Novel HTCC airtight waveguide structure and working method thereof

Abstract

The invention discloses a novel HTCC airtight waveguide structure and a working method thereof. The airtight waveguide structure is composed of a multilayer ceramic medium, a waveguide matching cavity, a metal hole and a metal bonding pad. A through groove is formed in the multilayer ceramic dielectric from the middle of the top layer ceramic dielectric to the middle of the bottom layer ceramic dielectric, a groove larger than the through groove is formed in the middle of the through groove of the multilayer ceramic dielectric, the groove forms a waveguide matching cavity, the multilayer ceramic dielectric is provided with metal holes, and the metal holes comprise the metal hole of the waveguide matching cavity and the metal hole of the dielectric windowing; metal holes of the waveguide matching cavity are formed in the four walls of the waveguide matching cavity, and a ceramic medium in the waveguide matching cavity is horizontally arranged in the waveguide matching cavity and divides the waveguide matching cavity into an upper part and a lower part. According to the invention, low-loss and high-airtightness transmission of radio-frequency signals along the transmission direction can be realized, and the radio-frequency signal transmission device is suitable for application scenes of high power, miniaturization, high airtightness, salt mist prevention and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communication equipment, and in particular to a novel HTCC airtight waveguide structure and a working method thereof. Background Art

[0002] In phased array radar and communication systems, particularly those in extremely high frequency or high-power systems, waveguides are often used for signal transmission. However, conventional waveguides are made of metal, which is large in size and weight. The integration of functional circuits such as waveguide windows increases complexity and difficulty in processing and assembly. Furthermore, in certain application scenarios, such as those involving humid environments and heavy salt spray, conventional airtight waveguide windows are susceptible to corrosion, resulting in performance degradation or even failure.

[0003] Existing waveguide transmission systems primarily achieve airtightness by installing waveguide airtight windows. However, conventional waveguide airtight windows can alter dielectric thickness and dielectric constant when exposed to water, and are also incapable of withstanding salt spray. This significantly impacts reliability in harsh environments such as offshore environments. Summary of the Invention

[0004] The present invention aims to address the deficiencies of the prior art by proposing a novel HTCC airtight waveguide structure and operating method. This invention utilizes high-strength and high-precision HTCC technology. The ceramic dielectric does not absorb water and is not susceptible to salt spray corrosion. This effectively addresses the inability of existing airtight waveguide structures to simultaneously meet the requirements of high power, miniaturization, airtightness, and salt spray resistance.

[0005] The present invention adopts the following technical solutions: A novel HTCC airtight waveguide structure comprises a multilayer ceramic dielectric, a waveguide matching cavity, metal holes, and metal pads. The multilayer ceramic dielectric is co-fired using the HTCC process. HTCC offers advantages such as high dielectric constant, high machining precision, stable physical and chemical properties, and flexible machining patterns, enabling customized patterns tailored to specific application scenarios.

[0006] A dielectric window is provided in the multilayer ceramic dielectric. The dielectric window is a rectangular through-slot that runs from the center of the top ceramic dielectric to the center of the bottom ceramic dielectric. A larger slot is provided in the middle of the through-slot in the multilayer ceramic dielectric, forming a waveguide matching cavity.

[0007] The multilayer ceramic dielectric is perforated with metal holes, including those for the waveguide matching cavity and those for the dielectric window. The metal holes are located on all four walls of the waveguide matching cavity. The ceramic dielectric is horizontally positioned within the cavity, dividing it into upper and lower sections. Adjusting the height, position, and size of the cavity allows for optimal matching and ensures optimal RF transmission performance.

