Dielectric filter
By introducing a coupling structure between the low-pass connector and the dielectric filter body into the dielectric filter, the dielectric filter design problem is solved in a limited space, and effective signal filtering and communication quality are achieved.
Patent Information
- Application Number
- CN202411037756.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-31
- Publication Date
- 2025-03-11
AI Technical Summary
In communication devices, the design of dielectric filters is difficult to meet the requirements of miniaturization and performance indicators in a limited space, resulting in design complexity and limited freedom.
A dielectric filter structure is adopted, which includes a low-pass connector and a dielectric filter body. The inner conductor of the low-pass connector is a low-pass filter structure, the cutoff frequency is greater than the passband of the dielectric filter, and is coupled to the first resonator in the dielectric filter body.
This structure effectively filters remote signal interference, shortens signal input distance, saves design costs, improves the signal-to-noise ratio and communication quality of the whole machine, and reduces interference risks.
Smart Images
Figure CN119601922A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of filters, and in particular to a dielectric filter. Background Art
[0002] Dielectric filters are one of the key components in the design of communication equipment. Their design structure is complex and varied. Due to the miniaturization of the product, space utilization is particularly important. In a limited space, the design difficulty of dielectric filters increases and the degree of freedom is limited. Under limited conditions, they must not only meet the performance index requirements, but also meet the difficulty of miniaturization design. The rationality and operability of the design of dielectric filters are very high, and miniaturization needs to be solved urgently. Summary of the invention
[0003] In view of the problems existing in the prior art and in the context of the requirement for miniaturization and lightness of communication equipment, a dielectric filter is provided.
[0004] The technical solution adopted by the present invention is as follows: a dielectric filter comprises a low-pass connector and a dielectric filter body, the low-pass connector comprises an outer conductor and an inner conductor, the low-pass connector is fixedly connected to the dielectric filter body, and the inner conductor of the low-pass connector is coupled to a first resonator in the dielectric filter body; wherein the inner conductor of the low-pass connector is a low-pass filter structure, and the cut-off frequency of the low-pass filter structure is greater than the passband of the dielectric filter.
[0005] As a preferred solution, the inner conductor of the low-pass connector is a candied haws-type low-pass filter structure.
[0006] As a preferred solution, the outer conductor of the low-pass connector is welded or tightly fitted to the outer conductor of the dielectric filter body to ensure impedance matching and intermodulation performance; the inner conductor of the low-pass connector is inserted near the first resonator of the dielectric filter body to achieve coupling between the input signal and the first resonator, and input the signal into the dielectric filter body.
[0007] As a preferred solution, the low-pass connector is integrated with the dielectric filter.
[0008] As a preferred solution, the outer conductor of the low-pass connector is machined using a conventional process to form an external connection connector of the dielectric filter.
[0009] As a preferred solution, the dielectric filter body is made of dielectric material.
[0010] As a preferred solution, the dielectric filter body is a CWG filter.
[0011] As a preferred solution, the inner conductor diameters of the low-pass connector are of different sizes and can be adjusted according to demand.
[0012] As a preferred solution, the impedance continuity of the low-pass main rod in the candied haws-shaped low-pass filter structure is achieved by simulation.
[0013] As a preferred solution, the coupling strength between the low-pass main rod of the candied haws-shaped low-pass filter structure and the first resonator of the dielectric filter body needs to be matched according to the bandwidth of the bandpass filter.
[0014] Compared with the prior art, the beneficial effects of adopting the above technical scheme are as follows: the present invention proposes a new signal input structure of a filter and a function expansion method thereof, which can effectively filter far-end signal interference, shorten the signal input distance, save signal input time, save design costs, and perform remote suppression debugging for communications, thereby improving the signal-to-noise ratio of the entire machine, improving communication quality, and improving intermodulation stability and reducing interference risks. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is a schematic diagram of the dielectric filter structure proposed by the present invention. DETAILED DESCRIPTION
[0016] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar modules or modules with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limitations on the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.
[0017] In order to meet the performance index requirements in a limited space, the embodiment of the present invention proposes a dielectric filter and its input structure. Since each filter has an input connector structure, and the distance between the connector and the filter provides the possibility of embedding a low-pass structure. In this embodiment, please refer to Figure 1 The dielectric filter includes a low-pass connector and a dielectric filter body.
