A storage welding package AGC intermediate frequency amplifier and its test fixture

Abstract

The present invention relates to the field of radio electronic circuits, and specifically to an energy storage welding package AGC intermediate frequency amplifier and a test fixture thereof, comprising a PCB circuit board, components, and a metal shell, wherein a solder pad is provided on the top layer of the PCB circuit board, and the components are loaded on the PCB circuit board by welding; the back of the PCB circuit board is a full gold-plated area; the metal shell comprises a tube seat and a tube cap, wherein the gold-plated area at the bottom of the PCB circuit board is bonded to the tube seat by conductive glue, the PCB circuit board is welded to the tube seat by wire welding, and finally the tube cap is covered on one end of the tube seat with the PCB circuit board attached, and energy storage welding is performed in a nitrogen-filled environment to achieve airtight packaging of the amplifier. The present invention can effectively resist complex electromagnetic interference through circuit board layout optimization design, airtight packaging and full shielding structure.

Description

Technical Field

[0001] The invention relates to the field of radio electronic circuits, and in particular to an energy storage welding packaged AGC intermediate frequency amplifier and a test fixture thereof. Background Art

[0002] The AGC intermediate frequency amplifier is a small signal amplifier in the medium wave band with automatic gain control (AGC) function for communication equipment. It has a wide range of applications and is often used in communication receivers. The signal received by the antenna is amplified by the front end and mixed to the baseband. After filtering, it is amplified by the intermediate frequency amplifier to provide a signal with sufficient strength for the post-processing. Its AGC function keeps the signal gain within a reasonable range, ensuring the stability of the signal energy used for system processing, such as Figure 1 shown.

[0003] There are usually two ways to apply the intermediate frequency amplifier to the communication system: the first is to implement it in the form of monolithic integration, which is a bare chip that needs to be packaged in a shell, and then assembled again after airtight or non-airtight packaging. The second is to implement it in the form of a component with a circuit board as the carrier. The AGC intermediate frequency amplifier with a circuit board as the carrier has components such as resistors and capacitors welded on the PCB circuit board, and then the circuit board is fixed in the case or chassis with screws for non-airtight packaging. Summary of the invention

[0004] In order to solve the above problems, the present invention provides an energy storage welding package AGC intermediate frequency amplifier.

[0005] An energy storage welding packaged AGC intermediate frequency amplifier comprises a PCB circuit board, components and a metal shell, wherein the top layer of the PCB circuit board is provided with a soldering pad, and the components are loaded on the PCB circuit board by welding; the back side of the PCB circuit board is a full gold-plated area; the metal shell comprises a tube seat and a tube cap, wherein the gold-plated area at the bottom of the PCB circuit board is bonded to the tube seat by conductive glue, the PCB circuit board is welded to the tube seat by wire welding, and finally the tube cap is covered on one end of the tube seat to which the PCB circuit board is bonded, and energy storage welding is performed in a nitrogen-filled environment to realize the airtight packaging of the amplifier.

[0006] In a preferred embodiment, the six-layer board structure of the PCB circuit board specifically includes: a top layer of the circuit board, a first ground layer, an inner layer of the circuit board, a second ground layer, a third ground layer and a bottom layer.

[0007] In a preferred embodiment, a plurality of ground vias are provided on the PCB circuit board, and the ground vias are distributed around the AGC feedback control circuit and various levels of matching networks through which the amplified signal passes, and the spacing between every two ground vias does not exceed 3 mm.

[0008] In a preferred embodiment, the circuit layout within the PCB circuit board includes: placing signal lines with low noise sensitivity on the top layer of the circuit board, and placing sensitive signal lines that are greatly affected by noise on the inner layer of the circuit board and being wrapped and protected by the ground layers on both sides of the inner layer.

[0009] Furthermore, the tube seat of the metal shell is adapted to the structure and size of the PCB circuit board; the tube seat includes two rows of symmetrically designed straight sockets, in which external leads and internal leads are arranged, the external leads are arranged at the lower end of the tube seat, and the internal leads are arranged at the upper end of the tube seat.

[0010] Furthermore, the lead wires include brazing leads and fusion-sealed leads. The brazing leads are connected to the tube holder by means of brazing sintering. The bottom of the tube holder is connected to the fusion-sealed leads by means of insulating material.

