Monolithic ceramic band-stop and band-pass combiner

Abstract

The present invention relates to a monolithic ceramic band-stop and band-pass combiner, which is configured to be arranged between a shared antenna and a plurality of transmitters, comprising: a ceramic core body having a plurality of resonators formed therein; a plating pattern configured to substantially cover the side surface and bottom surface of the ceramic core body to define a ground; a first input / output coupling portion in signal connection with the shared antenna; a second input / output coupling portion and a third input / output coupling portion in signal connection with a first transmitter and a second transmitter respectively, wherein the third input / output coupling portion and the first input / output coupling portion form a band-pass filter via a plurality of resonators located therebetween; and a microstrip line, wherein the microstrip line and a plurality of resonators located between the first and second input / output coupling portions jointly form a band-stop filter located therebetween, the band-stop filter and the band-pass filter being connected in parallel by sharing at least one resonator. Thus, provided is a monolithic ceramic band-stop and band-pass combiner which has low process cost and compact size and which can meet the technical requirements for the combination of high-frequency and low-frequency passbands.

Description

Monolithic ceramic band reject band pass combiner TECHNICAL FIELD

[0001] The present invention relates to ceramic block filter for radio frequency signal application, in particular to a monolithic ceramic band reject band pass combiner. BACKGROUND

[0002] Combiner is a key component in the transceiver of modern wireless and mobile communication system. In recent years, with the development of modern communication technology, various communication systems emerge as the times require, leading to dense frequency use. If a transceiving system is established for each frequency, it will inevitably cause waste of resources and unnecessary interference to other systems. Therefore, a combiner is needed to establish a transceiving integrated communication system for multiple frequencies.

[0003] Combiner can be divided into two types: same frequency combiner and different frequency combiner. The same frequency combiner is used to combine signals of the same frequency, while the different frequency combiner is used to combine signals of different frequencies. The inverse process of power divider is generally used for the synthesis of signals of the same frequency. The different frequency combiner is composed of filters. The different frequency combiner can be divided into the following categories:

[0004] a. Waveguide combiner. The characteristics are low loss and high power capacity, but the large size leads to integration, high manufacturing cost, and is not conducive to mass production. It is commonly used in microwave and millimeter wave frequency bands, such as military satellite navigation systems.

[0005] b. Coaxial cavity combiner. Since the electromagnetic field is transmitted entirely in the closed coaxial cavity, there is no radiation loss, and the loss is low, like the waveguide combiner. The cavity has high power capacity and is not easy to be broken down. Therefore, such combiners are commonly used in base stations of mobile communication systems. The disadvantages are large size, heavy weight, and high cost.

[0006] With the rapid development and continuous upgrading of communication technology, the frequency domain division and use are more and more, the isolation frequency band between systems is more and more narrow, the communication quality requirement is more and more high, and the cost requirement is more and more low. Solving the problems of system interference, power consumption, system compatibility, cost, etc. has become an important topic for communication development. Therefore, a low-cost, multi-system, low-loss, high-isolation combiner is needed to solve these problems. At present, in order to solve these problems, people have commercially developed the following several forms of combiners, but there are various problems and shortcomings.

[0007] 1. Cavity low pass band pass combiner, large size, high cost, large sideband loss, complex process, and small out-of-band attenuation;

[0008] 2. Cavity band reject band pass combiner, large size, heavy weight, high cost, and complex process;

[0009] 3. Bandpass and bandpass combiner, with narrow passband, unable to cover wide frequency requirements.

[0010] 4. Cavity highpass and bandpass combiner, large volume, high cost, large sideband loss, complex process, small out-of-band attenuation;

[0011] Therefore, there is still a technical demand in the art to provide a low-process-cost, small-volume, high-frequency and low-frequency passband combiner, and to meet the practical demand of small passband loss between wide and narrow frequency bands, and high mutual suppression between two passbands. SUMMARY

[0012] Therefore, the task of the present application is to provide a single-body ceramic bandstop and bandpass combiner, by which at least some of the above-mentioned drawbacks of the prior art are overcome.

