Terahertz frequency band waveguide-coaxial conversion structure waveguide microwave probe

Abstract

The invention relates to the technical field of waveguide microwave probes, in particular to a terahertz-band waveguide microwave probe with a waveguide-coaxial conversion structure, which comprises an elastic needle tip, the elastic needle tip is positioned outside a waveguide cavity and is connected with one end of a coaxial cable, the other end of the coaxial cable is connected with a waveguide ball, and the waveguide ball is connected with the waveguide cavity. The coaxial cable extends into the main body from the outside of the waveguide cavity, a waveguide channel is arranged in the waveguide cavity, and the small waveguide ball is arranged at one end of the waveguide channel. The elastic needle point is connected to one end of the coaxial cable and is mainly used as a detection needle point to transmit a signal to the coaxial cable, and the other tail end of the elastic needle point is connected with the small waveguide ball and goes deep into the waveguide cavity to transmit a coaxial line signal to an internal waveguide channel.

Description

Technical Field

[0001] This invention relates to the field of waveguide microwave probe technology, and specifically to a waveguide microwave probe with a waveguide-coaxial conversion structure in the terahertz band. Background Technology

[0002] In the wave of high-frequency advancements in microwave integrated circuits, moving towards millimeter-wave, Asia-Pacific Hertz, and even terahertz bands, traditional coaxial probes are gradually becoming ineffective due to problems such as increased transmission loss and difficulty in mode control caused by excessively high frequencies (generally above 110 GHz). Waveguide probes, with their core advantages of low loss, high stability, and high compatibility at high frequencies, have become a key hub connecting instruments and devices and ensuring the performance of high-frequency circuits. Their applications are deeply intertwined with the entire chain of R&D, testing, and mass production of high-frequency integrated circuits.

[0003] Since vector network analyzers above 110 GHz all use waveguide interfaces, waveguide interface probes are required for chip measurements above 110 GHz.

[0004] Domestic research in this field is limited. CN 108134171 A describes a waveguide-to-microstrip converter, and CN119881407 A describes a waveguide-to-microstrip plate conversion structure probe. International research on waveguide probes is more mature. US Patent US2009 / 0189623 A1 uses a dielectric substrate as the tip of the waveguide probe. US Patent US2009 / 0079451 A1 uses a similar external structure to that of this invention, but does not describe the specific internal structure.

[0005] The 220GHz coaxial probe product mentioned in CN 119881407 A is a product jointly developed by MPI Probes and Anritsu. This probe needs to be used with Anritsu's vector network analyzer and requires the purchase of a corresponding spread spectrum module. It is expensive and subject to import restrictions, making it unsuitable for domestic testing needs. Currently, all waveguide probes used in China are imported, mainly the Infinity and T-wave series. The Infinity series uses a thin-film process for the tip, a technology that China has not yet mastered. The T-wave series uses a microstrip tip, which is very thin, only about 20 micrometers thick, making it fragile and with a short lifespan. Summary of the Invention

[0006] The purpose of this invention is to provide a waveguide microwave probe with a waveguide-coaxial conversion structure in the terahertz band, which solves the technical problems of high cost and long cycle of terahertz band testing in the prior art, which cannot meet the needs of scientific research and production.

[0007] This invention discloses a waveguide microwave probe with a waveguide-coaxial conversion structure in the terahertz band, comprising an elastic tip located outside the waveguide cavity, one end of which is connected to a coaxial cable, and the other end of which is connected to a waveguide ball. The coaxial cable extends from outside the waveguide cavity into the main body, and a waveguide channel is provided inside the waveguide cavity, with the waveguide ball disposed at one end of the waveguide channel.

[0008] The flexible needle tip is connected to one end of the coaxial cable. Its main function is to act as a probe tip to transmit signals to the coaxial cable. The other end is connected to a waveguide ball that goes deep into the waveguide cavity and can transmit coaxial signals to the internal waveguide channel.

[0009] Furthermore, a cable fixing bracket is provided on the outside of the coaxial cable.

[0010] By setting up a cable fixing bracket, the cable can be fitted together with the coaxial cable to prevent bending and ensure proper audio signal transmission.

[0011] Furthermore, the cable fixing bracket is fixedly connected to the waveguide cavity by screws.

[0012] By fixing the cable mounting bracket to the waveguide cavity, sufficient support can be provided for the coaxial cable.

[0013] Furthermore, the waveguide cavity includes a left probe cavity and a right probe cavity.

[0014] By setting up a left and right probe cavity, the waveguide cavity can be designed according to requirements to meet different application scenarios.

