Low-temperature ceramic phased array antenna and manufacturing process thereof

Abstract

The application provides a low-temperature ceramic phased array antenna and a manufacturing process thereof. The antenna comprises, in sequence, an antenna array layer, a radio frequency component, and a packaging feed layer. The radio frequency component is welded on a back plate of the antenna array layer, which is called primary welding, and the primary welding temperature is higher than 220 DEG C. The antenna array layer and the packaging feed layer are respectively formed by co-firing of a plurality of low-temperature ceramic green ceramic tape pieces and metal circuits. The sintering temperature of the low-temperature ceramic green ceramic tape is 850-900 DEG C. The packaging feed layer comprises upper and lower parts. The upper part is used for packaging the radio frequency component, and the lower part is used for feed output. The upper and lower parts are co-fired together. The phased array antenna is entirely formed by stacking and sintering of low-temperature ceramic green ceramic tapes. The low-temperature ceramic green ceramic tapes are used as base materials, and the antenna has high reliability and stability under large temperature change and other harsh environments, thereby avoiding antenna plane warping caused by temperature change, prolonging the service life of the antenna, and facilitating heat dissipation of the antenna.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antenna, in particular to a low-temperature ceramic phased array antenna and a manufacturing process thereof. BACKGROUND

[0002] Most of the antenna units of the conventional phased array antenna are processed from the PCB substrate or are separately sintered from the high-temperature co-fired ceramic or are mixedly processed from the high-temperature ceramic and the low-temperature ceramic.

[0003] The base material of the common PCB is insulating material, which has low thermal conductivity, weak heat dissipation and heat conduction capacity, and affects the service life of the whole antenna; the mechanical strength of the common PCB is low, and the common PCB is easily affected by temperature and humidity and other factors, leading to the warping of the common PCB and other phenomena that cause the performance of the phased array antenna to decrease, especially the scanning accuracy.

[0004] The high-temperature ceramic has congenital defects in processing. Since the sintering temperature is about 1650℃, the high-temperature ceramic 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℃), but can only be used together with high-melting-point metals such as Al2O3 (melting point above 2700℃) or other high-melting-point metals (including metal compounds); the processing cost of the high-temperature ceramic is much higher than that of the low-temperature ceramic; at the same time, the high-temperature ceramic is not suitable for being used as the base material of the phased array antenna because of the poor conductivity of the high-melting-point metals or compounds. SUMMARY

[0005] Therefore, the present application aims 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 comprises, in sequence, an antenna array layer, radio frequency components and a packaging and feeding layer, the radio frequency components are welded on the back plate of the antenna array layer, which is called primary welding, and the primary welding temperature is higher than 220℃; the antenna array layer and the packaging and feeding layer are respectively co-sintered from a plurality of low-temperature ceramic green ceramic tapes and metal circuits, the sintering temperature of the low-temperature ceramic green ceramic tape is 850-900℃, and the packaging and feeding layer comprises an upper part and a lower part, the upper part is used for packaging the radio frequency components, the lower part is used for feeding output, and the upper part and the lower part are co-sintered together.

[0007] Optionally, the antenna array layer comprises at least the first ceramic layer, the second ceramic layer, the third green ceramic layer and the fourth ceramic layer along the antenna signal receiving direction, each ceramic layer is composed of a plurality of green ceramic strip pieces; the first ceramic layer is printed with a metal microwave circuit 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 mesh metal ground.

[0008] Optionally, the packaging feed layer comprises 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 the sixth ceramic layer is printed with a metal circuit and a second mesh metal ground.

[0009] Optionally, a plurality of metal holes are arranged on the fifth ceramic layer at the outer periphery of the cavity, 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, the plurality of 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 wall and the mesh metal ground on the sixth ceramic layer together form a plurality of metal cavities with open upper ends; the number of the metal cavities is the same as the number of the radio frequency components and the positions are one-to-one corresponding; the packaging feed layer with the metal cavities with open upper ends is subjected to secondary welding with the antenna array layer on which the radio frequency components are welded, and the secondary welding is at least 30℃ lower than the primary welding.

