WO2024060070A1

WO2024060070A1 - Dielectric resonator and microwave device

Info

Publication number: WO2024060070A1
Application number: PCT/CN2022/120238
Authority: WO
Inventors: Shou Li JIA; Yu Zhe WEI; Hao Wang; Pan Pan YANG
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy
Priority date: 2022-09-21
Filing date: 2022-09-21
Publication date: 2024-03-28

Abstract

Embodiments of the present disclosure relate to a dielectric resonator and a microwave device. A dielectric resonator comprises a housing defining a cavity and a dielectric body arranged within the cavity. The housing is at least surface conductive. The cavity comprises a first top surface, a first bottom surface and at least four side surfaces. The dielectric body comprises a second top surface in conductive contact with the first top surface, a second bottom surface in conductive contact with the first bottom surface and eight side surfaces. A first set of four side surfaces among the eight side surfaces are parallelly separate from the four side surfaces of the cavity. A second set of four side surfaces among the eight side surfaces face four lateral edges of the cavity. In this way, the dielectric resonator has a reduced volume, low manufacturing cost, and reliable performance.

Description

DIELECTRIC RESONATOR AND MICROWAVE DEVICE

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular to a dielectric resonator and a microwave device.

BACKGROUND

With the development of wireless communication systems, microwave devices, such as radio frequency (RF) filters, have become critical parts of base stations for the wireless communication systems. In base stations of 5G and massive multiple-input multiple-output (MIMO) systems, the requirements for the microwave devices are growing more and more. On one hand, the microwave devices are required to be smaller in size so as to accommodate 5G and massive MIMO base station applications. On the other hand, in the 5G and massive MIMO base stations, the microwave devices are required to provide better performance. The performance of the microwave devices will affect the sensitivity and power consumption of the entire system.

SUMMARY

In general, example embodiments of the present disclosure provide a dielectric resonator and a microwave device.

In a first aspect, there is provided a dielectric resonator in a microwave device. The dielectric resonator comprises a housing defining a cavity and a dielectric body arranged within the cavity. The housing is at least surface conductive. The cavity comprises a first top surface, a first bottom surface and at least four side surfaces. The dielectric body comprises a second top surface, a second bottom surface and eight side surfaces. The second top surface is in conductive contact with the first top surface. The second bottom surface is in conductive contact with the first bottom surface. A first set of four side surfaces among the eight side surfaces are parallelly separate from the four side surfaces of the cavity. A second set of four side surfaces among the eight side surfaces face four lateral edges of the cavity.

In a second aspect, there is provided a microwave device. The microwave device comprises at least one dielectric resonator as described in the first aspect. The microwave device also comprises at least two coaxial resonators. The at least one dielectric resonator and the at least two coaxial resonators are coupled with one another.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, in which:

Fig. 1 illustrates a schematic structural view of a 5G Massive MIMO active antenna unit (AAU) in which example embodiments of the present disclosure may be implemented;

Fig. 2A illustrates a perspective view of a dielectric resonator in accordance with a first embodiment of the present disclosure;

Figs. 2B-2D illustrate an exploded perspective view, a top view and a side view of the dielectric resonator shown in Fig. 2, respectively;

Fig. 3A illustrates an electromagnetic field distribution diagram of the dielectric resonator shown in Fig. 2A in a first working mode in a top view;

Fig. 3B illustrates an electric field distribution diagram of the dielectric resonator shown in Fig. 2A in the first working mode in a side view;

Fig. 3C illustrates an electromagnetic field distribution diagram of the dielectric resonator shown in Fig. 2A in a second working mode in a top view;

Fig. 3D illustrates an electric field distribution diagram of the dielectric resonator shown in Fig. 2A in the second working mode in a side view;

Fig. 4 illustrates a top view of the dielectric resonator shown in Fig. 2A labelled with dimensions;

Fig. 5 illustrates a frequency change curve of working modes of the dielectric resonator shown in Fig. 2A;

Fig. 6 illustrates a schematic structural view of a dielectric resonator in accordance with a second embodiment of the present disclosure;

Fig. 7 illustrates a schematic structural view of a dielectric resonator in accordance with a third embodiment of the present disclosure;

