High-frequency microwave device for PCVD machine tool

Abstract

The utility model relates to a high-frequency microwave device for a PCVD (plasma chemical vapor deposition) machine tool, which comprises a microwave generating device communicated with a resonant cavity through a circulator and a waveguide tube, and is characterized in that the microwave generating device comprises a solid-state microwave source power supply and a solid-state microwave source, and the output end of the solid-state microwave source is connected with the waveguide tube through the circulator. According to the utility model, the frequency of the microwave frequency matching resonant cavity can be directly adjusted, so that the output frequency is more matched with the use frequency, and the reflection power of the whole high-frequency system is lower, thereby not only reducing the energy consumption and the equipment loss, but also greatly reducing the debugging difficulty of the microwave source high-frequency system. The solid-state microwave source is long in service life and has no power attenuation problem, the use stability of the high-frequency microwave device is improved, the parameter stability of the optical fiber preform can be effectively improved in the use process, and the defects of bubbles, cracks and the like of the optical fiber preform are reduced, so that the deposition quality of the optical fiber preform is improved.

Description

Technical Field

[0001] The utility model relates to a high-frequency microwave device for a PCVD machine tool, belonging to the technical field of optical fiber preform processing equipment. Background Art

[0002] The PCVD process, namely the plasma chemical vapor deposition method, is one of the main processing techniques for manufacturing optical fiber preforms. The PCVD process mainly generates high-temperature plasma through a microwave resonator, enabling the reaction gas to undergo a chemical reaction within the glass tube to form doped glass, which is deposited on the inner wall of the glass tube. The high-frequency microwave device of the PCVD machine tool is the main device for generating, transmitting, and coupling microwaves, generally consisting of a microwave power supply, a magnetron, a circulator, a waveguide, and a resonator. As the core component of high frequency, the magnetron is actually a diode placed in a constant magnetic field, having a certain service life and a fixed frequency, generally between 2420 - 2470 MHz, and the frequencies of different magnetrons vary greatly. For the existing high-frequency microwave devices of PCVD machine tools, as the service life of the magnetron changes, its output power and performance will also change, resulting in parameter fluctuations at the least and defects such as bubbles and cracks in the preform at the worst.

[0003] On the other hand, since the microwave resonator is designed and manufactured according to a certain high-frequency (such as 2450 MHz), only when the microwave frequency output by the magnetron is around 2450 MHz, the frequency matching is the best and the reflected power of the high-frequency system is the smallest. However, due to the certain service life of the magnetron, it needs to be frequently replaced, and each time the magnetron is replaced, the frequency will change to some extent. When the frequencies do not match, the reflected power is very high, and the energy output by the high-frequency system cannot reach the required level. When this situation occurs, it is necessary to readjust the matching, which is not only time-consuming and laborious but also difficult to adjust, bringing great inconvenience to the use. Summary of the Invention

[0004] The technical problem to be solved by the utility model is to provide a high-frequency microwave device for a PCVD machine tool in view of the deficiencies of the above-mentioned existing technologies. It can adjust the microwave frequency as needed to match the resonance of the resonator, and has stable performance and a long device life.

[0005] The technical solution adopted by the utility model to solve the above problems is as follows: It includes a microwave generating device, and the microwave generating device is connected to the resonator through a circulator and a waveguide. It is characterized in that the microwave generating device includes a solid-state microwave source power supply and a solid-state microwave source, and the output end of the solid-state microwave source is connected to the waveguide through a circulator.

[0006] According to the above solution, the solid-state microwave source is a frequency-adjustable solid-state microwave source.

[0007] According to the above solution, the frequency adjustment range of the frequency-tunable solid-state microwave source is 2380 - 2520 MHz.

[0008] According to the above solution, when the frequency of the solid-state microwave source is fixed, its power is adjustable, and the power adjustment range is 1000 W - 15000 W.

[0009] According to the above solution, a three-pin automatic tuner is connected in series between the circulator and the waveguide.

[0010] According to the above solution, the three-pin automatic tuner is used to detect the output power of the solid-state microwave source and the reflected power returned by the resonant cavity.

[0011] According to the above solution, the operating frequency of the resonant cavity is 2450 ± 30 MHz.