[0013] According to one aspect of the present application, a single-body ceramic bandstop and bandpass combiner is provided, which is configured to be disposed between a shared antenna and multiple transmitters, and comprises: a ceramic core defined by a top surface, a bottom surface and side surfaces, wherein the top surface of the ceramic core is defined with opposite upper and lower peripheral longitudinal edges and is disposed along its length direction with multiple through-holes separated from each other, which extend through the ceramic core between the top surface and the bottom surface and are surrounded by a conductive metal pattern at the top surface to form multiple resonators; a plating pattern having an inner surface conforming to the upper and lower peripheral longitudinal edges of the ceramic core and configured to substantially cover the side surfaces and the bottom surface of the ceramic core to define a ground; a first input / output coupling part connected with a signal of the shared antenna at the middle of the ceramic core; a second input / output coupling part and a third input / output coupling part connected with signals of first and second transmitters respectively at both sides of the first input / output coupling part, wherein the third input / output coupling part and the first input / output coupling part form a bandpass filter via the multiple resonators therebetween; and a microstrip line on the top surface of the ceramic core for signal connection between the first input / output coupling part and the second input / output coupling part, wherein the microstrip line is substantially parallel to and spaced apart from the multiple through-holes, so that it and the multiple resonators therebetween together form a bandstop filter between the first and second input / output coupling parts, wherein the bandstop filter and the bandpass filter are connected in parallel via at least one resonator in common.

[0014] Compared with the prior art, the ceramic band-stop band-pass combiner according to the present application can solve the technical requirement of combining or inputting wide band and narrow band. Meanwhile, it also solves the problems that the frequency between wide band and narrow band is close and the attenuation requirement of the pass band is low, and the mutual suppression requirement between two pass bands is high. Meanwhile, since the ceramic band-stop band-pass combiner according to the present application is designed as a single structure using ceramic medium substrate, it meets the technical requirement of small size and simplified process and low cost of the existing radio frequency components. Moreover, the ceramic band-stop band-pass combiner according to the present application can not only realize the combination of low frequency wide band and narrow band, but also realize the combination of high frequency wide band and narrow band, thereby effectively meeting the technical requirement of combination of high and low frequency wide band and narrow band.

[0015] As a preferred aspect of the present application, the ceramic core comprises twelve through-holes arranged in a substantially collinear sequence, wherein at least the seventh through-hole is designed as a part of the resonator shared by the band-stop filter and the band-pass filter.

[0016] As a preferred aspect of the present application, the microstrip line has a first end extending at least partially interleaved with the first through-hole and its metal pattern, and a second end extending at least partially interleaved with the seventh through-hole and its metal pattern, wherein the first end and the second end define the length of the microstrip line.

[0017] As a preferred aspect of the present application, the microstrip line has a plurality of protrusions along the length protruding towards the resonators, wherein the plurality of protrusions protrude into the adjacent resonators.

[0018] As a preferred aspect of the present application, the third input / output coupling portion has a plurality of fingers interleaved with the resonators, wherein at least one finger protrudes into the adjacent two resonators.

[0019] As a preferred aspect of the present application, the length and the width of the microstrip line are proportional to the equivalent inductance value of the microstrip line in the band-stop filter.

[0020] As a preferred aspect of the present application, the length of the microstrip line and the spacing between the microstrip line and the resonators are related to the attenuation pole of the band-stop filter.

[0021] As a preferred aspect of the present application, the length of the ceramic core is designed to be about 55 to 70 millimeters, the height is designed to be 6 to 10 millimeters, and the width is designed to be 8 to 12 millimeters.

[0022] As a preferred aspect of the present application, the plating layer pattern is designed as a silver-containing conductive layer sintered to the surface of the ceramic core via a silver-containing thick film conductive paste.

[0023] As a preferred aspect of the present application, a shield for signal shielding is also included, wherein the shield is snap-fitted to the front face of the ceramic core.

[0024] Some of the other features and advantages of the present application will be apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the application. BRIEF DESCRIPTION OF DRAWINGS

[0025] Embodiments of the present application will be described below in detail with reference to the accompanying drawings, in which:

[0026] In the drawings, Fig. 1 is an enlarged perspective view of a ceramic bandpass-reject combiner according to the present application, in which the individual components of the combiner are presented in an exploded manner to more clearly show the internal structure;

[0027] Fig. 2 is a top view of the bandpass-reject combiner of Fig. 1.