Fig. 8A illustrates a schematic structural view of a microwave device according to an embodiment of the present disclosure;

Fig. 8B illustrates a topological view of the microwave device shown in Fig. 8A;

Fig. 9A illustrates an exploded perspective view of the microwave device shown in Fig. 8A;

Fig. 9B illustrates a schematic structural view of a bottom housing of the microwave device shown in Fig. 8A;

Fig. 10 illustrates a schematic structural view of a coupling structure in the microwave device shown in Fig. 8A;

Fig. 11 illustrates frequency responses of the microwave device shown in Fig. 8A; and

Figs. 12A-12D illustrate schematic structural views of microwave devices according to further embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “some example embodiments, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with some example embodiments, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. It should be understood that, the terms “parallel” and “perpendicular” as used herein may refer to strictly parallel and strictly perpendicular, respectively, and may also refer to substantially parallel and substantially perpendicular within a margin of error due to the manufacturing process (e.g. within ± 0.5° or ±1°) . It will be appreciated by those skilled in the art that such errors do not result in significant degradation of performance and therefore would not depart from the scope of present disclosure.

The term “housing” used herein can refer to a structure that houses an object and at least partially covers and protects the object. The term “cavity” used herein can refer to a hollow space which can be filled with air or dielectric materials. The term “resonant component” or “resonator” used herein can refer to a structure that supports electromagnetic resonance.

A microwave device, for example, radio frequency (RF) filter, is a key component in 5G and Massive MIMO systems, which can reject the harmonics and spurious and make signals more clear. Conventional air-cavity filter requires a large filter size to provide a good performance in terms of low insertion loss and high rejection. Conventional ceramic waveguide filter may provide an acceptable RF performance for most of the 5G and Massive MIMO systems in a quite small size and thin thickness, but in the cost of poor insertion loss performance as well as poor attenuation performance at the far band. Therefore, there is a need for a resonator that is simple in structure, small in size, and reliable in performance. Principle and embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

Reference is first made to Fig. 1, which illustrates a schematic structural view of a 5G Massive MIMO AAU 1 in which example embodiments of the present disclosure may be implemented. As shown in Fig. 1, the AAU 1 may include at least three layers from bottom to the top, namely, a main board 13 in the bottom layer, an antenna array 11 in the top layer and microwave devices (e.g., filters) 12 in the middle layer. The main board 13 may include a printed circuit board implementing transceiver/power amplifier/power source supply functions. The antenna array 11 may include feeding networks in the printed circuit board assembly. The microwave devices 12 may include one or more filters for connecting the main board 13 to the antenna array 11. The thickness of the microwave devices 12 is quite critical to the overall AAU thickness, as is the weight.

It is to be understood that the AAU in Fig. 1 is only for the purpose of illustration without suggesting any limitations. In addition to the AAU, the dielectric resonator and the microwave device according to embodiments of the present disclosure may be implemented in any other devices or scenarios that need one or more dielectric resonators or need one or more microwave devices.

Fig. 2A illustrates a perspective view of a dielectric resonator 20 in accordance with a first embodiment of the present disclosure. Figs. 2B-2D illustrate an exploded perspective view, a top view and a side view of the dielectric resonator 20 shown in Fig. 2, respectively. As shown in Figs. 2A-2D, in general, the dielectric resonator 20 described herein is a dual mode resonator including a housing 22 defining a cavity 23 and a dielectric body 21 mounted in the cavity 23. The housing 22 is at least surface conductive. As used herein, the dielectric body 21 can also be termed as a dielectric puck 21 in some example embodiments. In some embodiments, the housing 22 may be made of various available metallic materials, such as Aluminium, and the scope of the present disclosure is not limited in this respect. In other embodiments, the housing 22 may be made of various non-metallic materials, such as plastics or ceramic materials, with a conductive coating.

