阅读说明：本技术 一种基于楔形波导膜片的波导到微带同向转换结构 (Waveguide-microstrip homodromous conversion structure based on wedge-shaped waveguide diaphragm ) 是由 张勇 吴成凯 曹天豪 延波 于 2021-07-30 设计创作，主要内容包括：本发明属于毫米波及太赫兹频段波导到微带线的转换结构技术领域,具体提供一种基于楔形波导膜片的波导到微带同向转换结构,用以解决现有波导到微带同向转换结构存在的输入和输出呈正交配置的问题；本发明通过在输入标准波导的末端增加终端短路的增高波导,并在增高波导中横向插入楔形波导膜片来形成超紧凑U型弯,借此将电磁波的传播方向旋转90度,从而实现波导到微带的同向共线转换,并且所引入的楔形波导膜片不仅参与阻抗匹配,同时有效抑制U型弯的寄生谐振模式,从而拓展转换结构的带宽；基于此,本发明具有结构简单紧凑、加工方便等优点,且有效提高转换性能,在混频器、倍频器、检波器和放大器等功能模块的设计中具有很好的实用价值。(The invention belongs to the technical field of conversion structures from millimeter wave and terahertz frequency band waveguides to microstrip lines, and particularly provides a waveguide-to-microstrip homodromous conversion structure based on a wedge-shaped waveguide diaphragm, which is used for solving the problem that the input and the output of the conventional waveguide-to-microstrip homodromous conversion structure are orthogonally configured; according to the invention, the heightening waveguide with the short-circuited terminal is added at the tail end of the input standard waveguide, and the wedge-shaped waveguide diaphragm is transversely inserted into the heightening waveguide to form the ultra-compact U-shaped bend, so that the propagation direction of the electromagnetic wave is rotated by 90 degrees, the co-directional and co-linear conversion from the waveguide to the microstrip is realized, and the introduced wedge-shaped waveguide diaphragm not only participates in impedance matching, but also effectively inhibits the parasitic resonance mode of the U-shaped bend, thereby expanding the bandwidth of the conversion structure; based on the advantages, the invention has the advantages of simple and compact structure, convenient processing and the like, effectively improves the conversion performance, and has good practical value in the design of functional modules such as a frequency mixer, a frequency multiplier, a wave detector, an amplifier and the like.)

1. A waveguide-to-microstrip homodromous conversion structure based on a wedge waveguide diaphragm comprises: an input standard waveguide (1) and an output microstrip line structure; the microstrip-to-waveguide homodromous conversion structure is characterized by further comprising an input heightening waveguide (2), wherein the input heightening waveguide (2) is connected to the input standard waveguide (1), the tail end of the input heightening waveguide is provided with a short circuit surface, and a wedge-shaped waveguide diaphragm (3) is arranged in the input heightening waveguide (2) to enable the inside of the input heightening waveguide (2) to form an ultra-compact U-shaped bend along the propagation direction of electromagnetic waves; the output microstrip line structure is inserted into the input heightening waveguide (2) from the short circuit surface of the input heightening waveguide (2) along the center line of the input standard waveguide (1), and is arranged along the E surface of the input standard waveguide (1).

2. The wedge waveguide iris-based waveguide-to-microstrip homodyne transition structure of claim 1, wherein said output microstrip line structure comprises: the probe comprises a substrate (4), an E-plane probe (5), a matching microstrip (6) and a main microstrip (7), wherein the E-plane probe, the matching microstrip and the main microstrip are arranged on the substrate; the E-plane probe, the matching microstrip and the main microstrip are arranged along the central line of the input standard waveguide (1) and are connected in sequence.

3. Waveguide-to-microstrip homodromous conversion architecture based on a wedge waveguide diaphragm according to claim 1, characterized in that the input riser waveguide (2) has a broadside dimension a₁The narrow side height is b₁Length L of₁And A is₁/a＝1、b₁/b＝λ₁、L₁/b＝λ₂A is the broadside dimension of the input standard waveguide, b is the broadside dimension of the input standard waveguide, and a is 2b, λ₁The value range of (A) is 0.5-0.7, lambda₂The value range of (A) is 1.6-1.8.

