WO2022067536A1

WO2022067536A1 - Filter, transmitter, receiver, and communication system

Info

Publication number: WO2022067536A1
Application number: PCT/CN2020/118956
Authority: WO
Inventors: 李彦涛; 张晓峰; 俞熹; 刘止愚
Original assignee: 华为技术有限公司
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2022-04-07

Abstract

The present application relates to the field of communications, and specifically relates to a filter, a transmitter, a receiver, and a communication system. The filter comprises a dielectric body and a metal layer; the dielectric body is provided with a plurality of resonant holes penetrating the dielectric body from the top surface to the bottom surface; the intersection of a first sub-hole and a second sub-hole of the resonant holes has a stepped surface; a first sub-metal layer of the metal layer is disposed on a hole wall of the second sub-hole, and a second sub-metal layer covers a portion of the stepped surface and is connected to the first sub-metal layer; a third sub-metal layer covers the remaining portion of the surface of the dielectric body, and the third sub-metal layer is provided with an open-circuit gap between the stepped surface and the second sub-metal layer; a communication groove is provided between at least two adjacent resonant holes, the bottom surface of the communication groove is arranged to be coplanar with the stepped surface, and the second sub-metal layers in the two adjacent resonant holes are capacitively coupled by means of the communication groove. The structure can improve the reliability of the filter, reduce the background noise with which the filter outputs signals, and improve the upper-limit suppression capabilities of the filter.

Description

Filters, Transmitters, Receivers and Communication Systems

technical field

The present application relates to the field of communications, and in particular, to a filter, a transmitter, a receiver and a communication system.

Background technique

With the development of wireless communication technology, the current communication system has higher and higher requirements on the reliability and performance of the filter. Transverse electromagnetic mode (TEM) dielectric filters are increasingly used in communication base stations due to their small size, low loss, and low cost.

However, traditional TEM dielectric filters require a metal shielding cover above the dielectric body, and the materials of the metal shielding cover and the dielectric body are different. When the filter is welded and installed, due to the different thermal expansion coefficients of the two materials, it is easy to cause welding. Insufficient or poor reliability in long-term use. In addition, a gap needs to be left between the metal shielding cover and the upper surface of the dielectric body, and the transmitted signal can leak through the gap. The leaked signal is not filtered by the resonator and is directly output, resulting in an increase in the noise floor of the output signal, which in turn makes the filtering The ultimate suppression capability that can be achieved by the device is limited.

SUMMARY OF THE INVENTION

The present application provides a filter, a transmitter, a receiver and a communication system to improve the reliability of the filter, reduce the noise floor of the output signal of the filter, and improve the limit suppression capability of the filter.

In a first aspect, an embodiment of the present application provides a filter, including a dielectric body and a metal layer. Wherein, the dielectric body includes a top surface, a bottom surface, and a side surface disposed between the top surface and the bottom surface, and the dielectric body is provided with a plurality of resonant holes penetrating the dielectric body from the top surface to the bottom surface; from the top surface to the bottom surface, any resonance hole The hole includes a first sub-hole and a second sub-hole arranged in communication. The metal layer covers the top surface, bottom surface, side surface of the dielectric body and the inner wall of the resonance hole, and an annular open-circuit slot is arranged in any resonance hole, and the open-circuit slot is arranged on the inner wall of the first sub-hole. Wherein, among the plurality of resonance holes, there are at least two adjacent resonance holes, and a communication slot is provided between the first sub-holes of the two adjacent resonance holes.

In the filter provided by the present application, the resonant holes penetrate through the top surface and the bottom surface of the dielectric body. In the direction from the top surface to the bottom surface, each resonant hole includes a first sub-hole and a second sub-hole, and the metal layer covers the top surface of the dielectric body. The surface, bottom surface, side surface and inner wall of the resonance hole are formed, and an annular open-circuit slot is formed on the inner wall of the first sub-hole, so that the open-circuit surface of the filter can be sunk into the first sub-hole. After the inner wall of the second sub-hole is provided with a metal layer, the second sub-hole can be used as an equivalent inductance in the resonant circuit, and the metal layers on both sides of the open-circuit slot can form a capacitance as an equivalent capacitance in the resonant circuit. Wherein, among the plurality of resonant holes, there are at least two adjacent resonant holes, and the first sub-holes of the two adjacent resonant holes are connected by a communication slot, so that the two adjacent resonant holes are connected. Capacitive coupling can be achieved between them. In the filter of this embodiment, the electric field of the resonant hole is bound in the first sub-hole. After the metal shielding cover is removed, the leakage of the transmission signal can be effectively avoided, and the signal noise floor after the filter can be effectively reduced. Improve the limit rejection capability of the filter. At the same time, since no metal shielding cover is provided in the filter of the embodiment of the present application, it can also avoid the problems of weak welding and low reliability in long-term use caused by different thermal expansion coefficients of materials.

The specific shapes of the first sub-hole and the second sub-hole are not limited in the embodiments of the present application. The first sub-hole and the second sub-hole can be, for example, cylindrical holes, rounded frustum holes, prismatic holes, etc., or other irregular-shaped hole structures.

In addition, it should be noted that the open-circuit slit in the embodiments of the present application is a closed annular structure. Wherein, the annular structure may be, for example, a circular ring, a square ring, an elliptical ring, or other irregular annular structures. Here, the shape thereof is not specifically limited in this application, and specific settings can be made according to the shapes of the first sub-hole and the second sub-hole.

In an embodiment of the present application, the minimum inner diameter of the first sub-hole is greater than the maximum inner diameter of the second sub-hole, so as to facilitate processing of the first sub-hole and the second sub-hole.

In an embodiment of the present application, the first sub-hole is a blind hole, the second sub-hole extends from the bottom wall of the first sub-hole toward the bottom surface of the medium body, and the bottom wall of the first sub-hole surrounds the second sub-hole The hole is arranged in an annular structure to form a stepped surface between the first sub-hole and the second sub-hole. By forming a stepped surface between the first sub-hole and the second sub-hole, the preparation of the metal layer can be facilitated.

In an embodiment of the present application, the open slot is arranged in the step surface, so as to facilitate the formation of the metal layer and the processing of the open slot.