Likewise, the dielectric body 21 may be made of a variety of available dielectric materials. For example, in some embodiments, the dielectric body 12 may be made of suitable dielectric materials with low losses. Typical materials are, for example, microwave ceramic materials such as BaTi ₄O ₉, Ba ₂Ti ₉O ₂₀ or (Zr, Sn) TiO ₄ and so on. The microwave ceramic materials have low losses and dielectric constant in a range from 5 to 120. For a dielectric resonator having the same structure and dimensions, the higher the dielectric constant of the resonator body, the lower the resonant frequency. For example, for mm-wave dielectric resonators, ceramics with lower dielectric constants may be used, while for dielectric resonators providing lower resonance frequencies, such as 600 MHz, ceramics with higher dielectric constants may be used. In other embodiments, the dielectric body 21 may be made of other materials, and the scope of the present disclosure is not limited in this respect.

As shown in Figs. 2A-2D, the cavity 23 of the housing 22 includes a first top surface 220, a first bottom surface 225 and four side surfaces 221-224. The dielectric body 21 includes a second top surface 210, a second bottom surface 219 and eight side surfaces 211-218. The second top surface 210 of the dielectric body 21 is in conductive contact with the first top surface 220 of the cavity 23 and the second bottom surface 219 of the dielectric body 21 is in conductive contact with the first bottom surface 225 of the cavity 23. A first set of four side surfaces 211-214 among the eight side surfaces of the dielectric body 21 are separate from the four side surfaces 221-224 of the cavity 23. The first set of four side surfaces 211-214 of the dielectric body 21 are substantially parallel to the four side surfaces 221-224 of the cavity 23, respectively. A second set of four side surfaces 215-218 among the eight side surfaces face four lateral edges of the cavity 23. In this way, the volume of the dielectric resonator can be reduced, such that it can be applied to the 5G and massive MIMO base stations. In addition, such a dielectric resonator is also simple in structure, low in manufacturing cost, and reliable in performance. It should be understood that the structure of the dielectric resonator 20 in Figs. 2A-2D are provided by way of example without suggesting any limitations. For example the cavity 23 may comprise additional side surfaces in addition to the four side surfaces 221-224 as shown.

In an embodiment, as shown in Fig. 2B, the housing 22 may include a top cover 230 defining the first top surface 220 of the cavity 23 and a bottom housing 240 defining the first bottom surface 225 and four side surfaces 221-224 of the cavity 23. The first top surface 220 and the first bottom surface 225 of the cavity 23 may be of a square shape or a rectangle shape. In other words, the cavity 23 may has a cross-section of a square shape or a rectangle shape in a thickness direction of the dielectric resonator 20 (i.e., +z direction in Figs. 2A-2D) . In examples of the present disclosure, the cross-section of the cavity 23 may be illustrated as a square shape. While this may be the case in some examples, it is not necessarily the case in all examples. In this way, the dielectric resonator has a simple structure and is easy to manufacture and to assembly.

In some embodiments, the second top surface 210 and the second bottom surface 219 of the dielectric body 21 may be of an octagon shape. In some embodiments, a first side surface 215 and a third side surface 217 among the second set of four side surfaces 215-218 of the dielectric body 21 may be opposite to and substantially in parallel with each other. Alternatively or additionally, a second side surface 216 and a fourth side surface 218 among the second set of four side surfaces 215-218 of the dielectric body 21 may be opposite to and substantially in parallel with each other. In this way, the dielectric resonator is able to support two independent working modes with a simple structure.

In some embodiments, the first side surface 215 and the third side surface 217 of the dielectric body 21 may be disposed relative to a first diagonal plane of the cavity 23 including two of the four lateral edges of the cavity 23 based on a required field distribution of a first working mode of the dielectric resonator 20. Alternatively or additionally, the second side surface 216 and the fourth side surface 218 of the dielectric body 21 may be disposed relative to a second diagonal plane of the cavity 23 comprising the other two of the four lateral edges of the cavity 23 based on a required field distribution of a second working mode of the dielectric resonator 20. In this way, the electromagnetic field distribution of the dielectric resonator is more regular, making it easy to achieve higher coupling strength and thus lower insertion losses.

In some embodiments, the dielectric resonator 20 may be configured to support a first working mode with a first resonant frequency and a second working mode with a second resonant frequency. Reference is now made to Figs. 3A to 3D, which illustrate electromagnetic field distribution diagrams of the dielectric resonator 20 shown in Fig. 2A in the two working modes.

