Low-temperature ceramic phased-array antenna and manufacturing process thereof

Abstract

The invention provides a low-temperature ceramic phased-array antenna and a manufacturing process thereof, the antenna sequentially comprises an antenna array surface layer, a radio frequency component and a packaging feed layer, the radio frequency component is welded on a back plate of the antenna array surface layer, which is called as primary welding, and the primary welding temperature is higher than 220 DEG C; the antenna array surface layer and the packaging feed layer are respectively formed by co-firing a plurality of layers of low-temperature ceramic green tape sheets and a metal circuit, the sintering temperature of the low-temperature ceramic green tape sheets is 850-900 DEG C, the packaging feed layer comprises an upper part and a lower part, the upper part is used for packaging a radio frequency component, the lower part is used for feed output, and the upper part and the lower part are co-fired together. The whole phased-array antenna is formed by stacking and sintering the low-temperature ceramic green tapes, and the low-temperature ceramic green tapes are adopted as base materials, so that the phased-array antenna has relatively high reliability and stability under large temperature change and other severe environments, and the problem of warping of an antenna plane caused by the temperature change is avoided; the service life of the antenna is prolonged; and heat dissipation of the antenna is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a low-temperature ceramic phased array antenna and a manufacturing process thereof. Background Art

[0002] Most antenna units of traditional phased array antennas are made from PCB substrates or fired from high-temperature co-fired ceramics alone or mixed with high-temperature ceramics and low-temperature ceramics.

[0003] The base material of ordinary PCB is insulating material with low thermal conductivity, weak heat dissipation and thermal conduction capabilities, which affects the life of the entire antenna; its mechanical strength is low and it is easily affected by factors such as temperature and humidity, causing it to be easily warped in outdoor environments with large temperature changes and humidity, and other phenomena that lead to a decline in the performance of phased array antennas, especially a greater impact on scanning accuracy.

[0004] High-temperature ceramics have inherent defects in processing. Due to the high sintering temperature of about 1650℃, they cannot be used together with low-melting-point metals, such as copper (Cu, melting point: 1084.3℃), silver (Ag, melting point: 961.78℃) and gold (Au, melting point: 1064.76℃); they can only be used with high-melting-point metals, such as Al2O3 (melting point above 2700℃) or other high-melting-point metals (including metal compounds); resulting in the processing cost of high-temperature ceramics being much higher than that of low-temperature ceramics; at the same time, coupled with the poor electrical conductivity of high-melting-point metals or compounds, high-temperature ceramics are not suitable for use as the substrate for phased array antennas. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a low-temperature ceramic phased array antenna and a manufacturing process thereof to solve at least one of the above problems.

[0006] In a first aspect, a low-temperature ceramic phased array antenna is provided, which includes in sequence: an antenna array surface layer, radio frequency components, and a packaged feed layer. The radio frequency components are welded to the back plate of the antenna array surface layer, which is called primary welding, and the primary welding temperature is higher than 220°C; the antenna array surface layer and the packaged feed layer are respectively co-fired by multiple layers of low-temperature ceramic raw tape sheets and metal circuits, and the sintering temperature of the low-temperature ceramic raw tape is 850-900°C, wherein the packaged feed layer includes an upper and a lower part, the upper part is used to encapsulate radio frequency components, and the lower part is used for feeding output, and the upper and lower parts are co-fired together.

[0007] Optionally, the antenna array layer includes at least a first ceramic layer, a second ceramic layer, a third raw ceramic layer and a fourth ceramic layer along the antenna signal receiving direction, and each ceramic layer is composed of several layers of raw ceramic tape sheets; a metal microwave circuit is printed on the first ceramic layer to form a radiation surface; a horizontal polarization electrode is printed on the second ceramic layer; a vertical polarization electrode is printed on the third ceramic layer; and a metal circuit and a first grid metal ground are printed on the fourth ceramic layer.

