Small-size high-suppression film band-pass filter

Abstract

The utility model provides a small-size high-suppression film band-pass filter, which belongs to the technical field of resonators, and comprises a substrate, the outer wall of the substrate is provided with a plurality of metal via holes, the outer wall of the substrate is electroplated with three groups of six transmission lines, and the outer wall of each transmission line is electrically connected with a resonator. One end of each transmission line is electrically connected with the metal via hole, and a short-circuit metal layer is electroplated on the side, away from the transmission lines, of the substrate and electrically connected with the metal via hole. The small-size high-suppression film band-pass filter has the advantages of simple processing, no debugging and compact structure, the small-size high-suppression film band-pass filter has good installation convenience, the size design not only reduces the occupied space of the filter, but also facilitates the integration with other circuit elements, and the size design is more compact. And the overall integration level and compactness of the system are further improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of resonator preparation, and particularly relates to a small-size and high-suppression thin-film band-pass filter. Background Technique

[0002] A resonator is an important electronic component that can generate a resonant frequency and plays a key role in various electronic products. The following is a detailed analysis of the resonator: Definition: A resonator is an electronic component that can generate a resonant frequency. It usually consists of an elastic system and a mass system and can oscillate at a certain frequency.

[0003] There are indeed some challenges and disadvantages in the processing, debugging, and structural compactness of resonators. The following is a detailed introduction to these disadvantages:

[0004] Precision processing requirements: The structure of a resonator is usually very delicate, and high-precision processing technology is required to ensure the accuracy of dimensions and shapes. For example, in the processing of a quartz crystal resonator, the cutting angle and size of the crystal need to be precisely controlled to ensure the stability and consistency of its resonant frequency. Such high-precision processing requirements increase the production difficulty and cost.

[0005] Frequency stability debugging: The resonant frequency of a resonator is one of its core performance indicators, but it is affected by various factors such as temperature, humidity, and vibration. Therefore, in the production and use of resonators, strict frequency stability debugging is required. This usually needs to be achieved by adjusting the structural parameters of the resonator or using an external compensation circuit, increasing the difficulty and complexity of debugging.

[0006] Impedance matching debugging: The impedance matching between a resonator and the input-output system is the key to ensuring effective signal transmission. However, due to the impedance characteristics of the resonator may be affected by various factors such as frequency offset and temperature change, impedance matching debugging needs to be carried out frequently. This requires the debuggers to have rich experience and professional knowledge to solve problems quickly and accurately.

[0007] Large volume: The design of traditional resonators is often limited by materials and processing technology, resulting in a large volume. This is not conducive to the development trend of miniaturization and lightweight of electronic products. Especially in modern portable electronic products, there are more stringent requirements for the volume and weight of components.

[0008] Layout limitation: The structural layout of a resonator is often affected by the circuit board design and space limitation. In a limited circuit board space, it is necessary to reasonably layout the resonator and other components to ensure stable signal transmission and normal operation of the system. However, the large volume of the resonator may increase the difficulty and complexity of the layout. Content of the Utility Model

[0009] The purpose of the present utility model is to provide a thin-film bandpass filter with a small volume and high suppression, aiming to solve the problems raised in the background art.

[0010] A thin-film bandpass filter with a small volume and high suppression includes

[0011] a substrate;

[0012] A plurality of metal vias are formed on the outer wall of the substrate. Three groups of six transmission lines are electroplated on the outer wall of the substrate, and a resonator is electrically connected to the outer wall of each transmission line. One end of each transmission line is electrically connected to the metal via. A short-circuit metal layer is electroplated on the side of the substrate away from the transmission lines, and the short-circuit metal layer is electrically connected to the metal via.

[0013] Further, the transmission line is made by bending a 1 / 4 wavelength.

[0014] Further, four of the metal vias are distributed at the two side edges of the outer wall of the substrate.

[0015] Further, the material of the substrate includes but is not limited to a silicon substrate and an oxide substrate.

[0016] Further, the mutually remote ends of two of the transmission lines both extend outwards.

[0017] Further, the protruding ends of two of the transmission lines are located on the axes of two of the metal vias.