In an embodiment of the present application, the metal layer includes a first sub-metal layer, a second sub-metal layer, and a third sub-metal layer. Wherein, the first sub-metal layer is disposed on the hole wall of the second sub-hole. The second sub-metal layer is connected to the first sub-metal layer, and extends from the connection between the second sub-hole and the first sub-hole to a direction away from the second sub-hole. The third sub-metal layer covers the surface of the dielectric body on which the first sub-metal layer and the second sub-metal layer are not disposed, and the third sub-metal layer is connected to the first sub-metal layer on the bottom surface. In the step surface, the third sub-metal layer and the second sub-metal layer are provided in isolation.

In this embodiment, the first sub-metal layer is disposed on the inner wall of the second sub-hole, and together with the second sub-hole forms an equivalent inductance of the resonant circuit. The first sub-metal layer and the third sub-metal layer are short-circuited at the bottom surface to form a short-circuit surface of the filter. The third sub-metal layer and the second sub-metal layer are insulated and arranged in the step surface, forming an open surface of the filter.

In an embodiment of the present application, the second sub-metal layer has an annular structure and is disposed around the opening of the second sub-hole. In this embodiment, the second sub-metal layer completely surrounds the first sub-metal layer, so that an open gap is formed between the second sub-metal layer and the third sub-metal layer.

In an embodiment of the present application, the step surface is a plane structure. The step surface of the plane structure is arranged, which is more convenient for the preparation of the metal layer and the open gap.

In an embodiment of the present application, the groove bottom of the communication groove and the bottom wall of the first sub-hole are coplanar.

In a possible implementation manner of the present application, the communication groove is formed inwardly from the top surface of the medium body, so as to facilitate processing and facilitate the provision of a metal layer on the groove wall of the communication groove.

In a possible implementation manner of the present application, a coupling metal is provided in the communication groove, and for two adjacent resonant holes, at least one coupling gap exists between the corresponding two second sub-metal layers and the coupling metal.

When specifically setting the coupling metal, in a possible implementation manner of the present application, for two adjacent resonant holes, the second sub-metal layer of at least one resonant hole is connected to the second sub-metal layer of the other resonant hole in the communication slot. The metal layer extends, forming a coupling metal. In a possible implementation manner of the present application, the two second sub-metal layers of the two resonant holes extend in directions approaching each other respectively to form the coupling metal.

In another possible implementation manner of the present application, between two adjacent resonant holes, the coupling metal extends from the bottom surface of the communication groove into the stepped surface, and both ends of the coupling metal are located in the stepped surface, and are respectively connected to the second sub-surface. A coupling gap is formed between the metal layers.

In another possible implementation manner of the present application, the coupling metal includes a plurality of metal segments arranged at intervals; wherein, in two adjacent resonant holes, the metal segment arranged near the second sub-metal layer of one resonant hole is the same as the second metal segment. The sub-metal layer is connected or set with a coupling slot, and the metal segment arranged in the second sub-metal layer close to another resonant hole is connected with another second sub-metal layer or set with a coupling slot; between the two metal segments, at least a metal segment.

In a possible implementation manner of the present application, the shape of the end portion of the coupling metal at the coupling slot includes, but is not limited to, any one of a straight line, a sawtooth shape, a wave shape, or an interdigital shape.

In a possible implementation manner of the present application, between two adjacent resonance holes, the dielectric body is further provided with a weakening groove; the weakening groove is formed inwardly from the bottom surface, and the weakening groove extends in the direction of the two adjacent resonant holes. The arrangement direction between the resonant holes is vertical; or, the dielectric body also includes a side surface arranged between the top surface and the bottom surface, the weakening groove is recessed inward from the side surface, and the extension direction of the weakening groove is the same as the distance between the two adjacent resonating holes. The arrangement direction is vertical. By setting the weakening slot, the inductive coupling effect between two adjacent resonant holes can be weakened, and then the relative size of the capacitive coupling effect and the inductive coupling effect of the entire filter can be flexibly adjusted to realize the filtering effect on different frequency bands.

In a possible implementation manner of the present application, when the weakening groove is formed inwardly from the side surface, the weakening groove penetrates through the top surface and the bottom surface. In a possible implementation manner of the present application, there are two weakening grooves, which are respectively disposed on both sides of the communicating groove. The setting of the weakening slot can effectively reduce the inductive coupling window between two adjacent resonant holes, thereby realizing the effect of weakening the inductive coupling.

In another possible implementation manner of the present application, when the weakening groove is formed inwardly from the bottom surface, the weakening groove penetrates two opposite side surfaces of the medium body.

In a possible implementation manner of the present application, between two adjacent resonant holes, the dielectric body further includes a reinforcing groove, the reinforcing groove is recessed inward from the bottom surface, and the extending direction of the reinforcing groove is the same as the distance between the two adjacent resonating holes. The arrangement direction is the same. By arranging the enhancement slot, the magnetic field lines between two adjacent resonant holes can more easily reach the inductive coupling window, thereby realizing the coupling enhancement effect.

In a possible implementation manner of the present application, the reinforcement slot is a blind slot, and both ends of the reinforcement slot are not connected to two adjacent resonance holes. In another possible implementation manner of the present application, at least one end of the reinforcing slot communicates with a resonance hole. Two ends of the enhancement slot are respectively connected with the two resonant holes, so as to realize a strong inductive coupling enhancement effect. The reinforcement slot of the structure can make the magnetic field lines of one of the resonant holes more easily reach the inductive coupling window.

In a possible implementation manner of the present application, two ends of the reinforcing slot are respectively communicated with the resonance holes on the corresponding side. By setting the reinforcing slot in the form of a blind slot, in the resonant circuit, the magnetic field lines between the two resonant holes can also be attracted to transmit in the direction of approaching each other, thereby realizing the inductive enhancement effect.

In a possible implementation manner of the present application, a side of the first sub-hole away from the second sub-hole is a stepped hole structure.

In a possible implementation manner of the present application, the resonant hole further includes a third hole communicating with the second sub-hole, and the third hole is provided on the bottom surface side of the dielectric body. Wherein, the third hole may be a stepped hole structure.

In a possible implementation manner of the present application, on the bottom surface of the dielectric body, a communication groove may also be provided between two adjacent resonance holes.