Fig. 3A illustrates an electromagnetic field distribution diagram of the dielectric resonator 20 shown in Fig. 2A in a first working mode in a top view, Fig. 3B illustrates an electric field distribution diagram of the dielectric resonator 20 shown in Fig. 2A in the first working mode in a side view, Fig. 3C illustrates an electromagnetic field distribution diagram of the dielectric resonator 20 shown in Fig. 2A in a second working mode in a top view, and Fig. 3D illustrates an electric field distribution diagram of the dielectric resonator 20 shown in Fig. 2A in the second working mode in a side view. The dielectric resonator 20 may have multiple resonant modes, among which, two resonant modes are selected as its working modes. In an example implementation, the working modes of the dielectric resonator 20 may be two transverse magnetic (TM) modes in the perspective of Figs. 3A-3D, namely, a TM21A mode and a TM21B mode. There is no coupling between the two working modes.

As shown in Figs. 3A and 3B, the first side surface 215 and the third side surface 217 of the dielectric body 21 may be perpendicular to a first diagonal plane of the cavity 23 comprising a first and a third lateral edges among the four lateral edges such that intensity peaks of an electric field and intensity peaks of a magnetic field of the TM21A mode are distributed along the first diagonal plane of the cavity 23. In other words, the electromagnetic field distribution of the TM21A mode is along the +45° diagonal line of the cross-section of the cavity 23. As shown in Fig. 3B, the electric field of the TM21A mode in the dielectric body 21 is directed from top to bottom near the first lateral edge and from bottom to top near the third lateral edge. As shown in Figs. 3C and 3D, the second side surface 216 and the fourth side surface 218 may be perpendicular to a second diagonal plane of the cavity 23 comprising a second and a fourth lateral edges among the four lateral edges such that intensity peaks of an electric field and intensity peaks of a magnetic field of the TM21B mode are distributed along the second diagonal plane of the cavity 23. In other words, the electromagnetic field distribution of the TM21B mode is along the -45° diagonal line of the cross-section of the cavity 23. As shown in Fig. 3D, the electric field of the TM21A mode in the dielectric body 21 is directed from top to bottom near the second lateral edge and from bottom to top near the fourth lateral edge. Such electromagnetic field distribution as shown in Figs. 3A-3D is important for the dual mode filter topology.

Fig. 4 illustrates a top view of the dielectric resonator 20 shown in Fig. 2A labelled with dimensions. By way of example only, the cross-section of the cavity 23 is of a square shape, and the cross-section of the dielectric body 21 is of an octagon shape formed by truncating four corners of a square shape. As shown in Fig. 4, the width of the cavity 23 in the lateral direction is a. The width of the dielectric body 21 in the lateral direction is b. The widths of the first side surface 215 and the third side surface 217 of the dielectric body 21 in the lateral direction are c1 and c2, respectively. The lateral direction refers to a direction normal to the thickness direction of the dielectric resonator 20. The widths of the second side surface 216 and the fourth side surface 218 of the dielectric body 21 in the lateral direction are d1 and d2, respectively. In some embodiments, at least one of widths of the second set of four side surfaces 215-218 of the dielectric body 21, i.e., the greatest one of widths c1, c2, d1, and d2, is smaller than a smallest one of widths of the first set of four side surfaces 211-214. In this way, the distribution of electromagnetic field along the two diagonal lines of the cross-section of the cavity is achieved.

In some embodiments, the first resonant frequency of the first working mode and the second resonant frequency of the second working mode of the dielectric resonator 20 can be tuned independently. Reference is now made to Fig. 5, which illustrates a frequency change curve of working modes of the dielectric resonator 20 shown in Fig. 2A. In the example embodiment of Fig. 5, assuming the dimension of the cavity 23 (e.g., the width a in Fig. 4) and the dimension of the dielectric body 21 (e.g., the width b in Fig. 4) may be kept unchanged. The first resonant frequency is tunable without substantially changing the second resonant frequency by adjusting at least one of the widths c1 and c2 of the first side surface 215 and the third side surface 217 of the dielectric body 21.

The widths c1 and c2 of the first side surface 215 and the third side surface 217 of the dielectric body 21 in the lateral direction may be the same. Alternatively or additionally, the widths d1 and d2 of the second side surface 216 and the fourth side surface 218 of the dielectric body 21 in the lateral direction are may be the same. Such symmetrical structure facilitates reducing the complexity of manufacturing and assembly of the dielectric resonator.

