A flexible package shell structure covering C-Ka band

Abstract

The application discloses a flexible packaging shell structure capable of covering C-Ka frequency bands, which comprises a shell structure main body, an input cavity and an output cavity are arranged on the front surface of the shell structure main body, and a radio frequency airtight packaging cavity is arranged on the back surface of the shell structure main body. The input cavity is connected to the radio frequency airtight packaging cavity through a first vertical transition channel, and the radio frequency airtight packaging cavity is connected to the output cavity through a second vertical transition channel, so that signals can only be transmitted through the vertical transition structure, electromagnetic radiation isolation is realized, the independence of the two regions is ensured, the packaging of the C-Ka frequency band LCAMP radio frequency part is realized, the types of components are effectively reduced, the process is simplified, the cost is reduced, and the system cost performance is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of radio frequency microwave assemblies, and relates to a packaging shell structure, in particular to a flexible packaging shell structure covering C-Ka frequency bands. BACKGROUND

[0002] In a microwave system, the size of the working frequency of a microwave device determines the size of the device. Generally, the lower the frequency, the larger the size of the device. When designing a microwave assembly, the device or assembly structure packaging needs to be designed according to the size of the device and the working frequency required by the task. With the development of integrated circuit technology, the size of the chip is continuously miniaturized, and the size difference between the low noise amplifier (LNA) of the Q frequency band (working frequency 40G) and the low noise amplifier (LNA) of the L frequency band (working frequency 1G) is not large, which makes the frequency compatibility of the radio frequency packaging cavity continuously improve, and the radio frequency packaging of the high frequency band can be downward compatible. However, some microwave devices, such as microstrip surface mount isolators and waveguide devices, are limited by materials and processes and cannot be designed to be chipped and miniaturized. The size difference of these devices is large at different working frequency bands. How to achieve frequency compatibility and unified packaging of these devices in radio frequency packaging design is an important research direction of microwave circuit design engineering. SUMMARY

[0003] In view of the deficiencies in the prior art, the purpose of the present application is to provide a packaging shell structure to solve the technical problem that the electromagnetic radiation isolation effect of the packaging shell structure in the prior art needs to be further improved.

[0004] Another purpose of the present application is to provide a flexible packaging shell structure covering C-Ka frequency bands to solve the technical problem that the packaging shell structure in the prior art is difficult to cover C-Ka frequency bands.

[0005] To solve the above technical problems, the present application adopts the following technical solutions:

[0006] A packaging shell structure comprises a shell structure main body, an input cavity and an output cavity are arranged on the front surface of the shell structure main body, and a radio frequency airtight packaging cavity is arranged on the back surface of the shell structure main body.

[0007] The input cavity and the radio frequency airtight packaging cavity are communicated through a first vertical transition channel, the central axis of the first vertical transition channel is perpendicular to the central surface of the input cavity, and the central axis of the first vertical transition channel is perpendicular to the central surface of the radio frequency airtight packaging cavity.

[0008] The output cavity and the radio frequency airtight packaging cavity are communicated through a second vertical transition channel, the central axis of the second vertical transition channel is perpendicular to the central surface of the output cavity, and the central axis of the second vertical transition channel is perpendicular to the central surface of the radio frequency airtight packaging cavity.

[0009] The application also has the following technical features:

[0010] The radio frequency airtight packaging cavity is divided into six independent small cavities.

[0011] The cavity width of the radio frequency airtight packaging cavity is 4.6 mm, and the height is 2.6 mm.

[0012] The movable shielding frame is detachably mounted on the shell structure body around the input cavity and the output cavity.

[0013] The material of the movable shielding frame is the same as that of the shell structure body.

[0014] Compared with the prior art, the application has the following technical effects:

[0015] (I) The input cavity and the output cavity are respectively electromagnetically isolated from the radio frequency airtight packaging cavity through the coaxial vertical transition structure, so that the signal can only be transmitted through the vertical transition structure, the independence of the two regions is ensured, the types of components are effectively reduced, the process is simplified, the cost is reduced, and the system cost-effectiveness is improved.

