Frequency tunable resonator

Abstract

The invention relates to a frequency tunable resonator (100) comprising a dielectric block (110) coated with a conductive layer (112) on the surface. The frequency tunable resonator (100) further comprises a conductive tuning pattern (114) of a surface of the dielectric block (110), the conductive tuning pattern (114) being defined by an opening (120) in the conductive layer (112). An electrically controllable switch (130) is used to conductively connect the conductive tuning pattern (114) to a conductive structure (112; 142) for a motor vehicle. Thus, when the electrically controllable switch (130) is operating in an inactive state, the frequency tunable resonator (100) will resonate at a first frequency (F1), and when the electrically controllable switch (130) is operating in an active state, the frequency tunable resonator (100) will resonate at a second frequency (F2).

Description

Technical Field

[0001] Embodiments of the present invention relate to frequency tunable resonators, such as frequency tunable resonators for filter applications in communication devices. Background Art

[0002] As the number of frequency bands that modern communication systems need to support continues to increase, and the demand for miniaturization leads to designs constrained by size limitations, tunable radio frequency (RF) components have received great attention. Due to these requirements, multi-band and / or multi-standard systems are desirable features for any RF front-end component such as RF filters in communication equipment.

[0003] The basic building block of an RF filter is a so-called resonator, which is set to pass RF signals within a frequency passband while rejecting signals outside the passband. The resonant frequency of the RF resonator determines the filter passband, and by using multiple tunable resonators, a frequency tunable filter can be realized. By using a single filter with tuning elements that can shift the filter frequency response to cover a wider range of frequency bands, tunable filters can increase flexibility and support more frequency bands without significantly increasing size.

[0004] In order to perform well in tunable filters, the tunable resonator needs to meet several desirable characteristics, such as high-Q resonator (i.e., low power loss), low power consumption, wide tuning range, fast tuning speed, good linearity, high power handling, and small tuning element footprint (i.e., small size).

[0005] There are several conventional tunable filter schemes, but few of them exhibit these desirable characteristics. This limits the use of tunable filters in practice. Summary of the invention

[0006] An object of embodiments of the present invention is to provide a solution to reduce or solve the disadvantages and problems of conventional solutions.

[0007] Another object of embodiments of the present invention is to provide a resonator solution that is easy to produce and easy to implement in multiple filter applications.

[0008] The above objects and other objects are achieved by the subject matter claimed in the independent claims. Further embodiments of the invention are provided in the dependent claims.

[0009] According to one aspect of the present invention, the above and other objects are achieved by a frequency tunable resonator, the resonator comprising:

[0010] a dielectric block comprising a surface coated with a conductive layer;

[0011] An input port for receiving an input signal;

[0012] Output port, used for outputting output signals;

[0013] a resonator disposed in the dielectric block and electromagnetically connected to the input and the output, respectively;

[0014] at least one dielectric opening in the conductive layer defining a conductive tuning pattern on the surface of the dielectric block;

[0015] at least one electrically controllable switch for conductively connecting the conductive tuning pattern to the conductive structure when operating in an activated state; and the frequency tunable resonator for:

[0016] The electrically controllable switch resonates at a first frequency when operating in an inactive state;

[0017] The electrically controllable switch resonates at a second frequency when operating in an activated state.

[0018] The electrically controllable switch being in an activated state can be understood as the electrically controllable switch being conductive, i.e. electrical signals can pass through the switch. This is in contrast to the situation when the electrically controllable switch is in an inactivated state, in which electrical signals cannot pass through the switch. The electrically controllable switch can be any type of switch with suitable characteristics.

[0019] An advantage of the frequency tunable resonator according to the first aspect is that the frequency tunable resonator can be used as a building block in any type of filter to achieve adjustable characteristics. In addition, the frequency tunable resonator also provides a system with a very small appearance and small footprint, which can be easily implemented on any substrate using existing methods of making dielectric opening slots on conductive layers. In addition, the tuning structure disclosed herein can be easily applied to any current or previously designed filter without significantly modifying the topology or resonator position. Any type of controllable switch can be used, so that the resonator can be configured with a switch type according to performance requirements. The frequency tunable resonator according to the first aspect is easy to modify according to specifications, such as the frequency tuning range, and the switches are interchangeable according to the priority of reducing insertion loss or increasing switching speed.