In a second aspect, an embodiment of the present application provides a transmitter, where the transmitter includes the filter of the present application.

Wherein, in a possible implementation manner of the present application, the transmitter includes a modulator, an up-converter, a power amplifier, and a filter according to the embodiment of the first aspect of the present application, which are connected in sequence. Both the modulator and the upconverter may be respectively connected with oscillators. The transmitter of this embodiment demodulates the obtained baseband signal through the modulator in turn, converts it into a radio frequency signal through an up-converter, then amplifies the video signal through a power amplifier, and finally transmits it to the sky of the communication system after being filtered by a filter. The feeder subsystem is radiated to free space by the antenna-feeder subsystem. Among them, in the process of processing the baseband signal by the modulator and the up-converter, the oscillator can be used for auxiliary processing.

In a third aspect, an embodiment of the present application provides a receiver, where the receiver includes the filter of the present application.

Wherein, in a possible implementation manner of the present application, the receiver includes a modulator, a downconverter, a power amplifier, and a filter according to the embodiment of the first aspect of the present application, which are connected in sequence. Both the modulator and the upconverter may be respectively connected with oscillators. In the receiver of this embodiment, after the radio frequency signal received from the antenna-feeder subsystem of the communication system is filtered by a filter, the signal is amplified by a power amplifier, and then the radio frequency signal is down-converted to an intermediate frequency signal by a downconverter. Finally, the baseband signal is formed after demodulation by the modulator. Among them, in the process of processing the radio frequency signal by the modulator and the downconverter, the oscillator can be used for auxiliary processing.

In a third aspect, an embodiment of the present application provides a communication system, which may include a control subsystem, a transmission subsystem, a baseband subsystem, a radio frequency subsystem, a power environment monitoring subsystem, and a clock subsystem. The radio frequency subsystem may include the transmitter of the second aspect of the present application and/or the receiver of the embodiment of the third aspect of the present application.

Description of drawings

FIG. 1 is a schematic structural diagram of a base station communication system according to an embodiment of the present application;

FIG. 2 is a schematic structural diagram of a transmitter according to an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a receiver according to an embodiment of the present application;

4 is a schematic partial cross-sectional structural diagram of a filter provided by an embodiment of the present application;

5 is an enlarged schematic view of the structure at A in the structure shown in FIG. 4;

FIG. 6 is a schematic structural diagram of a medium body provided by an embodiment of the present application;

7 is a schematic structural diagram of a metal coupling between two adjacent resonant holes in a filter provided by an embodiment of the present application;

FIG. 8 is a schematic top view of the structure shown in FIG. 7;

FIG. 9 is a schematic diagram of the end shape of another coupling metal at the coupling slit provided by the embodiment of the present application;

FIG. 10 is a schematic top view of the structure shown in FIG. 9;

FIG. 11 is a schematic diagram of the end shape of another coupling metal at the coupling slit provided by an embodiment of the present application;

12 is a schematic structural diagram of a metal coupling between two adjacent resonant holes in a filter provided by an embodiment of the present application;

13 is a schematic structural diagram of a metal coupling between two adjacent resonant holes in a filter provided by an embodiment of the present application;

FIG. 14 is a schematic diagram of the end shape of another coupling metal at the coupling slit provided by an embodiment of the present application;

FIG. 15 is a schematic diagram of the end shape of another coupling metal at the coupling slit provided by an embodiment of the present application;

FIG. 16 is a schematic partial structure diagram of a filter containing a weakening slot provided by an embodiment of the present application;

FIG. 17 is a schematic partial structure diagram of another filter containing a weakening slot provided by an embodiment of the present application;

FIG. 18 is a schematic partial structure diagram of a filter containing an enhancement slot provided by an embodiment of the present application;

FIG. 19 is a schematic partial structure diagram of another filter containing an enhancement slot provided by an embodiment of the application;

20 is a schematic partial structure diagram of yet another filter containing an enhancement slot provided by an embodiment of the application;

FIG. 21 is a schematic partial structure diagram of a filter provided by an embodiment of the application;

22 is a schematic partial structure diagram of another filter provided by an embodiment of the present application;

23 is a graph of the coupling coefficient of the resonance unit formed by two adjacent resonance holes in a filter provided by an embodiment of the present application as a function of signal frequency;

24 is a transmission characteristic curve of a filter provided by an embodiment of the application;

25 is a graph of the coupling coefficient of the resonance unit formed by two adjacent resonance holes in another filter provided by the embodiment of the application as a function of the signal frequency;

FIG. 26 is a transmission characteristic curve of a filter provided by an embodiment of the present application.

Reference number:

01-control subsystem; 02-transmission subsystem; 03-baseband subsystem; 04-radio frequency subsystem;

05-power environment monitoring subsystem; 06-clock subsystem; 041-modulator; 042-upconverter; 043-power amplifier;

044-filter; 045-oscillator; 046-downconverter;

11-dielectric body; 111-top surface; 112-bottom surface; 113-side surface; 114-resonant hole; 1141-first sub-hole;

1142-second sub-hole; 1143-step surface; 1144-third hole; 12-metal layer; 121-first sub-metal layer;

122-second sub-metal layer; 123-third sub-metal layer; 124-open gap; 13-connection slot; 14-coupling metal;

14a-coupling slot; 15-weakening slot; 16-enhancing slot.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings.

The terms used in the following embodiments are for the purpose of describing particular embodiments only, and are not intended to be limitations of the present application. As used in the specification of this application and the appended claims, the singular expressions "a," "an," "the," "above," "the," and "the" are intended to also Expressions such as "one or more" are included unless the context clearly dictates otherwise.

References in this specification to "one embodiment" or "some embodiments" and the like mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in other embodiments," etc. in various places in this specification are not necessarily All refer to the same embodiment, but mean "one or more but not all embodiments" unless specifically emphasized otherwise. The terms "including", "including", "having" and their variants mean "including but not limited to" unless specifically emphasized otherwise.