[0010] Optionally, the bottom layer green ceramic strip of the lower part of the packaging feed layer is pre-provided with circuits and gold-plated pads required by microwave components and other electronic components; the low-temperature green ceramic strips of the packaging feed layer are co-fired together, and after co-firing, the microwave frequency conversion components and other electronic components are welded on the pre-provided gold-plated pads of the packaging feed layer using the same welding temperature as the primary welding, so as to form a baseband processing component with intermediate frequency output which can be directly connected.

[0011] Optionally, the green ceramic strip pieces of each layer of the antenna array layer are further provided with a second metal hole and a plurality of third metal holes surrounding the second metal hole, the second metal holes of the green ceramic strip pieces of each layer are superimposed to form a first coaxial inner conductor; the third metal holes of the green ceramic strip pieces of each layer are superimposed to form a first coaxial outer conductor, the first coaxial inner conductor is welded and connected with the radio frequency components, and the first coaxial outer conductor is connected with the first mesh metal ground on the fourth ceramic layer.

[0012] Optionally, the ceramic layers of the upper part of the packaging feed layer are further provided with a fourth metal via hole and a plurality of fifth metal via holes surrounding the fourth metal via hole; the fourth metal via holes on the green ceramic strips of each layer are stacked to form a second coaxial inner conductor; the fifth metal via holes on the green ceramic strips of each layer are stacked to form a second coaxial outer conductor; one end of the second coaxial inner conductor is welded to the radio frequency component, and the other end of the second coaxial inner conductor is connected to the feed network of the lower part; the second coaxial outer conductor is connected to the second grid metal on the sixth ceramic layer.

[0013] Optionally, the metal via holes between the green ceramic strips are misaligned, and the misaligned metal via 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, and the process comprises:

[0015] The raw materials of the low-temperature ceramic green ceramic sheet are cut to obtain a plurality of low-temperature ceramic green ceramic strips;

[0016] According to the pre-designed antenna circuit structure, the corresponding low-temperature ceramic green ceramic strips are pre-processed, the pre-processing is a combination of one or more of punching, cutting, filling metal slurry, and printing metal circuit operations; and the low-temperature ceramic green ceramic strips to be sintered are obtained;

[0017] The low-temperature ceramic green ceramic strips to be sintered are stacked in a predetermined order and then sintered at one time to obtain an antenna array layer and a packaging feed layer; wherein the packaging feed layer and the antenna array layer are separately co-sintered; wherein the packaging feed layer includes an upper part and a lower part, the upper part is used for packaging radio frequency components, and the lower part is used for feed output, and the upper and lower parts are co-sintered together;

[0018] The radio frequency components are welded on the back plate of the antenna array layer, and the number of the radio frequency components is the same as the number of the antenna array units of the antenna array layer, which is called first welding, and the first welding temperature is higher than 220℃;

[0019] The packaging feed layer and the antenna array layer are fixed by second welding, and the second welding temperature is at least 30℃ lower than the first welding temperature.

[0020] Optionally, the method further comprises:

[0021] Cut cavities same in number as the radio frequency components on the upper part of the package feed layer, set a plurality of metal holes around the outer 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 same as the height of the cavity, 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 layer of the last layer of the upper part of the package feed layer together form a plurality of metal cavities with an open upper end; the positions of the metal cavities correspond one-to-one to the positions of the radio frequency components, and each radio frequency component is accommodated in a metal cavity.

[0022] The low-temperature ceramic phased array antenna and the manufacturing process thereof have at least the following advantages:

[0023] 1. In the microwave and millimeter wave frequency band, the antenna made of low-temperature ceramic material with a dielectric constant of 5.5 has better radio frequency performance than the PCB substrate with the same dielectric constant.

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

[0025] 3. It is suitable for use in environments with large temperature changes (such as aerospace), facilitates heat dissipation of the antenna, and effectively prolongs the service life of the antenna.

[0026] 4. When used in combination with a glass substrate, the ceramic substrate is easier to combine with the glass substrate than the PCB substrate, making it easier to integrate.

[0027] 5. Large-scale, one-to-one correspondence with radio frequency active devices, one-time molding of metal cavities, avoiding complex packaging requirements for each radio frequency active device, greatly reducing the cost of phased array antennas, and improving the corresponding electrical performance.