[0011] Furthermore, the tube seat adopts a gradient step design, including a sealing ring, a first step and a second step. A flat channel is arranged between the first step and the sealing ring (the flat channel can effectively absorb overflow solder after energy storage welding, and prevent excess solder from overflowing to the outer edge of the tube seat and affecting the appearance of the amplifier). There is a height difference between the second step and the first step, and the second step is higher than the first step.

[0012] Furthermore, the tube seat is made of 4J29 Kovar alloy with a gold-plated surface; the tube cap is made of 4J29 Kovar alloy with a nickel-plated surface; the lead material is made of 4J29 Kovar alloy with gold-plated surface.

[0013] Furthermore, the tube cap of the metal shell is adapted to the shape and size of the tube base, and the tube cap and the tube base are used in combination to realize the energy storage welding packaging of the amplifier.

[0014] A test fixture for an AGC intermediate frequency amplifier comprises a socket, a copper block and a test circuit board. The front and back surfaces of the test circuit board are both provided with grounding copper-clad areas. The copper block is screwed tightly to the center of the copper-clad area on the top layer of the test circuit board by screws. Sockets are provided on both sides of the copper block, and the copper block protrudes slightly higher than the sockets on both sides.

[0015] Beneficial effects of the present invention:

[0016] 1. The present invention designs matching and frequency selection networks at the input and output ends of the amplifier circuit and between the two-stage amplifiers to suppress the stray components on the output spectrum and improve the circuit performance.

[0017] 2. The present invention optimizes the circuit board layout design so that the device gain exceeds 80dB and the AGC range exceeds 85dB. It is a high-gain, large gain control range, and low-noise amplifier.

[0018] 3. The present invention combines the characteristics of micro-assembly process and component-level circuit board to produce a metal airtight package amplifier with circuit board as carrier, which has the characteristics of small size and simple assembly, filling the market gap of such products.

[0019] 4. The present invention adopts a fully shielded structure and performs airtight packaging, which can effectively resist complex electromagnetic interference. The unique assembly method and structural design can effectively avoid problems such as solder joint oxidation and component failure due to moisture, which is of great significance to improving product reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1 This is a common system diagram for intermediate frequency amplifiers;

[0022] Figure 2 A circuit block diagram of an AGC intermediate frequency amplifier provided in this embodiment;

[0023] Figure 3 A schematic diagram of an input-end matching circuit and an output-end matching circuit provided in this embodiment;

[0024] Figure 4 A board layer structure of a PCB circuit board provided in this embodiment;

[0025] Figure 5 A schematic diagram of a via on a circuit board provided in this embodiment;

[0026] Figure 6 A schematic diagram of a tube base and a tube cap of a metal shell provided in this embodiment;

[0027] Figure 7 A top view of a tube base of a metal shell provided in this embodiment;

[0028] Figure 8 A schematic diagram of a metal tube socket structure provided in this embodiment;

[0029] Fig. 9 A schematic diagram of a mounting frame provided in this embodiment;

[0030] Fig.10 A schematic diagram of an amplifier test fixture provided in this embodiment. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] This embodiment provides an energy storage welding package AGC intermediate frequency amplifier, the circuit schematic diagram of which is as follows Figure 2 As shown, in a preferred embodiment, the circuit structure of the AGC intermediate frequency amplifier includes two stages of cascaded voltage-controlled gain amplifiers, namely, a first-stage voltage-controlled gain amplifier and a second-stage voltage-controlled gain amplifier. The second-stage amplifier detects the signal output by the first stage and extracts the amplitude signal, and feeds the extracted amplitude signal back to the gain control terminals of the first-stage voltage-controlled gain amplifier and the second-stage voltage-controlled gain amplifier, respectively, thereby realizing an automatic gain control function, and maintaining a stable output when the input signal amplitude changes.

[0033] Further, in a preferred embodiment, the circuit structure of the AGC intermediate frequency amplifier also includes an input matching and frequency selection network, an intermediate matching and frequency selection network, and an output matching and frequency selection network. Since a single-stage voltage-controlled gain amplifier circuit can provide a gain of about 42dB, the present invention uses two single-stage voltage-controlled gain amplifier circuits in cascade, which can theoretically achieve a gain of 84dB, but the entire link must have losses, resulting in mismatches between the signal input end, the output end, and the stages. If the signal input end, the output end, and the impedance between the stages do not match, the amplification gain of the amplifier circuit will be greatly reduced, or the amplifier circuit will oscillate. In order to improve the performance of the entire circuit and suppress the stray components on the output spectrum, an input matching and frequency selection network is designed at the input end of the amplifier circuit, an output matching and frequency selection network is designed at the output end of the amplifier circuit, and an intermediate matching and frequency selection network is designed between the two-stage amplifier. There are frequency selection and matching networks at the input, output, and between the two-stage amplifiers of the product, which can effectively suppress the stray components on the output spectrum.