[0028] Fig. 3 is a top view of the core portion of the ceramic bandpass-reject combiner of Fig. 1;

[0029] Fig. 4 is a bottom view of the core portion of the ceramic bandpass-reject combiner of Fig. 3;

[0030] Fig. 5 is a top view of the core portion of the ceramic bandpass-reject combiner of Fig. 3, in which portions of the components are removed to more clearly show the internal structure;

[0031] Fig. 6 is a bottom view of the core portion of the ceramic bandpass-reject combiner of Fig. 5;

[0032] Fig. 7 is a side view of the core portion of the ceramic bandpass-reject combiner of Fig. 5;

[0033] Fig. 8 is a rear view of the core portion of the ceramic bandpass-reject combiner of Fig. 5

[0034] Fig. 9 is a schematic diagram of the scattering parameters of the bandpass transmission of the ceramic bandpass-reject combiner of Fig. 1;

[0035] Fig. 10 is a schematic diagram of the scattering parameters of the bandpass single-port reflection of the ceramic bandpass-reject combiner of Fig. 1;

[0036] Fig. 11 is a schematic diagram of the scattering parameters of the band-reject transmission of the ceramic bandpass-reject combiner of Fig. 1;

[0037] Fig. 12 is a schematic diagram of the scattering parameters of the band-reject single-port reflection of the ceramic bandpass-reject combiner of Fig. 1;

[0038] Fig. 13 is a schematic diagram of the scattering parameters of the common-port reflection of the ceramic bandpass-reject combiner of Fig. 1;

[0039] Figure 14 is a plot of the post-combining reflection and transmission scattering parameters of the ceramic bandstop bandpass combiner of Figure 1.

[0040] BRIEF DESCRIPTION OF DRAWINGS: 100. Ceramic core; 200. Shield; 300. Plating pattern; 10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H, 101, 10J, 10K, 10L. Via; 30A, 30B, 30C, 30D, 30E, 30F, 30G, 30H, 30I, 30J, 30K, 30L. Resonator pattern; 11. Top surface; 31, 32. Side surface; 33. Back surface; 34. Bottom surface; 35. Front surface; 20. Microstrip line; 20A. First end; 20B. Second end; 20C. Protrusion; 21. First input / output coupling section; 21A. First input / output coupling pattern; 21D. First non-metallized region; 22. Second input / output coupling section; 22A. Second input / output coupling pattern; 22D. Second non-metallized region; 23. Third input / output coupling section; 23A. Third input / output coupling pattern; 23D. Third non-metallized region; 101. Bandstop filter; 102. Bandpass filter; L. Length; W. Width; Z. Height; DETAILED DESCRIPTION

[0041] Referring now to the drawings, the exemplary embodiment of the monolithic ceramic bandstop bandpass combiner disclosed herein will be explained in detail. While the drawings are presented to illustrate some embodiments of the present application, the drawings are not necessarily drawn to scale, and certain features can be exaggerated, removed, or partially sectioned to better illustrate and explain the disclosure herein. Portions of the components in the drawings can be adjusted in position according to actual needs without affecting the technical effects. The phrase "in the drawings" or similar language appearing in the specification is not necessarily referring to all of the drawings or examples.

[0042] Certain directional terms used herein below to describe the drawings, such as "inner", "outer", "above", "below", and other directional terms, will be understood to have their normal meanings and refer to those directions involved when viewing the drawings normally. Unless otherwise indicated, the directional terms described in the specification are basically in accordance with the conventional directions as understood by those skilled in the art.

[0043] The terms "first", "the first", "second", "the second", and similar terms used herein in the present application do not indicate any order, number, or importance, but are used to distinguish one component from another.

