided near the center of the opening side of the first dielectric channel; the first ferrite plate and the second ferrite plate are respectively located in magnetic field environments of the same size and opposite directions; the first direction and the second direction are perpendicular to each other; it also 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 adhered 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.

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 size of 536G-1072G, along the first direction, the width of the first ferrite plate and the second ferrite plate is 4mm~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 material of the first ferrite plate and the second ferrite plate is yttrium iron garnet, and the characteristic circular frequency of the yttrium iron garnet is 2π×5×10 9 rad / s, and a relative dielectric constant of 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 material of the first metal plate and the second metal plate is copper.

4. 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 medium channel along the second direction is 6 mm and the width of the third medium channel is 6 mm, the splitting ratio of the broadband beam splitter at the second medium channel and the third medium 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 medium channel along the second direction is 6 mm and the width of the third medium channel is 9.2 mm, the splitting ratio of the broadband beam splitter at the second medium channel and the third medium channel is 67:

33.

6. 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 medium channel along the second direction is 6 mm and the width of the third medium channel is 11.3 mm, the splitting ratio of the broadband beam splitter at the second medium channel and the third medium channel is 75:

25.

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

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