4. The waveguide-to-microstrip homodromous transition structure based on a wedge waveguide diaphragm according to claim 1, characterized in that said wedge waveguide diaphragm (3) is formed by a rectangular diaphragm and a right-angled triangular diaphragm, wherein the right-angled triangular diaphragm is arranged facing the input standard waveguide; the width of the rectangular membrane is A₂A height of L₂The thickness is s, the distance between the rectangular diaphragm and the short-circuit surface of the input heightening waveguide is b₂And A is₂/a＝1、L₂/b＝λ₃、b₂/b＝λ₄、s/b＝λ₅，λ₃The value range of (A) is 0.7-0.9, lambda₄The value range of (A) is 0.5-0.7, lambda₅The value range of (A) is 0.05-0.1; the size of the right-angle side of the right-angle triangular diaphragm connected with the rectangular diaphragm is L₃The size of the right-angle side connected with the input heightening waveguide is L₄And L is₃/b＝λ₆、L₄/b＝λ₇，λ₆The value range of (A) is 0.5-0.9, lambda₇The value range of (A) is 0.5-0.9.

Technical Field

The invention belongs to the technical field of conversion structures from millimeter wave and terahertz frequency band waveguides to microstrip lines, and particularly relates to a waveguide-microstrip homodromous conversion structure based on a wedge-shaped waveguide diaphragm.

Background

In millimeter wave and terahertz frequency bands, standard waveguides are basically adopted by test equipment and component modules as interfaces and interconnection transmission lines to reduce loss; meanwhile, planar transmission lines such as microstrip lines or suspended microstrip lines are also widely used in order to facilitate interconnection with active devices. Since the waveguide and the microstrip line support different electromagnetic wave modes and have different characteristic impedances, it is necessary to realize the conversion of the electromagnetic wave from the waveguide (TE10 mode) to the microstrip (quasi-TEM mode); in all the waveguide-to-microstrip conversion structures, the E-plane probe is widely applied due to the characteristics of simple structure, wide frequency band, convenient processing and the like.

However, the input and output of the conventional waveguide-to-microstrip transition structure based on the E-plane probe are orthogonal (distributed at 90 °), which causes great inconvenience to actual circuit design, module test, and the like, and also increases the size of the circuit to some extent. Further, the same-direction conversion from the waveguide to the microstrip can be realized mainly by two types: the first mode is that special structures, such as a fin line structure, a fan-shaped structure, an air bridge and the like, are designed on a substrate to realize the same-direction conversion from a waveguide to a microstrip; however, designing these structures would undoubtedly increase the area of the circuit, and at the same time increase the loss of the circuit; meanwhile, the special structures often need special processes such as profile cutting, double-sided lithography, substrate drilling and the like, and the processes can greatly increase the complexity and manufacturing cost of circuit design and reduce the yield of circuits. The other mode is that a mode of waveguide gradual change bending is adopted, and a slow waveguide bending structure is adopted to adjust the port of the input waveguide and the output microstrip line to be on the same straight line; the mode is widely applied due to simple structure and easy operation; however, the gradual waveguide bend occupies a very large circuit area, which not only increases the waveguide loss, but also increases the module volume and weight.

Therefore, the traditional structure for converting the waveguide to the microstrip in the same direction is complex, so that the design cost of the circuit is increased; or bulky, occupying an excessive amount of circuit area.

Disclosure of Invention

The invention aims to provide a waveguide-to-microstrip homodromous conversion structure based on a wedge-shaped waveguide diaphragm aiming at the problems of complex structure or huge volume of the existing waveguide-to-microstrip homodromous conversion structure, so as to greatly simplify the design of waveguide-to-microstrip homodromous transition and improve the conversion performance.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a waveguide-to-microstrip homodromous conversion structure based on a wedge-shaped waveguide diaphragm inputs a standard waveguide 1 and outputs a microstrip line structure; the microstrip-to-waveguide homodromous conversion structure is characterized by further comprising an input heightening waveguide 2, wherein the input heightening waveguide 2 is connected to an input standard waveguide 1, the tail end of the input heightening waveguide is provided with a short circuit surface, and a wedge-shaped waveguide diaphragm 3 is arranged in the input heightening waveguide 2 so that an ultra-compact U-shaped bend is formed in the input heightening waveguide 2 along the electromagnetic wave propagation direction; the output microstrip line structure is inserted into the input heightening waveguide 2 from the short circuit surface of the input heightening waveguide 2 along the center line of the input standard waveguide 1, and the output microstrip line structure is arranged along the E surface of the input standard waveguide 1.

