A compact high-power dual-layer coaxial waveguide power divider

Abstract

The application discloses a compact high-power multilayer coaxial waveguide power divider, and belongs to the field of high-power mode power distribution. The power divider comprises an upper layer coaxial radial power division structure, a lower layer coaxial radial power division structure and a variable inner diameter coaxial line structure. The upper layer coaxial radial power division structure comprises n upper layer output ports, the lower layer coaxial radial power division structure comprises n lower layer output ports, and the variable inner diameter coaxial line structure is used for introducing part of power of an upper layer coaxial input port input signal into a lower layer coaxial line part, and the remaining power enters an upper layer radial line part. Signals entering the upper layer radial line part are equally divided into n paths of output, and signals entering the lower layer coaxial line part are equally divided into n paths of output through a lower layer radial line part. The application can break through the restriction of the number of radial power division, introduce more power division paths in a limited radial radius, and has the advantages of low loss, high power capacity and more compact structure compared with a single layer radial power division system under the premise of the same number of power division.

Description

Technical Field

[0001] This invention belongs to the field of high-power mode power distribution, specifically relating to a compact high-power dual-layer coaxial waveguide power divider. Background Technology

[0002] With the development of technologies such as pulsed power, plasma physics, and vacuum electronics, high-power microwave systems are increasingly common in industrial production and radio broadcasting. They also have wide applications in military fields such as directed energy weapons and electronic warfare. To enhance their lethality, research has been continuously focused on higher power levels; therefore, increasing the power capacity of microwave systems has always been a key objective in microwave development. High-power microwave systems have significant power distribution requirements. For example, in antenna feeding or phased array systems, it is often necessary to distribute the input signal to each subarray element. This requires the use of several power dividers combined into a feeding network. In conventional array antennas, the number of power dividing ports often reaches hundreds or more. Therefore, increasing the number of power dividing paths in a power divider has always been a development direction. Furthermore, in some applications, antenna arrays require different subarray feed signals, such as using amplitude weighting to reduce the sidelobe level of the array antenna. This means that the output signals of the power dividers are fed into the antenna array with unequal amplitudes. The above two types of power dividers are distinguished by energy distribution: equal-division power dividers and unequal-division power dividers. In high-power microwave systems, power dividers are widely used and indispensable.

[0003] A power divider is a microwave device that can split a single microwave signal into multiple signals. It plays a crucial role in systems requiring power distribution, and is particularly important in high-power microwave systems. Currently, common power dividers include microstrip line dividers and stripline power dividers, such as the popular Wilkinson microstrip line transmitter. Figure 8 As shown, the Wilkinson power divider, typically a tree-like structure with a 1-to-2 split, is a common type of power divider. It has an insertion loss of approximately -6.5 dB and an output port isolation of -15 dB. It features good amplitude and phase characteristics and a simple design, making it widely used in practical engineering. However, microstrip power dividers are generally thin, making them prone to breakdown when the input power increases. Furthermore, the dielectric of the substrate composing the microstrip line has lower breakdown resistance than vacuum, further reducing its power capacity. Therefore, microstrip lines are difficult to use in high-power systems.

[0004] Unlike microstrip linear power dividers, metallic waveguides offer superior heat dissipation and, due to their vacuum-like internal structure, can withstand higher breakdown field strengths, making them more suitable for transmitting high-power microwaves. Therefore, metallic waveguide power dividers are more common in high-power microwave systems. A commonly used waveguide power divider is the T-type, which boasts a reflection coefficient of less than -25dB, excellent transmission performance, and good port isolation. However, if… Figure 7 As shown, this type of power divider can only achieve two-way power division. When applied to multi-way scenarios, it can only be cascaded, such as... Figure 8 To achieve a four-way power splitter, three T-waveguide power dividers are needed, arranged in two stages: one T-waveguide in the first stage and two T-waveguides in the second stage. Calculations show that achieving an n-way power splitter requires n-1 T-waveguides. In applications requiring a large number of T-waveguides, the number of T-waveguides and cascade layers must be increased. During cascading, as the number of T-waveguides increases, system losses also increase. Furthermore, with increasing cascade levels, secondary T-waveguides may generate reflection modes and potentially create resonance within the preceding stages, disrupting the overall transmission performance. Additionally, the system size increases exponentially. Therefore, T-waveguide power splitters perform well with a small number of power splitters but are not suitable for large numbers of power splitters.