[0008] Due to the effect of the ceramic dielectric in the waveguide matching cavity, the upper and lower sides of the waveguide matching cavity are divided into two dielectric windows, and the four walls of the dielectric windows on both sides have metal holes for the dielectric windows. The dielectric windows on both sides and the metal holes of the dielectric windows form a waveguide-like structure. A single layer of ceramic dielectric is set on the top layer of the multilayer ceramic dielectric to seal the dielectric window on the upper side, and a single layer of ceramic dielectric is set on the bottom layer of the multilayer ceramic dielectric to seal the dielectric window on the lower side. The metal pad includes a metal probe, a gold wire, an RF chip and a signal output port. A metal probe is set on the ceramic dielectric in the waveguide matching cavity. The metal probe is connected to the RF chip in the multilayer ceramic dielectric through gold wire bonding. The RF chip is installed in the area without the window of the multilayer ceramic dielectric. A signal output port is set outside the single layer of ceramic dielectric sealed at the bottom layer of the multilayer ceramic dielectric for implanting solder balls to interconnect it with the external structure.

[0009] A novel HTCC airtight waveguide structure operates in a manner that transmits signals from the RF chip via a gold wire to a metal probe, and then to the outside through a signal output port at the bottom of a multilayer ceramic dielectric. The ceramic dielectric in the waveguide matching cavity completely separates the upper and lower portions of the cavity. A single layer of ceramic dielectric is provided on the top layer of the multilayer ceramic dielectric to seal the dielectric window on the upper side, while a layer of ceramic dielectric is provided on the bottom layer to seal the dielectric window on the lower side, thereby achieving airtight transmission of the RF signal.

[0010] Beneficial effects of the present invention: 1. Compared with existing waveguide transition structures, the present invention is based on the HTCC process, has smaller size, higher processing precision, and better consistency due to integrated processing. It is more suitable for high-power and miniaturized application scenarios, improves system integration and reliability, reduces weight, and saves size.

[0011] 2. The present invention can achieve airtightness. The present invention eliminates the traditional waveguide airtight window structure, reduces assembly complexity, has a smaller size, better consistency, and higher reliability.

[0012] 3. The present invention adopts ceramic substrate and metal tungsten as the wiring, which has more stable chemical properties and has the characteristics of salt spray resistance.

[0013] 4. The present invention adopts a ceramic substrate, which does not absorb water, has a stable dielectric constant, high reliability and stable performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a wireframe schematic diagram of the present invention.

[0015] Figure 2 It is a side view of the present invention.

[0016] Figure 3 It is a top view of the present invention.

[0017] Figure 4 It is an exploded schematic diagram of the application packaging structure of the present invention.

[0018] Figure 5 Schematic diagram of an application example of the present invention.

[0019] In the picture: 1-Multilayer ceramic dielectric, 11-Dielectric window; 2-waveguide matching cavity, 21-ceramic medium in the waveguide matching cavity; 3-metal hole, 31-metal hole of waveguide matching cavity, 32-metal hole of dielectric window; 4-metal pad, 41-metal probe, 42-gold wire, 43-RF chip, 44-signal output port. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0021] The present invention proposes a novel HTCC airtight waveguide structure and a working method thereof. The waveguide structure can achieve airtightness while having good waterproof performance, and also has the advantages of high processing precision, high structural strength, high reliability and easier miniaturization.

[0022] like Figures 1-4 As shown in the figure, a novel HTCC airtight waveguide structure of the present invention comprises a multilayer ceramic dielectric 1, a waveguide matching cavity 2, a metal hole 3, and a metal pad 4. The multilayer ceramic dielectric 1 is composed of several single-layer ceramic dielectrics. The multilayer ceramic dielectric 1 is manufactured using a high-temperature co-fired multilayer ceramic (HTCC) process, where multiple single-layer ceramic dielectrics are co-fired. HTCC offers advantages such as high dielectric constant, high processing precision, stable physical and chemical properties, and high processing pattern flexibility, enabling customized patterns based on actual application scenarios.

[0023] A dielectric window 11 is defined within the multilayer ceramic dielectric 1. Specifically, a rectangular slot is defined within the multilayer ceramic dielectric 1 as dielectric window 11. Dielectric window 11 is a through slot extending from the center of the top ceramic dielectric layer to the center of the bottom ceramic dielectric layer. A larger slot is defined within the through slot within the multilayer ceramic dielectric 1. This slot forms a waveguide matching cavity 2, which is used to compensate for any mismatches caused by achieving airtightness.

