High-power liquid cooling attenuator

Abstract

The invention discloses a high-power liquid cooling attenuator which comprises a shell with a cavity and a resistor rod arranged in the cavity, and the resistor rod is provided with a hollow liquid channel. Cooling liquid flows into the hollow liquid channel of the resistor rod from the liquid inlet connector to cool the resistor rod inside, and then cools the resistor rod from the outside through the cavity so as to take away heat generated in the working process of the resistor rod, and finally the heat is discharged from the liquid outlet connector. The resistor rod is cooled through the cooling liquid, it is ensured that the working temperature of the resistor rod is controlled within a low change range, power capacity changes and performance changes caused by temperature rise of a resistive film on the resistor rod are reduced, the attenuation precision fluctuation phenomenon caused by resistance changes in high-power long-time work is effectively avoided, and the resistor rod has the advantages of being small in occupied space, low in cost and the like. The noise is low, the service life is long, and the reliability is high.

Description

Technical Field

[0001] The invention belongs to the technical field of attenuators, and in particular relates to a high-power liquid-cooled attenuator. Background Art

[0002] In the field of microwave radio frequency, the attenuator is an energy-consuming element, and the power becomes heat after consumption. The high-power attenuators in the prior art (referring to attenuators with a power of more than 10KW) mostly use oil cooling or air cooling for heat dissipation, which cannot circulate the heat and have poor heat dissipation effect. For attenuators that use a coolant circulation heat dissipation solution, it is only achieved by setting a heat dissipation device on the outside of the attenuator housing. The coolant cannot directly contact the heating device of the attenuator, and the heat dissipation efficiency is not high. This will lead to a high core temperature of the attenuator resistor and a large temperature drift of the resistance value. At the same time, the long-term high-temperature working environment will also have an adverse effect on the working life and reliability of the attenuator, which is not conducive to high-standard continuous measurement in a long-term high-power environment, and seriously affects the accuracy of the test and the validity of the data. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a high-power liquid-cooled attenuator to overcome the deficiencies of the prior art.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A high-power liquid-cooled attenuator, comprising:

[0006] A housing having a cavity therein;

[0007] A resistance rod is installed in the cavity;

[0008] A radio frequency connector, mounted at one end of the housing and in conductive contact with the resistor rod;

[0009] A signal output connector is mounted on the side wall of the housing and is in conductive contact with the side of the resistor rod;

[0010] The characteristic is that: the resistor rod has a hollow liquid channel with two ends open inside, the shell has a liquid inlet joint connected to one end of the hollow liquid channel at the other end relative to the RF connector, the other end of the hollow liquid channel is connected to the cavity, and the shell is also provided with a liquid outlet joint connected to the cavity at a side wall position close to the liquid inlet joint.

[0011] The above technical solution is adopted, by introducing coolant into the liquid inlet joint, the coolant flows through the hollow liquid channel of the resistor rod to cool the resistor rod internally, and then cools the resistor rod from the outside through the cavity to take away the heat generated by the resistor rod during operation, and finally discharged from the liquid outlet joint. After the discharged coolant is cooled externally, it flows into the resistor rod from the liquid inlet joint again, and the cycle is repeated to continuously take away the heat generated by the resistor rod. It ensures that the operating temperature of the resistor rod is controlled within a relatively low variation range (less than 60°C), reduces the power capacity change and performance change caused by the temperature rise of the resistor film on the resistor rod, and effectively avoids the attenuation accuracy fluctuation caused by resistance change during long-term high-power operation. It has the characteristics of small space occupation, low noise, long service life and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0013] Figure 1 It is a structural cross-sectional view of the present invention;

[0014] Figure 2 for Figure 1 Enlarged schematic diagram at point A in the middle. DETAILED DESCRIPTION

[0015] like Figure 1 As shown, the high-power liquid-cooled attenuator of the present invention includes a housing 100 , a resistor rod 200 , an upper connecting member 300 , a lower connecting member 400 , a radio frequency connector 500 and a supporting member 600 .