[0020] In one implementation of the frequency tunable resonator according to the aspect of the invention, the electrically conductive tuning pattern comprises a first conductive portion connected to a second conductive portion via at least one additional electrically controllable switch.

[0021] The advantage of this implementation is that by adding additional controllable switches, the number of tuning states increases, where the number of achievable tuning states is 2 n , where n is the number of switches in a particular configuration.

[0022] In an implementation of the frequency tunable resonator according to the aspect of the present invention, the second conductive portion is circumferentially disposed around the first conductive portion.

[0023] An advantage of this implementation is that small incremental tuning steps can be achieved without significantly increasing the footprint of the tuning elements.

[0024] In one implementation of the frequency tunable resonator according to the aspect of the invention, the conductive tuning pattern includes a single conductive portion.

[0025] The advantage of this implementation is that it provides a very simple configuration for low-cost applications.

[0026] In one implementation of the frequency tunable resonator according to the aspect of the present invention, the conductive tuning pattern is disposed in the dielectric block coaxially with respect to the resonator.

[0027] The advantage of this implementation is that the tunability of the resonator is improved because the tuning pattern is arranged at the point of the strongest electromagnetic field.

[0028] In one implementation of the frequency tunable resonator according to the aspect of the present invention, the resonator is a resonant cavity including an opening extending inwardly from the surface of the dielectric block.

[0029] In one implementation of the frequency tunable resonator according to the aspect of the present invention, the opening of the resonant cavity and the conductive tuning pattern are provided on opposite surfaces of the dielectric block.

[0030] The advantage of this implementation is that the tunability of the resonator is improved because the tuning pattern is arranged at the point of the strongest electric field.

[0031] In one implementation of the frequency tunable resonator according to the aspect of the present invention, the dielectric block has a cubic or rectangular parallelepiped shape.

[0032] In an implementation of the frequency tunable resonator according to the aspect of the present invention, the electrically controllable switch is a semiconductor, a variable capacitor or a variable inductor.

[0033] The advantage of this implementation is that a large number of different components can be used in this regard, thus providing a wider range of design options.

[0034] In one implementation of the frequency tunable resonator according to the aspect of the present invention, the electrically controllable switch is installed at the dielectric block.

[0035] The advantage of this implementation is that by installing the electrically controllable switch on the dielectric block, the occupied space can be greatly reduced.

[0036] In an implementation of the frequency tunable resonator according to the aspect of the present invention, the conductive layer is the conductive structure.

[0037] An advantage of this implementation is that the controllable switch can be connected to a conductive ground without requiring additional structures or components.

[0038] In an implementation of the frequency tunable resonator according to the aspect of the present invention, the frequency tunable resonator includes a dielectric layer provided at the dielectric block, and the electrically controllable switch is installed at the dielectric layer.

[0039] The advantage of this implementation is that by moving the switch reference plane and mounting location to the outer dielectric layer / substrate, the controllable switch and feeding network can be designed without being restricted by the size of the resonator.

[0040] In one implementation of the frequency tunable resonator according to the aspect of the present invention, the electrically controllable switch is connected to the conductive tuning pattern through a conductive interface.

[0041] The advantage of this implementation is that by moving the switch reference plane and mounting location to the outer dielectric layer / substrate, the controllable switch and feeding network can be designed without being restricted by the size of the resonator.

[0042] In an implementation of the frequency tunable resonator according to the aspect of the present invention, the conductive structure is disposed on the dielectric layer or connected to the dielectric layer.

[0043] The advantage of this implementation is that by moving the switch reference plane and mounting location to the outer dielectric layer / substrate, the controllable switch and feeding network can be designed without being restricted by the size of the resonator.

[0044] In one implementation of the frequency tunable resonator according to the aspect of the present invention, the frequency tunable resonator includes at least one second resonator, at least one second conductive tuning pattern and at least one second controllable switch; and the resonator and the second resonator are electromagnetically coupled to each other.

[0045] The advantage of this implementation is that multiple resonators can be connected in cascade or in any arrangement to form a tunable radio frequency filter.