[0028] 6. The antenna design has both horizontal and vertical electrodes, making it easy to switch the polarization of the antenna through software, allowing it to switch between horizontal linear polarization, vertical linear polarization, left circular polarization and right circular polarization, making it suitable for almost all communication application scenarios.

[0029] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as a limitation to the scope. Other related drawings can also be obtained by those of ordinary skill in the art without any creative effort, on the premise of not paying any creative effort.

[0031] Figure 1 A schematic diagram of the layered structure of the low-temperature ceramic phased array antenna provided by the embodiments of the present application is shown.

[0032] Figure 2 A schematic diagram of the structure of the antenna array layer provided by the embodiments of the present application is shown.

[0033] Figure 3 A schematic diagram of the structure of the radiation surface of the antenna array layer provided by the embodiments of the present application is shown.

[0034] Figure 4 A schematic diagram of the layered structure of the upper part of the packaging feed layer provided by the embodiments of the present application is shown.

[0035] Figure 5 A schematic diagram of the cavity between the antenna array layer and the packaging feed layer provided by the embodiments of the present application is shown.

[0036] Figure 6 A flowchart of a manufacturing process of a low-temperature ceramic phased array antenna provided by the embodiments of the present application is shown.

[0037] Main element symbol explanation: 101, antenna array layer; 102, packaging feed layer; 1021, upper part of the packaging feed layer; 1022, lower part of the packaging feed layer; 103, antenna cover; 104, RF component; 105, gold wire; 1011, metal microwave circuit; 1012, horizontal polarization electrode; 1013, vertical polarization electrode; 1014, first mesh metal ground; 1015, radiation surface; 1016, first coaxial inner conductor; 1017, first coaxial outer conductor; 10211, cavity; 10212, metal side wall; 10213, second mesh metal ground; 10214, second coaxial inner conductor; 10215, second coaxial outer conductor. DETAILED DESCRIPTION

[0038] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0039] The embodiments of the present application provide a low-temperature ceramic phased array antenna, such as Figure 1 As shown in Fig. 1, it is an 8*8 array low-temperature ceramic base phased array antenna, which comprises, from top to bottom, an antenna array layer, radio frequency components, and a packaging and feeding layer. The radio frequency components are welded on the back plate of the antenna array layer, which is called primary welding, and the primary welding temperature is higher than 2200C. The antenna array layer and the packaging and feeding layer are respectively co-fired by multiple low-temperature ceramic green ceramic tapes and metal circuits. The sintering temperature of the low-temperature ceramic green ceramic tape is 850-900℃. The packaging and feeding layer comprises upper and lower parts. The upper part is used for packaging the radio frequency components, and the lower part is used for feeding output. The upper and lower parts are co-fired together.

[0040] The antenna array layer mainly functions to receive and radiate electromagnetic waves, and is co-fired by multiple low-temperature ceramic green ceramic tapes and metal circuits. In a feasible implementation, the co-firing process is as follows. First, a plurality of low-temperature ceramic green ceramic tapes are obtained by cutting. Holes are punched on each layer of green ceramic tape according to the designed antenna array structure. Metal paste is poured into each hole. The metal paste can be silver paste, copper paste or other low-melting-point metal. Then, a pre-designed metallized pattern is printed on the metal area. The green ceramic tapes are stacked and co-fired to obtain the antenna array layer. As shown in Fig. 2, the 8*8 array antenna array layer comprises 8*8 antenna units. Figure 1 The antenna array layer mainly functions to receive and radiate electromagnetic waves, and is co-fired by multiple low-temperature ceramic green ceramic tapes and metal circuits. In a feasible implementation, the co-firing process is as follows. First, a plurality of low-temperature ceramic green ceramic tapes are obtained by cutting. Holes are punched on each layer of green ceramic tape according to the designed antenna array structure. Metal paste is poured into each hole. The metal paste can be silver paste, copper paste or other low-melting-point metal. Then, a pre-designed metallized pattern is printed on the metal area. The green ceramic tapes are stacked and co-fired to obtain the antenna array layer. As shown in Fig. 2, the 8*8 array antenna array layer comprises 8*8 antenna units.

