Dielectric filter and radio transceiver

Abstract

The dielectric filter provided by the present invention provides a negative coupling groove at the connection position of two dielectric resonator bodies, and the negative coupling groove is a step-shaped blind groove formed by the shallow blind groove and the deep blind groove intersecting each other, so that the shallow blind groove has an opening on the upper surface of the dielectric filter body, the shallow blind groove also has an opening on the front surface and / or the rear surface of the dielectric filter body, the deep blind groove has an opening only on the upper surface of the dielectric filter body, and the groove depth of the deep blind groove in the vertical direction is greater than the groove depth of the shallow blind groove in the vertical direction. Capacitive coupling between the two dielectric resonators can be achieved through the negative coupling groove, the shape and precision of the negative coupling groove change little when the ceramic material is sintered at a high temperature, the electrical performance is stable, and due to the existence of the shallow blind groove, the volume of the negative coupling groove accounts for a small proportion in the entire dielectric filter, the structural strength is good, and the yield rate is high; the present invention also provides a radio transceiver, which includes the dielectric filter.

Description

Technical Field

[0001] The present application relates to the field of electronic communication equipment, and in particular to a dielectric filter and a radio transceiver. Background Art

[0002] With the advent of the "big bang" era of 5G communication, 5G base stations are gradually becoming popular around the world, and filters are the key components in communication base stations that determine the anti-interference characteristics of base stations. Traditional 4G base stations use aluminum cavity filters to make bulky cavity filters, which cannot be used on a large scale under the architecture of Massive MIMO of 5G base stations due to defects such as size, weight, and cost. Dielectric filters, however, have become the preferred solution for filters for 5G base stations due to their small size, low loss, low cost, and high reliability. At the same operating frequency, dielectric filters can reduce the overall filter volume and weight to a few tenths of traditional cavity filters by virtue of the volume compression effect brought by high dielectric constants, while maintaining good performance. With the occupation of radio spectrum resources and the improvement of base station performance requirements, strict requirements are placed on the out-of-band suppression indicators of filters. At present, the common solution in the industry is to use a cross-coupling structure to construct a transmission zero point outside the filter band, so that the rectangular coefficient of the filter can be improved and the suppression of out-of-band spurious can be increased.

[0003] When the filter constructs a cross-coupled transmission zero point, negative coupling is usually required to flip the filter transmission phase. For example, Chinese patent application CN110444849A discloses a dielectric filter with a long blind slot negative coupling structure. In order to meet some specific electrical performance requirements, for example, when the relative bandwidth of the filter is about 5%, the depth of the blind slot negative coupling needs to be designed to be very deep, and the ratio of the slot depth to the total height of the filter reaches about 95%; at the same time, the length of the blind slot is relatively long, and the shape and precision of the blind slot change greatly when the ceramic material is sintered at high temperature, which will cause a significant change in the shape and precision of the negative coupling structure of the dielectric filter, thereby affecting the electrical performance of the dielectric filter and reducing the yield rate; at the same time, the deeper blind slot also greatly reduces the structural strength of the dielectric filter, which is prone to cracking and leads to a decrease in the reliability of the filter. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a dielectric filter that realizes capacitive coupling through a negative coupling groove. By setting the negative coupling groove in the form of a step-shaped blind groove, the shape and precision of the negative coupling groove change little when the ceramic material is sintered at a high temperature, the electrical performance is stable, the structural strength is good, and the yield rate is high. The present invention also provides a radio transceiver device, which includes the dielectric filter.

[0005] To achieve the above object, the technical solution provided by the present invention is a dielectric filter, comprising at least two dielectric resonators, each of which comprises a dielectric resonator body made of ceramic material and a debugging hole located on the upper surface of the dielectric resonator body, wherein the debugging hole is a blind hole, and the blind hole is used to debug the resonant frequency of the dielectric resonator in which it is located; all the dielectric resonator bodies constitute the dielectric filter body, and the dielectric filter further comprises:

[0006] A negative coupling groove is provided on the upper surface of the dielectric filter body, the negative coupling groove extends downward in a direction perpendicular to the upper surface of the dielectric filter body, the negative coupling groove is a blind groove, the negative coupling groove is located at the connection position of two dielectric resonator bodies, and the position of the negative coupling groove is connected to the two dielectric resonators;

[0007] A conductive layer covering the surface of the dielectric filter body, the inner wall surface of the debugging hole and the inner wall surface of the negative coupling slot;

[0008] The negative coupling groove is a step-shaped blind groove formed by the shallow blind groove and the deep blind groove intersecting each other. The shallow blind groove has an opening on the upper surface of the dielectric filter body, and the shallow blind groove also has an opening on the front surface and / or the rear surface of the dielectric filter body. The deep blind groove only has an opening on the upper surface of the dielectric filter body. The groove depth of the deep blind groove in the up-down direction is greater than the groove depth of the shallow blind groove in the up-down direction. The negative coupling groove is used to realize capacitive coupling between the two dielectric resonators.