[0018] Specifically, the low-pass connector includes an outer conductor and an inner conductor, wherein the inner conductor is a low-pass filter structure, and the cutoff frequency of the low-pass filter structure is greater than the passband of the dielectric filter. When the low-pass connector is connected to the dielectric filter body, the inner conductor of the low-pass connector is coupled with the resonator inside the dielectric filter body. At this time, the dielectric filter has both the performance of in-band filtering and the demand for far-end suppression, which reduces the loss and the pain points of far-end suppression of the dielectric filter, and provides better performance and more reliable guarantee for signal quality.
[0019] In one embodiment, the inner conductor of the low-pass connector is a candied haws-shaped low-pass filter structure. The inner conductor diameter of the low-pass connector is different and can be adjusted according to demand, but it should be noted that the low-pass main rod in the structure adopts simulation to achieve impedance continuity, ensure low return loss and good matching.
[0020] Please continue to refer to Figure 1 The low-pass connector requires an outer conductor and an inner conductor to form a signal transmission loop. In this embodiment, the outer conductor is machined by a traditional process to form an external connection connector of the dielectric filter.
[0021] In one embodiment, the outer conductor of the low-pass connector is connected to the outer conductor of the dielectric filter body by welding or tight fitting to ensure impedance matching and intermodulation performance, for example, it can be assembled by screws. In other embodiments, the low-pass connector and the dielectric filter body can be connected by integrated manufacturing.
[0022] In this embodiment, the dielectric filter body is made of dielectric material, preferably a CWG filter. In this scenario, the dielectric filter can be connected through a low-pass connector. Compared with the traditional CWG filter soldered on the circuit board, the dielectric filter proposed in this application will not cause the risk of CWG filter cracking due to heat. Therefore, the dielectric filter proposed in this embodiment reduces the loss, reduces the noise coefficient of the whole machine, enhances the output power of the whole machine, and improves the communication quality.
[0023] In this embodiment, the input signal and the resonator of the dielectric filter are coupled to obtain the signal input through the connection between the inner conductor of the low-pass connector and the dielectric filter body, so that the input signal passes through the low-pass filter and the dielectric bandpass filter at the same time, so that the entire signal filtering is improved, which can solve both the in-band filter problem and the remote filtering problem. At the same time, the structure of the low-pass filter directly connected to the dielectric filter shortens the distance between the low-pass filter and the dielectric filter, thereby effectively reducing the loss in the entire communication line, increasing the transmission output power, and reducing the receiving noise coefficient. From a structural point of view, it also provides a technical solution for the miniaturization design of the filter.
[0024] When electromagnetic waves propagate in the air or in metal conductors, their wavelength is relatively long. However, research has found that when they propagate in materials with high dielectric constants, their wavelength can be shortened. Based on this characteristic, by changing the dielectric constant of the dielectric material through which electromagnetic waves propagate, the wavelength of the electromagnetic waves can be changed, thereby achieving electromagnetic wave propagation in a smaller volume. According to this theory, dielectric materials are used to design dielectric filters, and the volume of the filters is reduced accordingly.
[0025] The low-pass filter is the best device to solve the problem of far-end suppression of the passband. Through the low-pass filter, low-frequency signals pass through, allowing the low-pass cutoff frequency to be greater than the passband of the bandpass filter (i.e., the dielectric filter body). This forms a combination of a bandpass filter and a low-pass filter, thereby achieving simultaneous suppression of the near and far ends of the passband.
[0026] The low-pass connector is a device that connects the communication cable and the filter. The connector itself is essentially a 50-ohm transmission line. Based on this characteristic, the inner conductor of the low-pass connector is designed as the inner core of the connector to achieve the low-pass effect of the connector. The low-pass inner conductor is then inserted near the first resonator of the dielectric waveguide filter to achieve the coupling between the input signal and the first resonator, thereby inputting the signal into the dielectric filter. The integrated design of the connector low-pass filter and the dielectric waveguide filter is achieved.