[0005] In high-power microwave systems requiring multiple power divisions, coaxial radial power dividers outperform cascaded T-waveguides. The coaxial waveguide radial power divider structure simultaneously decomposes the input signal into several radial propagation modes, effectively reducing losses compared to cascaded systems. Furthermore, the coaxial waveguide's primary transmission mode is the TEM mode, exhibiting cylindrical symmetry, which facilitates consistent phase and amplitude of the output modes at each port. As a metallic waveguide, it also offers superior heat dissipation compared to microstrip lines. In recent years, my country has made significant progress in research on coaxial waveguide-based radial power dividers. Existing multipath radial power dividers achieve insertion loss of less than 0.3 dB and output imbalance of less than 0.5 dB in the 2.55-3.15 GHz frequency range, while also possessing advantages such as low loss, simple structure, and good heat dissipation. The volume of a coaxial waveguide radial line power divider system is related to the output port size and the number of power dividers. Although coaxial radial line waveguides are more suitable for high-power-divider systems than T-type systems, when the power divider requirement is particularly high, such as in large-array antennas, using a coaxial radial line power divider structure can also bring some problems to the system. A power divider count in the hundreds results in a huge radial radius of the power divider and a large system volume. While cascading a T-type power divider after using a radial line power divider can reduce the size of the radial line power divider to some extent, the cascading process introduces cascading losses into the system and disrupts the consistency of the output mode, causing the characteristic of coaxial power dividers to lose their ability to output equal amplitude and in-phase power at the output ports. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a dual-layer radial power divider structure based on a coaxial waveguide radial power divider. This invention overcomes the limitations of radial power divider capacity, enabling the introduction of more power divider paths within a finite radial radius. Furthermore, compared to a single-layer radial power divider system, it offers a more compact structure with the same number of power dividers, and boasts advantages such as low loss and high power capacity.

[0007] The technical solution of the present invention is as follows:

[0008] A compact, high-power dual-layer coaxial waveguide radial power divider includes: an upper coaxial radial power divider structure, a lower coaxial radial power divider structure, and a variable inner diameter coaxial line structure.

[0009] The upper coaxial radial power divider structure includes an upper coaxial line portion and an upper radial line portion; wherein, the upper coaxial line portion includes an upper coaxial input port; and the upper radial line portion includes n upper output ports;

[0010] The lower-level coaxial radial power divider structure includes a lower-level coaxial line portion and a lower-level radial line portion; wherein, the lower-level coaxial line portion includes a lower-level coaxial input port; and the lower-level radial line portion includes n lower-level output ports;

[0011] The variable inner diameter coaxial line structure is used to introduce part of the power of the input signal from the upper coaxial input port into the lower coaxial line section, while the remaining power enters the upper radial line section; the signal entering the upper radial line section is divided into n outputs, and the signal entering the lower coaxial line section is also divided into n outputs through the lower radial line section.

[0012] Furthermore, the variable inner diameter coaxial line structure is a coaxial structure with a constant outer diameter and a gradually decreasing inner diameter. The outer side of the variable inner diameter coaxial line structure is connected to the lower inner region of the upper coaxial line portion, and the lower end face is connected to the lower coaxial input port.

[0013] Furthermore, the slope of the inner surface of the variable inner diameter coaxial line structure is 1.45 to 1.6. If the slope is too small, the transmission coefficient of the entire double-layer coaxial waveguide radial power divider will deteriorate, and the system will generate large reflections. If the slope is too large, it will make it difficult for the variable inner diameter coaxial line structure to introduce the input power of the upper coaxial port into the lower coaxial line section.