[0008] Optionally, the package feed layer includes a plurality of fifth ceramic layers and a sixth ceramic layer; a plurality of cavities are cut on each of the fifth ceramic layers; and a metal circuit and a second grid metal ground are printed on the sixth ceramic layer.

[0009] Optionally, on the fifth ceramic layer, a plurality of metal holes are provided on the periphery of the cavity, and all the metal holes on the fifth ceramic layer are superimposed to form a first metal through hole; the height of the first metal through hole is the same as the height of the cavity, and a plurality of first metal through holes form a metal side wall around the cavity, and the first metal through hole is filled with metal; a plurality of cavities, metal side walls and the grid metal ground on the sixth ceramic layer together constitute a plurality of metal cavities with upper ends open; the number of metal cavities is the same as the number of RF components, and the positions correspond one to one; a secondary welding is performed between the packaged feed layer with the metal cavity with the upper end open and the antenna array layer with the RF components already welded thereon, and the secondary welding temperature is at least 30°C lower than the primary welding temperature.

[0010] Optionally, the bottom ceramic green tape at the lower part of the package feed layer is preset with circuits and gold-plated pads required for microwave components and other electronic components; the low-temperature ceramic green tapes of the package feed layer are co-fired together, and after co-firing, the microwave frequency conversion components and other electronic components are welded to the preset gold-plated pads of the package feed layer using the same welding temperature as the primary welding, so as to form a baseband processing component with intermediate frequency output that can be directly connected.

[0011] Optionally, each layer of the raw porcelain tape sheets of the antenna array surface layer is also provided with a second metal hole and a plurality of third metal holes surrounding the second metal holes, and the second metal holes of each layer of the raw porcelain tape sheets are superimposed to form a first coaxial line inner conductor; the third metal holes on each layer of the raw porcelain tape sheets are superimposed to form a first coaxial line outer conductor, the first coaxial line inner conductor is welded and connected to the radio frequency components, and the first coaxial line outer conductor is connected to the first grid metal ground on the fourth ceramic layer.

[0012] Optionally, each ceramic layer in the upper part of the package feed layer is also provided with a fourth metal through hole and a plurality of fifth metal through holes surrounding the fourth metal through holes; the fourth metal through holes on each layer of the raw porcelain tape sheets are superimposed to form a second coaxial line inner conductor; the fifth metal through holes on each layer of the raw porcelain tape sheets are superimposed to form a second coaxial line outer conductor; one end of the second coaxial line inner conductor is welded and connected to the RF component, and the other end of the second coaxial line inner conductor is connected to the feeding network of the lower part; the second coaxial line outer conductor is connected to the second grid metal ground on the sixth ceramic layer.

[0013] Optionally, the metal through holes between the layers of green porcelain tape sheets are staggered, and the staggered metal through holes are connected by planar metal microstrip lines.

[0014] In a second aspect, a manufacturing process of a low-temperature ceramic phased array antenna is provided, the process comprising:

[0015] Cutting the raw material of low-temperature ceramic green porcelain pieces into pieces to obtain a plurality of low-temperature ceramic green porcelain strip pieces;

[0016] According to the pre-designed antenna circuit structure, pre-processing is performed on the corresponding low-temperature ceramic green tape sheet, wherein the pre-processing is a combination of one or more operations of punching, cutting, pouring metal slurry and printing metal circuits; and the low-temperature ceramic green tape sheet to be sintered is obtained;

[0017] The low-temperature ceramic green tape sheets to be sintered are stacked in a preset order and sintered at one time to obtain an antenna array surface layer and a package feed layer respectively; wherein the package feed layer and the antenna array surface layer are co-fired separately; wherein the package feed layer includes an upper and a lower part, the upper part is used for encapsulating radio frequency components, and the lower part is used for feeding output, and the upper and lower parts are co-fired together;

[0018] Soldering the same number of RF components as the antenna array units of the antenna array layer on the back plate of the antenna array layer is called primary welding, and the primary welding temperature is higher than 220°C;

[0019] The package feed layer and the antenna array layer are fixed by secondary welding, and the secondary welding temperature is at least 30° C. lower than the primary welding temperature.