[0041] The packaging and feeding layer has two functions. On the one hand, it uses the metal cavity preset in the layer to package the required radio frequency components, mainly low-noise amplifiers or power amplifiers, to avoid mutual interference of electromagnetic field signals in different channels. On the other hand, it synthesizes the electromagnetic wave signals of all antenna units, amplifies and converts the microwave signals into intermediate frequency electrical signals, and then outputs them, or converts the electrical signals into electromagnetic wave signals and then outputs them.

[0042] In the embodiment of the present application, the antenna array layer and the packaging feed layer are all formed by stacking and sintering low-temperature ceramic green ceramic tapes, the low-temperature co-fired ceramic is a kind of microwave ceramic material with low cost, high performance and large-scale application in communication components, which has relatively high quality factor Q value and dielectric constant. The metallization layer on the surface of the low-temperature co-fired ceramic substrate has high conductivity. Therefore, it has the advantages of high working frequency, high integration density, high temperature and humidity resistance, and can integrate active components, which is beneficial to realize the unique technical advantages of microwave signal coupling or isolation, and is widely used in the fields of communication, aerospace, military, automotive electronics, medical treatment and the like.

[0043] Therefore, by using low-temperature ceramic material as a substrate, at least the following advantages are obtained:

[0044] 1. When applied in the microwave and millimeter wave frequency band, the antenna made of low-temperature ceramic material with a dielectric constant of 5.5 has better radio frequency performance than the PCB substrate with the same dielectric constant;

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

[0046] 3. It is suitable for use in environments with large temperature changes (such as aerospace), facilitates heat dissipation of the antenna, and can effectively prolong the service life of the antenna;

[0047] 4. Large-scale planarization of metal cavities on low-temperature ceramic substrates can effectively avoid the additional packaging cost of using separate metal cavities for each radio frequency component; at the same time, it also avoids the difficulty of manufacturing metal cavities on PCBs and the increase in processing cost;

[0048] 5. The planar laminated structure used in the present application can replace the traditional T / R module, fully utilize the micro-assembly process, effectively reduce the cost on one hand, and make the phased array antenna more planar and lightweight on the other hand, which is convenient for installation and use;

[0049] 6. In the present application, each array unit is designed with electrodes capable of realizing vertical and horizontal linear polarization respectively, which can receive and transmit single linearly polarized electromagnetic waves, or receive and transmit circularly polarized electromagnetic waves.

[0050] Based on the above embodiment, as shown in Figure 2 the antenna array layer along the antenna signal receiving direction comprises at least a first ceramic layer, a second ceramic layer, a third green ceramic layer and a fourth ceramic layer, each ceramic layer is composed of a plurality of green ceramic tape pieces, and the specific number of green ceramic tape pieces is determined by the antenna design; the first ceramic layer is printed with a metal microwave circuit to form a radiation surface, as shown in Figure 3The diagram shows a schematic of the radiating surface of one of the antenna elements; horizontal polarization electrodes are printed on the second ceramic layer; vertical polarization electrodes are printed on the third ceramic layer; and metal circuits and a first grid metal ground are printed on the fourth ceramic layer.

[0051] It should be noted that the first to fourth ceramic layers are each composed of several layers of green ceramic strips, and the number of green ceramic strips can be set according to the height of the antenna array design.

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

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

[0054] The cavity can be laser-cut, and its shape can be square or other regular shapes. The gridded metal ground helps balance the proportion of metallized and non-metallized areas, thereby improving the overall flatness of the structure after sintering; at the same time, it can also reduce the amount of metal paste used, effectively reducing antenna costs.

[0055] The number of green ceramic strips forming the fifth ceramic layer is determined by the required depth of the cavity. For example, when using 100µm low-temperature green ceramic strips, if a cavity depth of 500µm is required, five low-temperature green ceramic strips need to be laser-cut in the same way. These are then co-fired together with the sixth layer (which has a mesh metal ground) and other required low-temperature green ceramic strips.