[0018] Compared with the prior art, the beneficial effects of the present utility model are:

[0019] The thin-film bandpass filter with a small volume and high suppression has the advantages of simple processing, no debugging, and a compact structure. Moreover, the thin-film bandpass filter with a small volume and high suppression has good installation convenience. The volume design not only reduces the occupied space of the filter itself but also facilitates the integration with other circuit elements, further improving the overall integration and compactness of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings are used to provide a further understanding of the present utility model and constitute a part of the specification. They are used together with the embodiments of the present utility model to explain the present utility model and do not constitute a limitation to the present utility model. In the drawings:

[0021] Figure 1 is the front view of the present utility model.

[0022] In the figure: 1. Substrate; 2. Metal via; 3. Transmission line; 4. Resonator. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0024] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "top / bottom end", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0025] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "provided with", "sheathed / connected", "connected", etc. should be understood in a broad sense. For example, "connected" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0026] Please refer to Figure 1 , the technical solutions provided in this embodiment are as follows:

[0027] A small-volume high-rejection thin-film bandpass filter, comprising

[0028] an aluminum substrate 1;

[0029] A plurality of metal vias 2 are provided on the outer wall of the substrate 1. Three groups of six transmission lines 3 are electroplated on the outer wall of the substrate 1, and a resonator 4 is electrically connected to the outer wall of each transmission line 3. One end of each transmission line 3 is electrically connected to the metal via 2. A short-circuit metal layer is electroplated on the side of the aluminum substrate 1 away from the transmission line 3, and the short-circuit metal layer is electrically connected to the metal via 2.

[0030] In a specific embodiment of the present utility model, the small-sized high-rejection thin-film bandpass filter has the advantages of simple processing, no debugging, and compact structure. Moreover, the small-sized high-rejection thin-film bandpass filter has good installation convenience. The volume design not only reduces the occupied space of the filter itself but also facilitates the integration with other circuit components, further improving the overall integration and compactness of the system. It has good temperature stability: Thin-film materials usually have good temperature stability, which enables the filter to maintain stable performance in different working environments. It has high durability: High-quality materials and precise manufacturing processes are adopted to ensure the durability and long-term reliability of the filter. The front side of the substrate is composed of a transmission line 3 made of metal and multiple resonators 4. The transmission line 3 is electrically connected to the resonator. The resonator 4 is electrically connected by a transmission line 3 bent by 1 / 4 wavelength. One end of this transmission line 3 is open, and the other end is connected to a large-area metal short circuit on the back through a metal via 2.

[0031] Specifically, the transmission line 3 is made by bending a 1 / 4 wavelength.

[0032] In a specific embodiment of the present utility model, a key characteristic of the 1 / 4 wavelength transmission line 3 is its ability to achieve impedance matching along its length. Since the length of the transmission line is 1 / 4 times the standing wave, the signal will experience specific phase changes during transmission. This phase change helps to achieve impedance matching between the terminal load and the transmission line 3, which can reduce signal reflection during transmission, thereby improving the efficiency and quality of signal transmission.

[0033] Specifically, four of the metal vias 2 are distributed on both side edges of the outer wall of the aluminum substrate 1.

[0034] In a specific embodiment of the present utility model, it provides a return path for reducing electromagnetic interference (EMI): The metal vias penetrate multiple layers of the substrate 1 in the vertical direction, providing an additional return path for the high-frequency signal transmission line 3. This helps to reduce impedance changes during signal transmission, thereby reducing electromagnetic radiation. Shielding effect: When the high-frequency signal transmission line 3 changes layers through vias, TEM waves will be generated. These waves may propagate laterally between the resonant cavities formed by the two planes and radiate out to free space through the edge of the PCB. The shielding structure formed by the metal vias 2 can effectively reflect these radiations back into the inner layer space, thereby reducing EMI.

[0035] Specifically, the material of the aluminum substrate 1 includes but is not limited to silicon substrates and alumina substrates.