[0046] In one implementation of the frequency tunable resonator according to the aspect of the present invention, the frequency tunable resonator includes at least one inner cavity, which is coated with a conductive layer and forms a wall portion, the wall portion extends inside the dielectric block and is at least partially located between the resonator and the second resonator.

[0047] The advantage of this implementation is that it breaks the symmetry of the RF, so a tunable RF filter can be designed.

[0048] Other applications and advantages of embodiments of the present invention will be apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings are intended to illustrate and explain different embodiments of the present invention, in which:

[0050] Figure 1 A frequency tunable resonator according to an embodiment of the present invention is shown;

[0051] Figure 2 shows a conductive tuning pattern according to an embodiment of the present invention;

[0052] Figure 3 shows a conductive tuning pattern according to another embodiment of the present invention;

[0053] Figure 4 shows the design geometry of a frequency tunable resonator according to an embodiment of the present invention;

[0054] Figure 5 shows the design geometry of a frequency tunable resonator according to another embodiment of the present invention;

[0055] Figure 6 and Figure 7 A frequency tunable resonator including a dielectric layer according to an embodiment of the present invention is shown in a top view and a perspective view, respectively;

[0056] Figure 8 An exemplary topology of a frequency tunable resonator including a plurality of resonators is shown;

[0057] Fig. 9 A frequency tunable resonator including a plurality of resonators according to an embodiment of the present invention is shown;

[0058] Fig.10 The performance results of the frequency tunable filter 100 according to the embodiment of the present invention are shown. DETAILED DESCRIPTION

[0059] The main difference between single-band filters and tunable filters is the addition of tuning elements in tunable filters. Depending on the tuning scheme, this will have a significant impact on the overall system performance of the filter. In particular, tunable filters have lower quality (Q) factor values, which is a result related to the losses in the resonator due to the addition of tuning elements. Therefore, the performance of a high Q-factor resonator may be severely degraded by the addition of tuning elements. Therefore, it is best if the tuning elements have a small impact on the resonator Q factor.

[0060] Furthermore, while tuning of cavity filters is a well-explored area, tuning of ceramic block filters is less well-explored. Ceramic block filters limit the choice of tuning components due to their inherently solid structure. Most tunable filters have an air cavity into which the tuning components can simply be inserted. This is naturally not possible in ceramic block filters, so some traditional tuning methods are not physically feasible.

[0061] Thus, embodiments of the present invention explore new schemes for tuning ceramic block resonators that achieve a good compromise between the desired requirements for tunable filters through a novel tunable resonator structure. Among other things, a miniaturized tunable filter can thus be achieved. In ceramic block filters, previous tunable schemes were based on mechanical tuning with low tuning speeds or varactors with low Q factors. The scheme proposed herein instead utilizes controllable switches, eliminating the need for low Q factor varactors while still providing fast response times. Furthermore, the present frequency tunable resonator can be optimized in terms of losses and tuning speed based on component selection.

[0062] Figure 1 1 shows a top view of a frequency tunable resonator 100 according to an embodiment of the present invention. The frequency tunable resonator 100 includes a solid dielectric block 110, such as a high-Q ceramic with a large relative dielectric constant, which in turn includes a surface coated with a conductive layer 112. The frequency tunable resonator 100 also includes a device for receiving an input signal S In The input port 102 is used to output the output signal S Out The output port 104. The output signal S Out is the processed input signal S In Input signal S In and the output signal S Out High frequency signals, such as RF signals, may be included, and such RF signals may be used as communication signals in different types of communication systems.

[0063] The frequency tunable resonator 100 further includes a resonator 106 (shown by a dashed line) disposed inside the dielectric block 110 and electromagnetically connected to the input 102 and the output 104, respectively. Figure 1As shown, the resonator 106 may be a resonant cavity filled with air. However, the resonator 106 used herein need not be a resonant cavity. For example, in other examples, the resonator 106 may refer to the dielectric block itself without additional structures, and may utilize other propagation modes besides the fundamental mode.