[0015] Furthermore, the waveguide cavity is provided with a microwave absorber.

[0016] By setting up a microwave absorber, high-order modes generated during high-frequency microwave transmission can be suppressed.

[0017] Furthermore, the coaxial cable inside the waveguide cavity is welded with a cover plate.

[0018] By welding a cover plate to the coaxial cable, the stable operation of the coaxial cable within the waveguide cavity can be ensured.

[0019] Furthermore, the elastic needle tip 1 is made of beryllium copper.

[0020] Furthermore, the waveguide sphere is made of brass.

[0021] Furthermore, the other end of the waveguide channel is connected to other waveguide interfaces via a circular flange.

[0022] Furthermore, the coaxial cable has a diameter of 0.6 mm.

[0023] A smaller diameter is needed to meet the requirements of high-frequency transmission.

[0024] Furthermore, the surface of the elastic needle tip is gold-plated.

[0025] Compared with the prior art, the beneficial effects of the present invention are: 1. The highest test frequency of the existing domestic RF coaxial probe technology is only 110GHz. It cannot test frequency bands above 110GHz and all require the use of foreign probes. Import restrictions result in high costs and long cycles. This invention can realize on-chip measurement of frequencies up to 220GHz. 2. This invention can achieve on-chip measurement at frequencies up to 220GHz, and the entire structure is simple, easy to implement, and can meet the needs of domestic production; 3. The flexible needle tip is connected to one end of the coaxial cable. Its main function is to act as a probe tip to transmit signals to the coaxial cable. The other end is connected to a waveguide ball that goes deep into the waveguide cavity and can transmit coaxial signals to the internal waveguide channel. 4. By setting up a cable fixing bracket, it can be fitted to the coaxial cable to prevent the cable from bending and thus ensure proper audio signal transmission; 5. By fixing the cable fixing bracket to the waveguide cavity, sufficient support can be provided for the coaxial cable; 6. By setting up a left and right probe cavity, the waveguide cavity can be designed according to requirements to meet different application scenarios; 7. By setting up a microwave absorber, higher-order modes generated during high-frequency microwave transmission can be suppressed; 8. By welding a cover plate to the coaxial cable, the stable operation of the coaxial cable within the waveguide cavity can be ensured. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the three-dimensional structure of the waveguide microwave probe of the present invention.

[0028] Figure 2 This is a front view schematic diagram of the waveguide microwave probe structure of the present invention.

[0029] Figure 3 This is a schematic diagram of the waveguide microwave probe structure from an upward view.

[0030] Figure 4This is a schematic diagram of the cross-sectional structure of the waveguide microwave probe of the present invention.

[0031] Figure 5 This is a schematic diagram of a partial structure of the waveguide microwave probe of the present invention.

[0032] Figure 6 The graphs are obtained from the simulation model of the waveguide microwave probe of this invention in the DC~220GHz range.

[0033] In the above figures, the meanings of each mark are as follows: 1-elastic needle tip, 2-coaxial cable, 3-cable fixing bracket, 4-microwave absorber, 5-left cavity of probe, 6-right cavity of probe, 7-cover plate, 8-waveguide ball. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them.

[0035] Example 1 This embodiment discloses a waveguide-coaxial conversion structure waveguide microwave probe in the terahertz band, such as... Figures 1-5 As shown, it includes an elastic needle tip 1, which is located outside the waveguide cavity. One end of the elastic needle tip 1 is connected to a coaxial cable 2, and the other end of the coaxial cable is connected to a waveguide ball 8. The coaxial cable 2 extends from outside the waveguide cavity into the main body. A waveguide channel is provided inside the waveguide cavity, and the waveguide ball 8 is located at one end of the waveguide channel.

[0036] The flexible needle tip 1 is connected to one end of the coaxial cable 2. Its main function is to act as a probe tip to transmit signals to the coaxial cable 2. The other end is connected to the waveguide ball 8, which goes deep into the waveguide cavity and can transmit coaxial signals to the internal waveguide channel.

[0037] Example 2 This embodiment discloses a waveguide-coaxial conversion structure waveguide microwave probe in the terahertz band, such as... Figures 1-5 As shown, the only change from Embodiment 1 is that a cable fixing bracket 3 is provided outside the coaxial cable 2, and the cable fixing bracket 3 is fixedly connected to the waveguide cavity by screws.

[0038] By setting the cable fixing bracket 3, it can be fitted to the coaxial cable 2 to prevent the cable from bending and the audio signal transmission.