Further, the output microstrip line structure includes: the probe comprises a substrate 4, an E-plane probe 5, a matching microstrip 6 and a main microstrip 7, wherein the E-plane probe, the matching microstrip and the main microstrip are arranged on the substrate; the E-plane probe 5, the matching microstrip 6 and the main microstrip 7 are arranged along the central line of the input standard waveguide 1 and are connected in sequence.

Further, the input rib waveguide 2 has a broadside dimension A₁The narrow side height is b₁Length L of₁And A is₁/a＝1、b₁/b＝λ₁、L₁/b＝λ₂A is the broadside dimension of the input standard waveguide, b is the broadside dimension of the input standard waveguide, and a is 2b, λ₁The value range of (A) is 0.5-0.7, lambda₂The value range of (A) is 1.6-1.8.

Further, the wedge-shaped waveguide diaphragm 3 is formed by splicing a rectangular diaphragm and a right-angled triangular diaphragm, wherein the right-angled triangular diaphragm is arranged facing the input standard waveguide; the width of the rectangular membrane is A₂A height dimension of L₂The thickness is s, the distance between the rectangular diaphragm and the short-circuit surface of the input heightening waveguide is b₂And A is₂/a＝1、L₂/b＝λ₃、b₂/b＝λ₄、s/b＝λ₅，λ₃The value range of (A) is 0.7-0.9, lambda₄The value range of (A) is 0.5-0.7, lambda₅The value range of (A) is 0.05-0.1; the size of the right-angle side of the right-angle triangular diaphragm connected with the rectangular diaphragm is L₃The size of the right-angle side connected with the input heightening waveguide is L₄And L is₃/b＝λ₆、L₄/b＝λ₇，λ₆The value range of (A) is 0.5-0.9, lambda₇The value range of (A) is 0.5-0.9.

In terms of working principle:

in the waveguide-to-microstrip homodromous conversion structure based on the wedge-shaped waveguide diaphragm, the ultra-compact U-shaped bend is formed in the input heightening waveguide through the wedge-shaped waveguide diaphragm, and electromagnetic waves are input in TE₁₀The mode is fed from the input standard waveguide, and after passing through the wedge waveguide diaphragm, the propagation direction of the electromagnetic wave is rotated by 90 degrees; at the same time, the wedge waveguide diaphragm provides a waveguide sidewall for the E-plane probe, so that electromagnetic energy is efficiently coupled to the output microstrip through the E-plane probe. Furthermore, on the basis of the theory, the invention adopts the unique design that the rectangular diaphragm and the right-angled triangular diaphragm are spliced to form the wedge-shaped waveguide diaphragm, and the size of the heightened waveguide and the sizes of the rectangular diaphragm and the right-angled triangular diaphragm are matched and designed on the basis of the structure, thereby effectively reducing the volume of the resonant cavity at the ultra-compact U-shaped bend and greatly reducing the volume of the conversion structure; meanwhile, the structure of the invention effectively eliminates the parasitic resonance mode of the ultra-compact U-shaped bend at the high frequency band, avoids the problem that the conversion performance is seriously deteriorated due to the resonance caused when the parasitic resonance mode enters the required working frequency band, and simultaneously the wedge-shaped waveguide film provides a smooth transition for the coupling of the electromagnetic wave to the E-plane probe.

In conclusion, the beneficial effects of the invention are as follows:

the invention provides a waveguide-to-microstrip homodromous conversion structure based on a wedge-shaped waveguide diaphragm, which is characterized in that a section of heightened waveguide with a short-circuited terminal is added at the tail end of an input standard waveguide, and a wedge-shaped waveguide diaphragm is transversely inserted into the heightened waveguide to form an ultra-compact U-shaped bend, so that the propagation direction and the electric field of electromagnetic waves are rotated by 90 degrees, the homodromous collinear conversion from the waveguide to the microstrip is realized, the problem of direction orthogonality (90 degrees) between the traditional E-surface probe transition input waveguide and output microstrip is solved, and the introduced wedge-shaped waveguide diaphragm not only participates in impedance matching, but also effectively inhibits a parasitic resonance mode, thereby expanding the bandwidth of the conversion structure.

Based on the advantages, the invention has the advantages of simple and compact structure, convenient processing and the like, greatly simplifies the design of transition from the homodromous waveguide to the microstrip, improves the conversion performance, and has good practical value in the design of functional modules such as millimeter wave and terahertz frequency band mixers, frequency multipliers, detectors, amplifiers and the like.