In order to facilitate the understanding of the filter of the present application, the following first introduces the application scenario of the filter. Taking the base station communication system as an example, the architecture of the base station communication system is shown in Figure 1, which may include a control subsystem 01, a transmission subsystem 02, a baseband subsystem 03, a radio frequency subsystem 04, a power environment monitoring subsystem 05, and a clock subsystem. System 06. Among them, the control subsystem 01 is mainly used to complete the control and management functions of the internal resources of the base station, providing the management plane interface between the base station and the operation and maintenance center, the control plane interface between the base station and other network elements, and the control and negotiation interface of the public equipment in the multi-mode base station. . The transmission subsystem 02 can be used to complete the internal data forwarding function of the transmission network and the base station, so as to provide the physical interface between the base station and the transmission network, and the user plane interface between the base station and other network elements. The baseband subsystem 03 can be used to complete the uplink and downlink baseband data processing functions. The radio frequency subsystem 04 can be used to complete the function of sending and receiving wireless signals, so as to provide the interface between the base station and the antenna feeder system. The baseband subsystem 03 and the radio frequency subsystem 04 are connected through a general public wireless interface, and the general public wireless interface supports a variety of flexible networking modes such as star, chain, ring, and star. The clock subsystem 06 can be used to complete the clock synchronization function of the base station, and provide an interface between the base station and an external clock source. Clock resources can be shared among multiple standards, or clock resources can be used independently. The power supply environment monitoring subsystem 05 can be used to complete the functions of power supply, heat dissipation, and environment monitoring of the base station, and provide the monitoring interface of the site equipment.

The filters in the embodiments of the present application are mainly applied to the radio frequency subsystem 04, and the radio frequency subsystem 04 is generally composed of a transmitter and a receiver. The general architecture of the transmitter is shown in Figure 2 below, and its work flow is as follows: the baseband signal is demodulated by the modulator 041 in turn, and converted into a radio frequency signal by the up-converter 042; then the signal is amplified by the power amplifier 043, and finally filtered by the filter. After 044 filtering, it is transmitted to the antenna-feeder subsystem and radiated to free space. Wherein, in the process of processing the baseband signal by the modulator 041 and the up-converter 042, the oscillator 045 is required for auxiliary processing.

The general architecture of the receiver is shown in Figure 3 below, and its workflow is as follows: the RF signal received by the antenna-feeder subsystem is first filtered by the filter 044, and the signal is amplified by the power amplifier 043, and then the down-converter 046 The radio frequency signal is down to the intermediate frequency signal, and is finally demodulated by the modulator 041 and then sent to the baseband subsystem for processing. Wherein, in the process of processing the radio frequency signal by the modulator 041 and the downconverter 046, the oscillator 045 is required for auxiliary processing.

When the filter of the embodiment of the present application is applied to the radio frequency subsystem, its main function is to pass the useful frequency signal of the system and attenuate the unwanted frequency signal to a sufficiently low level, so that the system is not disturbed by the unwanted frequency signal, and the normal work.

The TEM dielectric filter is a commonly used filter at present. The TEM dielectric filter usually includes a dielectric body and a metal layer covering the surface of the dielectric body. The road surface, the top surface and the bottom surface are arranged opposite. From the top surface to the bottom surface, the dielectric body is provided with a plurality of resonant holes penetrating the top surface and the bottom surface, such as two, three or more than three resonant holes, and a metal layer is also arranged in the resonant holes. The working principle of the TEM dielectric filter is: when the signal enters the filter through the input pad, an electromagnetic field is excited inside the filter, and multiple metallized resonant holes inside the filter resonate at a specific frequency, and there are also The electromagnetic field coupling allows only the signals near the resonant frequency of the resonant hole to pass through, and the signals of other frequency components cannot pass through, thereby realizing the filter effect.

In the traditional TEM dielectric filter, the open surface is arranged on the top surface of the dielectric body. In the filter of this structure, a metal shielding cover needs to be provided near the top surface to shield noise signals, and there is a certain gap between the metal shielding cover and the top surface to prevent the metal shielding cover and the metal layer on the surface of the dielectric body from being short-circuited. Therefore, in the filter of this structure, part of the signal leaks from the gap between the metal shielding cover and the top surface, thereby increasing the noise floor. In addition, the thermal expansion system of the metal shielding cover and the dielectric body material is quite different. When the filter is welded and installed, the problems of weak welding and poor long-term stability are prone to occur.

The embodiment of the present application provides a filter, so as to improve the reliability of the filter and reduce the noise floor of the output signal of the filter. As shown in FIG. 4 , the filter provided in this embodiment of the present application includes a dielectric body 11 and a metal layer 12 . FIG. 5 is an enlarged view of the partial structure at A in FIG. 4. In order to facilitate the identification of the dielectric body 11 and the metal layer 12, in the structures shown in FIG. 4 and FIG. The surface of the dielectric body 11 at the open portion is also provided with a metal layer 12 .

FIG. 6 is a schematic structural diagram of a medium body 11 according to an embodiment of the present application. Referring to FIG. 6 , the medium body 11 includes a top surface 111 and a bottom surface 112 disposed opposite to each other, and a side surface 113 disposed between the top surface 111 and the bottom surface 112 . As shown in FIG. 6 , the medium body 11 in the embodiment of the present application may be, for example, a hexahedral structure. In addition, the medium body 11 may also be a three-dimensional structure such as a cylindrical structure, and the shape of the medium body 11 is not specifically limited here. .

Continuing to refer to FIG. 6 , in this embodiment, four side surfaces 113 are included between the top surface 111 and the bottom surface 112 of the medium body 11 . The dielectric body 11 is further provided with a plurality of resonance holes 114 penetrating the top surface 111 and the bottom surface 112 , and the number of the resonance holes 114 may be, for example, two, three, four, five or six, and so on. The plurality of resonant holes 114 may be arranged in an in-line shape, or may be arranged in an array form.

Wherein, in the direction from the top surface 111 to the bottom surface 112 of the dielectric body 11 , the resonance hole 114 includes a first sub-hole 1141 and a second sub-hole 1142 that are communicated with each other. The first sub-hole 1141 and the second sub-hole 1142 may be cylindrical through holes, and may also be through-hole structures with gradually changing inner diameters. For example, in the direction from the first sub-hole 1141 to the second sub-hole 1142, the The inner diameter of the hole 1141 is gradually reduced to form a rounded truncated hole, and the inner diameter of the second sub-hole 1142 can also be gradually reduced to form a rounded truncated hole.