[0034] Specifically, Figure 3 As shown, the input matching and frequency selection network includes a circuit composed of a capacitor, a resistor, an inductor and a pre-stage circuit connected in series; the output matching and frequency selection network includes a circuit composed of a capacitor, a resistor, an inductor and a pre-stage circuit connected to each other. In a preferred embodiment, the circuit of the output matching and frequency selection network includes: three capacitors, a resistor, an inductor and a pre-stage circuit, a capacitor, an inductor, a resistor and a pre-stage circuit are connected in series in sequence, and two capacitors are connected in parallel between the capacitor and the inductor.

[0035] Preferably, the power supply signal of the AGC intermediate frequency amplifier is filtered through a filter network before being input into the amplifier. In terms of power supply filtering, the power supply signal of the AGC intermediate frequency amplifier is filtered through a π-type filter network before being input into the first-stage voltage-controlled gain amplifier and the second-stage voltage-controlled gain amplifier. Each π-type filter network includes 1 inductor and 2 capacitors, which can fully avoid contamination on the power supply.

[0036] This embodiment provides an energy storage welding packaged AGC intermediate frequency amplifier, whose physical structure includes: the AGC amplifier uses a PCB circuit board as a carrier, assembles various required components on the PCB circuit board, and designs a metal shell, loads the amplifier PCB circuit board into the metal shell, and performs energy storage welding in a nitrogen-filled environment to achieve airtight packaging. In a preferred embodiment, the structure of the AGC intermediate frequency amplifier includes but is not limited to: a PCB circuit board, amplifier chips, resistors, capacitors and other components welded on the PCB circuit board, and a metal shell for loading the PCB circuit board.

[0037] The top layer of the PCB is provided with pads for assembling components, and the back of the PCB is a full gold-plated area. The bottom gold-plated area is bonded with conductive glue, and the lead pins pass through the via holes of the PCB pads and are mounted in the metal housing by welding. This structural design grounds the PCB installed in the metal housing over a large area, making the PCB have excellent anti-interference performance.

[0038] In order to make the technical solution of the embodiment of the present invention clearer and more complete, the following further introduces the circuit board layout design, metal shell structure and mounting structure of the amplifier structure.

[0039] Circuit board layout design: Since components are only mounted on the front side of the circuit board, if all the wiring is located on the front side, the output signal may leak to the input end through the feedback control line. In order to improve circuit performance, suppress noise and prevent signal leakage, the present invention designs the PCB circuit board as a six-layer board, and the signal lines with low noise sensitivity are arranged on the top layer of the circuit board ( Figure 4 The "TopLayer" layer in the circuit board is used to set the feedback control circuit (sensitive signal line) that is highly sensitive to noise on the inner layer of the circuit board ( Figure 4 The "MidLayer" layer in the circuit board is set up on both sides of the inner layer of the circuit board. Figure 4 The "GND" layer in the circuit) is wrapped around the sensitive signal line to provide a low impedance return path for the leaked signal.

[0040] See also Figure 4 In a preferred embodiment, the six-layer board structure of the PCB circuit board specifically includes: the top layer of the circuit board ( Figure 4 The "TopLayer" layer in the Figure 4"Ground Layer1(GND)" layer in the circuit board), inner layer of the circuit board ( Figure 4 The "MidLayer" layer in the Figure 4 "Ground Layer2(GND)" layer in the Figure 4 "Ground Layer3(GND)" layer in the Figure 4 The prepreg and core of the PCB circuit board structure are as follows: Figure 4 It should be noted that the PCB circuit board shown in this embodiment and the accompanying drawings is a six-layer board, which is merely exemplary and an optional implementation, rather than a limitation on the structure of the present invention. It should be understood that the PCB circuit board of the present invention can also be designed as other multi-layer structures, and this specification does not limit this.