[0064] The frequency tunable resonator 100 further includes at least one dielectric opening 120 in the conductive layer 112, the dielectric opening defining a conductive tuning pattern 114 at the surface of the dielectric block 110. The frequency tunable resonator 100 further includes at least one electrically controllable switch 130, 130' for conductively connecting the conductive tuning pattern 114 to the conductive structure 112 when operating in an activated state. Thus, the frequency tunable resonator 100 is configured to resonate at a first frequency F1 when the electrically controllable switch 130 operates in an inactive state, and resonate at a second frequency F2 when the electrically controllable switch 130 operates in an activated state. The first frequency F1 is different from the second frequency F2, thereby providing a tunable resonator.

[0065] The dielectric block 110 may be molded or produced in any other suitable manner. The dielectric block 110 may be a ceramic dielectric block wrapped in a conductive coating (e.g., a silver or copper coating). However, any other dielectric substrate and conductor may be used as the dielectric block with the same effect. The dielectric block 110 is designed to resonate at a desired design frequency or frequencies. The dielectric block 110 may have any shape and have any internal structure without affecting the basic functionality of the resonator scheme disclosed herein.

[0066] In an embodiment of the present invention, the conductive layer 112 is a conductive structure itself. This means that in this case, the conductive layer 112 acts as a ground for the resonator 100 and is interrupted by the dielectric openings 120 in the conductive layer 112. By introducing a direct ceramic-dielectric interface in the form of dielectric openings 120 in the conductive layer 112, the electrical characteristics of the resonator 100 change with the perturbation of the internal electric field. The dielectric openings 120 in the conductive layer 112 form and define a conductive tuning pattern 114, in which a point located on the conductive layer 112 is separated from another point on the conductive layer 112 by a dielectric opening in the conductive ground. These two points can still be connected to the conductive layer 112 and the ground plane of the resonator 100. With this separation, the surface current must use different paths through the conductive layer 112 to connect the two points. One or more of these points can be electrically connected to a conductive ground that is not part of the conductor housing. This conductive ground can be mounted on a dielectric substrate, which in turn can be connected to one or more controllable switches 130. Thus, a new electrical path is introduced for electromagnetic coupling between the surface current on the conductive layer 112 and the internal electric field of the resonator 100. The electrical path may be connected to a common ground separated by the controllable switch 130. Figure 6 and Figure 7 Embodiments using dielectric substrates are described.

[0067] The introduction of an alternative electrical path from the conductive layer 112 to the external tuning element enables the capacitance seen by the resonator 100 to be varied by selecting the controllable switches 130 and the conductive tuning pattern 114. The change in capacitance is a perturbing effect on the internal electric field. Thus, the resonant frequency of the resonator 100 can be varied in a predictable and controllable manner by varying the characteristics of the external conductor path, for example, by closing or opening one or more controllable switches 130 that connect the external conductor to the ground plane.

[0068] Another advantage of the present resonator structure over conventional solutions is that a fast switching speed tuning network can be achieved using conventional off-the-shelf RF controllable switches. By utilizing a controllable switch for tuning, rather than a capacitor bank or variable capacitor, the negative effects of the tuning element are reduced, especially in the off state of the controllable switch, i.e., when the controllable switch is not conducting. Thus, embodiments of the present invention include a controllable switch 130, and the basic functionality of the frequency tunable resonator 100 does not change with the selection of the controllable switch. Thus, the electrically controllable switch 130 can be any suitable controllable switch known in the art. For example, a semiconductor, a variable capacitor, or a variable inductor.

[0069] In an embodiment of the present invention, and also Figure 1 As disclosed in the above, the electrically controllable switch 130 may be directly mounted at the dielectric block 110. However, in other proposed embodiments, the electrically controllable switch 130 may be disposed at a dielectric layer separate from the dielectric block 110, which will be referred to in the following disclosure. Figure 6 and Figure 7 Detailed description.

[0070] Figure 2 A top view of a conductive tuning pattern 118 according to an embodiment of the present invention is shown. In the disclosed example, the conductive tuning pattern 118 includes a single conductive portion 118. A controllable switch 130 is disposed in a portion between the single conductive portion 118 and the surrounding conductive layer 112, which portion may be denoted as a bridging portion hereinafter because the portion bridges the conductive portion 118 to the surrounding conductive layer 112. The single conductive portion 118 is bounded or defined by an opening 120 in the conductive layer 112. The controllable switch 130 may operate in an activated state (i.e., conductive) or an inactivated state (i.e., non-conductive). Depending on whether the surface current can pass through the controllable switch 130, the frequency passband of the resonator 100 will change, thereby providing a tunable resonator function as described above.