In an embodiment of the present application, the inner diameter of the first sub-hole 1141 may gradually decrease, and the second sub-hole 1142 is a cylindrical hole. As shown in FIG. 6 , in some embodiments of the present application, the first sub-hole 1141 and the second sub-hole 1142 may be coaxially disposed through holes to facilitate processing.

Continuing to refer to FIG. 6 , the minimum inner diameter of the first sub-hole 1141 is larger than the maximum inner diameter of the second sub-hole 1142 , so as to facilitate the processing of the first sub-hole 1141 and the second sub-hole 1142 . In an embodiment of the present application, the first sub-hole 1141 is a blind hole, the second sub-hole 1142 extends from the bottom wall of the first sub-hole 1141 toward the bottom surface of the medium body, and the bottom wall of the first sub-hole 1141 is An annular structure disposed around the second sub-hole 1142 to form a stepped surface 1143 between the first sub-hole 1141 and the second sub-hole 1142 .

FIG. 7 is a schematic structural diagram of two adjacent resonance holes 114 in a filter according to an embodiment. FIG. 8 is a schematic top view of the structure shown in FIG. 7 . Referring to FIG. 5 , FIG. 7 and FIG. 8 together, in this embodiment, when the metal layer 12 is specifically arranged, the metal layer 12 may include a first sub-metal layer 121 , a second sub-metal layer 122 and a third sub-metal layer 122 Layer 123. The first sub-metal layer 121 covers the hole wall of the second sub-hole 1142 , and the second sub-metal layer 122 covers a part of the stepped surface 1143 and is connected to the first sub-metal layer 121 . In an embodiment of the present application, the second sub-metal layer 122 is an annular structure, the opening surrounding the second sub-hole 1142 is circumferentially disposed, and is integrally disposed with the first sub-metal layer 121 .

The third sub-metal layer 123 covers the rest of the surface of the dielectric body 11 , and forms an open gap 124 as shown in FIG. 7 with the second sub-metal layer 122 on the stepped surface 1143 . For example, the third sub-metal layer 123 covers the bottom surface 112 , the side surface 113 and the top surface 111 of the dielectric body 11 and the inner wall of the first sub-hole 1141 . The third sub-metal layer 123 is connected to the first sub-metal layer 121 on the bottom surface 112 of the dielectric body 11 , and the two can be integrally formed to form a shorted surface. A step surface 1143 as shown in FIG. 6 is formed between the first sub-hole 1141 and the second sub-hole 1142 , and an open gap as shown in FIG. 8 is formed between the third sub-metal layer 123 and the second sub-metal layer 122 124 , so that the third sub-metal layer 123 and the second sub-metal layer 122 are completely disconnected, so as to form an open road at the step surface 1143 .

In the embodiment of the present application, by setting the first sub-holes 1141 and the second sub-holes 1142 arranged in a stepped structure, the open surface of the filter is lowered to the stepped surface 1143, and the electric field of the resonance hole 114 is bound in the stepped surface 1143, even if it is not Setting a metal shield cover will not cause signal leakage and increase the noise floor. In addition, since no metal shielding cover is provided in the filter of the embodiment of the present application, it can also avoid the problems of weak welding and low reliability in long-term use caused by different thermal expansion coefficients of materials.

Continuing to refer to FIG. 7 and FIG. 8 , in an embodiment of the present application, a communication slot 13 is provided between at least two adjacent resonance holes 114 . The communication groove 13 is formed by being recessed downward from the top surface 111 of the medium body 11 , and the surface where the groove bottom is located is coplanar with the stepped surface 1143 . Therefore, the communication groove 13 makes the two adjacent resonance holes 114 communicate between the corresponding first sub-holes 1141 . Wherein, the side wall of the communication groove 13 is also provided with a third sub-metal layer 123 . Since the groove bottom of the communication groove 13 and the stepped surface 1143 are coplanar, the communication groove 13 can be used to realize capacitive coupling between the two mutually connected resonant holes 114 and the corresponding second metal sub-layers 122 respectively.

In the filters of the embodiments of the present application, by opening the communication slot 13 between the two adjacent resonant holes 114 , the capacitive coupling path between the two resonant holes 114 can be opened, so as to realize capacitive coupling between the two adjacent resonant holes 114 . At this time, the combination of capacitive coupling structure and inductive coupling can realize frequency-dependent coupling, and more transmission zeros can be realized without adding additional filter orders. The frequency-variable coupling can also enable the filter to realize more transmission zeros out of band, flexibly adjust the position of the filter transmission zero, and make the topology of the filter out-of-band transmission zero more diverse. In addition, in this embodiment of the present application, the relevant parameters of the capacitive coupling structure and the inductive coupling structure can also be adjusted by changing factors such as the size of the resonant hole 114 and the number of the communication slots 13. By changing the capacitive coupling and the inductive coupling The strength of the frequency-dependent coupling transmission zero can be adjusted.

Figures 7 to 15 respectively list the schematic structural diagrams in the communication slot 13 in the filters of several embodiments. In an embodiment of the application, capacitive coupling can be achieved by arranging the coupling metal 14 in the communication groove 13 . Referring to FIGS. 7 to 15 together, in an embodiment of the present application, a coupling metal 14 is provided in the communication groove 13 , and the coupling metal 14 is between the second sub-metal layers 122 in two adjacent resonant holes 114 . There is at least one coupling slot 14a. The number of the coupling slots 14a may be one, two, or three, etc. Therefore, the second sub-metal layers 122 in the two adjacent resonant holes 114 may utilize the coupling metal 14 to realize capacitive coupling.

Wherein, in a specific embodiment of the present application, as shown in FIG. 7 and FIG. 8 , between the two second sub-metal layers 112 of two adjacent resonant holes 114 , the coupling metal 14 is divided into two sections, wherein the coupling metal 14 is divided into two sections. One section of the coupling metal 14 is connected to one of the second sub-metal layers 112 , the other section of the coupling metal 14 is connected to the other second sub-metal layer 112 , and a coupling gap 14 a is formed between the two sections of the coupling metal 14 . In this embodiment, each section of the coupling metal 14 can be formed by extending from the corresponding second sub-metal layers 122 at the bottoms of the communication grooves 13 in a direction approaching each other. In this embodiment, at the coupling slot 14a, the shape of the end of the coupling metal 14 is straight.

