75-ohm broadband four-ridge orthogonal mode coupler

Abstract

The utility model provides a 75-ohm broadband four-ridge orthogonal mode coupler, and relates to the field of four-ridge orthogonal mode couplers. One of each pair of ridge sheets of the coupler is provided with a through hole, and the ratio of the diameter of the through hole to the diameter of the coaxial probe is 3.444-3.544; the coaxial probe is arranged in the through hole in a penetrating mode, and the end portion of the coaxial probe extends into the matching hole and is connected with the bottom of the matching hole. According to the coupler, the ratio of the diameter of the outer conductor to the diameter of the inner conductor of the coaxial input end is set to be 3.444-3.544, it is guaranteed that the input impedance value is about 75 ohms, and therefore the coupler can be suitable for the output occasion with the impedance value of 75 ohms. By arranging the matching holes at the joints of the coaxial probes and the opposite ridge pieces, the capacitive reactance between the coaxial probes and the ridge pieces is increased, part of inductive reactance is offset, impedance matching is improved, and effective propagation of energy is facilitated.

Description

Technical Field

[0001] This utility model relates to the technical field of four-ridge orthogonal mode couplers, and more specifically, to a 75-ohm broadband four-ridge orthogonal mode coupler. Background Technology

[0002] A quadrature-mode transducer (OMT) can separate or mix two orthogonally polarized signals and is an important component of satellite communication and radio astronomy feed systems. An OMT has a common port that transmits two orthogonal master mode signals. After passing through the OMT, these two master mode signals are transmitted to the respective single-mode signal ports, with high polarization isolation between the two signals.

[0003] OMT implementation structures include finned structures, four-ridge structures, and traditional cross-shaped rotating structures. Among them, the four-ridge structure mainly comes in two forms: one is a gradient structure, which requires short-circuit pins and absorbing materials at the rear of the OMT structure; the other is a straight cylindrical structure, which does not require short-circuit pins and absorbing materials. Both structures have superior performance in all aspects, especially in terms of reflection loss and isolation.

[0004] However, the existing four-ridged orthogonal mode coupler is only suitable for applications with a 50-ohm impedance output, and not for applications with other impedance outputs. Utility Model Content

[0005] The purpose of this invention is to provide a 75-ohm broadband four-ridge orthogonal mode coupler to solve the technical problem that existing four-ridge orthogonal mode couplers are only suitable for output with an impedance value of 50 ohms and not suitable for output with other impedance values.

[0006] The 75-ohm broadband four-ridge orthogonal mode coupler provided by this utility model includes a cylindrical shell and four ridges disposed on the cylindrical shell. The four ridges are arranged opposite each other in pairs, and the two pairs of ridges are orthogonal. In each pair of ridges, one ridge is provided with a through hole, and the ratio of the diameter of the through hole to the diameter of the coaxial probe is in the range of 3.444-3.544. The other ridge is provided with a matching hole, and the coaxial probe passes through the through hole. The end of the coaxial probe extends into the matching hole and is connected to the bottom of the matching hole.

[0007] Furthermore, the ratio of the diameter of the through hole to the diameter of the coaxial probe is 3.494.

[0008] Furthermore, the depth of the matching hole is 0.00875λ, and the diameter is 0.01λ, where λ is the center wavelength of the design band.

[0009] Furthermore, the minimum spacing between the two opposing ridges ranges from 0.025λ to 0.0275λ.

[0010] Furthermore, the minimum distance between the two opposing ridges is 0.0275λ.

[0011] Furthermore, the shape change curve of the spine is a sine function to the power of 1.75.

[0012] Furthermore, the ratio of the diameter of the coaxial probe to the thickness of the ridge is in the range of 1 / 5 to 1 / 4.

[0013] Furthermore, the ratio of the diameter of the coaxial probe to the thickness of the ridge is in the range of 0.235.

[0014] Furthermore, the axial length of the 75-ohm broadband four-ridge orthogonal mode coupler ranges from 4.025λ to 4.05λ.

[0015] Furthermore, the thickness of the ridge plate ranges from 0.0385λ to 0.05λ.

[0016] The 75-ohm broadband four-ridge orthogonal mode coupler provided by this utility model can produce the following beneficial effects:

[0017] The 75-ohm broadband four-ridge orthogonal mode coupler provided by this utility model sets the ratio of the diameter of the through hole in one of the opposing ridges to the diameter of the coaxial probe to 3.444-3.544, that is, the ratio of the diameter of the outer conductor and the inner conductor of the coaxial input terminal to 3.444-3.544, ensuring that the input impedance is about 75 ohms. Thus, the four-ridge orthogonal mode coupler can be used in output applications with an impedance of 75 ohms.