[0041] In this embodiment, the PCB circuit board is provided with a plurality of ground vias, which are distributed around the AGC feedback control circuit, around the matching networks at various levels through which the amplified signal passes, and in the blank copper-clad area of ​​the circuit board. The ground vias around the AGC feedback control circuit and around the matching networks at various levels through which the amplified signal passes are more densely distributed than the ground vias in the blank copper-clad area. The interference signal can be returned to the low-impedance ground layer nearby through the ground vias to avoid causing significant radiation interference. Figure 5 The present invention designs a ground via on the circuit board, so that the interference signal can be returned to the low-impedance ground layer nearby, without causing significant radiation interference.

[0042] Furthermore, the distance between every two ground vias does not exceed 3 mm, and the transmission wavelength of the mid-frequency band in the FR4 circuit board material is much larger than the via spacing, which can fully isolate the interference signal that exists in a radiation manner.

[0043] Metal shell structure design: The metal shell consists of two parts: the tube base and the tube cap. The size and lead position of the metal shell are designed according to the size of the circuit board and the position of the functional pins, such as Figures 6-7 shown.

[0044] The tube base includes two rows of symmetrically designed straight sockets, each row has 12 sockets, and the straight sockets are provided with external leads and internal leads, the external leads are provided at the lower end of the tube base, and the internal leads are provided at the upper end of the tube base. Figure 6 The lead wire below the middle tube seat), the inner lead wire ( Figure 6 The leads above the center tube socket are designed to prevent wrong insertion, and the two rows are asymmetrical.

[0045] The lead wire material is 4J29 Kovar alloy, and the lead wire surface is gold plated.

[0046] There are two types of leads: one is a brazed lead, that is, the lead and the tube seat are fused together by brazing sintering; the other is a sealed lead, the lead and the tube seat need to be insulated, and the bottom of the tube seat and the sealed lead are connected by insulating materials, preferably silicon boron hard glass insulators. The expansion coefficients of the two materials of the brazed lead and the sealed lead are similar, and an airtight structure is formed by high-temperature sealing, which has good thermal shock resistance. The sealing of silicon boron hard glass insulators and Kovar alloys is a high-reliability glass-metal matching seal, which further makes the airtight structure better.

[0047] The tube holder is adapted to the structure and size of the PCB circuit board. If the PCB circuit board is rectangular, the structure of the tube holder is rectangular, and its size is the same as that of the circuit board.

[0048] The tube seat adopts a gradient step design, including a sealing ring, a first step and a second step, see Figure 8 . First, a sealing ring and a first step are milled on the metal base plate. The sealing ring corresponds to the sealing position of the tube cap to facilitate energy storage welding packaging. A flat channel is set between the first step and the sealing ring. The channel can effectively absorb the overflow solder after energy storage welding to prevent excess solder from overflowing to the outer edge of the tube seat and affecting the appearance of the amplifier; the first step enables the tube cap to be effectively aligned when it is covered on the tube seat, and the tube cap and the tube seat will not shift during energy storage welding packaging. The second step is designed to be brazed on the milled first step. There is a height difference between the second step and the first step, and the second step is higher than the first step. When the bottom of the circuit board is bonded to the second step with conductive glue, the uncured excess conductive glue can overflow from the edge of the second step and flow to the first step along the gradient, avoiding the situation where the excess conductive glue overflows to the inner lead and causes a short circuit inside the amplifier. Therefore, the design of the second step ensures the operability of the process and greatly improves the product yield.

[0049] The tube seat is made of 4J29 Kovar alloy with a gold-plated surface.

[0050] The tube cap is adapted to the tube base in shape and size and is used in conjunction with the tube base to achieve energy storage welding packaging.

[0051] The pipe cap is made of 4J29 Kovar alloy with a nickel-plated surface.

[0052] Mounting design: When installing the circuit board into the metal casing, if the tube holder and the circuit board are not fully short-circuited over a large area, the interference signal transmitted to the tube holder will form a large loop when returning to the ground, thereby causing obvious radiation interference to the circuit board. In addition, due to the small space inside the metal casing, the commonly used method of short-circuiting the circuit board and the casing in RF components (such as fully tightening with screws) cannot be used.