FIG. 9 is the shape of the end of the coupling metal 14 at the coupling slot 14a in another embodiment of the present application, and FIG. 10 is a schematic top view of the structure shown in FIG. 9 . In this embodiment, the shape of the end portion of the coupling metal 14 at the coupling slot 14a may be a sawtooth shape. FIG. 11 shows the shape of the end portion of the coupling metal 14 at the coupling slot 14a in yet another embodiment of the present application. In this embodiment, the shape of the end portion of the coupling metal 14 at the coupling slot 14a may be an interdigital shape. In addition to the structures shown in FIGS. 7 to 11 , the shape of the coupling metal 14 at the coupling slot 14a may also be a wave shape. It can be understood that the shape of the end portion of the coupling metal 14 shown in FIGS. 7 to 11 is only an exemplary illustration. In addition, those skilled in the art can also adjust the setting method according to the specific usage scenario, all of which are Within the protection scope of the present application, they will not be listed one by one here.

FIG. 12 is a schematic structural diagram of a coupling metal 14 in a filter according to another embodiment of the present application. Referring to FIG. 5 and FIG. 12 together, in an embodiment of the present application, a section of coupling metal 14 is provided in the communication groove 13 between two adjacent resonant holes 114 , and two ends of the coupling metal 14 are The bottom surfaces 112 of the communication grooves 13 respectively extend into the stepped surfaces 1143 in the corresponding resonant holes 114 , the two ends of the coupling metal 14 are located in the stepped surfaces 1143 , and the two ends of the coupling metal 14 are respectively connected with the corresponding second sub-metals. Coupling slits 14a are formed between the layers 122 . In this embodiment, as shown in FIG. 12 , the shape of the end portion of the coupling metal 14 can be a circular arc shape, and the opening direction thereof faces the second sub-metal layer 122 to increase the coupling area between the coupling metal 14 and the corresponding second sub-metal layer 122 . .

As shown in FIG. 13 , in an embodiment of the present application, the coupling metal 14 provided in the communication groove 13 may be divided into multiple segments and metal segments arranged at intervals. Exemplarily, the coupling metal 14 may be divided into three segments , four or five paragraphs, etc. Continuing to refer to FIG. 10 , in this embodiment, the coupling metal 14 is divided into three metal segments, wherein the metal segments of the second sub-metal layers 122 close to two adjacent resonant holes 114 are respectively connected to the corresponding second sub-metal layers 122 , there is another metal segment between the two metal segments, and a coupling gap 14a exists between any two adjacent metal segments. It can be understood that, two or more metal segments may be disposed between the two metal segments connected to the two second metal sub-layers 122 respectively, so that different numbers of coupling slits 14a may be formed. In this embodiment, the shape of the coupling metal 14 at the coupling slot 14a is a straight line.

The metal section of the coupling metal 14 disposed close to the second sub-metal layer 122 can not only be directly connected to the second sub-metal layer 122, but also set a certain gap therewith, so that the metal section can be connected to the second sub-metal layer 122 with a certain gap. The sub-metal layer 122 forms an additional coupling slot 14a.

FIG. 14 shows the shape of the end of the coupling metal 14 at the coupling slot 14a in another embodiment of the present application. In this embodiment, the shape of the end portion of the coupling metal 14 at the coupling slot 14a may be a sawtooth shape. FIG. 15 shows the shape of the end portion of the coupling metal 14 at the coupling slot 14a in yet another embodiment of the application. In this embodiment, the shape of the end portion of the coupling metal 14 at the coupling slot 14a may be an interdigital shape. In addition to the structures shown in FIGS. 13-15 , the shape of the coupling metal 14 at the coupling slot 14a may also be a wave shape. It can be understood that the shape of the end portion of the coupling metal 14 shown in FIGS. 13 to 15 is only an exemplary illustration. In addition, those skilled in the art can also adjust the setting method according to the specific usage scenario. Within the protection scope of the present application, they will not be listed one by one here.

As shown in FIG. 16 , the filter according to an embodiment of the present application may further include a weakening slot 15 for reducing the inductive coupling effect between two adjacent resonant holes 114 . Referring to FIG. 6 , the weakening groove 15 is formed inwardly from the side surface 113 of the dielectric body 11 , and from the top surface 111 to the bottom surface 112 of the dielectric body 11 , the weakening groove 15 penetrates through the top surface 111 and the bottom surface of the dielectric body 11 . 112. There is an inductive coupling window between two adjacent resonant holes 114 , and the inductive coupling window is located in the middle of the connecting line between the two adjacent resonant holes 114 . The weakening grooves 15 on the surface 111 and the bottom surface 112 can reduce the size of the inductive coupling window between the two resonant holes 114 , thereby weakening the inductive coupling strength of the two resonant holes 114 .

Continuing to refer to FIG. 16 , in an embodiment of the present application, the number of weakening grooves 15 may be two, and the two weakening grooves 15 are symmetrically arranged on two opposite sides 113 of the medium body 11 and located on two sides of the communication groove 13 . side. The inductive coupling strength between the two adjacent resonant holes 114 can be adjusted by adjusting the depth of the weakening groove 15 recessed inward from the side surface 113 of the dielectric body 11 .

As shown in FIG. 17 , in an embodiment of the present application, the weakening groove 15 is recessed inward from the bottom surface 112 of the medium body. The weakening slot 15 is located between two adjacent resonance holes 114 , and its extending direction is perpendicular to the arrangement direction of the two resonance holes 114 . In addition, the weakening slot 15 penetrates two opposite side surfaces 113 of the dielectric body. The inductive coupling strength between two adjacent resonant holes 114 can be adjusted by adjusting the depth of the weakening groove 15 recessed inward from the bottom surface 112 of the dielectric body.

