A conformal structure of coaxial filter and heat dissipation system

Abstract

The present invention relates to a conformal structure of a coaxial filter and a heat dissipation system, and belongs to the field of microwave circuit integration technology. The low-pass filter is implemented by a coaxial structure embedded in a heat dissipation tooth plate. Considering the heat dissipation requirements, the filter size is reduced as much as possible under the premise of meeting the filter performance indicators. The design concept of the coaxial filter and the heat dissipation system is integrated in the structure, which can perfectly solve the electromagnetic compatibility and heat dissipation requirements of the system. It can be directly embedded between the radiation unit and the transceiver component as an integral structure, which plays a role in improving the heat dissipation efficiency and suppressing each harmonic. The high-low impedance line coaxial low-pass filter and the heat dissipation system conformal design have the characteristics of low insertion loss, strong heat dissipation performance, and high integration.

Description

Technical Field

[0001] The present invention belongs to the field of microwave circuit integration technology, specifically a coaxial filter and heat dissipation system conformal structure. It is applied in the front-end circuits of thunder communication, communication, and electronic warfare phased arrays, solves the problems of final stage power amplifier harmonic suppression and tile array heat dissipation performance improvement, and has good engineering feasibility. Background Art

[0002] In most active phased array radar front-end circuits, the active transceiver components and the antenna array are often designed in an integrated manner, and in order to maximize the integration, the two are often connected in a direct manner. Although the front-end volume is reduced, this simple interconnection greatly reduces the electromagnetic compatibility of the radar. In particular, the useless spurious and harmonics at the output of the transceiver component may become a source of interference to the radar system, affecting the system performance. In addition, if the coaxial filter is embedded between the transceiver component and the antenna as an independent device, its size is often too large, which will affect the heat dissipation efficiency of the heat dissipation system. Summary of the invention

[0003] Technical issues to be solved

[0004] In order to solve the dual requirements of electromagnetic compatibility and heat dissipation in active phased array radar, the present invention provides a coaxial filter and heat dissipation system conformal structure, which has the characteristics of small insertion loss, strong heat dissipation performance, high integration, etc.

[0005] Technical Solution

[0006] A coaxial filter and heat dissipation system conformal structure, characterized by comprising a temperature averaging plate, a heat dissipation fin, and a coaxial low-pass filter; a plurality of heat dissipation fins are arranged under the temperature averaging plate, and a plurality of coaxial low-pass filters are embedded in each heat dissipation fin; the coaxial low-pass filter and the heat dissipation fin are designed as an integrated whole, and the outer conductor of the coaxial low-pass filter is shared by the heat dissipation fin.

[0007] The coaxial low-pass filter comprises, in sequence, a first matching branch 7, a first branch 9 of a coaxial inner conductor low-impedance line, a first branch 10 of a coaxial inner conductor high-impedance line, a second branch 14 of a coaxial inner conductor low-impedance line, a second branch 15 of a coaxial inner conductor high-impedance line, a third branch 17 of a coaxial inner conductor low-impedance line, and a second matching branch 18; outside the first matching branch 7, the first branch 10 of a coaxial inner conductor high-impedance line, the second branch 15 of a coaxial inner conductor high-impedance line, and the second matching branch 18 are air media.

[0008] A dielectric is filled between the inner conductor and the outer conductor of the coaxial low-pass filter to ensure its strength.

[0009] The medium is Teflon.

[0010] The external connector of the coaxial low-pass filter adopts SSMP, SMP, wool button or spring pin.

[0011] The coaxial low-pass filters are arranged at equal intervals, and the entire coaxial low-pass filter is arranged in an N*M array.

[0012] Beneficial Effects

[0013] The present invention provides a conformal structure of a coaxial filter and a heat dissipation system, which is different from the design in which the filter and the heat sink are separated. It adopts an integrated design concept, efficiently utilizes the space between the T / R component and the radiation unit, overcomes the shortcomings of the filter occupying a large space and having an adverse effect on the heat dissipation performance when the two are designed separately, and completes the function of harmonic suppression of the final power amplifier under the premise of meeting the system heat dissipation needs in a limited space.

[0014] The coaxial filter and heat dissipation system have a conformal structure with low loss and high power handling capacity. The filter and heat dissipation system are designed as an integrated unit and embedded between the transceiver component and the antenna, which can solve the signal interconnection problem, effectively suppress the spurious and harmonic output of the transceiver component, and improve the heat dissipation efficiency.