[0071] Figure 3A conductive tuning pattern 114 according to a further embodiment of the invention is shown, which instead comprises a plurality of conductive portions. In this example, the conductive tuning pattern 114 comprises a first conductive portion 118 connected to a second conductive portion 118' by at least one additional electrically controllable switch 130. Figure 3 The example in FIG. 1 includes four controllable switches 130, wherein two controllable switches 130 connect the first conductive portion 118 to the second conductive portion 118', and the other two controllable switches 130 connect the second conductive portion 118' to the surrounding conductive layer 112 via a bridge portion. Figure 3 As shown, the second conductive portion 118 ′ may be disposed circumferentially around the first conductive portion 118 so as to completely surround the first conductive portion 118 on the surface of the dielectric block 110 .

[0072] However, it can be appreciated that the present conductive tuning pattern 114 can include any number of conductive portions 118 connected by one or more electrically controllable switches of the bridge portion to achieve a suitable frequency tuning characteristic. Therefore, a large number of different frequency configurations can be provided depending on the number of conductive portions 118, the shape of the conductive portions 118, the interconnection structure, the number of controllable switches 130, the location of the controllable switches 130, etc. Therefore, an unlimited number of different frequency passbands F1, F2, up to Fn can be configured using the present solution.

[0073] also, Figure 4 FIG. 1 is a perspective view showing the geometry of a frequency tunable resonator 100 according to an embodiment of the present invention. Figure 5 Shown with Figure 4 The resonators shown have slightly different geometries than the frequency tunable resonator 100. In these examples, the controllable switch 130 is surface mounted directly on the dielectric block 110. Even if the two bridge sections are directly connected to ground, the controllable switch 130 will introduce a shift in the resonant frequency. This means that any arbitrary shape is achievable as long as there is at least one controllable switch 130 and a conductive tuning pattern 114 as a tuning element.

[0074] exist Figure 4 In the figure, the conductive pattern 114 includes an inner conductive portion surrounded by an outer conductive portion. The inner conductive portion and the outer conductive portion are defined by an opening in the conductive layer 112 and are connected to each other by two controllable switches 130, so that the surface current can flow in two different ways depending on the state of the two controllable switches. The added structure includes an opening 120 in the conductive layer 112, exposing the internal electromagnetic field at the interface between the dielectric block 110 and the surrounding air. The opening 120 in the conductive layer 112 can be obtained by any milling process or manually. A bridge portion connecting the intermediate conductive portion to ground is also shown, showing the principle of connecting two separate points on the conductive layer. From Figure 4 and Figure 5 It can be clearly seen that the electrical path changes as the controllable switch 130 is turned on or off. Figure 5 In the embodiment, the conductive pattern 114 includes a single conductive portion which is also defined relative to the surrounding conductive layer 112 by an opening 120 in the conductive layer. The single conductive portion is connected to the surrounding conductive layer 112 via four bridge portions. Two controllable switches 130 are provided at the two bridge portions.

[0075] exist Figure 4 and Figure 5 In both examples shown, the conductive tuning pattern 114 is coaxially arranged in the dielectric block 110 relative to the resonant cavity 106. This can be understood as that both the conductive tuning pattern 114 and the resonant cavity 106 are symmetrically arranged around an axis A extending through the dielectric block 110. This axis can be defined as a central axis as shown in the examples, but in examples not shown, this axis can be misaligned or offset from the center of the dielectric block 110.

[0076] In addition, for Figure 4 and Figure 5 The common point of the two examples disclosed in is that the resonant cavity 106 includes an opening 108 extending inward from the surface of the dielectric block 110. It can also be noted that the opening 108 of the resonant cavity 106 and the conductive tuning pattern 114 are arranged on opposite surfaces of the dielectric block 110. The interior of the resonant cavity 106 is coated with a conductive layer to provide suitable conductive properties. Figure 4 and Figure 5 In the example disclosed in , the dielectric block 110 has a substantially cubic or cuboid shape. However, the general shape of the dielectric block 110 may vary depending on the application. The same is true for the shape of the resonant cavity 106.