[0056] On the fifth ceramic layer, several metal vias are provided on the outer periphery of the sidewall of the cavity. All the metal vias on the fifth ceramic layer are stacked to form a first metal via. The height of the first metal via is the same as the height of the cavity. Several first metal vias surround the cavity to form a metal sidewall, and the first metal via is filled with metal. In one example, the metal is silver. Several cavities, metal sidewalls, and a grid metal ground on the sixth ceramic layer together form several metal cavities with open tops. The number of metal cavities is the same as the number of RF components, and their positions correspond one-to-one. The encapsulation feed layer with the metal cavities with open tops is secondary welded to the antenna array layer with RF components already soldered on. The secondary welding temperature is at least 30°C lower than the primary welding temperature.

[0057] The traditional way is to directly brush a layer of metal on the side wall of the cavity to avoid the interference of electromagnetic waves between the mutual channels, but due to the large number of cavities, it is impossible to realize the metal brushing one by one, therefore, the embodiment of the present application realizes the form of the equivalent metal side wall of the existing mode through the metal through hole on the outer periphery of the cavity, and the electromagnetic wave shielding function between the adjacent channels can be realized.

[0058] It should be noted that the metal through hole is arranged according to a preset arrangement rule to ensure that electromagnetic wave signals cannot be leaked out. And a preset distance is designed between each metal side wall and the side wall of the cavity to prevent the collapse caused by too many layers of low-temperature ceramic green tapes.

[0059] As shown in Figure 5 , a plurality 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 embedded in the cavities, and the number of the radio frequency components is the same as that of the cavities.

[0060] As shown in Figure 5 , the second metal through hole and a plurality of third metal through holes surrounding the second metal through hole are further arranged on each layer of the ceramic green tape, the second metal through holes of each layer of the ceramic green tape are superimposed to form an equivalent inner conductor of a coaxial line; the third metal through holes on each layer of the ceramic green tape are superimposed to form an equivalent outer conductor of the first coaxial line, the first coaxial line inner conductor is welded and connected with the radio frequency component, and the first coaxial line outer conductor is connected with the first grid metal ground on the fourth ceramic layer.

[0061] As shown in Figure 4 and Figure 5 , the fourth metal through hole and a plurality of fifth metal through holes surrounding the fourth metal through hole are further arranged on each layer of the ceramic green tape on the upper part of the packaging feed layer; the fourth metal through holes on each layer of the ceramic green tape are superimposed to form an equivalent inner conductor of a second coaxial line; the fifth metal through holes on each layer of the ceramic green tape are superimposed to form an equivalent outer conductor of the second coaxial line; one end of the second coaxial line inner conductor is welded and connected with the radio frequency component, and the other end of the second coaxial line inner conductor is connected with the feed network of the lower part; the second coaxial line outer conductor is connected with the second grid metal ground on the sixth ceramic layer.

[0062] In the embodiment of the present application, the first coaxial line inner conductor, the first coaxial line outer conductor, the second coaxial line inner conductor and the second coaxial line outer conductor respectively form equivalent coaxial structures, and the electromagnetic wave signals received by the antenna array layer are transmitted into the feed network through the coaxial structure.

[0063] It should be noted that, as shown in Figure 4 , the second grid metal ground and the second coaxial line inner conductor and the second coaxial line outer conductor should avoid contact to prevent the electromagnetic wave from being absorbed and thus unable to be radiated out.

[0064] In the embodiment of the present application, the metal through holes between the layers of green ceramic strips are arranged in a staggered manner, and the staggered metal through holes are connected by planar metal microstrip lines.

[0065] By staggering, the warping problem of the ceramic plane caused by the concentration of a large number of metal through holes can be avoided. This staggering is one of the reasons why larger size antennas can be produced compared to those on the market.

[0066] As shown in Figure 1 , the bottom layer of the green ceramic strip of the lower part of the packaging feed layer is pre-provided with the circuit and gold-plated pads required by the microwave components and other electronic components; the low-temperature ceramic green ceramic strips of the packaging feed layer are co-fired together, and after co-firing, the microwave frequency conversion components and other electronic components are soldered on the pre-provided gold-plated pads of the packaging feed layer using the same soldering temperature as the first soldering, 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 for a low-temperature ceramic phased array antenna is provided, as shown in Figure 6 , the process comprises the following steps:

[0068] Step S601: cutting the raw material of the low-temperature ceramic green ceramic sheet to obtain a plurality of low-temperature ceramic green ceramic strips.