[0016] The housing 100 is made of aluminum material, and is connected by an upper end cover 110, a main body 120 and a lower end cover 130, with a sealing ring between the three, and a cavity 140 formed inside. Specifically, the upper end cover 110 is fixed to the top opening of the main body 110 by screws. A sealing ring is sealed between the upper end cover 110 and the top opening of the main body 110. The center of the upper end cover 110 has an upper end hole 111. The lower end cover 130 is fixed to the bottom opening of the main body 110 by screws. A sealing ring is sealed between the lower end cover 130 and the bottom opening of the main body 110. The center of the lower end cover 130 has a lower end hole 131. The RF connector 500 is fixed to the outer end surface of the upper end cover 110 by screws, and the conductive contact part 501 is exactly located at the position of the upper end hole 111. A sealing ring is also sealed between the RF connector 500 and the outer end surface of the upper end cover 110.

[0017] The resistor rod 200 is a ceramic resistor, and is disposed in the cavity 140. The resistor rod 200 is a tubular structure, and has a hollow liquid channel 201 with two ends opened inside. The surface of the resistor rod 200 has a resistor film 202.

[0018] The upper connector 300 is an elastic conductive connector, which is made of an elastic conductive metal, such as beryllium copper or tin-phosphor bronze. The upper connector 300 has a closed end 301 at one end and an open end 302 at the other end. The interior is a hollow cavity 303, and the side is provided with through holes 304 along the circumference. The closed end 301 of the upper connector 300 abuts against the conductive contact portion 501 of the RF connector 500, and the open end 302 is sleeved on the upper end of the resistor rod 200.

[0019] The lower connector 400 is an elastic insulating connector, which is specifically made of insulating engineering plastics, such as modified polyphenylene sulfide. The lower connector 400 has a hollow flow channel 401 with two ends open. The lower end of the lower connector 400 is positioned at the edge of the lower end hole 131 of the lower end cover 130, and the upper end surface supports the lower end of the resistor rod 200, and a sealing gasket 402 is provided between the two.

[0020] Since the upper connector 300 and the lower connector 400 have a certain elasticity, the upper and lower ends of the resistor rod 200 can be reliably connected to the RF connector 500 and the lower end cover 130 in the housing 100, respectively, thereby overcoming the problem of unreliable connection and poor contact caused by the two ends of the resistor rod 300 being in direct rigid contact with the RF connector 500 and the lower end cover 130. In addition, the upper connector 300 is made of conductive metal, so that the signal connected to the RF connector 500 can be transmitted to the resistor rod through the upper connector 300. The lower connector 400 is made of insulating engineering plastic, which isolates the resistor rod from leaking the signal from the lower end cover 130.

[0021] In order to ensure the stability of the upper connector 300, a support member 600 is provided in the cavity 140. The insulating support member 600 is also made of insulating engineering plastics, such as modified polyphenylene sulfide. The support member 600 has a central hole 601 fixedly supported on the upper connector 300, and the outer edge is positioned at the top opening edge of the main body 110 and is pressed and fixed by the upper end cover 110. The support member 600 divides the cavity 140 into an upper cavity 141 and a lower cavity 142. The support member 600 is also provided with hollows 602 connecting the upper cavity 141 and the lower cavity 142 around the upper connector 300. The through hole 304 of the upper connector 300 is opened at a position corresponding to the upper cavity 141.

[0022] A signal output connector 800 is sealed and mounted on the signal lead-out hole on the side of the main body 110 . The signal output connector 800 is conductively connected to the side of the resistor rod 200 .