As shown in FIG. 18 , the filter according to an embodiment of the present application may further include an enhancement slot 16 for enhancing the inductive coupling effect between two adjacent resonant holes 114 . The reinforcing groove 16 is formed inwardly from the bottom surface 112 of the dielectric body, and the reinforcing groove 16 is located between two adjacent resonating holes 114 , and its extending direction is consistent with the arrangement direction between the two resonating holes 114 . At the same time, the reinforcing groove 16 is A certain distance is maintained between the groove wall of 16 and the side surface 113 of the medium body 11 . In the arrangement direction of the two resonant holes 114 , by arranging the reinforcing grooves 16 , the magnetic field lines between the two adjacent resonant holes 114 can more easily reach the inductive coupling window, thereby realizing the coupling enhancement effect. Continuing to refer to FIG. 18 , in an embodiment of the present application, the two ends of the reinforcing slot 16 are respectively communicated with the two resonant holes 114 to achieve a strong inductive coupling enhancement effect.

In another embodiment of the present application, as shown in FIG. 19 , one end of the reinforcing slot 16 is in communication with one of the resonance holes 114 , and the other end is in a non-communication state with the other resonance hole 114 . The reinforcement slot 16 of this structure can make it easier for the magnetic field lines of one of the resonant holes 114 to reach the inductive coupling window.

In yet another embodiment of the present application, as shown in FIG. 20 , the reinforcing slot 16 is a blind slot, and the two ends of the reinforcing slot 16 are in a non-communication state with the corresponding resonance hole 114 respectively. By arranging the reinforcing slot 16 in the form of a blind slot, in the resonant circuit, the magnetic field lines between the two resonant holes 114 can also be attracted to transmit in the direction of approaching each other, so as to realize the inductive enhancement effect.

FIG. 21 is a schematic structural diagram of two adjacent resonance holes 114 of a filter according to an embodiment of the present application. As shown in FIG. 21 , the first sub-hole 1141 may be a stepped hole structure. The inner diameter of each hole in the first sub-hole 1141 decreases one by one from the top surface 111 to the bottom surface 112 of the medium body.

FIG. 22 is a schematic structural diagram of two adjacent resonance holes 114 of a filter according to another embodiment of the present application. As shown in FIG. 22 , the resonant hole 114 may include a third hole 1144 that communicates with the second sub-hole 1142 , the third hole 1144 is disposed on the side of the bottom surface 112 of the dielectric body 11 , and may be, but not limited to, communicate with the second sub-hole 1142 . 1142 coaxial cable set.

Continuing to refer to FIG. 22 , in an embodiment of the present application, the third hole 1144 may be a stepped hole structure. In the direction from the bottom surface 112 to the top surface 111 of the medium body, the diameter of each hole in the third hole 1144 decreases one by one. Wherein, in an optional embodiment of the present application, the intersection of the third hole 1144 and the second sub-hole 1142 may also form a stepped surface. In addition, at the stepped surface formed by the second sub-hole 1142 and the third hole 1144 , a communication groove 13 may also be provided between two adjacent resonant holes 114 .

In the filter provided by each embodiment of the present application, by setting the first sub-hole 1141 and the second sub-hole 1142 arranged in a stepped structure, the open surface of the filter sinks to the stepped surface 1143, and the electric field of the resonance hole 114 is bound to the stepped surface 1143. In the surface 1143, even if no metal shielding cover is provided, signal leakage and noise floor increase will not be caused. In addition, since no metal shielding cover is provided in the filter of the embodiment of the present application, it can also avoid the problems of weak welding and low reliability in long-term use caused by different thermal expansion coefficients of materials.

In addition, in the filters of the embodiments of the present application, by opening the communication slot 13 between the two adjacent resonant holes 114 , the capacitive coupling path between the two resonant holes 114 can be opened, so that the capacitive coupling path between the two adjacent resonant holes 114 can be realized. coupling. At this time, the combination of capacitive coupling structure and inductive coupling can realize frequency-dependent coupling, and more transmission zeros can be realized without adding additional filter orders. Therefore, the frequency-variable coupling can also enable the filter to realize more transmission zeros out of band, flexibly adjust the position of the transmission zero of the filter, and make the topology structure of the out-of-band transmission zero of the filter more diverse. In addition, in this embodiment of the present application, the relevant parameters of the capacitive coupling structure and the inductive coupling structure can also be adjusted by changing factors such as the size of the resonant hole 114 and the number of the communication slots 13. By changing the capacitive coupling and the inductive coupling The relative strength of , the position of the zero point of the frequency-dependent coupling transmission can be adjusted.

Taking the structure shown in Fig. 7 as an example, the performance of two experimental filters of different sizes is tested. Among them, after testing the filter of experimental example 1, the coupling coefficient curve of the resonant unit composed of two resonant holes 114 in the filter of this experimental example is shown in Figure 23, and the transmission characteristic curve of the filter of this experimental example is shown in Figure 24 Show. After testing the filter of experimental example 2, the coupling coefficient curve of the resonant unit composed of two resonant holes 114 in the filter of this experimental example is shown in Figure 25, and the transmission characteristic curve of the filter of this experimental example is shown in Figure 26.

As shown in FIG. 23 and FIG. 25 , in the filter of the embodiment of the present application, the coupling coefficient of the resonance unit composed of the two resonance holes 114 of the structure shown in FIG. 7 changes with the change of frequency, so that frequency-dependent coupling can be realized.

Among them, in Figure 23, the frequency corresponding to m1 is the resonant frequency, and the coupling coefficient is zero at m2. As shown in Figure 23, the frequency corresponding to m2 is lower than the frequency corresponding to m1. This shows that by adjusting the specific structure of the filter, such as the number of resonant holes, the size of the resonant holes, the arrangement of the resonant holes, the number of communication slots, and the location of the communication slots, etc. (Low frequency band) Realize the setting of transmission zero point.

Among them, in Figure 25, the frequency corresponding to m1 is the resonant frequency, and the coupling coefficient is zero at m2. As shown in Figure 25, the frequency corresponding to m2 is higher than the frequency corresponding to m1. This shows that by adjusting the specific structure of the filter, such as the number of resonant holes, the size of the resonant holes, the arrangement of the resonant holes, the number of communication slots and the location of the communication slots, etc. (High frequency band) Realize the setting of transmission zero point.