[0053] In order to solve the problems existing in the above-mentioned traditional packaging methods, the present invention integrates the technology of the chip micro-assembly process platform into the component-level product mounting, applies uncured conductive glue to the gold-plated area at the bottom of the PCB circuit board, passes the edge pad via holes of the circuit board through the inner leads of the tube holder, and the conductive glue bonds the tube holder to the circuit board with the components welded together, such as Fig. 9 As shown. After the conductive glue is cured, it becomes a hard silver-containing good conductor, which not only increases the heat dissipation area of ​​the circuit board, but also realizes the maximum range of the circuit board and the metal shell integrated grounding. At the same time, after the conductive glue is cured, it also has a mechanical strength comparable to that of solder sintering, realizing the mechanical reinforcement of the circuit board and the metal tube seat.

[0054] At the same time, during the installation, the PCB circuit board is welded to the tube holder by wire welding. Specifically, the inner lead of the tube holder is passed through the circuit board pad and connected by lead-tin welding to realize the electrical connection between the circuit board functional pin and the tube holder functional lead. Finally, the tube cap is covered on one end of the tube holder with the PCB circuit board attached to complete the installation of the amplifier. After the installation is completed, it is cleaned and baked, and then energy storage welding is performed in a nitrogen-filled environment. In this embodiment, the encapsulated amplifier is tested in a helium mass spectrometer leak detector, and a pressure of 207±14kpa is applied for 4 hours. The leakage rate is less than 2×10 －1 Pa·cm3 / s.

[0055] After the packaging is completed, the entire metal shell is connected to the ground in the amplifier circuit. For the amplifier circuit, the metal shell forms a complete shielding cover, which can effectively resist the interference of the complex electronic system environment and maintain the stability of the electrical performance of the amplifier in the electronic system.

[0056] The encapsulated amplifier needs to be tested for electrical performance, and the high-gain amplifier needs to be well grounded. The traditional test method requires the ground layer of the input and output coaxial lines to be directly short-circuited with the tube socket by welding to obtain good test results. When the coaxial line ground is connected to the "ground" pin of the module for testing, the noise floor on the output spectrum increases and resonance points are prone to appear. After analysis, it is found that this is because the "ground" pin of the encapsulated amplifier is relatively slender, and its parasitic inductance is much greater than that of the flat tube socket, which easily couples interference signals into the input end.

[0057] Therefore, in order to test the electrical performance of the energy storage welding package AGC intermediate frequency amplifier of the invention, this embodiment provides a test fixture suitable for the amplifier of the invention, such as Fig.10 As shown, the test fixture includes: a socket, a copper block, and a test circuit board. A large grounding copper-clad area is provided on both the front and back sides of the test circuit board. The copper block is a rectangular copper block with a smooth surface. The copper block is screwed to the center of the copper-clad area on the top layer of the test circuit board by screws; sockets are provided on both sides of the copper block, and the copper block protrudes slightly higher than the sockets on both sides.

[0058] Furthermore, in a preferred embodiment, the socket includes one row of jacks, and the number and spacing of the jacks on a single socket are adapted to the number and spacing of the single row of external leads on the amplifier tube socket. The spacing of the jacks between two sockets is consistent with the spacing of the two rows of external leads on the amplifier tube socket.

[0059] When using this test fixture to test the performance of the amplifier, the external lead of the amplifier under test is inserted into the socket and pressed down firmly, so that the bottom of the amplifier's tube seat is fully in contact with the copper block to achieve short circuit. When the external lead of the amplifier under test is inserted into the socket and pressed down, the bottom of the tube seat is naturally fully short-circuited with the copper block, so that the ground of the internal circuit board of the amplifier under test - the tube seat - the copper block - the ground of the test circuit board are connected into a fully short-circuited whole, and the ground of the test coaxial line is fully short-circuited with the copper cladding of the test circuit board, so it has a very low grounding inductance.

[0060] The test shows that the parameters measured by the above-mentioned fixture are consistent with the results measured after directly welding the coaxial line to the tube shell, which solves the test problem of the module.

[0061] The intermediate frequency amplifier of the embodiment of the present invention has the following characteristics:

[0062] 1. Taking the intermediate frequency amplifier with an operating frequency of 70MHz as an example, through the optimization design of the circuit board layout, the device gain exceeds 80dB and the AGC range exceeds 85dB. It is a high-gain, large gain control range, and low-noise amplifier.

[0063] 2. By integrating the characteristics of micro-assembly technology and component-level circuit boards, a metal airtight package amplifier with circuit boards as carriers was produced. It has the characteristics of small size and simple assembly, filling the market gap for such products.