[0009] Preferably, the groove width of the deep blind groove in the left-right direction is greater than or equal to the groove width of the shallow blind groove in the left-right direction.

[0010] Further preferably, the width of the deep blind groove in the left-right direction is less than or equal to half of the distance between the debugging holes on the two dielectric resonators, and the distance between the debugging holes on the two dielectric resonators refers to the shortest distance between the inner walls of the two debugging holes.

[0011] Preferably, the groove depth of the deep blind groove in the up-down direction is greater than the hole depth of the debugging hole.

[0012] Further preferably, the groove depth of the deep blind groove in the up-down direction is less than twice the hole depth of the debugging hole.

[0013] Preferably, the groove depth of the shallow blind groove in the up-down direction is smaller than the hole depth of the debugging hole.

[0014] Preferably, the center line of the deep blind groove and the center line of the shallow blind groove form a virtual plane, and the debugging holes on the two dielectric resonator bodies are symmetrically distributed on both sides of the plane.

[0015] Preferably, the cross section of the deep blind groove in a direction parallel to the upper surface of the dielectric filter body is a rectangle or a rectangle with chamfered angles, and the cross section of the shallow blind groove in a direction parallel to the front surface of the dielectric filter body is a rectangle or a rectangle with chamfered angles.

[0016] The technical solution provided by the present invention also includes a radio transceiver device, wherein the radio transceiver device includes any one of the dielectric filters described above.

[0017] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0018] The dielectric filter provided by the present invention provides a negative coupling groove at the connection position of two dielectric resonator bodies, and the negative coupling groove is a step-shaped blind groove formed by the shallow blind groove and the deep blind groove intersecting each other, so that the shallow blind groove has an opening on the upper surface of the dielectric filter body, the shallow blind groove also has an opening on the front surface and / or the rear surface of the dielectric filter body, the deep blind groove has an opening only on the upper surface of the dielectric filter body, and the groove depth of the deep blind groove in the vertical direction is greater than the groove depth of the shallow blind groove in the vertical direction. Capacitive coupling between the two dielectric resonators can be achieved through the negative coupling groove, the shape and precision of the negative coupling groove change little when the ceramic material is sintered at a high temperature, the electrical performance is stable, and due to the existence of the shallow blind groove, the volume of the entire negative coupling groove accounts for a small proportion in the entire dielectric filter, the structural strength is good, and the yield rate is high; the present invention also provides a radio transceiver, which includes the dielectric filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a three-dimensional perspective schematic diagram of a dielectric filter embodiment 1 of the present invention.

[0021] Figure 2 for Figure 1 Schematic top view of .

[0022] Figure 3 for Figure 2 Cross-sectional view along the AA direction.

[0023] Figure 4 for Figure 2 Cross-sectional view along the BB direction.

[0024] Figure 5It is a perspective schematic diagram of a dielectric filter embodiment 2 of the present invention.

[0025] Figure 6 for Figure 5 Schematic diagram from top view.

[0026] Figure 7 for Figure 6 Cross-sectional view along CC direction.

[0027] Figure 8 It is a three-dimensional perspective schematic diagram of Example 3 of the dielectric filter in the present invention.

[0028] Fig. 9 This is a diagram of the electrical performance of dielectric filter embodiment 1 of the present invention.

[0029] Wherein: 100. dielectric filter; 101. dielectric filter body; 200. first dielectric resonator; 201. first dielectric resonator body; 202. first debugging hole; 300. second dielectric resonator; 301. second dielectric resonator body; 302. second debugging hole; 400. deep blind groove; 500. shallow blind groove; 600. conductive layer. DETAILED DESCRIPTION

[0030] The following will describe the technical solutions in the embodiments of the present invention in detail in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate directions or positional relationships based on the attached Figure 1 The orientation or positional relationship shown is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] Example 1