[0018] Furthermore, by setting a matching hole in the other ridge of each pair of opposing ridges, and connecting the insertion end of the coaxial probe to the bottom of the matching hole, the capacitive reactance between the coaxial probe and the ridge can be increased, and part of the inductive reactance can be offset. This can improve the impedance matching between the coaxial probe and the ridge, which is beneficial for the efficient propagation of energy between the two. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1A schematic diagram of the structure of the 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment of the present invention;

[0021] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0022] Figure 3 A schematic diagram of the 75-ohm broadband four-ridge orthogonal mode coupler provided in an embodiment of this utility model, wherein hidden lines are shown;

[0023] Figure 4 A top view of the 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment of the utility model;

[0024] Figure 5 for Figure 4 Enlarged view of point B in the middle;

[0025] Figure 6 A schematic diagram of the cross-section of the coaxial probe of the 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment of the utility model;

[0026] Figure 7 for Figure 6 Enlarged view of point C in the middle;

[0027] Figure 8 The reflection loss curve of the 75-ohm broadband four-ridge orthogonal mode coupler provided in the embodiment of this utility model in the L-band;

[0028] Figure 9 The isolation curve of the 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment of the utility model in the L-band.

[0029] Explanation of reference numerals in the attached figures:

[0030] 100-Cylinder shell;

[0031] 200 - Ridge; 210 - Through hole; 220 - Matching hole;

[0032] 300-coaxial probe. Detailed Implementation

[0033] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit it.

[0034] This embodiment provides a 75-ohm broadband four-ridge orthogonal mode coupler. Figure 1 This is a schematic diagram of the 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment. Figure 2for Figure 1 Enlarged view of point A in the middle; Figure 3 This is a schematic diagram of the structure of the 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment when the hidden lines are displayed. Figure 4 This is a top view of the 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment. Figure 5 for Figure 4 Enlarged view of point B in the middle; Figure 6 This is a schematic diagram of the cross-section of the coaxial probe of the 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment. Figure 7 for Figure 6 Enlarged diagram of point C in the middle.

[0035] like Figures 1 to 7 As shown, the 75-ohm broadband four-ridge orthogonal mode coupler includes a cylindrical shell 100 and four ridges 200 disposed on the cylindrical shell 100. The four ridges 200 are arranged opposite each other in pairs, and the two pairs of ridges 200 are orthogonal. In each pair of ridges 200, one ridge 200 is provided with a through hole 210, and the ratio of the diameter of the through hole 210 to the diameter of the coaxial probe 300 is in the range of 3.444-3.544. The other ridge 200 is provided with a matching hole 220, and the coaxial probe 300 passes through the through hole 210. The end of the coaxial probe 300 extends into the matching hole 220 and is connected to the bottom of the matching hole 220.

[0036] The 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment ensures an input impedance of approximately 75 ohms by setting the ratio of the diameter of the through hole 210 of one of the opposing ridges 200 to the diameter of the coaxial probe 300 to 3.444-3.544. That is, by setting the ratio of the diameter of the outer conductor and the inner conductor of the coaxial input terminal to 3.444-3.544. This makes the four-ridge orthogonal mode coupler suitable for output applications with an impedance of 75 ohms.

[0037] Furthermore, by providing a matching hole 220 in another ridge 200 of each pair of opposing ridges 200, and connecting the insertion end of the coaxial probe 300 to the bottom of the matching hole 220, the capacitive reactance between the coaxial probe 300 and the ridge 200 can be increased, and part of the inductive reactance can be offset. This can improve the impedance matching between the coaxial probe 300 and the ridge 200, which is beneficial for the efficient propagation of energy between them.

[0038] Specifically, in this embodiment, the ratio of the diameter of the through-hole 210 to the diameter of the coaxial probe 300 is 3.494. This ratio provides better matching between the coupler and devices with a 75-ohm impedance.

[0039] In this embodiment, the depth of the matching hole 220 is 0.00875λ and the diameter is 0.01λ, where λ is the center wavelength of the design band.

[0040] In this embodiment, the minimum spacing Lmin between the two opposing ridges 200 ranges from 0.025λ to 0.0275λ. This arrangement ensures a minimum spacing between the two opposing ridges 200 to guarantee response to low-frequency signals.

[0041] Specifically, in this embodiment, the minimum spacing between the two ridges 200 is 0.0275λ.

[0042] In this embodiment, the shape change curve of the ridge plate 200 is a sine function to the power of 1.75. With this shape, the ridge plate 200 has a good response to each frequency band, whether it is high frequency or low frequency.

[0043] In this embodiment, the ratio of the diameter of the coaxial probe 300 to the thickness of the ridge 300 ranges from 1 / 5 to 1 / 4. With this configuration, the width at the connection between the coaxial probe 300 and the ridge 300 is relatively large, and the perimeter of the cross-section where the coaxial probe 300 is located is relatively long. This is beneficial for enhancing the low-frequency matching effect, improving the low-frequency response, and also for increasing isolation.

[0044] Specifically, in this embodiment, the ratio of the diameter of the coaxial probe 300 to the thickness of the ridge 200 is in the range of 0.235.

[0045] Specifically, in this embodiment, the axial length range of the 75-ohm broadband four-ridge orthogonal mode coupler is 4.025λ-4.05λ.

[0046] Specifically, in this embodiment, the thickness of the ridge 200 ranges from 0.0385λ to 0.05λ, and preferably, the thickness of the ridge 200 is 0.0385λ. With this configuration, the thickness of the ridge 200 is relatively small, which is beneficial for improving the response to high frequencies.