[0012] According to the above solution, the waveguide includes a straight waveguide and a bent waveguide.

[0013] The beneficial effects of the present utility model are as follows: 1. Using the solid-state microwave source high-frequency system can directly adjust the frequency of the microwave to match the frequency of the resonant cavity, making the output frequency and the operating frequency more matched, and the reflected power of the entire high-frequency system is lower, generally less than 20 W. This not only reduces energy consumption, alleviates equipment loss, but also greatly reduces the debugging difficulty of the microwave source high-frequency system. 2. The solid-state microwave source has a long service life and no power attenuation problem, improving the operating stability of the high-frequency microwave device, effectively improving the parameter stability of the optical fiber preform during use, reducing defects such as bubbles and cracks in the optical fiber preform, and thus improving the deposition quality of the optical fiber preform. Description of the Drawings

[0014] Figure 1 It is a schematic structural diagram of an embodiment of the present utility model. Detailed Embodiment

[0015] The present utility model will be described in detail below with reference to the drawings and embodiments.

[0016] An embodiment of the present utility model is as Figure 1As shown in the figure, it includes a microwave generating device. The microwave generating device is connected to a resonant cavity 6 through a circulator 3 and a waveguide 5. The microwave generating device includes a solid-state microwave source power supply 1 and a solid-state microwave source 2. The solid-state microwave power supply is connected to the solid-state microwave source by cables and signal lines. The microwave frequency and power of the solid-state microwave source can be directly adjusted on the control panel of the solid-state microwave source power supply. The output end of the solid-state microwave source is connected to the waveguide through a circulator and a three-pin automatic tuner 4. The circulator can absorb the reflected high-frequency power to protect the solid-state microwave source. The circulator is connected to the three-pin automatic tuner. The three-pin automatic tuner can measure the output power of the solid-state microwave source and the reflected power on the one hand, and can adjust the matching of the high-frequency system within a small range to reduce the reflected power of the high-frequency system on the other hand. The three-pin automatic tuner is connected to the waveguide. The waveguide includes a straight waveguide and a bent waveguide for transmitting microwave energy. The waveguide is connected to the resonant cavity. The resonant cavity outputs microwave energy to convert reaction gas into plasma.

[0017] When replacing the microwave generating device of the present utility model, it only needs to adjust the microwave output frequency on the control panel of the solid-state microwave power supply 1. For example, when the frequency is adjusted to 2436 MHz, the matching of the high-frequency system is completed, greatly reducing the debugging workload. The adjustment accuracy is 1 MHz and the power accuracy is 10 W.

Claims

1. A high-frequency microwave device for a PCVD machine tool, comprising a microwave generator, the microwave generator being connected to a resonant cavity through a circulator and a waveguide, characterized in that The microwave generating device comprises a solid-state microwave source power supply and a solid-state microwave source, and the output end of the solid-state microwave source is connected to the waveguide through a circulator.

2. The high-frequency microwave device for PCVD machine tool according to claim 1, characterized in that The solid-state microwave source is a frequency-adjustable solid-state microwave source.

3. The high-frequency microwave device for PCVD machine tool according to claim 2, characterized in that The frequency adjustment range of the frequency-adjustable solid-state microwave source is 2380-2520 MHz.

4. The high-frequency microwave device for PCVD machine tool according to claim 3, characterized in that The solid-state microwave source has adjustable power when the frequency is fixed, and the power adjustment range is 1000W-15000W.

5. The high-frequency microwave device for PCVD machine tool according to claim 1 or 2, characterized in that A three-pin automatic distributor is connected in series between the circulator and the waveguide.

6. The high-frequency microwave device for PCVD machine tool according to claim 5, characterized in that The three-pin automatic distributor is used to detect the output power of the solid-state microwave source and the reflected power returned by the resonant cavity.

7. The high-frequency microwave device for PCVD machine tool according to claim 1 or 2, characterized in that The resonant cavity uses a frequency of 2450±30 MHz.

8. The high-frequency microwave device for PCVD machine tool according to claim 1 or 2, characterized in that The waveguide includes a straight waveguide and a curved waveguide.

Images