[0036] In the specific embodiments of the present utility model, the silicon substrate and the alumina substrate can bring the following comprehensive advantages: Efficient heat dissipation: Whether it is the thermal conductivity of the aluminum substrate itself or the high thermal conductivity of the alumina substrate, it can effectively manage the heat generated by electronic devices, improving the stability and reliability of the system. High integration: The silicon substrate supports high-density integration, helping to reduce the volume and mass of the system and improve the integration level. Good electrical insulation: The high electrical insulation of the alumina substrate can ensure the safe operation of the circuit. Durability: The high hardness and mechanical strength of the alumina substrate and the firmness of the aluminum substrate make the entire system more durable and reliable.

[0037] Specifically, the mutually remote ends of the two transmission lines 3 both extend outwards.

[0038] In the specific embodiments of the present utility model, reducing signal interference and crosstalk: When the two transmission lines 3 are mutually remote and extend outwards, the electromagnetic coupling between them will be weakened, thereby reducing crosstalk between signals. This is particularly important for high-speed and high-frequency signals because such signals are more sensitive to interference. Reducing reflection and return loss: The ends of the extended transmission lines 3 can be designed with appropriate termination matching to reduce signal reflection and return loss during transmission, thereby improving signal integrity and stability.

[0039] Specifically, the protruding ends of the two transmission lines 3 are located at the axes of the two metal vias 2.

[0040] In the specific embodiments of the present utility model, signal transmission and integrity, signal path optimization: Designing the protruding ends of the transmission lines 3 at the axes of the metal vias 2 can optimize the signal transmission path. This layout helps to reduce impedance mismatch and reflection during signal transmission, thereby improving signal integrity and transmission quality. Reducing signal interference: The metal vias 2 themselves have a shielding effect, which can reduce electromagnetic radiation and interference generated by high-frequency signals during transmission. Aligning the protruding ends of the transmission lines 3 with the via axes can further enhance this shielding effect and protect the signals from external interference.

[0041] Working principle:

[0042] The small-size high-inhibition thin-film bandpass filter has the advantages of simple processing, no debugging, and compact structure. Moreover, the small-size high-inhibition thin-film bandpass filter has good installation convenience. The volume design not only reduces the occupied space of the filter itself, but also facilitates the integration with other circuit components, further improving the overall integration and compactness of the system. It has good temperature stability: Thin-film materials usually have good temperature stability, which enables the filter to maintain stable performance in different working environments. It has high durability: High-quality materials and precise manufacturing processes are adopted to ensure the durability and long-term reliability of the filter. The front side of the substrate is composed of a transmission line 3 made of metal and multiple resonators 4. The transmission line 3 is electrically connected to the resonator. The resonator 4 is electrically connected by a transmission line 3 bent by 1 / 4 wavelength. One end of the transmission line 3 is open, and the other end is connected to a large-area metal short circuit on the back through a metal via 2.

[0043] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A small-sized high-rejection thin-film bandpass filter, characterized in that Including, a substrate (1); a plurality of metal vias (2) are formed on the outer wall of the substrate (1), three groups of six transmission lines (3) are electroplated on the outer wall of the substrate (1), and a resonator (4) is electrically connected to the outer wall of each transmission line (3), and one end of each transmission line (3) is electrically connected to the metal via (2). A short-circuit metal layer is electroplated on the side of the substrate (1) away from the transmission line (3), and the short-circuit metal layer is electrically connected to the metal via (2).

2. The small-sized high-rejection thin-film bandpass filter according to claim 1, wherein The transmission line (3) is made by bending a 1 / 4 wavelength.

3. A small-size high-rejection thin-film bandpass filter according to claim 2, characterized in that, Four of the metal vias (2) are distributed at the two side edges of the outer wall of the substrate (1).

4. A small-size high-rejection thin-film bandpass filter according to claim 3, characterized in that, The material of the substrate (1) includes but is not limited to a silicon substrate and an oxide substrate.

5. A small-size high-rejection thin-film bandpass filter according to claim 4, characterized in that, One end of each of the two transmission lines (3) away from each other extends outward.

6. A small-sized high-rejection thin-film bandpass filter according to claim 5, characterized in that, The protruding ends of two of the transmission lines (3) are located at the axes of two of the metal vias (2).

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