[0015] Compared with the existing technology, its significant advantages are: (1) From the perspective of thermal design, more heat dissipation fins are needed to achieve better heat dissipation performance, and the heat dissipation fins are required to be as thin as possible. From the perspective of the electrical performance and processing technology of the filter, the high and low impedance lines of the filter should be as small as possible to achieve better out-of-band suppression characteristics and facilitate processing and manufacturing. The two have a contradiction in the design concept of space. The conformal design of the filter and the heat dissipation system makes the most of the limited space to maximize the electromagnetic compatibility design and thermal design; (2) The position and number of coaxial filters are flexible and can be customized according to the requirements of the array channel; (3) The use of high and low impedance resonators has a more compact structure and is easy to process and manufacture. The passband range can be adjusted by changing the branch parameters according to the requirements to meet the high harmonic suppression requirements of the final power amplifier; (4) The position of the parasitic channel can be conveniently adjusted by adjusting the ratio of the high and low impedance of the resonator; (5) Flexible and changeable interface forms, a coaxial filter and heat dissipation system conformal structure can be an interface form that can adopt SSMP, SMP, wool button, spring pin, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0017] Figure 1 Side view of the conformal structure of the coaxial low-pass filter and the heat dissipation system;

[0018] Figure 2 Top view of the coaxial low-pass filter and heat dissipation system conformal structure;

[0019] Figure 3 Coaxial low-pass filter and heat dissipation system structure;

[0020] Figure 4 Coaxial low-pass filter end main body structure;

[0021] Figure 5 Coaxial low-pass filter simulation diagram. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0023] like Figure 1 As shown, the coaxial low-pass filter of the present invention has a conformal structure with the heat dissipation system, which includes a temperature equalizing plate 1 and a coaxial low-pass filter 2 designed conformally with the heat dissipation fins, wherein the coaxial low-pass filter part is composed of an external metal conductor, a middle medium and an internal metal conductor. The coaxial low-pass filter is implemented by a coaxial structure embedded in the heat dissipation fins. Considering the heat dissipation requirements, the filter size is minimized as much as possible while meeting the filter performance indicators. The design concept of the coaxial filter and the heat dissipation system is integrated in the structure, which can perfectly solve the electromagnetic compatibility and heat dissipation requirements of the system. It can be directly embedded between the radiation unit and the transceiver assembly as an integral structure to improve the heat dissipation efficiency and suppress each harmonic.

[0024] The thickness of the temperature equalizing plate 1 can be selected as needed, and it is 3 mm in this embodiment; the length of the temperature equalizing plate 1 can be selected as needed, and it is 47 mm in this embodiment; the length of the temperature equalizing plate 1 can be selected as needed, and it is 47 mm in this embodiment; the width of the temperature equalizing plate 1 can be selected as needed, and it is 46 mm in this embodiment; the spacing of the heat dissipation fins can be selected as needed, and it is 3 mm in this embodiment.

[0025] like Figure 2-4As shown, the main structure of the coaxial low-pass filter is embedded in the middle of the heat dissipation fins. The external connectors of the coaxial low-pass filter are various in form, such as SSMP, SMP, wool buttons, spring pins, etc. The coaxial low-pass filter is composed of a first matching branch 7, a first air medium 8, a first branch 9 of a coaxial inner conductor low-impedance line, a first branch 10 of a coaxial inner conductor high-impedance line, a second air medium 11, a second branch 14 of a coaxial inner conductor low-impedance line, a second branch 15 of a coaxial inner conductor high-impedance line, a third air medium 16, a third branch 17 of a coaxial inner conductor low-impedance line, a second matching branch 18, and a fourth air medium 13; the second branch 14 of the coaxial inner conductor low-impedance line is located in the middle, and one side is placed as the first branch of the coaxial inner conductor high-impedance line. Section 10, the first branch section 9 of the coaxial inner conductor low impedance line, and the first matching branch section 7; the other side is placed with the second branch section 15 of the coaxial inner conductor high impedance line, the third branch section 17 of the coaxial inner conductor low impedance line, and the second matching branch section 18; the structures on both sides are placed symmetrically; the outside of the first branch section 10 of the coaxial inner conductor high impedance line is the second air medium 11, the outside of the second branch section 15 of the coaxial inner conductor high impedance line is the third air medium 16, the outside of the first matching branch section 7 is the first air medium 8, and the outside of the second matching branch section 18 is the fourth air medium 13.