[0020] Optionally, the method further comprises:

[0021] The same number of cavities as the number of RF components are cut on the upper part of the package feed layer, and a number of metal holes are punched on the periphery of each cavity, and a plurality of metal holes are superimposed to form a first metal through hole; the height of the first metal through hole is the same as the height of the cavity, and a plurality of first metal through holes form a metal side wall around the cavity, and the first metal through hole is filled with metal; a plurality of cavities, metal side walls and the last layer of grid metal ground of the upper part of the package feed layer together constitute a plurality of metal cavities with upper ends opened; the positions of the metal cavities correspond one-to-one to the positions of the RF components, and each RF component is accommodated in a metal cavity.

[0022] The embodiment of the present invention provides a low-temperature ceramic phased array antenna and a manufacturing process thereof. The phased array antenna is entirely formed by stacking and sintering low-temperature ceramic green tapes, and uses low-temperature ceramic green tapes as a substrate, which has at least the following advantages:

[0023] 1. In the microwave and millimeter wave frequency band, when an antenna is made of low-temperature ceramic material with a dielectric constant of 5.5, its RF performance is better than that of a PCB substrate with the same dielectric constant;

[0024] 2. The ceramic substrate has high mechanical strength and bending resistance, and has high reliability and stability in severe environments with large temperature changes and other harsh environments, avoiding the problem of antenna warping caused by temperature changes;

[0025] 3. Suitable for applications in environments with large temperature changes (such as aerospace), which facilitates the heat dissipation of the antenna and effectively extends the life of the antenna;

[0026] 4. When it is necessary to combine with a glass substrate, the ceramic substrate is easier to combine with the glass substrate than the PCB substrate, and is more convenient for integration;

[0027] 5. The large-scale, one-to-one corresponding metal cavity design avoids the complex packaging requirements for each RF active device, greatly reduces the cost of the phased array antenna, and also improves the corresponding electrical performance;

[0028] 6. The antenna design has both horizontal and vertical electrodes, so that the antenna can be easily switched in polarization through software. It can switch freely between horizontal linear polarization, vertical linear polarization, left-hand circular polarization and right-hand circular polarization, making it suitable for almost all communication application scenarios.

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A schematic diagram of the layered structure of a low-temperature ceramic phased array antenna provided by an embodiment of the present invention is shown;

[0032] Figure 2 A schematic diagram of the structure of an antenna array surface layer provided in an embodiment of the present invention is shown;

[0033] Figure 3 A schematic structural diagram of the radiation surface of the antenna array layer provided in an embodiment of the present invention is shown;

[0034] Figure 4 A schematic diagram of the layered structure of the upper part of the package feed layer provided by an embodiment of the present invention is shown;

[0035] Figure 5 A schematic diagram of a cavity between an antenna array layer and a package feed layer provided in an embodiment of the present invention is shown;

[0036] Figure 6 A schematic flow chart of a manufacturing process of a low-temperature ceramic phased array antenna provided by an embodiment of the present invention is shown.

[0037] Explanation of main component symbols: 101, antenna array layer; 102, package feed layer; 1021, upper part of package feed layer; 1022, lower part of package feed layer; 103, antenna mask; 104, RF components; 105, gold wire; 1011, metal microwave circuit; 1012, horizontal polarization electrode; 1013, vertical polarization electrode; 1014, first grid metal ground; 1015, radiating surface; 1016, first coaxial line inner conductor; 1017, first coaxial line outer conductor; 10211, cavity; 10212, metal side wall; 10213, second grid metal ground; 10214, second coaxial line inner conductor; 10215, second coaxial line outer conductor. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0039] An embodiment of the present invention provides a low temperature ceramic phased array antenna, such as Figure 1 As shown, it is an 8*8 array of low-temperature ceramic-based phased array antenna, which includes, from top to bottom: an antenna array surface layer, RF components, and a package feed layer. The RF components are welded to the back plate of the antenna array surface layer, which is called primary welding. The primary welding temperature is higher than 2200C; the antenna array surface layer and the package feed layer are respectively co-fired by multiple layers of low-temperature ceramic green tape and metal circuits. The sintering temperature of the low-temperature ceramic green tape is 850-900℃, wherein the package feed layer includes an upper and lower part, the upper part is used to encapsulate RF components, and the lower part is used for feeding output, and the upper and lower parts are co-fired together.