[0069] Step S602: according to the pre-designed antenna circuit structure, pre-treat the corresponding low-temperature ceramic green ceramic strip by one or more of the following operations: punching, cutting, filling metal slurry and printing metal circuit; obtain the low-temperature ceramic green ceramic strip to be sintered.

[0070] Step S603: stack the low-temperature ceramic green ceramic strips to be sintered in a predetermined order and sinter them at one time to obtain an antenna array layer and a packaging feed layer; wherein the packaging feed layer and the antenna array layer are separately co-fired; wherein the packaging feed layer includes upper and lower parts, the upper part is used for packaging radio frequency components, and the lower part is used for feed output, and the upper and lower parts are co-fired together.

[0071] Taking the packaging 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 ceramic strips to be cut according to the depth of the cavities to be cut.

[0073] Step S6032: laser cut a plurality of cavities on the low-temperature ceramic green ceramic strip to be cut, and the cavity positions between the layers correspond.

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

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

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

[0077] The plurality of cavities, the metal side wall and the second grid metal ground together form a plurality of open-end metal cavities. The number of metal cavities is the same as the number of radio frequency components, and the positions are one-to-one corresponding, each radio frequency component is contained in a metal cavity.

[0078] Step S6035: sinter the low-temperature ceramic green ceramic tape with the metal cavities and the second grid metal ground, and other low-temperature ceramic green ceramic tapes for feeding output which are not cut.

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

[0080] Step S605: secondary welding and fixing the packaging feeding layer and the antenna array layer, the secondary welding temperature is at least 30℃ lower than the primary welding temperature.

[0081] In this step, the antenna array layer and the packaging feeding layer are welded and connected, and the welding temperature is about 180℃.

[0082] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the present application is used, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only used for differentiation 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 parts must be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0084] In the description of the present application, it also needs to be explained that, unless otherwise explicitly specified and limited, the terms "set", "install", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0085] Finally, it should be noted that: the above-described embodiments are only specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, and are not limited thereto, the protection scope of the present application is not limited thereto, although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art within the technical range disclosed by the present application can still modify or easily think of changes to the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to some technical features thereof; and these modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application. They should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A low-temperature ceramic phased array antenna, characterized in that, In order, they include: The antenna array layer, radio frequency (RF) components, and encapsulation feed layer are provided. The RF components are soldered onto the backplate of the antenna array layer, a process referred to as primary soldering, which takes place at a temperature higher than 220°C. The antenna array layer and encapsulation feed layer are respectively formed by co-firing multiple layers of low-temperature ceramic green ceramic strips and metal circuits. The sintering temperature of the low-temperature ceramic green ceramic strips is 850-900°C. The encapsulation feed layer comprises upper and lower parts. The upper part is used to encapsulate the RF components, and the lower part is used for power output. The upper and lower parts are co-fired together. The encapsulation power supply layer includes several fifth ceramic layers and a sixth ceramic layer; several cavities are cut into each of the fifth ceramic layers; metal circuits and a second grid metal ground are printed on the sixth ceramic layer; several metal holes are provided on the outer periphery of the cavities on the fifth ceramic layers, and the metal holes on all the fifth ceramic layers 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 several first metal through-holes surround the cavity to form a metal sidewall, and the first metal through-holes are filled with metal; the several cavities, the metal sidewalls, and the grid metal ground on the sixth ceramic layer together form several metal cavities with open tops; The positions of the metal cavities correspond one-to-one with the positions of the radio frequency components, and each radio frequency component is housed within one of the metal cavities.

2. The low-temperature ceramic phased array antenna according to claim 1, characterized in that, The antenna array layer, along the antenna signal transmission direction, includes at least a first ceramic layer, a second ceramic layer, a third ceramic layer, and a fourth ceramic layer, each ceramic layer being composed of several layers of green ceramic strips; a metal microwave circuit is printed on the first ceramic layer to form a radiating surface; The second ceramic layer has horizontally polarized electrodes printed on it; the third ceramic layer has vertically polarized electrodes printed on it; and the fourth ceramic layer has metal circuitry and a first grid metal ground printed on it.