[0016] (II) The movable shielding frame can effectively realize frequency compatibility of large-size microwave devices such as microstrip surface-mounted isolators, and realizes the packaging of the radio frequency part of the C-Ka frequency band linear channel amplifier (LCAMP).

[0017] (III) The flexible packaging shell structure adopts a unified packaging shell, which can effectively reduce the types of packaging, ensure that microwave assembly products of the same type and different frequencies are completely consistent in mechanical, electrical and thermal interfaces, reduce the cost problems caused by repeated design and inconsistent materials, and lay a foundation for low-cost and batch development of satellites. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 FIG. 1 is a schematic diagram of the basic framework of the packaging shell structure.

[0019] FIG. 2(a) is a front view of the packaging shell structure.

[0020] FIG. 2(b) is a side view of the packaging shell structure.

[0021] FIG. 2(c) is a back view of the packaging shell structure.

[0022] Fig. 3(a) is a schematic diagram of a class A movable shield frame structure.

[0023] Fig. 3(b) is a schematic diagram of a class B movable shield frame structure.

[0024] Fig. 4(a) is a schematic diagram of a class A movable shield frame structure and a package shell installation.

[0025] Fig. 4(b) is a schematic diagram of a class B movable shield frame structure and a package shell installation.

[0026] Figure 5 Fig. 5 is a schematic diagram of a linearized traveling wave tube amplifier principle block diagram.

[0027] Figure 6 Fig. 6 is a compatible photo of the movable shield frame at different frequencies.

[0028] Figure 7 Fig. 7 is a schematic diagram of a coaxial vertical transition structure partition.

[0029] The meanings of the various reference numerals in the drawings are as follows: 1 - shell structure main body, 2 - input cavity, 3 - output cavity, 4 - radio frequency airtight package cavity, 5 - first vertical transition channel, 6 - second vertical transition channel, 7 - movable shield frame, 8 - microstrip surface mount isolator, 9 - microwave radio frequency chip.

[0030] The specific content of the present application is further described below in combination with the drawings and examples. DETAILED DESCRIPTION

[0031] It should be noted that all components and devices in the present application, if not specifically stated, all use components and devices known in the prior art.

[0032] In the present application, the linearized traveling wave tube amplifier is composed of a linearized channel amplifier, a traveling wave tube power supply and a traveling wave tube, as shown in Fig. 5. Figure 5 Among them, the radio frequency part of the linearized channel amplifier is composed of a radio frequency assembly, a package shell and a control circuit.

[0033] Different satellites have different mission functions, and the working frequencies are also different. The present application mainly designs the package shell and frequency compatibility of the linearized channel amplifier (LCAMP) in the linearized traveling wave tube amplifier, realizing the package uniform type covering the C ~ Ka band linearized channel amplifier (LCAMP) radio frequency part.

[0034] In accordance with the above technical solution, the specific embodiments of the present application are given below. It should be noted that the present application is not limited to the following specific embodiments, and any equivalent transformation based on the technical solution of the present application falls within the protection scope of the present application.

[0035] Embodiment:

[0036] The embodiment provides a package shell structure, as shown in the figure, which comprises a shell structure body 1, wherein a front surface of the shell structure body 1 is provided with an input cavity 2 and an output cavity 3, and a back surface of the shell structure body 1 is provided with a radio frequency airtight package cavity 4. Figures 1 to 2(c) The input cavity 2 and the radio frequency airtight package cavity 4 are communicated through a first vertical transition channel 5, a central axis of the first vertical transition channel 5 is perpendicular to a central surface of the input cavity 2, and the central axis of the first vertical transition channel 5 is perpendicular to a central surface of the radio frequency airtight package cavity 4.