[0040] The main function of the antenna array surface layer is to receive and radiate electromagnetic waves. It is formed by co-firing multiple layers of low-temperature ceramic raw tape and metal circuits. In a feasible implementation, the co-firing process is to first cut a number of low-temperature ceramic raw tape sheets, punch holes on each layer of raw tape sheets according to the designed antenna array structure, and pour metal slurry into each hole. The metal slurry can be a low-melting-point metal such as silver paste or copper paste, and then print a pre-designed metallization pattern on the metal area, stack the layers of raw tape sheets, and sinter them once to obtain the antenna array surface layer. Figure 1 The antenna array layer of the 8*8 array is composed of 8*8 antenna units.

[0041] The function of the package feed layer is, on the one hand, to package the required RF components, mainly low-noise amplifiers or power amplifiers, using metal cavities preset in the layer to avoid mutual interference between electromagnetic field signals in different channels. On the other hand, it is to synthesize the electromagnetic wave signals of all antenna units, amplify and convert the frequency, convert the microwave signal into an intermediate frequency electrical signal and then output it, or vice versa, convert the electrical signal into an electromagnetic wave signal and then send it out.

[0042] In the embodiment of the present invention, the antenna array surface layer and the package feed layer are all formed by stacking and sintering low-temperature ceramic raw tapes. Low-temperature co-fired ceramics are a low-cost, high-performance microwave ceramic material that can be widely used in communication components and has a relatively high quality factor Q value and dielectric constant. The metallization layer on the surface of the low-temperature co-fired ceramic substrate has a high conductivity. Therefore, it has unique technical advantages such as high operating frequency, high integration density, high temperature and humidity resistance, and can integrate active components, which is conducive to realizing microwave signal coupling or isolation. It is widely used in communications, aerospace, military, automotive electronics, medical and other fields.

[0043] Therefore, using low-temperature ceramic materials as substrates has at least the following advantages:

[0044] 1. When used in the microwave and millimeter wave frequency band, when using an antenna made of low-temperature ceramic material with a dielectric constant of 5.5, its RF performance is better than that of a PCB substrate with the same dielectric constant;

[0045] 2. The ceramic substrate has high mechanical strength and bending resistance, and has high reliability and stability in severe environments with large temperature changes and other harsh environments, avoiding the problem of antenna warping caused by temperature changes;

[0046] 3. Suitable for applications in environments with large temperature changes (such as aerospace), which facilitates the heat dissipation of the antenna and can effectively extend the life of the antenna;

[0047] 4. Directly using metal cavities on low-temperature ceramic substrates on a large scale and in a planar manner can effectively avoid the additional packaging costs caused by the need to use separate metal cavities for each RF component; it also avoids the difficulty of making metal cavities on PCBs and the resulting increase in processing costs;

[0048] 5. The planar stacked structure used in the present invention can replace the traditional T / R components and make full use of the micro-assembly processing technology. On the one hand, it can effectively reduce the cost, and on the other hand, it also makes the phased array antenna more planar and lightweight, which is convenient for installation and use;

[0049] 6. In the present invention, each array unit is designed with electrodes that can respectively realize vertical and horizontal linear polarization, and can receive and transmit single linear polarization electromagnetic waves, and can also receive and transmit circular polarization electromagnetic waves.