[0014] Furthermore, the difference between the inner and outer diameters of the upper coaxial input port is R. a The difference between the inner and outer diameters of the lower coaxial input port is R. b When the upper coaxial input port inputs half of the power to the lower coaxial cable section for transmission, then R b >R aThe reason is that when the input signal from the upper coaxial input port introduces half of the power into the lower coaxial line section for transmission, it cannot all be channeled into the lower radial line section. The signal that is not channeled into the lower radial line section will interfere with the distribution of the variable inner diameter coaxial line structure, thereby increasing the power channeled into the upper radial line section. Therefore, increasing the difference between the inner and outer diameters of the lower coaxial input port makes it easier for the lower coaxial line section to transmit signals to the lower radial line section.

[0015] Furthermore, when the upper coaxial input port transmits half of its power to the lower coaxial line section, the height L2 of the variable inner diameter coaxial line structure connected to the upper coaxial line section is greater than the difference R between the inner and outer diameters of the upper coaxial input port. a And L2 < 1.5*R a .

[0016] Furthermore, by controlling the height L2 of the variable inner diameter coaxial cable structure connected to the upper coaxial cable, the slope of the inner surface of the variable inner diameter coaxial cable structure, and the difference R between the inner and outer diameters of the lower coaxial input port, the system can achieve the desired effect. b It can change the power ratio of the lower coaxial cable section.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. Existing single-layer radial power dividers, due to the direct proportional relationship between radial radius and the number of power outputs, have a limiting radial radius to maintain a small size, thus restricting the number of power outputs. The power divider of this invention employs a double-layer structure, which, compared to a single-layer structure, allows for a smaller radial radius while maintaining the same number of output ports, resulting in a more compact design and smaller size.

[0019] 2. Without sacrificing a large amount of power capacity, the present invention can achieve more power distribution port outputs and the transmission efficiency can reach 99.9%; and the present invention also has good phase stability for output modes.

[0020] 3. Generally, the consistent phase amplitude at the output port of a coaxial power divider is one of its advantages over T-type, Y-type, or other power dividers, ensuring greater uniformity of the antenna feed. However, in some applications, such as unequal amplitude feed systems, the output port signal requires cascaded amplitude modulation devices, which undoubtedly adds complexity to the engineering. The coaxial section of the power divider in this invention exhibits better power distribution, achieved by controlling the height L2 of the variable inner diameter coaxial line structure connected to the upper coaxial line, the slope of the inner surface of the variable inner diameter coaxial line structure, and the difference R between the inner and outer diameters of the lower coaxial input port. b It enables free adjustment of the power ratio between upper and lower layers, providing convenience for the application of coaxial power dividers in unequal amplitude feed systems. Attached Figure Description

[0021] Figure 1 This is a model of a two-layer coaxial power divider.

[0022] Figure 2 This is a cross-sectional view of a double-layer coaxial power divider.

[0023] Figure 3 This is a cross-sectional view of a two-layer coaxial power divider.

[0024] Figure 4 This is a schematic diagram of the structural parameters of a double-layer coaxial power divider.

[0025] Figure 5 This is a schematic diagram for calculating the radial radius of a radial power divider.

[0026] Figure 6 This is a comparison chart of the number of channels in a dual-layer coaxial power divider and the size of a single-layer power divider (left: dual-layer eight-channel waveguide; right: single-layer sixteen-channel waveguide).

[0027] Figure 7 This is a structural diagram of a Wilkinson power divider.

[0028] Figure 8 A schematic diagram of a four-way power divider implemented using a two-stage T-type waveguide arrangement.

[0029] Figure 9 The image shown is an example of the correlation calculation between the transmission coefficient and L1.

[0030] Figure 10 The transmission characteristic curve of the port of the dual-layer coaxial power divider is shown in the example.

[0031] Figure 11 The field strength distribution of the dual-layer coaxial power divider under a 3.5GW input is shown in the example.

[0032] Figure 12 The output port phase curve of a single-layer eight-channel coaxial power divider is shown in the example.