[0037] The output cavity 3 and the radio frequency airtight package cavity 4 are communicated through a second vertical transition channel 6, a central axis of the second vertical transition channel 6 is perpendicular to a central surface of the output cavity 3, and the central axis of the second vertical transition channel 6 is perpendicular to the central surface of the radio frequency airtight package cavity 4.

[0038] In the embodiment, signals can only be transmitted through the first vertical transition channel 5 and the second vertical transition channel 6, so that electromagnetic radiation isolation is realized.

[0039] In the embodiment, the radio frequency airtight package cavity 4 is divided into six independent small cavities. The independent small cavities can prevent microwave crosstalk between internal stages. When the cavity layout is performed, the power supply insulator is arranged on one side of the cavity, so that the chip layout width can be effectively increased when the cavity width is constant. Through the above measures, the working frequency band of the product is widened, the link length that can be accommodated is lengthened, the applicability of the radio frequency airtight package cavity 4 is effectively improved, and the radio frequency airtight package cavity 4 can be applied to various types of product design.

[0040] In the embodiment, the input cavity 2 and the output cavity 3 are used for packaging microstrip surface-mounted isolators 8, and the radio frequency airtight package cavity 4 is used for packaging microwave radio frequency chips 9.

[0041] In the embodiment, the microstrip surface-mounted isolators 8 have different sizes. For a small-power microwave module, a small-power microstrip surface-mounted isolator 8 needs to be added to a front stage of the radio frequency airtight package cavity 4, so as to improve the standing wave and protect the small-power microwave amplifier, so that the reflected power is not too large to cause damage or failure of the power amplifier in a mismatching case. At this time, the reflected power is absorbed by the load of the microstrip surface-mounted isolator 8.

[0042] As a preferred scheme of the embodiment, the cavity width of the radio frequency airtight package cavity 4 is 4.6 mm, and the height is 2.6 mm.

[0043]

[0044] ​In this embodiment, the radio frequency airtight packaging cavity 4 adopts laser sealing cover plate for airtightness. When designing the radio frequency airtight packaging cavity 4, compatibility of different frequencies should be considered, so through simulation calculation, it can be obtained from table 1 that the cavity width of the radio frequency airtight packaging cavity 4 is 4.6 mm, the height is 2.6 mm, and the lowest resonance frequency is 33.6 GHz through calculation, which can meet the design requirements of Ka-band products, and at the same time, the cavity width can also accommodate microwave devices as low as C-band, which has good universality.

[0045] Table 1 resonance frequency calculation results of different cavities

[0046] Cavity number Cavity size mm Cavity resonance frequency GHz Front cavity 1 18.35×4.6×2.6 33.6 Front cavity 2 18.35×4.6×2.6 33.6 Front cavity 3 19.5×4.6×2.6 33.6 Front cavity 4 19.5×4.6×2.6 33.6 Front cavity 5 18.35×4.6×2.6 33.6 Front cavity 6 18.35×4.6×2.6 33.6

[0047] As a preferred scheme of the embodiment, the movable shielding frame 7 is detachably mounted on the shell structure body 1 around the input cavity 2 and the output cavity 3.

[0048] In the application, the sizes of the microstrip surface-mounted isolators 8 of different frequency bands are different, and according to the installation requirements, the resonance frequency simulation of the structure meeting the installation is carried out, as shown in table 1, the simulation shows that the resonance frequencies of different cavity sizes are different, the larger the size, the smaller the resonance frequency, the lowest resonance frequency of the cavity meeting the assembly and work of the microstrip surface-mounted isolator of C-band is 12.57 GHz, the lowest resonance frequency of the cavity meeting the assembly and work of the microstrip surface-mounted isolator of X-band is 16 GHz, which cannot meet the requirements of Ku (above 12 GHz) and Ka band (above 18 GHz) working frequency, so that different frequency products must use different packaging and corresponding frequency structure, which seriously restricts the product unification and the low-cost development goal. Therefore, the movable shielding frame 7 is needed to meet the requirements of Ku (above 12 GHz) and Ka band (above 18 GHz) working frequency.