[0034] like Figure 1-4 As shown, the dielectric filter 100 provided by the present invention comprises a first dielectric resonator 200 and a second dielectric resonator 300 having the same structure. The first dielectric resonator 200 comprises a first dielectric resonator body 201 made of a ceramic material and a first debugging hole 202 located on the upper surface of the first dielectric resonator body 201, wherein the first debugging hole 202 is a blind hole and is used to debug the resonance frequency of the first dielectric resonator 200; the second dielectric resonator 300 comprises a second dielectric resonator body 301 made of a ceramic material and a second debugging hole 302 located on the upper surface of the second dielectric resonator body 301, wherein the second debugging hole 302 is a blind hole and is used to debug the resonance frequency of the second dielectric resonator 300; the first dielectric resonator body 201 and the second dielectric resonator body 202 together constitute a dielectric filter body 101, and the dielectric filter 100 further comprises a negative coupling slot and a conductive layer 600.

[0035] The negative coupling groove is provided on the upper surface of the dielectric filter body 101, and extends downward in a direction perpendicular to the upper surface of the dielectric filter body 101. The negative coupling groove is a blind groove, and is located at the connection position of the first dielectric resonator body 201 and the second dielectric resonator body 301. The position of the negative coupling groove is connected to the first dielectric resonator 200 and the second dielectric resonator 300. The negative coupling groove is a step-shaped blind groove formed by the deep blind groove 400 and the shallow blind groove 500 intersecting each other. The deep blind groove 400 has an opening only on the upper surface of the dielectric filter body 101, the shallow blind groove 500 has an opening on the upper surface of the dielectric filter body 101, and the shallow blind groove 500 also has an opening on the front surface of the dielectric filter body 101. The groove depth of the deep blind groove 400 in the up-down direction is greater than the groove depth of the shallow blind groove 500 in the up-down direction. The negative coupling groove is used to realize the capacitive coupling between the first dielectric resonator 200 and the second dielectric resonator 300.

[0036] The conductive layer 600 covers the surface of the dielectric filter body 101 , the inner wall surface of the first debugging hole 202 , the inner wall surface of the second debugging hole 302 , the inner wall surface of the deep blind groove 400 and the inner wall surface of the shallow blind groove 500 . The conductive layer 600 is made of silver.

[0037] The groove width of the deep blind groove 400 in the left-right direction is equal to the groove width of the shallow blind groove 500 in the left-right direction. The groove width of the deep blind groove 400 in the left-right direction is less than or equal to half of the distance between the first debugging hole 202 and the second debugging hole 302. The distance between the first debugging hole 202 and the second debugging hole 302 refers to the shortest distance between the inner wall of the first debugging hole 202 and the inner wall of the second debugging hole 302.

[0038] The groove depth of the deep blind groove 400 in the vertical direction is greater than the hole depth of the first debugging hole 202 / the second debugging hole 302, and the groove depth of the deep blind groove 400 in the vertical direction is less than twice the hole depth of the first debugging hole 202 / the second debugging hole 302.

[0039] The groove depth of the shallow blind groove 500 in the up-down direction is smaller than the hole depth of the first debugging hole 202 / the second debugging hole 302 .

[0040] The center line of the deep blind groove 400 is perpendicular to the center line of the shallow blind groove 500 , and the center line of the deep blind groove 400 and the center line of the shallow blind groove 500 form a virtual plane, and the first debugging hole 202 and the second debugging hole 302 are symmetrically distributed on both sides of the plane.

[0041] The cross section of the deep blind groove 400 in a direction parallel to the upper surface of the dielectric filter body 101 is rectangular, and the cross section of the shallow blind groove 500 in a direction parallel to the front surface of the dielectric filter body 101 is rectangular.

[0042] like Fig. 9 As shown, the dielectric filter 100 generates a transmission zero point A at the low-frequency end of the filter passband B through the step-shaped blind groove formed by the deep blind groove 400 and the shallow blind groove 500 intersecting each other; the negative coupling and the strength of the transmission zero point A are adjusted by adjusting the groove length, groove width and groove depth of the deep blind groove 400 and / or the shallow blind groove 500; the longer the groove length of the deep blind groove 400 and / or the shallow blind groove 500 in the front-to-back direction, the weaker the negative coupling strength and the weaker the transmission zero point A; the wider the groove width of the deep blind groove 400 and / or the shallow blind groove 500 in the left-to-right direction, the weaker the negative coupling strength and the weaker the transmission zero point A; the deeper the groove depth of the deep blind groove 400 and / or the shallow blind groove 500 in the up-down direction, the weaker the negative coupling strength and the weaker the transmission zero point A.