[0023] The lower center hole 131 of the lower end cover 130 is threadedly connected with a liquid inlet connector 701. The side of the main body 110 near the lower end cover 130 is also connected with a lateral hole, and the lateral hole is threadedly connected with a liquid outlet connector 702. In this way, the liquid inlet connector 701, the hollow flow channel 401 of the lower connecting piece 400, the hollow liquid channel 201 of the resistor rod 200, the hollow cavity 303 of the upper connecting piece 300, the through hole 304, the upper cavity 141, the hollow 602, the lower cavity 142 and the liquid outlet connector 702, which are connected in sequence, form a cooling liquid channel. The coolant entering from the liquid inlet connector 701 passes through the hollow liquid channel 201 of the resistor rod 200 to cool the resistor rod internally, and then cools the resistor rod from the outside through the cavity 140 to take away the heat generated during the operation of the resistor rod, and finally discharges it from the liquid outlet connector 702. After the discharged coolant is cooled externally, it flows into the resistor rod 200 from the liquid inlet joint 701, and the cycle continues to take away the heat generated by the resistor rod 200. This ensures that the working temperature of the resistor rod is controlled within a relatively low variation range (less than 60°C), reduces the power capacity change and performance change caused by the temperature rise of the resistor film on the resistor rod 200, and effectively avoids the attenuation accuracy fluctuation caused by resistance change during long-term high-power operation. It has the characteristics of small footprint, low noise, long service life and high reliability.

[0024] In the present invention, the resistance distribution of the resistance rod 200 is a T-type attenuation network or a π-type attenuation network.

[0025] In the present invention, the coolant to be introduced should be insulated. For this purpose, the coolant of the present invention is pure water, or a mixture of pure water and ethylene glycol. Adding ethylene glycol to pure water can work in a low temperature environment, and the coolant will not freeze even at -20°C.

[0026] In addition, the cavity of the present invention is a conical cavity, which is large at the end close to the RF connector 500 and small at the end close to the liquid inlet connector 701, that is, the cavity gradually changes from large to small from the end close to the RF connector 500 to the end close to the liquid inlet connector 701. The cavity of such a structure has the advantage of impedance matching.

Claims

1. A high-power liquid-cooled attenuator, comprising: A housing having a cavity therein; A resistance rod is installed in the cavity; A radio frequency connector, mounted at one end of the housing and in conductive contact with the resistor rod; A signal output connector is mounted on the side wall of the housing and is in conductive contact with the side of the resistor rod; The characteristic is that: the resistor rod has a hollow liquid channel with two ends open inside, the shell has a liquid inlet joint connected to one end of the hollow liquid channel at the other end relative to the RF connector, the other end of the hollow liquid channel is connected to the cavity, and the shell is also provided with a liquid outlet joint connected to the cavity at a side wall position close to the liquid inlet joint, and coolant is introduced from the liquid outlet joint, the coolant flows through the resistor rod through the hollow liquid channel, and then flows out from the liquid outlet joint through the cavity.

2. The high-power liquid-cooled attenuator according to claim 1, characterized in that: The resistor rod is a ceramic resistor.

3. The high-power liquid-cooled attenuator according to claim 1 or 2, characterized in that: The shell is also provided with an elastic conductive upper connecting piece, one end of the upper connecting piece is a closed end, the other end is an open end, and the interior is a hollow cavity; the closed end is in conductive contact with the RF connector, and the other end is sleeved on the end of the resistor rod, and the side wall of the upper connecting piece also has a through hole connected to the cavity.

4. The high-power liquid-cooled attenuator according to claim 3, characterized in that: An insulating support member is also fixed in the shell, and the support member has a central hole fixedly supported on the upper connecting member. The support member divides the cavity into an upper cavity and a lower cavity, and hollows are distributed on the support member to connect the upper cavity and the lower cavity.

5. The high-power liquid-cooled attenuator according to claim 1, characterized in that: The cavity is a conical cavity with a larger end close to the radio frequency connector and a smaller end close to the liquid inlet interface.

6. The high-power liquid-cooled attenuator according to claim 1, characterized in that: An insulating lower connecting piece supporting the resistor rod is fixed in the cavity, and the lower connecting piece has a hollow flow channel connecting the liquid inlet joint and the hollow liquid channel.

7. The high-power liquid-cooled attenuator according to claim 1, characterized in that: The coolant is pure water, or a mixture of pure water and ethylene glycol.

8. The high-power liquid-cooled attenuator according to claim 1, characterized in that: The resistance distribution of the resistance rod is a T-type attenuation network or a π-type attenuation network.

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