[0050] Based on the above embodiments, Figure 2 As shown, the antenna array layer includes at least a first ceramic layer, a second ceramic layer, a third raw ceramic layer and a fourth ceramic layer along the antenna signal receiving direction. Each ceramic layer is composed of several layers of raw ceramic tape sheets. The specific number of raw ceramic tape sheets is determined by the antenna design. A metal microwave circuit is printed on the first ceramic layer to form a radiation surface. Figure 3It is a schematic diagram of the radiation surface of one of the antenna units; the second ceramic layer is printed with a horizontally polarized electrode; the third ceramic layer is printed with a vertically polarized electrode; the fourth ceramic layer is printed with a metal circuit and a first grid metal ground.

[0051] It should be noted that the first to fourth ceramic layers are respectively composed of several layers of raw ceramic tape sheets, and the number of the raw ceramic tape sheets can be set according to the designed height of the antenna array.

[0052] In an embodiment of the present invention, a circularly polarized antenna unit is formed by two polarization electrodes laid vertically and horizontally, so as to generate the circular polarization required for satellite communication. Switching between left-hand circular polarization and right-hand circular polarization can be achieved through relevant software control methods.

[0053] Based on the above embodiments, Figure 4 As shown, the RF device package includes a plurality of fifth ceramic layers and a sixth ceramic layer; a plurality of cavities are cut on each of the fifth ceramic layers; and a metal circuit and a second grid metal ground are printed on the sixth ceramic layer.

[0054] The cavity can be cut by laser, and the shape of the cavity can be square or other regular shapes. The gridded metal ground helps to balance the proportion of metallized area and non-metallized area, thereby improving the flatness of the overall structure after sintering; at the same time, it can also reduce the use of metal slurry and effectively reduce the cost of the antenna.

[0055] The number of green ceramic tape sheets that make up the fifth ceramic layer is determined according to the required depth of the cavity. For example, when using 100um low-temperature ceramic green ceramic tape sheets, if a 500um deep cavity is required, 5 low-temperature ceramic green ceramic tape sheets need to be laser cut in the same way. Then, they are co-fired with the sixth layer of grid metal ground and other required low-temperature ceramic green ceramic tape sheets.

[0056] On the fifth ceramic layer, a plurality of metal through holes are provided on the periphery of the side wall of the cavity, and all the metal through holes on the fifth ceramic layer are superimposed to form a first metal through hole; the height of the first metal through hole is the same as the height of the cavity, and a plurality of first metal through holes surround the cavity to form a metal side wall, and the first metal through hole is filled with metal. In one example, the metal is silver. A plurality of cavities, metal side walls and the grid metal ground on the sixth ceramic layer together form a plurality of metal cavities with upper ends opened; the number of metal cavities is the same as the number of RF components, and the positions correspond one to one; a secondary welding is performed between the package feed layer with the metal cavity with the upper end opened and the antenna array layer with the RF components already welded thereon, and the secondary welding temperature is at least 30°C lower than the primary welding temperature.

[0057] The traditional method is to directly brush a layer of metal on the side wall of the cavity to avoid interference of electromagnetic waves between channels. However, due to the large number of cavities, it is impossible to brush metal one by one. Therefore, the embodiment of the present invention realizes the form of metal side walls equivalent to the existing method through metal through holes on the periphery of the cavity, which can achieve electromagnetic wave shielding function between adjacent channels.

[0058] It should be noted that the metal through holes are arranged according to the preset arrangement rules to ensure that no electromagnetic wave signal can be leaked. And when designing, each metal side wall is separated from the cavity side wall by a preset distance to prevent collapse caused by too many layers of low-temperature ceramic green tape.

[0059] like Figure 5 As shown, a number of radio frequency components are installed on the other side of the antenna array layer opposite to the radiation surface. The radio frequency components are buried in the cavity, and the number of the radio frequency components is the same as the cavity.