[0047] In summary, this embodiment provides a 75-ohm broadband four-ridge orthogonal mode coupler. By setting the diameter ratio of the outer and inner conductors of the coaxial input terminal to 3.444-3.544, an input impedance of approximately 75 ohms is ensured, making this four-ridge orthogonal mode coupler suitable for output applications with an impedance of 75 ohms. By providing a matching hole 220 in one of the opposing ridges 200, the insertion end of the coaxial probe 300 is connected to the bottom of the matching hole 220, increasing the capacitive reactance between the coaxial probe 300 and the ridge 200, partially offsetting the inductive reactance, and improving the matching between the coaxial probe 300 and the ridge 200. Furthermore, by setting the minimum spacing Lmin between the opposing ridges 200 and the shape curve of the ridges 200, the response to each frequency band is improved.

[0048] Therefore, the 75-ohm broadband four-ridged orthogonal mode coupler provided in this embodiment is very suitable for applications with a 75-ohm impedance output. For example, in specific applications, radio astronomy requires low-noise temperature sensitivity. Low-noise amplifiers with a noise level below 10K have been developed for the 75-ohm room-temperature L-band (radio wave band with frequencies between 1-2 GHz and a center frequency of 1.5 GHz; this application can cover 1.05 GHz-1.95 GHz in less demanding applications). The 75-ohm broadband four-ridged orthogonal mode coupler provided in this embodiment can be connected to the aforementioned 75-ohm low-noise amplifier, ensuring a relatively low system noise temperature at room temperature and significantly reducing the cost of a single receiver unit.

[0049] Figure 7 and Figure 8 The simulation structures of the 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment in the L-band are shown respectively. Figure 7 The reflection loss curve of the 75-ohm broadband four-ridged orthogonal mode coupler provided in this embodiment in the L-band is shown. Figure 8 The isolation curve of the 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment in the L-band is shown. Figure 7 As shown, within the L-band bandwidth, the reflection loss of the 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment is greater than 20 dB; Figure 8 As shown, within the L-band bandwidth, the isolation of the 75-ohm broadband four-ridge orthogonal mode coupler provided in this embodiment is greater than 30dB. That is, after adopting the various technical means of this embodiment, the coupler can meet the design requirements for both reflection loss and isolation within the design bandwidth after impedance changes.

[0050] In summary, the 75-ohm broadband four-ridged orthogonal mode coupler provided in this embodiment achieves good performance under 75-ohm input impedance, which is beneficial for use with a room temperature 75-ohm L-band low-noise amplifier, and can obtain a relatively low noise temperature.

[0051] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0052] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A 75-ohm broadband four-ridge orthogonal mode coupler, characterized in that, The device includes a cylindrical shell (100) and four ridges (200) disposed on the cylindrical shell (100). The four ridges (200) are arranged opposite each other in pairs, and the two pairs of ridges (200) are orthogonal. In each pair of ridges (200), one ridge (200) is provided with a through hole (210), and the ratio of the diameter of the through hole (210) to the diameter of the coaxial probe (300) is in the range of 3.444-3.

544. The other ridge (200) is provided with a matching hole (220), and the coaxial probe (300) passes through the through hole (210). The end of the coaxial probe (300) extends into the matching hole (220) and is connected to the bottom of the matching hole (220).

2. The 75-ohm broadband four-ridge orthogonal mode coupler according to claim 1, characterized in that, The ratio of the diameter of the through hole (210) to the diameter of the coaxial probe (300) is 3.

494.

3. The 75-ohm broadband four-ridge orthogonal mode coupler according to claim 1 or 2, characterized in that, The matching hole (220) has a depth of 0.00875λ and a diameter of 0.01λ, where λ is the center wavelength of the design band.

4. The 75-ohm broadband four-ridge orthogonal mode coupler according to claim 1 or 2, characterized in that, The minimum spacing between the two opposing ridges (200) ranges from 0.025λ to 0.0275λ.

5. The 75-ohm broadband four-ridge orthogonal mode coupler according to claim 4, characterized in that, The minimum distance between the two opposing ridges (200) is 0.0275λ.

6. The 75-ohm broadband four-ridge orthogonal mode coupler according to claim 1 or 2, characterized in that, The shape change curve of the spine (200) is a sine function to the power of 1.

75.

7. The 75-ohm broadband four-ridge orthogonal mode coupler according to claim 1 or 2, characterized in that, The ratio of the diameter of the coaxial probe (300) to the thickness of the ridge (200) is in the range of 1 / 5 to 1 / 4.

8. The 75-ohm broadband four-ridge orthogonal mode coupler according to claim 7, characterized in that, The ratio of the diameter of the coaxial probe (300) to the thickness of the ridge (200) is in the range of 0.

235.

9. The 75-ohm broadband four-ridge orthogonal mode coupler according to claim 1 or 2, characterized in that, The axial length range of the 75-ohm broadband four-ridge orthogonal mode coupler is 4.025λ-4.05λ.

10. The 75-ohm broadband four-ridge orthogonal mode coupler according to claim 1, characterized in that, The thickness of the ridge plate (200) ranges from 0.0385λ to 0.05λ.

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