[0027] Example 1
[0028] This embodiment proposes a dielectric filter, including a low-pass connector and a dielectric filter body, the low-pass connector including an outer conductor and an inner conductor, the low-pass connector is fixedly connected to the dielectric filter body, and the inner conductor of the low-pass connector is coupled to a first resonator in the dielectric filter body; wherein the inner conductor of the low-pass connector is a low-pass filter structure.
[0029] Example 2
[0030] On the basis of Example 1, the inner conductor of the low-pass connector in this embodiment is a candied haws-like low-pass filter structure.
[0031] Example 3
[0032] On the basis of Embodiment 2, the outer conductor of the low-pass connector in this embodiment is assembled with screws to the dielectric filter body.
[0033] Example 4
[0034] On the basis of Embodiment 3, in this embodiment, the low-pass connector and the dielectric filter are integrated into one.
[0035] Example 5
[0036] On the basis of Embodiment 4, the outer conductor of the low-pass connector in this embodiment is machined using a conventional process to form an external connection connector of the dielectric filter.
[0037] Example 6
[0038] On the basis of Embodiment 5, the dielectric filter body in this embodiment is a CWG filter.
[0039] Example 7
[0040] On the basis of Example 6, the inner conductor diameters of the low-pass connector in this embodiment are different and can be adjusted according to needs.
[0041] Example 8
[0042] On the basis of Example 7, in this embodiment, the inner conductor of the connector and the low-pass main rod need to be simulated to achieve impedance continuity, low return loss, and perfect matching.
[0043] Example 9
[0044] On the basis of Embodiment 8, the coupling strength between the main rod of the low-pass filter and the first resonator of the dielectric filter in this embodiment needs to be matched according to the bandwidth of the band-pass filter.
[0045] Example 10
[0046] On the basis of Example 9, the outer conductor of the low-pass filter in this embodiment is connected to the outer conductor of the dielectric waveguide filter by welding or tight fitting to ensure impedance matching and intermodulation performance.
[0047] The present invention can be better implemented through Examples 1 to 10.
[0048] It should be noted that in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "setting" and "connection" 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 direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances; the drawings in the embodiments are used to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are 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 herein can be arranged and designed in various different configurations.
[0049] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.
Claims
1. A dielectric filter, characterized in that: It comprises a low-pass connector and a dielectric filter body, wherein the low-pass connector comprises an outer conductor and an inner conductor, the low-pass connector is fixedly connected to the dielectric filter body, and the inner conductor of the low-pass connector is coupled to a first resonator in the dielectric filter body; wherein the inner conductor of the low-pass connector is a low-pass filter structure, and the cut-off frequency of the low-pass filter structure is greater than the passband of the dielectric filter.
2. The dielectric filter according to claim 1, characterized in that: The inner conductor of the low-pass connector is a candied haws-like low-pass filter structure.
3. The dielectric filter according to claim 1, characterized in that The outer conductor of the low-pass connector is connected to the outer conductor of the dielectric filter body by welding or tight fitting to ensure impedance matching and intermodulation performance; the inner conductor of the low-pass connector is inserted near the first resonator of the dielectric filter body to achieve coupling between the input signal and the first resonator, and input the signal into the dielectric filter body.
4. The dielectric filter according to claim 1, characterized in that: The low-pass connector is formed integrally with the dielectric filter.
5. The dielectric filter according to claim 1, characterized in that: The outer conductor of the low-pass connector is machined by conventional technology to form an external connection joint of the dielectric filter.
6. The dielectric filter according to claim 1, characterized in that The dielectric filter body is made of dielectric material.
7. The dielectric filter according to claim 1, characterized in that: The dielectric filter body is a CWG filter.
8. The dielectric filter according to claim 1 or 2, characterized in that: The inner conductor diameter of the low-pass connector is of different sizes and can be adjusted according to needs.
9. The dielectric filter according to claim 1, characterized in that The impedance continuity of the low-pass main rod in the candied haws-shaped low-pass filter structure is achieved by simulation.
10. The dielectric filter according to claim 1, characterized in that The coupling strength between the low-pass main rod of the candied haws-shaped low-pass filter structure and the first resonator of the dielectric filter body needs to be matched according to the bandwidth of the band-pass filter.