[0026] The first matching branch 7 has a diameter of 1mm and a length of 0.5mm; the first branch 9 of the coaxial inner conductor low-impedance line has a diameter of 1.5mm and a length of 0.5mm; the first branch 10 of the coaxial inner conductor high-impedance line has a diameter of 0.25mm and a length of 3.03mm; the second branch 14 of the coaxial inner conductor low-impedance line has a diameter of 1.5mm and a length of 1.61mm; the length and diameter of the second branch 15 of the coaxial inner conductor high-impedance line are consistent with those of the first branch 10 of the coaxial inner conductor high-impedance line; the third branch 17 of the coaxial inner conductor low-impedance line is consistent with the length and diameter of the first branch 9 of the coaxial inner conductor low-impedance line; the second matching branch 18 is consistent with the length and diameter of the first matching branch 7.

[0027] Since the diameter of the inner conductor low-resistance line with sudden changes in the thickness of the dielectric material is less than 1.5mm, and the diameter of the high-resistance line is even only 0.25mm (determined by the process limit, the smaller the better while ensuring the strength), in order to ensure that it has a certain strength, Teflon material 12 is filled between the coaxial outer conductor and the coaxial inner conductor low-impedance line.

[0028] The outer conductor of the internal filter and the heat sink of the radiator are designed as one body. The width of the heat sink is affected by the size of the inner and outer conductors of the filter. The size of the outer conductor of the filter is determined by the filter performance indicators, the thickness of the heat sink, the process accuracy and the limit. The sudden change in the diameter of the inner conductor and the size of the outer conductor of the filter will affect the performance indicators of the filter. The size of the outer conductor affects the thickness of the heat sink, and then affects the heat dissipation efficiency. Its design should take into account both electrical indicators and thermal design indicators. The present invention adopts the following method to determine the initial diameter and length of the high and low impedance lines, and obtains the final result through simulation optimization.

[0029] Assume that w1 is the filter cutoff frequency, where w1 = 7.5 GHz. According to the filter passband and stopband attenuation indicators, select the appropriate normalized low-pass prototype and calculate the actual filter component values, where L1 = 360 pH, L3 = 1.5 nH, L5 = 1.5 nH, L7 = 360 pH, C2 = 0.4 pF, C4 = 0.65 pF, C6 = 0.4 pF. Calculate the actual filter component values, then Y l =1 / R l ,Y h =1 / R h , dielectric constant is approximately equal to: 2.02, V h is the speed of light in vacuum, Look up the table to get C f =0.1632fF.

[0030]

[0031] ...

[0032]

[0033] ...

[0034] It can be seen from the simulation results that the insertion loss in the passband range is less than 0.2dB, the frequency suppression in the stopband range is greater than 23dB, and the length of the filter along the microwave transmission direction is equal to 9.67mm.

[0035] It should be noted that the length does not include the connectors at both ends, and the connectors at both ends can be selected according to specific needs.

[0036] The examples given here are only for principle analysis. The actual filter length and radius can also be customized according to needs. Different lengths and radii can achieve different filter performances.

[0037] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A coaxial filter and heat dissipation system conformal structure, characterized in that The invention comprises a temperature averaging plate, a heat dissipation plate, and a coaxial low-pass filter; a plurality of heat dissipation plates are arranged under the temperature averaging plate, and a plurality of coaxial low-pass filters are embedded in each heat dissipation plate; the coaxial low-pass filter and the heat dissipation plate are designed as an integrated whole, and the outer conductor of the coaxial low-pass filter is shared by the heat dissipation plate; the coaxial low-pass filter comprises, in sequence, a first matching branch (7), a first branch (9) of a coaxial inner conductor low-impedance line, a first branch (10) of a coaxial inner conductor high-impedance line, a second branch (14) of a coaxial inner conductor low-impedance line, a second branch (15) of a coaxial inner conductor high-impedance line, a third branch (17) of a coaxial inner conductor low-impedance line, and a second matching branch (18); and air medium is provided outside the first matching branch (7), the first branch (10) of the coaxial inner conductor high-impedance line, the second branch (15) of the coaxial inner conductor high-impedance line, and the second matching branch (18).

2. The coaxial filter and heat dissipation system conformal structure according to claim 1, characterized in that: A dielectric is filled between the inner conductor and the outer conductor of the coaxial low-pass filter to ensure its strength.

3. The coaxial filter and heat dissipation system conformal structure according to claim 2, characterized in that: The medium is Teflon.

4. The coaxial filter and heat dissipation system conformal structure according to claim 1, characterized in that: The external connector of the coaxial low-pass filter adopts SSMP, SMP, wool button or spring pin.

5. The coaxial filter and heat dissipation system conformal structure according to claim 1, characterized in that: The coaxial low-pass filters are arranged at equal intervals, and the entire coaxial low-pass filter is arranged in an N*M array.

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