As shown in Fig. 5, assuming c1=c2=c, by increasing the widths c of the first side surface 215 and the third side surface 217, the first resonant frequency of the TM21A mode increases while the second resonant frequency of the TM21B mode remains substantially unchanged. Similarly, the second resonant frequency is tunable without substantially changing the first resonant frequency by adjusting at least one of the widths d1 and d2 of the second side surface 216 and the fourth side surface 218 of the dielectric body 21. In this way, the resonant frequency of each working mode of the dual mode dielectric resonator may be adjusted independently with little impact or even no impact on the other working mode. In some embodiments, if c1=c2=d1=d2, the first and second resonant frequencies of the TM21A mode and the TM21B mode may be the same.

Fig. 6 illustrates a schematic structural view of a dielectric resonator 20 in accordance with a second embodiment of the present disclosure. The dielectric resonator 20 as shown in FIG. 6 has a similar structure to the dielectric resonator 20 as shown in Fig. 2A. The same components will be denoted by the same reference numerals, and their specific details will not be described again. The difference between the two dielectric resonators 20 mainly lies in the widths of the second set of side surfaces 215-218 of the dielectric body 21 in the lateral direction. Specifically, as shown in Fig. 6, the widths c1 and c2 of the first side surface 215 and the third side surface 217 of the dielectric body 21 in the lateral direction may be different. Alternatively or additionally, the widths d1 and d2 of the second side surface 216 and the fourth side surface 218 of the dielectric body 21 in the lateral direction may be different.

Fig. 7 illustrates a schematic structural view of a dielectric resonator 20 in accordance with a third embodiment of the present disclosure. The dielectric resonator 20 as shown in FIG. 7 has a similar structure to the dielectric resonator 20 as shown in Fig. 2A. The same components will be denoted by the same reference numerals, and their specific details will not be described again. The difference between the two dielectric resonators 20 mainly lies in a hole 24. Specifically, as shown in Fig. 7, the dielectric body 21 may be provided with the hole 24 substantially in a center of the dielectric body 21 extending in the thickness direction from the second top surface 210 to the second bottom surface 219 of the dielectric body 21. As shown in the electromagnetic field distributions in Figs. 3A-3D, there is no/less electric field in the center of the dielectric body 21, so the hole 24 can be designed in the center without substantially changing the electromagnetic field distribution. A fixing screw through the hole 24 may be used to fix the dielectric body 21 to the housing 22. In this way, the assembly of the dielectric body in the dielectric resonator is more stable and reliable.

The dielectric resonator 20 according to various embodiments described above with reference to Figs. 2A-7 may be used in microwave devices such as radio frequency filters. Some exemplary embodiments of the microwave devices are described below with reference to Figs. 8A-12D.

Fig. 8A illustrates a schematic structural view of a microwave device 12 according to an embodiment of the present disclosure. The microwave device 12 shown in Fig. 8A is a linear microwave device including one dielectric resonator 20 as described above and two coaxial resonators 30. The dielectric resonator 20 and the two coaxial resonators 30 are coupled with one another. Therefore, as used herein, the microwave device 12 can also be referred to as a hybrid dual mode microwave device. In some embodiments, the two coaxial resonators 30 are coupled with the dielectric resonator 20 at two opposite side surfaces of the dielectric resonator 20. In some embodiments, the microwave device 12 has an input port 81 and an output port 82. RF signals may be transferred from one port to another port.

Fig. 8B illustrates a topological view of the microwave device 12 shown in Fig. 8A. As shown in Fig. 8B, the microwave device 12 has an input and an output, the first node corresponds to the first coaxial resonator 30 shown in Fig. 8A, the second node and the third node correspond to the two working modes of the dielectric resonator 20 shown in Fig. 8A, and the fourth node corresponds to the second coaxial resonator 30 shown in Fig. 8A. In this way, a hybrid dual mode microwave device with good attenuation performance is provided. The reason is that one property of the ceramic dual-mode resonator is frequencies of the high modes are close to the pass band, normally 1.5*f0 or 2*f0; but the high modes of air-cavity coaxial resonators with caps are quite faraway to more than 3*f0 or even 5*f0, in which f0 represents a center frequency of the pass band.