[0060] like Figure 5 As shown, each layer of the raw porcelain tape sheets of the antenna array surface layer is also provided with a second metal through hole and a plurality of third metal through holes surrounding the second metal through holes, and the second metal through holes of the raw porcelain tape sheets of each layer are superimposed to form an equivalent coaxial line inner conductor; the third metal through holes on the raw porcelain tape sheets of each layer are superimposed to form an equivalent first coaxial line outer conductor, the first coaxial line inner conductor is welded and connected to the radio frequency components, and the first coaxial line outer conductor is connected to the first grid metal ground on the fourth ceramic layer.

[0061] like Figure 4 and Figure 5 As shown, each layer of raw porcelain tape sheets in the upper part of the package feed layer is also provided with a fourth metal through hole and a plurality of fifth metal through holes surrounding the fourth metal through holes; the fourth metal through holes on each layer of raw porcelain tape sheets are superimposed to form an equivalent second coaxial line inner conductor; the fifth metal through holes on each layer of raw porcelain tape sheets are superimposed to form an equivalent second coaxial line outer conductor; one end of the second coaxial line inner conductor is welded and connected to the RF component, and the other end of the second coaxial line inner conductor is connected to the feeding network of the lower part; the second coaxial line outer conductor is connected to the second grid metal ground on the sixth ceramic layer.

[0062] In an embodiment of the present invention, equivalent coaxial structures are formed by the first coaxial inner conductor, the first coaxial outer conductor, the second coaxial inner conductor, and the second coaxial outer conductor, respectively, and the electromagnetic wave signal received by the antenna array layer is transmitted to the feeding network through the coaxial structure.

[0063] It should be noted that if Figure 4 As shown, the second mesh metal ground should avoid contact with the second coaxial inner conductor and the second coaxial outer conductor to prevent electromagnetic waves from being absorbed and thus unable to radiate.

[0064] In the embodiment of the present invention, the metal through holes between the layers of green porcelain tapes are staggered, and the staggered metal through holes are connected by planar metal microstrip lines.

[0065] The problem of ceramic plane warping caused by the concentrated arrangement of a large number of metal through holes can be avoided by staggered arrangement. The staggered arrangement is one of the reasons why antennas with larger sizes than those on the market can be produced.

[0066] like Figure 1 As shown, the bottom ceramic green tape at the lower part of the package feed layer is preset with circuits and gold-plated pads required for microwave components and other electronic components; the low-temperature ceramic green tapes of the package feed layer are co-fired together, and after co-firing, the microwave frequency conversion components and other electronic components are welded to the preset gold-plated pads of the package feed layer using the same welding temperature as the primary welding, so as to form a baseband processing component with intermediate frequency output that can be directly connected.

[0067] Based on the same inventive concept, a manufacturing process of a low-temperature ceramic phased array antenna is provided, such as Figure 6 As shown, the process includes the following steps:

[0068] Step S601: cutting the raw material of low-temperature ceramic green tiles into a plurality of low-temperature ceramic green tiles.

[0069] Step S602: Preprocessing is performed on the corresponding low-temperature ceramic green tape according to the pre-designed antenna circuit structure, wherein the preprocessing is a combination of one or more operations of punching, cutting, pouring metal slurry and printing metal circuits; and a low-temperature ceramic green tape to be sintered is obtained.

[0070] Step S603: stack the low-temperature ceramic green tape sheets to be sintered in a preset order and then sinter them at one time to obtain the antenna array surface layer and the package feed layer respectively; wherein the package feed layer and the antenna array surface layer are co-fired separately; wherein the package feed layer includes an upper and a lower part, the upper part is used for packaging RF components, and the lower part is used for feeding output, and the upper and lower parts are co-fired together.

[0071] Taking the package feed layer as an example, the sintering process is described in detail. It includes the following steps:

[0072] Step S6031: Determine the number of low-temperature ceramic green tape sheets that need to be cut according to the depth of the cavity that needs to be cut.

[0073] Step S6032: laser cutting a plurality of cavities on the low-temperature ceramic green tape sheet to be cut, with the positions of the cavities between the layers corresponding to each other.