[0049] Table 2 resonance frequency calculation results of different sizes

[0050]

[0051] In this embodiment, the movable shielding frame 7 is a structure for shielding the input cavity 2 and the output cavity 3 according to the size and working frequency of the microstrip surface-mounted isolator 8. As shown in Figures 3(a) to 4(b) When the working frequency of the product is 10 GHz and below, the A-type movable shielding frame is selected; when the working frequency of the product is 10 GHz and above, the B-type movable shielding frame is selected.

[0052] In this embodiment, the design of the movable shielding frame 7 adopts known simulation method for accurate electromagnetic simulation, which guarantees the shielding effect and frequency compatibility.

[0053] As a preferred solution of the embodiment, the material of the movable shielding frame 7 is the same as that of the shell structure body 1, for ensuring the same thermal expansion coefficient and ensuring that the movable shielding frame 7 and the shell structure body 1 are in good contact in a wide temperature range.

[0054] In the embodiment, the movable shielding frame 7 and the shell structure body 1 are connected and fastened by means of screws, ensuring the flexibility of operation of the movable shielding frame 7.

[0055] In the embodiment, the use of the movable shielding frame 7 realizes a frequency coverage of 3-30 GHz for the application of a linear channel amplifier (LCAMP) radio frequency module.

[0056] As shown in Figure 6 , for the shielding frame technology for frequency flexibility matching, by arranging several groups of movable shielding frames 7 on the shell of the radio frequency hermetic packaging cavity 4, through accurate simulation calculation, frequency compatibility can be effectively realized for large-size microwave devices such as microstrip surface mount isolators 8. As shown in Figure 7 , after the signal passes through the microstrip surface mount isolator 8 in the input cavity 2, it enters the microwave radio frequency chip 9 in the radio frequency hermetic packaging cavity 4 through the coaxial vertical transition structure, and then enters the microstrip surface mount isolator 8 in the output cavity 3 through the coaxial vertical transition structure after the microwave radio frequency chip 9, and is output, thereby realizing the unified type of the packaging shell.

[0057] The packaging design method proposed in the embodiment has been applied to C-Ka band linearized traveling wave tube amplifiers in CS9C and CS10R communication satellites, and after use, a packaging shell realizes a frequency coverage of 3-30 GHz, and different frequency band linearized traveling wave tube amplifiers have consistent shapes.

Claims

1. A packaging shell structure, comprising a shell structure body (1), characterized in that, The front of the main body of the outer shell structure (1) is provided with an input cavity (2) and an output cavity (3), and the back of the main body of the outer shell structure (1) is provided with an RF hermetically sealed cavity (4). The input cavity (2) and the radio frequency hermetically sealed cavity (4) are connected by a first vertical transition channel (5). The central axis of the first vertical transition channel (5) is perpendicular to the central plane of the input cavity (2) and the central axis of the first vertical transition channel (5) is perpendicular to the central plane of the radio frequency hermetically sealed cavity (4). The output cavity (3) and the radio frequency hermetically sealed cavity (4) are connected by a second vertical transition channel (6). The central axis of the second vertical transition channel (6) is perpendicular to the central plane of the output cavity (3) and the central axis of the second vertical transition channel (6) is perpendicular to the central plane of the radio frequency hermetically sealed cavity (4).

2. The packaging shell structure as described in claim 1, characterized in that, The radio frequency hermetically sealed cavity (4) is divided into six independent small cavities.

3. The packaging shell structure as described in claim 1, characterized in that, The width of the radio frequency hermetically sealed cavity (4) is 4.6 mm and the height is 2.6 mm.

4. The packaging shell structure as described in claim 1, characterized in that, A movable shielding frame (7) is detachably installed on the outer shell structure (1) surrounding the input cavity (2) and the output cavity (3).

5. The packaging shell structure as described in claim 4, characterized in that, The material of the active shielding frame (7) is the same as that of the outer shell structure body (1).

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