It should be noted that, here, through the analysis of FIG. 23 and FIG. 25 , it can be obtained that the filter in the embodiment of the present application can realize frequency-dependent coupling. The values in the coupling coefficient curves shown in Fig. 23 and Fig. 25 are only illustrative, and the specific frequency values and coupling coefficient values may vary with the change of various parameters of the filter. Those skilled in the art should understand that the above The specific numerical value should not form a specific limitation on the filter of the present application.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art who is familiar with the technical scope disclosed in the present application can easily think of changes or replacements, which should cover within the scope of protection of this application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A filter, characterized in that it comprises a dielectric body and a metal layer;

The medium body includes a top surface, a bottom surface, and a side surface disposed between the top surface and the bottom surface. a resonance hole; from the top surface to the bottom surface, any of the resonance holes includes a first sub-hole and a second sub-hole that are communicated and arranged;

The metal layer covers the top surface, bottom surface, side surface of the dielectric body and the inner wall of the resonance hole, and an annular open-circuit slot is arranged in any of the resonance holes, and the open-circuit slot is arranged in the first The inner wall of the sub-hole;

Wherein, among the plurality of resonance holes, there are at least two adjacent resonance holes, and a communication slot is provided between the first sub-holes of the two adjacent resonance holes.
The filter according to claim 1, wherein the minimum inner diameter of the first sub-hole is greater than the maximum inner diameter of the second sub-hole.
The filter according to claim 2, wherein the first sub-hole is a blind hole, and the second sub-hole extends from the bottom wall of the first sub-hole toward the bottom surface of the dielectric body, The bottom wall of the first sub-hole is an annular structure arranged around the second sub-hole, so as to form a stepped surface between the first sub-hole and the second sub-hole.
The filter according to claim 3, wherein the open-circuit slit is provided in the stepped surface.
The filter according to claim 4, wherein the metal layer comprises a first sub-metal layer, a second sub-metal layer and a third sub-metal layer;

the first sub-metal layer is arranged on the hole wall of the second sub-hole;

the second sub-metal layer is connected to the first sub-metal layer, and extends from the connection of the second sub-hole with the first sub-hole to a direction away from the second sub-hole;

The third sub-metal layer covers the surface of the dielectric body on which the first sub-metal layer and the second sub-metal layer are not provided, and the third sub-metal layer is on the bottom surface and the first sub-metal layer. A sub-metal layer connection;

Wherein, in the stepped surface, the third sub-metal layer and the second sub-metal layer are provided in isolation.
The filter according to claim 5, wherein the second sub-metal layer has a ring structure and is disposed around the opening of the second sub-hole.
The filter according to any one of claims 3-6, wherein the stepped surface is a plane structure.
The filter according to claim 7, wherein the groove bottom of the communication groove and the bottom wall of the first sub-hole are coplanar.
The filter according to any one of claims 3-8, wherein the communication groove is formed inwardly from the top surface of the dielectric body.
The filter according to claim 9, wherein a coupling metal is provided in the communication groove, and for two adjacent resonant holes, between the two second sub-metal layers and the coupling metal At least one coupling gap exists.
The filter according to claim 10, wherein, for two adjacent resonant holes, the second sub-metal layer of at least one of the resonant holes is connected to the other one of the resonant holes in the communication groove. The second sub-metal layer of the resonance hole extends to form the coupling metal.
The filter according to claim 10, wherein between two adjacent resonant holes, the coupling metal extends from the bottom surface of the communication groove into the stepped surface, and two ends of the coupling metal The coupling gaps are located in the step surface and are respectively formed with the second sub-metal layer.
The filter according to claim 10, wherein the coupling metal comprises a plurality of metal segments arranged at intervals; wherein, among the two adjacent resonant holes, the second sub-metal is close to one of the resonant holes The metal segment provided in the layer is connected to the second sub-metal layer or a coupling slot is provided, and the metal segment provided in the second sub-metal layer close to the other resonant hole is connected to the other second sub-metal layer. A coupling gap is connected or arranged; at least one of the metal segments is also arranged between the two metal segments.
The filter according to any one of claims 9-13, wherein the shape of the end of the coupling metal at the coupling slot is any one of a straight line, a sawtooth shape, a wave shape or an interdigital shape kind.
The filter according to any one of claims 1-14, characterized in that, between two adjacent resonant holes, the dielectric body is further provided with a weakening groove;

The weakening groove is formed inwardly from the bottom surface, and the extending direction of the weakening groove is perpendicular to the arrangement direction between the two adjacent resonant holes; On the side surface between the bottom surface and the bottom surface, the weakening groove is formed inwardly from the side surface, and the extending direction of the weakening groove is perpendicular to the arrangement direction between the two adjacent resonant holes.
The filter according to claim 15, wherein when the weakening groove is formed inwardly from the side surface, the weakening groove penetrates through the top surface and the bottom surface.
The filter according to claim 16, wherein there are two weakening grooves, which are respectively disposed on both sides of the communicating groove.
The filter according to claim 15, wherein when the weakening groove is formed inwardly from the bottom surface, the weakening groove penetrates through the two opposite side surfaces of the dielectric body.
The filter according to any one of claims 1-14, characterized in that, between two adjacent resonant holes, the dielectric body further comprises a reinforcing groove, and the reinforcing groove is recessed inward from the bottom surface is formed, and the extending direction of the reinforcing groove is consistent with the arrangement direction between the two adjacent resonant holes.
The filter according to claim 19, wherein the reinforcing slot is a blind slot, and both ends of the reinforcing slot are not in communication with the two adjacent resonant holes.
The filter according to claim 19, wherein at least one end of the reinforcing slot communicates with one of the resonance holes.
The filter according to claim 20, wherein two ends of the reinforcing slot are respectively communicated with the resonance holes on the corresponding side.
The filter according to any one of claims 1-22, wherein a side of the first sub-hole away from the second sub-hole is a stepped hole structure.
The filter according to any one of claims 1-23, wherein the resonant hole further comprises a third hole communicating with the second sub-hole, and the third hole is provided on the side of the dielectric body. bottom side.
The filter according to claim 24, wherein the third hole is a stepped hole structure.
The filter according to claims 1-25, characterized in that, on the bottom surface, the communication groove is provided between two adjacent resonant holes.
A transmitter, characterized by comprising the filter according to any one of claims 1-26.
A receiver, characterized by comprising the filter described in any one of claims 1-26.
A communication system, characterized by comprising the transmitter of claim 27 and/or the receiver of claim 28 .