Reference numerals C12, C13, C24 and C34 are used to indicate the coupling between the respective resonators. The coupling between the respective resonators can be achieved by a coupling window structure in the microwave device design. As shown in Fig. 8B, there is no coupling between the two working modes of the dielectric resonator 20. The coupling topology of the microwave device 12 is referred to as a parallel coupling structure.

Fig. 9A illustrates an exploded perspective view of the microwave device 12 shown in Fig. 8A. Fig. 9B illustrates a schematic structural view of a bottom housing 98 of the microwave device 12 shown in Fig. 8A. Fig. 10 illustrates a schematic structural view of a coupling structure 83 in the microwave device 12 shown in Fig. 8A. As shown in Figs. 8A-10, the microwave device 12 may include a first coupling structure 83 between the first coaxial resonator 30 and the dielectric resonator 20 and a second coupling structure 83 between the second coaxial resonator 30 and the dielectric resonator 20.

Based on the electromagnetic field distributions shown in Figs. 3A-3D, each coupling structure 83 may designed to include a first coupling window 91 and a second coupling window 92. Each coupling window in the coupling structure 83 may be configured to couple a corresponding working mode of the dielectric resonator 20 with the coaxial resonator 30. In some embodiments, the coupling structure 83 may further include a rib structure 95 between the two coupling windows to enhance the coupling. The coupling strengths C12, C13, C24 and C34 in Figs. 8B may be controlled by adjusting the dimensions w1, w2, w3, w4 and h1, h2, h3, h4 of the coupling structures 83.

For example, the first coupling window 91 in the second coupling structure 83 may be configured to couple the first working mode of the dielectric resonator 20 with the second coaxial resonator 30. The second coupling window 92 in the second coupling structure 83 may be configured to couple the second working mode of the dielectric resonator 20 with the second coaxial resonator 30. The coupling strength C24 between the first working mode of the dielectric resonator 20 and the third coaxial resonator 30 is controllable by adjusting dimensions of the first coupling window 91, e.g., the dimensions h1, h3 and w2 in Fig. 10. Similarly, the coupling strength C34 between the second working mode of the dielectric resonator 20 and the third coaxial resonator 30 is controllable by adjusting dimensions h2, h4 and w3 of the second coupling window 92.

In an embodiment, as shown in Fig. 9A, the housing 22 may include a top cover 97 defining top surfaces of the dielectric resonator 20 and the coaxial resonators 30 and a bottom housing 98 defining bottom surfaces and side surfaces of the dielectric resonator 20 and the coaxial resonators 30. The microwave device 12 may further include at least one of a first tuning screw 93 or a second tuning screw 94. The first tuning screw 93 may extend into the first coupling window 91 for tuning the coupling strength C24. The second tuning screw 94 may extend into the second coupling window 92 for tuning the coupling strength C34.

Fig. 11 illustrates frequency responses of the microwave device 12 shown in Fig. 8A. Fig. 11 shows a first frequency response curve 1110 with a low-end zero point in lower frequency band and a second frequency response curve 1120 with a high-end zero point in upper frequency band. By adjusting the coupling strength of the microwave device topology in Fig. 8B, the low-end or high-end transmission zero in the frequency response of the microwave device 12 may be controlled. In some embodiments, by adjusting the coupling strength of the microwave device topology in Fig. 8B, there may be no transmission zero in the frequency response of the microwave device 12.

Figs. 12A-12D illustrate schematic structural views of microwave devices according to further embodiments of the present disclosure. As shown in Fig. 12A, the microwave device 12 is a linear microwave device including two dielectric resonators 20 as described above and two coaxial resonators 30. The two dielectric resonators 20 may be coupled with each other and coupled between the two coaxial resonators 30. In some other embodiments, the microwave device 12 may include more than two dielectric resonators 20 coupled with each other in a dielectric resonator line between the two coaxial resonators 30.

As shown in Fig. 12B, the microwave device 12 is a linear microwave device including multiple dielectric resonators 20 as described above and at least two coaxial resonators 30. The multiple dielectric resonators 20 and the at least two coaxial resonators 30 may be coupled with one another alternately.