[0074] In this step, the number of cavities is the same as the number of RF components.

[0075] Step S6033: punching along the periphery of the cavity to obtain a plurality of metal holes; pouring metal into each metal hole to form a first metal through hole, and the plurality of first metal through holes surround the cavity to form a metal side wall.

[0076] Step S6034: designing a second grid metal ground on the next layer of low-temperature ceramic green tape sheet of the cut low-temperature ceramic green tape sheet.

[0077] The plurality of cavities, the metal sidewalls and the second mesh metal ground together form a plurality of metal cavities with upper ends opened. The number of metal cavities is the same as the number of RF components, and the positions correspond one to one, so that each RF component is accommodated in a metal cavity.

[0078] Step S6035: sintering the metal cavity, the low-temperature ceramic green tape sheet where the second grid metal ground is located, and other uncut low-temperature ceramic green tape sheets for power feeding output together.

[0079] Step S604: welding the same number of radio frequency components as the antenna array units of the antenna array layer on the back plate of the antenna array layer, which is called primary welding, and the primary welding temperature is higher than 220°C.

[0080] Step S605: Fix the package feed layer and the antenna array layer by secondary welding, wherein the secondary welding temperature is at least 30° C. lower than the primary welding temperature.

[0081] In this step, the antenna array layer is connected to the package feed layer by welding, and the welding temperature is about 180°C.

[0082] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0083] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0084] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0085] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can still modify the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or perform equivalent replacements on some of the technical features thereof; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. They should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A low temperature ceramic phased array antenna, characterized in that: Including in order: Antenna array surface layer, radio frequency components, and packaged feed layer. The radio frequency components are welded on the back plate of the antenna array surface layer, which is called primary welding. The temperature of the primary welding is higher than 220°C. The antenna array surface layer and the packaged feed layer are respectively co-fired by multiple layers of low-temperature ceramic raw tape and metal circuits. The sintering temperature of the low-temperature ceramic raw tape is 850-900°C. The packaged feed layer includes an upper and a lower part. The upper part is used to encapsulate the radio frequency components, and the lower part is used for feeding output. The upper and lower parts are co-fired together.

2. The low-temperature ceramic phased array antenna according to claim 1, characterized in that: The antenna array layer includes at least a first ceramic layer, a second ceramic layer, a third ceramic layer and a fourth ceramic layer along the antenna signal transmission direction, each ceramic layer is composed of a plurality of layers of raw ceramic tape sheets; a metal microwave circuit is printed on the first ceramic layer to form a radiation surface; The second ceramic layer is printed with a horizontal polarization electrode; the third ceramic layer is printed with a vertical polarization electrode; and the fourth ceramic layer is printed with a metal circuit and a first grid metal ground.

3. The low temperature ceramic phased array antenna according to claim 1, characterized in that: The package feed layer includes a plurality of fifth ceramic layers and a sixth ceramic layer; a plurality of cavities are cut on the plurality of fifth ceramic layers; a metal circuit and a second grid metal ground are printed on the sixth ceramic layer.

4. The low-temperature ceramic phased array antenna according to claim 3, characterized in that: On the fifth ceramic layer, a plurality of metal holes are provided on the periphery of the cavity, and the metal holes on all the fifth ceramic layers are superimposed to form a first metal through hole; the height of the first metal through hole is the same as the height of the cavity, and a plurality of the first metal through holes form a metal side wall around the cavity, and the first metal through hole is filled with metal; the plurality of cavities, the metal side walls and the grid metal ground on the sixth ceramic layer together constitute a plurality of metal cavities with upper ends opened; the number of the metal cavities is the same as the number of RF components, and the positions correspond one to one; a secondary welding is performed between the package feed layer with the metal cavity with the upper end opened and the antenna array layer with the RF components already welded thereon, and the secondary welding temperature is at least 30°C lower than that of the primary welding.