[0043] Example 2

[0044] like Figure 5-7 As shown, Example 2 is substantially the same as Example 1, except that: in Example 2, the groove width of the deep blind groove 400 in the left-right direction is greater than the groove width of the shallow blind groove 500 in the left-right direction.

[0045] Example 3

[0046] like Figure 8 As shown, the embodiment 3 is substantially the same as the embodiment 1, except that the shallow blind groove 500 in the embodiment 3 has openings on the upper surface, the front surface and the rear surface of the dielectric filter body 101 .

[0047] The dielectric filter provided by the present invention realizes capacitive coupling between the two dielectric resonators by arranging blind-groove-type deep blind grooves and shallow blind grooves at the connection positions of two dielectric resonator bodies, making the groove depth of the deep blind groove in the up-down direction greater than the groove depth of the shallow blind groove in the up-down direction, and making the shallow blind groove extend backward and penetrate the inner wall of the deep blind groove, so that the cavity in the deep blind groove is connected with the cavity in the shallow blind groove, and the deep blind groove and the shallow blind groove have little change in shape and precision when the ceramic material is sintered at high temperature, and the electrical performance is stable. Due to the existence of the shallow blind groove, the volume of the entire negative coupling groove accounts for a small proportion in the entire dielectric filter, the structural strength is good, and the yield rate is high; and the electrical performance of the dielectric filter can be debugged by matching the size, shape and relative position of the two negative coupling grooves, and the debugging methods are various and the debugging efficiency is high.

[0048] The present invention further provides a transceiver device, which includes any one of the dielectric filters in the above embodiments. The dielectric filter in the transceiver device can be used to filter radio frequency signals.

[0049] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0050] The above is only a specific implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A dielectric filter, comprising at least two dielectric resonators, each of which comprises a dielectric resonator body made of ceramic material and a debugging hole located on the upper surface of the dielectric resonator body, wherein the debugging hole is a blind hole, and the blind hole is used to debug the resonant frequency of the dielectric resonator in which it is located; all the dielectric resonator bodies constitute the dielectric filter body, and the dielectric filter further comprises: A negative coupling groove is provided on the upper surface of the dielectric filter body, the negative coupling groove extends downward in a direction perpendicular to the upper surface of the dielectric filter body, the negative coupling groove is a blind groove, the negative coupling groove is located at the connection position of two dielectric resonator bodies, and the position of the negative coupling groove is connected to the two dielectric resonators; A conductive layer covering the surface of the dielectric filter body, the inner wall surface of the debugging hole and the inner wall surface of the negative coupling slot; Features: The negative coupling groove is a step-shaped blind groove formed by the shallow blind groove and the deep blind groove intersecting each other, the center line of the shallow blind groove is perpendicular to the center line of the deep blind groove, the shallow blind groove has an opening on the upper surface of the dielectric filter body, the shallow blind groove also has an opening on the front surface and / or the rear surface of the dielectric filter body, and the deep blind groove only has an opening on the upper surface of the dielectric filter body; The groove depth of the deep blind groove in the up-down direction is greater than the groove depth of the shallow blind groove in the up-down direction, the groove depth of the deep blind groove in the up-down direction is greater than the hole depth of the debugging hole and less than twice the hole depth of the debugging hole, the groove depth of the shallow blind groove in the up-down direction is less than the hole depth of the debugging hole, and the negative coupling groove is used to realize capacitive coupling between the two dielectric resonators.

2. The dielectric filter according to claim 1, characterized in that: The groove width of the deep blind groove in the left-right direction is greater than or equal to the groove width of the shallow blind groove in the left-right direction.

3. The dielectric filter according to claim 2, characterized in that: The width of the deep blind groove in the left-right direction is less than or equal to half of the distance between the debugging holes on the two dielectric resonators, and the distance between the debugging holes on the two dielectric resonators refers to the shortest distance between the inner walls of the two debugging holes.

4. The dielectric filter according to claim 1, characterized in that: The center line of the deep blind groove and the center line of the shallow blind groove form a virtual plane, and the debugging holes on the two dielectric resonator bodies are symmetrically distributed on both sides of the plane.

5. The dielectric filter according to claim 1, characterized in that: The cross section of the deep blind groove in a direction parallel to the upper surface of the dielectric filter body is a rectangle or a rectangle with a chamfered angle, and the cross section of the shallow blind groove in a direction parallel to the front surface of the dielectric filter body is a rectangle or a rectangle with a chamfered angle.

6. Radio transceiver equipment, characterized in that The invention comprises the dielectric filter according to any one of claims 1 to 5.

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