3. The low-temperature ceramic phased array antenna according to claim 2, characterized in that, The number of metal cavities is the same as the number of radio frequency components, and their positions correspond one-to-one. The encapsulation feed layer with the metal cavity with the upper opening is welded to the antenna array layer with the radio frequency components already soldered on, and the secondary welding temperature is at least 30°C lower than the primary welding temperature.

4. The low-temperature ceramic phased array antenna according to claim 3, characterized in that, The bottom layer of the encapsulation feed layer has pre-set circuits and gold-plated pads for microwave frequency conversion components and other electronic components on the underlying ceramic green ceramic strip. The low-temperature ceramic green ceramic strips of the encapsulation feed layer are co-fired together. After co-firing, the microwave frequency conversion components and other electronic components are soldered onto the pre-set gold-plated pads of the encapsulation feed layer using the same soldering temperature as the first soldering, so as to form a baseband processing component with intermediate frequency output that can be directly connected.

5. The low-temperature ceramic phased array antenna according to claim 2, characterized in that, Each layer of the green ceramic strip in the antenna array layer is further provided with a second metal hole and a plurality of third metal holes surrounding the second metal hole. The second metal holes of each layer of green ceramic strip are stacked to form a first coaxial inner conductor. The third metal holes of each layer of green ceramic strip are stacked to form a first coaxial outer conductor. The first coaxial inner conductor is soldered to the radio frequency component, and the first coaxial outer conductor is connected to the first grid metal ground on the fourth ceramic layer.

6. The low-temperature ceramic phased array antenna according to claim 1, characterized in that, The upper portion of the encapsulation feed layer is further provided with a fourth metal via and a plurality of fifth metal vias surrounding the fourth metal via; the fourth metal vias on the green ceramic tapes of each layer are stacked to form a second coaxial inner conductor; the fifth metal vias on the green ceramic tapes of each layer are stacked to form a second coaxial outer conductor; one end of the second coaxial inner conductor is soldered to the radio frequency component, and the other end of the second coaxial inner conductor is connected to the feed network of the lower portion; the second coaxial outer conductor is connected to the second grid metal ground on the sixth ceramic layer.

7. The low-temperature ceramic phased array antenna according to any one of claims 3, 5, and 6, characterized in that, The metal through-holes between the green ceramic strips are staggered, and the staggered metal through-holes are connected by planar metal microstrip lines.

8. A manufacturing process for the low-temperature ceramic phased array antenna according to any one of claims 1-7, characterized in that, The process includes: The raw material of low-temperature ceramic green ceramic sheets is cut into several low-temperature ceramic green ceramic strips; According to the pre-designed antenna circuit structure, pre-treatment is performed on the corresponding low-temperature ceramic green ceramic strip. The pre-treatment includes one or more of the following operations: punching, cutting, pouring metal slurry, and printing metal circuits; to obtain the low-temperature ceramic green ceramic strip to be sintered. The low-temperature ceramic green ceramic strips to be sintered are stacked in a preset order and then sintered in one go to obtain an antenna array layer and an encapsulation feed layer. The encapsulation feed layer and the antenna array layer are co-fired separately. The encapsulation feed layer includes upper and lower parts, the upper part is used to encapsulate radio frequency components, and the lower part is used for feed output. The upper and lower parts are co-fired together. Soldering radio frequency components with the same number of antenna array elements as the antenna array layer onto the back plate of the antenna array layer is called a first soldering, and the first soldering temperature is higher than 220°C. The encapsulation feed layer is fixed to the antenna array layer by secondary welding, and the secondary welding temperature is at least 30°C lower than the primary welding temperature. A number of cavities, the same number as the number of RF components, are cut into the upper portion of the package feed layer. Several metal holes are punched around the outer periphery of each cavity, and the multiple 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. Several first metal through-holes form a metal sidewall around the cavity, and the first metal through-holes are filled with metal. Several cavities, metal sidewalls, and the last layer of the mesh metal ground of the upper portion of the package feed layer together form several metal cavities with open tops. The positions of the metal cavities correspond one-to-one with the positions of the RF components, and each RF component is accommodated in one of the metal cavities.

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