[0039] By fixing the cable fixing bracket 3 to the waveguide cavity, sufficient support can be provided for the coaxial cable 2.

[0040] Example 3 This embodiment discloses a waveguide-coaxial conversion structure waveguide microwave probe in the terahertz band, such as... Figures 1-5 As shown, the only change from Embodiment 2 is that the waveguide cavity includes a left probe cavity 5 and a right probe cavity 6, the waveguide cavity is provided with a microwave absorber 4, and the coaxial cable 2 inside the waveguide cavity is welded with a cover plate 7.

[0041] By setting the left cavity 5 and the right cavity 6 of the probe, the waveguide cavity can be designed according to requirements to meet different application scenarios.

[0042] By setting up the microwave absorber 4, the high-order modes generated during high-frequency microwave transmission can be suppressed.

[0043] By welding the cover plate 7 to the coaxial cable 2, the stable operation of the coaxial cable 2 within the waveguide cavity can be ensured.

[0044] Example 4 This embodiment discloses a waveguide-coaxial conversion structure waveguide microwave probe in the terahertz band, such as... Figures 1-5 As shown, the only changes from Embodiment 3 are that the elastic needle tip 1 is made of beryllium copper, the waveguide ball 8 is made of brass, the other end of the waveguide channel is connected to other waveguide interfaces through a circular flange, and the coaxial cable 2 has a diameter of 0.6 mm.

[0045] A smaller diameter is needed to meet the requirements of high-frequency transmission.

[0046] A simulation model of the waveguide probe's elastic tip in the DC~220GHz range was established according to the structure in Example 4. The simulation curves are shown below. Figure 6 As shown, the return loss is ≤-14dB and the insertion loss is less than 1.5dB across the entire frequency band. In the high-frequency band above 110GHz, the performance can achieve a return loss of ≤-20dB and an insertion loss of less than 1.5dB. These performance indicators enable good microwave detection capabilities.

[0047] The above are the embodiments listed in this example. However, this example is not limited to the optional embodiments described above. Those skilled in the art can arbitrarily combine the above methods to obtain other various embodiments. Anyone can derive other various forms of embodiments based on the inspiration of this example. The above specific embodiments should not be construed as limiting the scope of protection of this example. The scope of protection of this example should be determined by the claims, and the specification can be used to interpret the claims.

Claims

1. A waveguide microwave probe with a waveguide-coaxial conversion structure in the terahertz band, characterized in that: Includes an elastic needle tip (1), which is located outside the waveguide cavity. One end of the elastic needle tip (1) is connected to a coaxial cable (2), and the other end of the coaxial cable (2) is connected to a waveguide ball (8). The coaxial cable (2) extends from outside the waveguide cavity into the main body. A waveguide channel is provided inside the waveguide cavity, and the waveguide ball (8) is located at one end of the waveguide channel.

2. The waveguide microwave probe with a terahertz band waveguide-coaxial conversion structure according to claim 1, characterized in that: The coaxial cable (2) is provided with a cable fixing bracket (3).

3. A waveguide microwave probe with a terahertz band waveguide-coaxial conversion structure according to claim 2, characterized in that: The cable fixing bracket (3) is fixedly connected to the waveguide cavity by screws.

4. A waveguide microwave probe with a terahertz band waveguide-coaxial conversion structure according to claim 1, characterized in that: The waveguide cavity includes a left probe cavity (5) and a right probe cavity (6).

5. A waveguide microwave probe with a terahertz band waveguide-coaxial conversion structure according to claim 1, characterized in that: The waveguide cavity is provided with a microwave absorber (4).

6. A waveguide microwave probe with a terahertz band waveguide-coaxial conversion structure according to claim 1, characterized in that: The coaxial cable (2) inside the waveguide cavity is welded with a cover plate (7).

7. A waveguide microwave probe with a terahertz band waveguide-coaxial conversion structure according to claim 5, characterized in that: The coaxial cable (2) inside the waveguide cavity is welded with a cover plate (7).

8. A waveguide microwave probe with a terahertz band waveguide-coaxial conversion structure according to claim 1, characterized in that: The other end of the waveguide channel is connected to other waveguide interfaces via a circular flange.

9. A waveguide microwave probe with a terahertz band waveguide-coaxial conversion structure according to claim 1, characterized in that: The coaxial cable (2) has a diameter of 0.6 mm.

10. A waveguide microwave probe with a terahertz band waveguide-coaxial conversion structure according to claim 1, characterized in that: The surface of the elastic needle tip (1) is gold-plated.

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