[0064] 3. The unique assembly method and structural design make the product have airtight packaging and full shielding structure, which can effectively resist complex electromagnetic interference. The internal circuit board and the components on the circuit board are not affected by external oxidation and moisture, effectively avoiding problems such as solder joint oxidation and component failure due to moisture, which is of great significance to improving the reliability of the product; the metallized shell has the advantages of salt spray resistance and corrosion resistance, and can be applied to more, especially harsh environments. The structural scheme designed by the present invention can also be applied to other similar components and has wide adaptability.

[0065] When introducing elements of various embodiments of the present application, the articles "a," "an," "the," and "said" are intended to mean that there are one or more elements. The words "comprising," "including," and "having" are all inclusive and mean that there may be additional elements in addition to the listed elements.

[0066] In the description of this embodiment, it needs to be understood that the orientations or positional relationships indicated by terms such as "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "center", "both ends", etc. are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on this embodiment.

[0067] In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first", "second", "third" and "fourth" may explicitly or implicitly include at least one of such features.

[0068] In this embodiment, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation", "screw-on" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, for ordinary technicians in this field, the specific meanings of the above terms in this embodiment can be understood according to the specific circumstances.

[0069] Although embodiments of the present embodiment have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present embodiment, and the scope of the present embodiment is defined by the appended claims and their equivalents.

Claims

1. An energy storage welding package AGC intermediate frequency amplifier, including a PCB circuit board, components, and a metal shell, characterized in that: The top layer of the PCB circuit board is provided with a soldering pad, and the components are loaded on the PCB circuit board by welding; the back of the PCB circuit board is a full gold-plated area; the metal shell includes a tube seat and a tube cap, the gold-plated area at the bottom of the PCB circuit board is bonded to the tube seat by conductive glue, the PCB circuit board is welded to the tube seat by wire welding, and finally the tube cap is covered on one end of the tube seat with the PCB circuit board, and energy storage welding is performed in a nitrogen-filled environment to achieve airtight packaging of the amplifier; the tube seat of the metal shell is adapted to the structure and size of the PCB circuit board; the tube seat includes two rows of symmetrically designed straight jacks, and the straight jacks are provided with external leads and internal leads, the external leads are arranged at the lower end of the tube seat, and the internal leads are arranged at the upper end of the tube seat; the tube seat adopts a gradient step design, including a sealing ring, a first step and a second step, a flat channel is arranged between the first step and the sealing ring, there is a height difference between the second step and the first step, and the second step is higher than the first step; The PCB circuit board is provided with a plurality of ground vias, the ground vias are distributed around the AGC feedback control circuit and the matching networks of various levels through which the amplified signal passes, and the spacing between every two ground vias does not exceed 3 mm; The circuit layout within the PCB circuit board includes: placing signal lines with low noise sensitivity on the top layer of the circuit board, and placing sensitive signal lines that are greatly affected by noise on the inner layer of the circuit board and being wrapped and protected by the ground layers on both sides of the inner layer.

2. The energy storage welding package AGC intermediate frequency amplifier according to claim 1, characterized in that: The six-layer board structure of the PCB circuit board specifically includes: a circuit board top layer, a first ground layer, a circuit board inner layer, a second ground layer, a third ground layer and a bottom layer.

3. The energy storage welding package AGC intermediate frequency amplifier according to claim 1, characterized in that: The leads include brazing leads and fusion-sealed leads. The brazing leads are connected to the tube holder by brazing sintering. The fusion-sealed leads are connected to the bottom of the tube holder by insulating material.

4. The energy storage welding package AGC intermediate frequency amplifier according to claim 1, characterized in that: The tube seat is made of 4J29 Kovar alloy, and the surface is gold-plated; the lead wire is made of 4J29 Kovar alloy, and the surface of the lead wire is gold-plated.

5. The energy storage welding package AGC intermediate frequency amplifier according to claim 1, characterized in that: The tube cap of the metal shell is adapted to the shape and size of the tube base, and the tube cap and the tube base are used in conjunction with each other to realize the energy storage welding packaging of the amplifier.

6. A test fixture for an energy storage welding packaged AGC intermediate frequency amplifier as claimed in any one of claims 1 to 5, characterized in that: It includes a socket, a copper block, and a test circuit board. The front and back sides of the test circuit board are both provided with grounding copper-clad areas. The copper block is tightly screwed to the center of the copper-clad area on the top layer of the test circuit board by screws; sockets are arranged on both sides of the copper block, and the copper block protrudes slightly higher than the sockets on both sides.

Images