As shown in Fig. 12C, the microwave device 12 is an inverted L-type microwave device including a dielectric resonator 20 as described above and two coaxial resonators 30. The two coaxial resonators 30 may be coupled with the dielectric resonator 20 at two adjacent side surfaces of the dielectric resonator 20.

As shown in Fig. 12D, the microwave device 12 may include a first dielectric resonator 20 and a second dielectric resonator 20. The first dielectric resonator 20 may be coupled with a first coaxial resonator 30 and a second coaxial resonator 30 at two adjacent side surfaces of the first dielectric resonator 20. The second dielectric resonator 20 may be coupled with a third coaxial resonator 30 and a fourth coaxial resonator 30 at two adjacent side surfaces of the second dielectric resonator 20. The second coaxial resonator 30 may be coupled to the third coaxial resonator 30.

Although the microwave device 12 is described above in connection with Figs. 8A to 12D, these embodiments are merely provided as examples. It is to be understood that the dielectric resonator 20 according to various embodiments of the present disclosure may also be used in other microwave devices 12. Other microwave devices may be designed according to the microwave device requirement and interface. Further, the microwave device 12 may include one or more dielectric resonators 20 as described above.

Where a structural feature has been described, it may be replaced by means for performing one or more of the functions of the structural feature whether that function or those functions are explicitly or implicitly described.

Further, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A dielectric resonator (20) in a microwave device, comprising:

a housing (22) that is at least surface conductive, the housing defining a cavity (23) comprising a first top surface (220) , a first bottom surface (225) and at least four side surfaces (221, 222, 223, 224) ; and

a dielectric body (21) arranged within the cavity (23) and comprising a second top surface (210) , a second bottom surface (219) and eight side surfaces (211, 212, 213, 214, 215, 216, 217, 218) ,

wherein the second top surface (210) is in conductive contact with the first top surface (220) , the second bottom surface (219) is in conductive contact with the first bottom surface (225) , a first set of four side surfaces (211, 212, 213, 214) among the eight side surfaces are parallelly separate from the four side surfaces (221, 222, 223, 224) of the cavity (23) , and a second set of four side surfaces (215, 216, 217, 218) among the eight side surfaces face four lateral edges of the cavity (23) .
The dielectric resonator (20) of claim 1, wherein at least one of:

the first top surface (220) and the first bottom surface (225) of the cavity (23) are of a square shape or a rectangle shape; or

the second top surface (210) and the second bottom surface (219) of the dielectric body (21) are of an octagon shape.
The dielectric resonator (20) of claim 1 or 2, wherein at least one of:

a first side surface (215) and a third side surface (217) among the second set of four side surfaces are opposite to and in parallel with each other; or

a second side surface (216) and a fourth side surface (218) among the second set of four side surfaces are opposite to and in parallel with each other.
The dielectric resonator (20) of any of claims 1-3, wherein at least one of:

a first side surface (215) and a third side surface (217) among the second set of four side surfaces are disposed relative to a first diagonal plane of the cavity (23) comprising two of the four lateral edges based on a required field distribution of a first working mode of the dielectric resonator; or

a second side surface (216) and a fourth side surface (218) among the second set of four side surfaces are disposed relative to a second diagonal plane of the cavity (23) comprising the other two of the four lateral edges based on a required field distribution of a second working mode of the dielectric resonator.
The dielectric resonator (20) of claim 4, wherein at least one of:

the first side surface (215) and the third side surface (217) are perpendicular to the first diagonal plane such that intensity peaks of an electric field and intensity peaks of a magnetic field of the first working mode are distributed along the first diagonal plane; or

the second side surface (216) and the fourth side surface (218) are perpendicular to the second diagonal plane such that intensity peaks of an electric field and intensity peaks of a magnetic field of the second working mode are distributed along the second diagonal plane.
The dielectric resonator (20) of any of claims 3-5, wherein at least one of:

a first width (c1) of the first side surface (215) and a third width (c2) of the third side surface (217) are the same; or

a second width (d1) of the second side surface (216) and a fourth width (d2) of the fourth side surface (218) are the same.
The dielectric resonator (20) of any of claims 1-6, wherein the dielectric resonator (20) is configured to support a first working mode with a first resonant frequency and a second working mode with a second resonant frequency, and wherein at least one of:

the first resonant frequency is tunable by adjusting at least one of a first width (c1) of a first side surface (215) among the second set of four side surfaces and a third width (c2) of a third side surface (217) , among the second set of four side surfaces, opposite to the first side surface (215) ; or

the second resonant frequency is tunable by adjusting at least one of a second width (d1) of a second side surface (216) among the second set of four side surfaces and a fourth width (d2) of the fourth side surface (218) , among the second set of four side surfaces, opposite to the second side surface (216) .
The dielectric resonator (20) of any of claims 1-7, wherein at least one of widths of the second set of four side surfaces (215, 216, 217, 218) is smaller than a smallest one of widths of the first set of four side surfaces (211, 212, 213, 214) .
The dielectric resonator (20) of any of claims 1-8, wherein the dielectric body (21) is provided with a hole (24) in a center of the dielectric body (21) extending from the second top surface (210) to the second bottom surface (219) , and a fixing screw through the hole (24) fixes the dielectric body (21) to the housing (22) ; and

wherein the dielectric body (21) comprises a ceramic material with a dielectric constant in a range from 5 to 120.
A microwave device (12) comprising:

at least one dielectric resonator (20) of any one of claims 1-9; and

at least two coaxial resonators (30) ,

the at least one dielectric resonator (20) and the at least two coaxial resonators (30) being coupled with one another.
The microwave device (12) of claim 10, further comprising:

a coupling structure (83) between a dielectric resonator among the at least one dielectric resonator (20) and a coaxial resonator among the at least two coaxial resonators (30) , the coupling structure (83) comprising a first coupling window (91) configured to couple a first working mode of the dielectric resonator with the coaxial resonator and a second coupling window (92) configured to couple a second working mode of the dielectric resonator with the coaxial resonator.
The microwave device (12) of claim 11, wherein:

a coupling strength between the first working mode of the dielectric resonator and the coaxial resonator is controllable by adjusting a dimension of the first coupling window (91) ; and

a coupling strength between the second working mode of the dielectric resonator and the coaxial resonator is controllable by adjusting a dimension of the second coupling window (92) .
The microwave device (12) of claim 11 or 12, wherein the coupling structure (83) further comprise a rib structure (95) between the first coupling window (91) and the second coupling window (92) .
The microwave device (12) of any of claims 11-13, further comprising at least one of:

a first tuning screw (93) extending into the first coupling window (91) ; or

a second tuning screw (94) extending into the second coupling window (92) .
The microwave device (12) of any of claims 10-14, wherein:

the at least one dielectric resonator (20) comprises a dielectric resonator (20) , and

the at least two coaxial resonators (30) comprise two coaxial resonators (30) coupled with the dielectric resonator (20) at two opposite side surfaces of the dielectric resonator (20) .
The microwave device (12) of any of claims 10-14, wherein:

the at least one dielectric resonator (20) comprises a plurality of dielectric resonators coupled with each other in a dielectric resonator line,

the at least two coaxial resonators (30) comprise two coaxial resonators (30) , and

the dielectric resonator line is coupled between the two coaxial resonators (30) .
The microwave device (12) of any of claims 10-14, wherein:

the at least one dielectric resonator (20) comprises a plurality of dielectric resonators, and

the plurality of dielectric resonators and the at least two coaxial resonators (30) are coupled with one another alternately.
The microwave device (12) of any of claims 10-14, wherein:

the at least one dielectric resonator comprises a first dielectric resonator, and

the at least two coaxial resonators comprise a first coaxial resonator and a second coaxial resonator coupled with the first dielectric resonator at two adjacent side surfaces of the first dielectric resonator.
The microwave device (12) of claim 18, wherein:

the at least one dielectric resonator (20) further comprises a second dielectric resonator,

the at least two coaxial resonators (30) further comprises a third coaxial resonator and a fourth coaxial resonator coupled with the second dielectric resonator at two adjacent side surfaces of the second dielectric resonator, and

the second coaxial resonator is coupled to the third coaxial resonator.
The microwave device (12) of any of claims 10-19, wherein the microwave device is a filter.