[0077] Figure 6 and Figure 7 The top view ( Figure 6 ) and perspective view ( Figure 7) shows a frequency tunable resonator 100 including an additional dielectric layer 140 according to an embodiment of the present invention. The frequency tunable resonator 100 includes a dielectric layer 140 disposed at a dielectric block 110. The dielectric layer 140 may be a so-called PCB layer or any other suitable dielectric layer. The dielectric layer 140 may include a conductor. The separate dielectric layer 140 may be attached to the dielectric block 110 using welding, adhesive or any other suitable attachment technique. In these examples, the electrically controllable switch 130 is mounted at the dielectric layer 140, rather than being directly mounted at the dielectric block 110 as shown previously. The controllable switch 130 may be attached to either side of the dielectric layer 140, i.e., on the surface of the dielectric layer 140 facing the dielectric block 110 or on the surface of the dielectric layer 140 pointing in the opposite direction away from the dielectric block 110.

[0078] Furthermore, the conductive structure 142 may be disposed at or connected to the dielectric layer 140. Furthermore, the electrically controllable switch 130 may be connected to the conductive tuning pattern 114 via a conductive interface 144, also as Figure 6 and Figure 7 Connecting the dielectric layer 140 and the conductive tuning pattern 114 by overlapping conductors enables the frequency of the resonator 100 to be controlled by the controllable switch 130 .

[0079] By using the dielectric layer 140, the direct connection of the controllable switch 130 to the resonator ground can be removed. It is also disclosed that the reference plane offset of the controllable switch 130 can be achieved by connecting the dielectric layer 140 to the tuning pattern. The controllable switch 130 will act as an on-off connection between the ground of the dielectric layer 140 and the conductive tuning pattern 114. The ground of the dielectric layer 140 is stacked on top of the resonator ground. The input port 102 and the output port 104 are also shown as Figure 6 and Figure 7 shown.

[0080] exist Figure 6 and Figure 7The configuration disclosed in enables considerable flexibility in the placement of the controllable switch 130. By moving the tuning elements away from the surface mount arrangement on top of the conductive filter coating, an easier mounting process and a more flexible resonator design can be achieved. In addition, a signal feed network (not shown) can be easily implemented in the resonator 100 because the use of the dielectric layer 140 eliminates the spatial limitations of a directly mounted controllable switch. The signal feed network is used to turn off / on or activate / deactivate the controllable switch 130, and can also be used to feed and / or bias the controllable switch 130. However, the offset of the reference plane of the controllable switch 130 introduces less insertion loss than when the controllable switch 130 is directly mounted on the dielectric block 110. On the other hand, the configuration with the dielectric layer 140 enables the selection of components without being subject to the strict size and space limitations of the resonator 100 including the dielectric layer 140. Therefore, it is possible to simplify the optimization of the resonator 100 by selecting a controllable switch. Furthermore, when the dielectric-air interface is replaced by a dielectric-dielectric interface, a shift in the center frequency is introduced and can be reoptimized to shift the center frequency back. The tuning range of the resonator 100 can also be increased by introducing the dielectric layer 140 because the range of switch selections is wider, and the tuning range of the resonator 100 can also be increased by changing the tuning pattern.

[0081] Figure 8 System topologies of a frequency tunable resonator 100 including a plurality of resonant cavities connected to each other are shown, wherein (a) shows a 5-pole straight inline filter structure and (b) shows a 6-pole filter structure with a triplet section producing a transmission zero. The different resonant cavities are shown as circles, numbered 1 to 5 in (a) or 1 to 6 in (b), and are arranged between the input 102 and the output 104 of the frequency tunable resonator 100. The electromagnetic coupling between the resonant cavities is represented by lines connecting the circles. The 5-pole straight inline structure shows a very simple setup with symmetrical tuning elements. On the other hand, the 6-pole shows a system topology in which the resonant cavities can be geometrically offset relative to a straight line or row. Both examples can be implemented with a dielectric layer 140 as discussed above.