Drawings

FIG. 1 is a schematic structural diagram of a waveguide-to-microstrip homodromous conversion structure based on a wedge-shaped waveguide diaphragm according to the present invention;

FIG. 2 is a cross-sectional view of a simulation model of a waveguide-to-microstrip homodromous conversion structure based on a wedge-shaped waveguide diaphragm along the E plane of a waveguide in the embodiment of the invention;

FIG. 3 is a diagram showing simulation results of a waveguide-to-microstrip homodromous conversion structure based on a wedge-shaped waveguide diaphragm in the embodiment of the present invention;

wherein, 1 is an input standard waveguide, 2 is an input heightening waveguide, 3 is a wedge-shaped waveguide diaphragm, 4 is a substrate, 5 is an E-plane probe, 6 is a matching microstrip, and 7 is a main microstrip.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments; it should be understood that the embodiments described herein are only for the purpose of illustrating the present invention and are not to be construed as limiting the present invention.

Example 1

In this embodiment, a waveguide-to-microstrip homodromous conversion structure based on a wedge waveguide diaphragm is provided, and its structure is shown in fig. 1, including: an input standard waveguide 1, an input heightening waveguide 2 and an output microstrip line structure; wherein, output microstrip line structure includes: the probe comprises a substrate 4, an E-plane probe 5, a matching microstrip 6 and a main microstrip 7, wherein the E-plane probe, the matching microstrip and the main microstrip are arranged on the substrate; the E-plane probe 5, the matching microstrip 6 and the main microstrip 7 are arranged along the central line of the input standard waveguide 1 and are connected in sequence; a wedge-shaped waveguide diaphragm 3 is arranged in the input heightening waveguide 2, so that an ultra-compact U-shaped bend is formed in the input heightening waveguide 2 along the propagation direction of electromagnetic waves, and the wedge-shaped waveguide diaphragm 3 is formed by splicing a rectangular diaphragm and a right-angled triangular diaphragm, wherein the right-angled triangular diaphragm is arranged facing an input standard waveguide; the E-plane probe 5 on the output microstrip line structure is inserted into the input heightening waveguide from the short-circuit plane of the input heightening waveguide 2 along the center line of the input standard waveguide 1, and the output microstrip line structure is arranged along the E-plane of the waveguide.

In the embodiment, a soft substrate Rogers 5880 is selected as a substrate 4, and a waveguide-to-microstrip homodromous conversion structure shown in FIG. 2 is established in field simulation software HFSS; the input standard waveguide is a standard WR10 waveguide with dimensions: 2.54mm (a) x 1.27mm (b); the input rib waveguide has a broadside dimension of A₁: 2.54mm, the height of the narrow side is b₁：0.73mm(λ₁0.575) and length L₁：0.92mm(λ₂1.732); the width of the rectangular membrane is A₂: 2.54mm and a height dimension L₂：1mm(λ₃0.787), thickness s: 100um (lambda)₄0.079), and the distance between the rectangular diaphragm and the short-circuited surface of the input booster waveguide is b₂：0.77mm(λ₅0.61), the size of the right-angle side of the right-angle triangular diaphragm connected with the rectangular diaphragm is L₃：0.8mm(λ₆0.63) and the dimension of the right-angle side connected with the input heightening waveguide is L₄：1mm(λ₇0.787); in addition, in the above structure for converting the waveguide into the microstrip homodromous direction, the length L of the standard waveguide is input₀The homodromous conversion structure is not influenced, and only needs to be freely selected in the environment meeting the practical device application, namely L in the embodiment₀5 mm; the thickness (height) of the rectangular membrane is as thin as possible under the premise of meeting the processing precision requirement and mechanical strength, and is 100um in the embodiment.

Based on the above model, the simulation is performed on the microstrip homodromous conversion structure of the waveguide in this embodiment, and the simulation result of the S parameter is shown in fig. 3, which can be seen from the following figure: in the whole W frequency band, the return loss is better than 20dB, the insertion loss is better than 0.2dB, the output characteristic is flat, and no resonance point exists; therefore, the invention realizes the homodromous output from the waveguide to the microstrip and solves the problem of converting the traditional waveguide to the microstrip in different directions; the invention has simple and compact structure and is beneficial to reducing the volume of a circuit and a system.

While the invention has been described with reference to specific embodiments, any feature disclosed in this specification may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise; all of the disclosed features, or all of the method or process steps, may be combined in any combination, except mutually exclusive features and/or steps.