[0033] The following are the annotations for the diagram: 1. Upper coaxial radial power distribution structure; 11. Upper coaxial line section; 12. Upper radial line section; 13. Upper first-order chamfer; 14. Upper second-order chamfer; 2. Lower coaxial radial power distribution structure; 21. Lower coaxial line section; 22. Lower radial line section; 23. Lower first-order chamfer; 24. Lower second-order chamfer; 25. Right-angle step; 3. Variable inner diameter coaxial line structure. Detailed Implementation

[0034] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] This embodiment presents a compact, high-power, dual-layer coaxial waveguide radial power divider, such as... Figure 1-3As shown, it includes: an upper coaxial radial power distribution structure, a lower coaxial radial power distribution structure, and a variable inner diameter coaxial line structure.

[0036] The upper coaxial radial power divider structure includes an upper coaxial line section and an upper radial line section; wherein, the upper coaxial line section includes an upper coaxial input port; the upper radial line section includes eight upper output ports, and a second-order chamfer transition is provided at the lower corner of the upper radial line section to improve the transmission performance of the upper coaxial radial power divider structure.

[0037] The lower-level coaxial radial power divider structure includes a lower-level coaxial line portion and a lower-level radial line portion. The lower-level coaxial line portion includes a lower-level coaxial input port. The lower-level radial line portion includes eight lower-level output ports, and a second-order chamfer transition is provided at the lower corner of the lower-level radial line portion to improve the transmission performance of the lower-level coaxial radial power divider structure. In addition, a right-angle step is provided at the beginning of the first-order chamfer to further improve the transmission performance of the lower-level coaxial portion merging into the lower-level radial line portion.

[0038] The variable inner diameter coaxial line structure is a coaxial structure with a constant outer surface radius and a gradually decreasing inner surface radius. The outer surface of the variable inner diameter coaxial line structure is connected to the lower inner region of the upper coaxial line section, and the lower end face is connected to the lower coaxial input port. This is used to introduce half of the power of the input signal from the upper coaxial input port into the lower coaxial line section, while the remaining half of the power enters the upper radial line section. The signal entering the upper radial line section is divided into 8 output channels, and the signal entering the lower coaxial line section is also divided into 8 output channels through the lower radial line section.

[0039] like Figure 4 As shown, the structural dimensions in this embodiment are as follows: R1 = 20mm, R2 = 30mm, R3 = 9.6mm, L1 = 6.5mm, L2 = 13mm, m1 = 9.5mm, n1 = 6mm, m2 = 1mm, n2 = 6mm, m3 = 7mm, n3 = 5mm, m4 = 1mm, n4 = 3mm, m5 = 1mm, n5 = 0.6mm, m6 = 15mm, n6 = 10.4mm, b = 10mm.

[0040] Figure 5 This is a schematic diagram for calculating the radial radius of a radial power divider, where 'a' is the length of the wide side of the rectangular output port, a = 30 mm, and the radial radius R... i It is related to the width 'a' of the rectangular port and the corresponding central angle 'θ' of the rectangular port, and can be calculated using trigonometric functions. The central angle θ corresponding to the rectangular port is related to the number of power distribution channels n, and θ = 360 / n.

[0041] Figure 6This image compares the size of a dual-layer coaxial power divider with the same number of output channels as a single-layer power divider (left: dual-layer eight-channel coaxial power divider; right: single-layer sixteen-channel coaxial power divider). With both having sixteen output channels, the power divider in the left image has n=8 per layer, and its radial area is significantly smaller than that of the right image. Figure 10 1 / 4 of a six-channel power divider.

[0042] Figure 10 The figure shows the port transmission characteristic curves of a dual-layer coaxial power divider as an example. This figure indicates that the transmission coefficient of the output port of the dual-layer eight-channel coaxial power divider is distributed at approximately -12.05dB, which is close to perfect transmission performance (-12dB).