5. The low temperature ceramic phased array antenna according to claim 4, characterized in that: The bottom ceramic raw tape at the lower part of the package feed layer is preset with circuits and gold-plated pads required for microwave components and other electronic components; the low-temperature ceramic raw tapes of the package feed layer are co-fired together, and after co-firing, the microwave frequency conversion components and other electronic components are welded on the preset gold-plated pads of the package feed layer using the same welding temperature as the primary welding, so as to form a baseband processing component with intermediate frequency output that can be directly connected.

6. The low temperature ceramic phased array antenna according to claim 2, characterized in that: Each layer of the raw porcelain tape sheets of the antenna array surface layer is also provided with a second metal hole and a plurality of third metal holes surrounding the second metal holes, and the second metal holes of the raw porcelain tape sheets of each layer are superimposed to form a first coaxial line inner conductor; the third metal holes on the raw porcelain tape sheets of each layer are superimposed to form a first coaxial line outer conductor, the first coaxial line inner conductor is welded and connected to the radio frequency components, and the first coaxial line outer conductor is connected to the first grid metal ground on the fourth ceramic layer.

7. The low-temperature ceramic phased array antenna according to claim 3, characterized in that: A fourth metal through hole and a plurality of fifth metal through holes surrounding the fourth metal through hole are also provided on each ceramic layer in the upper part of the package feed layer; the fourth metal through holes on each layer of the raw porcelain tape sheets are superimposed to form a second coaxial line inner conductor; the fifth metal through holes on each layer of the raw porcelain tape sheets are superimposed to form a second coaxial line outer conductor; one end of the second coaxial line inner conductor is welded and connected to the RF component, and the other end of the second coaxial line inner conductor is connected to the feeding network of the lower part; the second coaxial line outer conductor is connected to the second grid metal ground on the sixth ceramic layer.

8. The low temperature ceramic phased array antenna according to any one of claims 4, 6 and 7, characterized in that: The metal through holes between the layers of raw porcelain tape sheets are staggered, and the staggered metal through holes are connected by planar metal microstrip lines.

9. A process for manufacturing a low-temperature ceramic phased array antenna, characterized in that: The process comprises: Cutting the raw material of low-temperature ceramic green porcelain pieces into pieces to obtain a plurality of low-temperature ceramic green porcelain strip pieces; According to the pre-designed antenna circuit structure, pre-processing is performed on the corresponding low-temperature ceramic green tape sheet, wherein the pre-processing is a combination of one or more operations of punching, cutting, pouring metal slurry and printing metal circuits; and the low-temperature ceramic green tape sheet to be sintered is obtained; The low-temperature ceramic green tape sheets to be sintered are stacked in a preset order and sintered at one time to obtain an antenna array surface layer and a package feed layer respectively; wherein the package feed layer and the antenna array surface layer are co-fired separately; wherein the package feed layer comprises an upper part and a lower part, the upper part is used for encapsulating radio frequency components, and the lower part is used for feeding output, and the upper and lower parts are co-fired together; Soldering the same number of radio frequency components as the antenna array units of the antenna array layer on the back plate of the antenna array layer is called primary welding, and the primary welding temperature is higher than 220° C.; The package feed layer and the antenna array surface layer are fixed by secondary welding, and the secondary welding temperature is at least 30° C. lower than the primary welding temperature.

10. The manufacturing process of the low temperature ceramic phased array antenna according to claim 9, characterized in that: The method further comprises: The same number of cavities as the number of RF components are cut on the upper part of the package feed layer, and a plurality of metal holes are punched on the periphery of each cavity, and a plurality of metal holes are stacked to form a first metal through hole; the height of the first metal through hole is the same as the height of the cavity, and a plurality of the first metal through holes form a metal side wall around the cavity, and the first metal through hole is filled with metal; a plurality of cavities, metal side walls and the last layer of grid metal ground of the upper part of the package feed layer together constitute a plurality of metal cavities with upper ends open; the positions of the metal cavities correspond one-to-one to the positions of the RF components, and each RF component is accommodated in one of the metal cavities.

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