[0024] The multilayer ceramic dielectric 1 is provided with metal holes 3, primarily for ensuring a good RF ground loop and ground continuity. These holes 3 include metal holes 31 for the waveguide matching cavity and metal holes 32 for the dielectric window. The metal holes 31 are located on all four walls of the waveguide matching cavity 2. A ceramic dielectric 21 is horizontally arranged within the cavity, separating the cavity 2 into upper and lower sections to ensure airtightness. Adjusting the height, position, and size of the cavity 2 allows for optimal matching and ensures optimal RF transmission performance.

[0025] The ceramic dielectric 21 in the waveguide matching cavity divides the upper and lower sides of the waveguide matching cavity 2 into two dielectric windows 11. Each of the four walls of the dielectric windows 11 has metal holes 32 for these windows. These dielectric windows 11 and the metal holes 32 form a waveguide-like structure. The dielectric windows 11 can reduce dielectric loss in the waveguide.

[0026] A single layer of ceramic dielectric is provided on the top layer of the multilayer ceramic dielectric 1 to seal the dielectric window 11 on the upper side, and a single layer of ceramic dielectric is provided on the bottom layer of the multilayer ceramic dielectric 1 to seal the dielectric window 11 on the lower side.

[0027] Metal pad 4 includes a metal probe 41, a gold wire 42, an RF chip 43, and a signal output port 44. Metal probe 41 is mounted on ceramic dielectric 21 within the waveguide matching cavity. Metal probe 41 is bonded to RF chip 43 within multilayer ceramic dielectric 1 via gold wire 42. RF chip 43 is mounted in an unopened area of ​​multilayer ceramic dielectric 1. Signal output port 44 is located outside the sealed bottom layer of multilayer ceramic dielectric 1 for solder balls to interconnect with external structures. Compared to traditional HTCCs, which transmit RF signals through bump placement, waveguide boundary bumping reduces RF performance variations caused by bump placement, achieving superior RF transmission performance.

[0028] A novel HTCC airtight waveguide structure operates in a manner that transmits signals from the RF chip via a gold wire to a metal probe, and then to the outside through a signal output port at the bottom of a multilayer ceramic dielectric. The ceramic dielectric in the waveguide matching cavity completely separates the upper and lower portions of the cavity. A single layer of ceramic dielectric is provided on the top layer of the multilayer ceramic dielectric to seal the dielectric window on the upper side, while a layer of ceramic dielectric is provided on the bottom layer to seal the dielectric window on the lower side, thereby achieving airtight transmission of the RF signal.

[0029] Example like Figure 5 As shown, a novel HTCC airtight waveguide structure of the present invention has a metal probe 41 on a ceramic dielectric 21 in a waveguide matching cavity within a waveguide matching cavity 2. The metal probe 41 is bonded to an RF chip 43 in a multilayer ceramic dielectric 1 via a gold wire 42. The RF chip 43 is mounted in an unwindowed area of ​​the multilayer ceramic dielectric 1. Signals are transmitted from the RF chip 43 via the gold wire 42 to the metal probe 41 and then to the outside through a signal output port 44 at the bottom of the multilayer ceramic dielectric 1. The ceramic dielectric 21 in the waveguide matching cavity completely separates the upper and lower portions of the waveguide matching cavity 2. Since a single layer of ceramic dielectric is provided on the top layer of the multilayer ceramic dielectric 1 to seal the dielectric window 11 on the upper side, and a layer of ceramic dielectric is provided on the bottom layer of the multilayer ceramic dielectric 1 to seal the dielectric window 44 on the lower side, airtight transmission of RF signals is achieved.

[0030] The existing traditional waveguide transmission structure adopts a straight-through waveguide window plus a probe. If airtightness is to be achieved, an additional welded waveguide airtight window is required. Compared with this, the present invention highly integrates the waveguide and probe to achieve airtight isolation, reduces the installation size of the additional waveguide airtight window originally required, and achieves miniaturization. The ceramic medium 21 in the waveguide matching cavity has an isolation effect, can achieve an airtight effect, and has an anti-salt spray effect, thereby improving the reliability of RF signal transmission.