[0082] Typically, a frequency tunable resonator 100 for multi-resonator applications includes at least one second resonator 106', at least one second conductive tuning pattern 114', and at least one second controllable switch 130'. The resonator 106 and the second resonator 106' are electromagnetically coupled to each other. Therefore, the frequency tunable resonator 100 can be realized by cascading any number of resonant cavities in any configuration by electromagnetic coupling between the resonators. The design methods used to manufacture multi-pole resonators are no different from conventional synthesized and designed filters, because the basic ceramic filter can be designed to introduce the tuning element, i.e., the controllable switch 130, in the last manufacturing step. Therefore, adding the controllable switch 130 to an existing ceramic block filter design is easily accomplished. By choosing certain symmetries, the tuning of the open and closed switch positions can be simplified.

[0083] Fig. 9 Shown as Figure 8 (b) shows a frequency tunable resonator 100 including multiple resonators. The frequency tunable resonator 100 includes six interconnected resonant cavities arranged between the input 102 and the output 104 of the resonator 100. In this particular example, the resonant cavities 106, 106' are arranged in a single dielectric block. In order to achieve electromagnetic coupling between different resonant cavities, the frequency tunable resonator 100 may also include at least one inner cavity 160, which is coated with a conductive layer and forms a wall portion extending inside the dielectric block 110. Such a wall portion will help to guide the electromagnetic coupling between the resonant cavities of the multi-cavity resonator 100, especially when the layout of the resonant cavities is not arranged in a straight line or row. The tuning range of the resonator 106 can be adjusted by modifying the size and shape of the conductive tuning pattern 114. Each subsequent conductive tuning pattern 114' can be modified individually to obtain the desired tuning range of each corresponding resonator 106'.

[0084] In this configuration, each resonator 106 has two controllable switches 130. However, any number of controllable switches 130 may be used without departing from the scope of the present disclosure. For example, the controllable switches 130 may be electrically controlled by a signal feed network that sends control signals and / or bias currents to change the state of the controllable switches. For example, the signal feed network may include a microcontroller or central processing unit (CPU), control lines, etc. Additionally, in other configurations, the present frequency tunable resonator 100 may include one conductive tuning pattern 114 that interacts with multiple resonators, etc.

[0085] Fig.10 The simulated response of a ceramic passband filter including a resonator according to an embodiment of the present invention is shown, where for Fig. 9The same filter structure is shown, with a specified center frequency of 3.5 GHz, a bandwidth of 200 MHz (activated state), and a second passband at 3.4 GHz (inactivated state). The x-axis shows the frequency in GHz and the y-axis shows the scattering parameter in dB. The upper passband shows the filtering characteristics of the structure in the activated switching state, while the lower passband shows the response of the filter in the inactivated switching state, illustrating the principle of a tunable filter composed of multiple tunable resonators 100. The increase in mismatch in the low passband is partly due to the fact that the absolute bandwidth remains constant over the tuning range.

[0086] The frequency tunable resonator 100 can be implemented and used in many different applications. A non-limiting example is in a communication device and communication equipment configured for different communication systems (e.g., 3GPP 5G, WiFi, etc.). For example, the communication device and communication equipment can be part of a network access node or a client device.

[0087] The client device in this article can be represented as a user device, user equipment (UE), mobile station, Internet of Things (IoT) device, sensor device, wireless terminal and / or mobile terminal, capable of wireless communication in a wireless communication system (sometimes also referred to as a cellular wireless system). UE can also be referred to as a mobile phone, cellular phone, tablet computer or laptop computer with wireless capabilities. For example, the UE in this context can be a portable, pocket storage, handheld, computer-based or vehicle-mounted mobile device that can communicate voice and / or data with another communication entity (such as another receiver or server) through a radio access network (RAN). UE can also be a station (STA), that is, any device that includes a media access control (MAC) and physical layer (PHY) interface to a wireless medium (WM) that complies with IEEE 802.11. The UE can be used to communicate in the following: 3GPP-related long term evolution (LTE), advanced LTE, fifth generation (5G) wireless systems, such as new radio (NR) and its evolutions, and IEEE-related Wi-Fi, worldwide interoperability for microwave access (WiMAX) and its evolutions.