[0043] Figure 11 The figure shows the field strength distribution of a dual-layer coaxial power divider under a 3.5GW input. It demonstrates that the dual-layer eight-channel coaxial power divider did not experience breakdown under a 3.5GW input, indicating that its power capacity can reach 3.5GW.

[0044] Figure 12 The figure shows the phase curves of the output ports of a single-layer eight-channel coaxial power divider as an example. This figure demonstrates that the output ports of a traditional coaxial radial power divider have good phase consistency.

[0045] When the radial radius of the upper radial power divider structure is R1 = 20mm and R2 = 30mm, the chamfer parameters m1, m2, n1, n1 are adjusted to match the radial radius. Changing the chamfer slope of the coaxial power divider structure (m6 and n6), the distance L1 between the coaxial power divider structure and the input coaxial port, and the height L2 of the variable inner diameter coaxial line structure connected to the upper coaxial line, can change the input power of the lower radial power divider structure. Therefore, by adjusting L1, L2, m6, and n6, the proportion of the lower layer's transmitted power within the input power can be changed, thereby adjusting the transmission efficiency of the upper and lower output ports to a certain ratio. When the upper and lower port outputs are consistent, this structure can achieve two-port power division. n6 is related to the inner diameter of the lower radial power divider coaxial line, and n6 = R1 - R3. With m6, n6, and L2 unchanged, adjusting L1 yields the following results: Figure 9 As shown, adjusting the L1 parameter can change the power ratio between the upper and lower layer ports.

Claims

1. A compact, high-power, double-layer coaxial waveguide radial power divider, characterized in that, include: Upper coaxial radial power distribution structure, lower coaxial radial power distribution structure, variable inner diameter coaxial line structure; The upper coaxial radial power divider structure includes an upper coaxial line portion and an upper radial line portion; wherein, the upper coaxial line portion includes an upper coaxial input port; and the upper radial line portion includes n upper output ports; The lower-level coaxial radial power divider structure includes a lower-level coaxial line portion and a lower-level radial line portion; wherein, the lower-level coaxial line portion includes a lower-level coaxial input port; and the lower-level radial line portion includes n lower-level output ports; The variable inner diameter coaxial line structure is used to introduce part of the power of the input signal from the upper coaxial input port into the lower coaxial line section, while the remaining power enters the upper radial line section; the signal entering the upper radial line section is divided into n outputs, and the signal entering the lower coaxial line section is also divided into n outputs through the lower radial line section. The variable inner diameter coaxial line structure is a coaxial structure with a constant outer diameter and a gradually decreasing inner diameter. The outer side of the variable inner diameter coaxial line structure is connected to the lower inner region of the upper coaxial line section, and the lower end face is connected to the lower coaxial input port.

2. A compact high-power double-layer coaxial waveguide radial power divider as described in claim 1, characterized in that, The slope of the inner surface of the variable inner diameter coaxial structure is 1.45 to 1.

6.

3. A compact high-power double-layer coaxial waveguide radial power divider as described in claim 2, characterized in that, The difference between the inner and outer diameters of the upper coaxial input port is R. a The difference between the inner and outer diameters of the lower coaxial input port is R. b When the upper coaxial input port inputs half of the power to the lower coaxial cable section for transmission, then R b >R a .

4. A compact high-power double-layer coaxial waveguide radial power divider as described in claim 2 or 3, characterized in that, When the upper coaxial input port transmits half of its power to the lower coaxial line section, the height L2 of the variable inner diameter coaxial line structure connected to the upper coaxial line section is greater than the difference R between the inner and outer diameters of the upper coaxial input port. a And L2 < 1.5*R a .

5. A compact high-power double-layer coaxial waveguide radial power divider as described in claim 4, characterized in that, By controlling the height L2 of the variable inner diameter coaxial cable structure connected to the upper coaxial cable, the slope of the inner surface of the variable inner diameter coaxial cable structure, and the difference R between the inner and outer diameters of the lower coaxial cable input port, the following parameters are used: b It can change the power ratio of the lower coaxial cable section.

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