[0031] The airtightness of existing waveguide transmission is mainly achieved by installing a waveguide airtight window. After absorbing water, the dielectric thickness and dielectric constant of the traditional waveguide airtight window will change, and it cannot resist salt spray. Long-term use in harsh environments such as at sea has a significant impact on reliability. After long-term use, the impedance matching mismatch caused by changes in dielectric thickness, dielectric constant and salt spray erosion affects the power index of the original system, resulting in a reduction in the system power index.

[0032] The ceramic medium used in the present invention does not absorb water and is not corroded by salt spray. It can effectively solve the impedance matching mismatch problem caused by changes in medium thickness, dielectric constant and salt spray corrosion in existing airtight waveguide structures. The system power index is not affected, thereby solving the problems of high power, miniaturization, airtightness and salt spray resistance.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A new HTCC airtight waveguide structure, characterized in that: The invention comprises a multilayer ceramic medium, a waveguide matching cavity, a metal hole and a metal pad; the multilayer ceramic medium is formed by co-firing multiple single-layer ceramic dielectrics using the HTCC process, and a dielectric window is provided in the multilayer ceramic medium. The dielectric window is a through groove from the middle of the top ceramic medium to the middle of the bottom ceramic medium in the multilayer ceramic medium, and a groove larger than the through groove is provided in the middle of the through groove of the multilayer ceramic medium, and the groove forms a waveguide matching cavity. The multilayer ceramic medium is provided with a metal hole, and the metal hole includes a metal hole of the waveguide matching cavity and a metal hole of the dielectric window; the four walls of the waveguide matching cavity are provided with a metal hole of the waveguide matching cavity, and the ceramic medium in the waveguide matching cavity is horizontally arranged in the waveguide matching cavity, and the ceramic medium in the waveguide matching cavity divides the waveguide matching cavity into The upper and lower parts divide the upper and lower sides of the waveguide matching cavity into two dielectric windows, and the four walls of the dielectric windows on both sides have metal holes for the dielectric windows. The dielectric windows on both sides and the metal holes of the dielectric windows form a waveguide-like structure. A single-layer ceramic dielectric is arranged on the top layer of the multilayer ceramic dielectric to seal the dielectric window on the upper side, and a single-layer ceramic dielectric is arranged on the bottom layer of the multilayer ceramic dielectric to seal the dielectric window on the lower side. The metal pad includes a metal probe, a gold wire, an RF chip and a signal output port. A metal probe is provided on the ceramic dielectric in the waveguide matching cavity, and the metal probe is connected to the RF chip in the multilayer ceramic dielectric through gold wire bonding. A signal output port is provided outside the single-layer ceramic dielectric sealed at the bottom layer of the multilayer ceramic dielectric.

2. The novel HTCC airtight waveguide structure according to claim 1, characterized in that: The through slot is rectangular.

3. The novel HTCC airtight waveguide structure according to claim 1, characterized in that: The radio frequency chip is mounted in an area of ​​the multilayer ceramic medium where no window is opened.

4. The novel HTCC airtight waveguide structure according to claim 1, characterized in that: Adjusting the height, position and size of the waveguide matching cavity can adjust the matching RF performance to achieve the optimal matching effect, thereby ensuring RF transmission performance.

5. The novel HTCC airtight waveguide structure according to claim 1, characterized in that: Solder balls are implanted in the signal output port to interconnect it with the external structure.

6. A novel method for operating a HTCC airtight waveguide structure, characterized in that: The signal is transmitted from the RF chip through the gold wire to the metal probe, and then transmitted to the outside through the signal output port at the bottom of the multilayer ceramic medium. The ceramic medium in the waveguide matching cavity completely separates the upper and lower parts of the waveguide matching cavity. A single-layer ceramic medium is set on the top layer of the multilayer ceramic medium to seal the dielectric window on the upper side, and a layer of ceramic medium is set on the bottom layer of the multilayer ceramic medium to seal the dielectric window on the lower side, thereby realizing the airtight transmission of the RF signal.

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