[0088] The network access node in this article can also be expressed as a wireless network access node, access network access node, access point (AP) or base station (BS), for example, a radio base station (RBS), which can be called a transmitter, "gNB", "gNodeB", "eNB", "eNodeB", "NodeB" or "B node" in some networks, depending on the standards, technologies and terminology used. Based on the transmission power and cell size, wireless network access nodes can have different categories or types, such as macro eNodeB, home eNodeB or mini base station. A wireless network access node can also be a station (STA), that is, any device that includes a media access control (MAC) and physical layer (PHY) interface to a wireless medium (WM) that complies with IEEE 802.11. The wireless network access node can be used to communicate in the following: 3GPP-related long term evolution (LTE), advanced LTE, fifth generation (5G) wireless systems, such as new radio (NR) and its evolutions, and IEEE-related Wi-Fi, worldwide interoperability for microwave access (WiMAX) and its evolutions.

[0089] Finally, it should be understood that the present invention is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the attached independent claims.

Claims

1. A frequency tunable resonator (100), include: A dielectric block (110) comprising a surface coated with a conductive layer (112); Input port (102), for receiving an input signal (S In ); Output port (104), used to output output signal (S Out ); a resonator (106) disposed in the dielectric block (110) and electromagnetically connected to the input (102) and the output (104), respectively; at least one dielectric opening (120) in the conductive layer (112) defining a conductive tuning pattern (114) on the surface of the dielectric block (110); at least one electrically controllable switch (130) for conductively connecting the conductive tuning pattern (114) to the conductive structure (112; 142) when operating in an activated state; and the frequency tunable resonator (100) for: When the electrically controllable switch (130) operates in an inactive state, it resonates at a first frequency (F1); When the electrically controllable switch (130) operates in an activated state, it resonates at a second frequency (F2).

2. The frequency tunable resonator (100) according to claim 1, in, The conductive tuning pattern (114) includes a first conductive portion (118) connected to a second conductive portion (118') via at least one additional electrically controllable switch (130).

3. The frequency tunable resonator (100) according to claim 2, in, The second conductive portion (118') is circumferentially disposed around the first conductive portion (118).

4. The frequency tunable resonator (100) according to claim 1, in, The conductive tuning pattern (114) includes a single conductive portion (118).

5. The frequency tunable resonator (100) according to any one of the preceding claims, in, The conductive tuning pattern (114) is disposed coaxially with respect to the resonator (106) in the dielectric block (110).

6. The frequency tunable resonator (100) according to any one of the preceding claims, in, The resonator (106) is a resonant cavity including an opening (108) extending inwardly from the surface of the dielectric block (110).

7. The frequency tunable resonator (100) according to claim 6, in, The opening (108) of the resonant cavity and the conductive tuning pattern (114) are disposed on opposite surfaces of the dielectric block (110).

8. The frequency tunable resonator (100) according to any one of the preceding claims, in, The dielectric block (110) has a cube or a rectangular parallelepiped shape.

9. The frequency tunable resonator (100) according to any one of the preceding claims, in, The electrically controllable switch (130) is a semiconductor, a variable capacitor or a variable inductor.

10. The frequency tunable resonator (100) according to any one of claims 1 to 9, in, The electrically controllable switch (130) is installed at the dielectric block (110).

11. The frequency tunable resonator (100) according to claim 10, in, The conductive layer (112) is the conductive structure (112).

12. The frequency tunable resonator (100) according to any one of claims 1 to 9, in, The frequency tunable resonator (100) includes a dielectric layer (140) disposed at the dielectric block (110), and the electrically controllable switch (130) is installed at the dielectric layer (140).

13. The frequency tunable resonator (100) according to claim 12, in, The electrically controllable switch (130) is connected to the conductive tuning pattern (114) via a conductive interface (144).

14. The frequency tunable resonator (100) according to claim 12 or 13, in, The conductive structure (142) is disposed at the dielectric layer (140) or connected to the dielectric layer (140).

15. The frequency tunable resonator (100) according to any one of the preceding claims, in, The frequency tunable resonator (100) includes at least one second resonator (106'), at least one second conductive tuning pattern (114') and at least one second controllable switch (130'); and the resonator (106) and the second resonator (106') are electromagnetically coupled to each other.

16. The frequency tunable resonator (100) according to claim 15, in, The frequency tunable resonator (100) comprises at least one inner cavity (160) coated with a conductive layer and forming a wall portion extending inside the dielectric block (110) and at least partially located between the resonator (106) and the second resonator (106').

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