[0044] The present application relates to a monolithic ceramic band reject band pass combiner configured to be arranged between a plurality of transmitters and a common antenna for combining radio frequency signals of different frequency bands output from the plurality of transmitters into one path and for transmitting and receiving via the common antenna. It is noted that although the combiner is mainly described herein with respect to its function and action of combining, the skilled person knows that it can also be used as a power divider for dividing radio frequency signals from the common antenna into a plurality of output signals. By way of example, in case of a mobile phone or a walkie-talkie, the monolithic ceramic band reject band pass combiner according to the present application is typically post soldered to a printed circuit board comprising radio frequency transmitters, receivers and a common antenna.

[0045] Referring to Figs. 1 and 2 of the present application, wherein the monolithic ceramic band reject band pass combiner according to the present application is artificially disassembled in order to better illustrate its individual parts (it is noted that in the working state of the combiner it is assembled), it comprises from left to right in Fig. 1 a shield 200 for the purpose of "clean" and signal shielding, a ceramic core 100 and a plating pattern 300 covering the surface of the ceramic core 100. The shield 200 is preferably snap attached to the front face of the ceramic core 100.

[0046] In particular, the monolithic ceramic band reject band pass combiner shown in Figs. 1 and 2 comprises an elongated, parallelepipedal (or "box-shaped") ceramic core 100 made of a ceramic dielectric material. The ceramic core 100 has three sets of opposite faces: a top surface 11 (the elongated plane visible in Fig. 1) and a bottom surface (the back of the elongated plane visible in Fig. 1, not visible), opposite long sides and opposite narrow ends or narrow faces, which are covered by a plating pattern 300 described in detail below. The intersections between these sides of the ceramic core 100 define a plurality of parallel edges. As shown in Fig. 2, the length, width and height of the ceramic core 100 are denoted by L, H, W, respectively. Preferably, the length L of the ceramic core is designed to be about 55 to 70 mm, the height H is designed to be 6 to 10 mm and the width W is designed to be 8 to 12 mm.

[0047] The ceramic core 100 is rigid and is preferably composed of a ceramic material selected for mechanical strength, dielectric properties, plating suitability and cost. The preparation of suitable dielectric ceramics is well known to the skilled person. The ceramic core 100 is preferably manufactured by mixing the individual components (e.g. AI2O3, TiO2, Zr2O3) in particulate form with a heating step, followed by compression molding, and then with a firing step to react and interlink the individual components.

[0048] As best shown in FIG. 1, the ceramic core 100 includes twelve vias 10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H, 10I, 10J, 10K, 10L, each extending from the top surface 11 to a bottom surface (not shown) and arranged in order from the left side of FIG. 1, preferably in a generally collinear or aligned manner along the length L. The interior walls defining the vias (10A through 10L) are also plated with an electrically conductive material. Each of the plated vias 10A through 10L will form, along with the metal patterns 30A, 30B, 30C, 30D, 30E, 30F, 30G, 30H, 30I, 30J, 30K, and 30L of the plating pattern 300 described in detail below, a set of via resonator cavities. The coupling between the resonators achieved by the interior plating of the vias 10A through 10L with an electrically conductive material is achieved at least in part through the dielectric material of the ceramic core 100 and can be varied by varying the width of the dielectric material and the distance between adjacent resonators. The width of the dielectric material between adjacent vias 10A through 10L can be adjusted in any suitable conventional or non-conventional manner as is known in the art, for example, by using slotted, cylindrical, square or rectangular, or irregularly shaped holes. Although the ceramic core 100 shown herein is a twelve via plated ceramic core 100, the present application is not so limited and includes filters having more or fewer vias.

[0049] As shown in FIGS. 1 and 2, the top surface 11 of the ceramic core 100 defines opposite peripheral longitudinal edges and opposite peripheral side edges, wherein the plating pattern 300 has an interior surface conforming to the peripheral longitudinal edges and opposite peripheral side edges of the ceramic core 100 and the top surface 11 of the ceramic core 100 is also selectively plated with an electrically conductive material similar to that plated on the ceramic core 100. The material of the plating pattern 300 is electrically conductive, preferably copper, silver or alloys thereof. Here, the metallization of the plating pattern 300 is presently a preferred silver-containing electrically conductive layer. Suitable silver-containing thick film electrically conductive pastes are available from the Microcircuit Materials Division of Dupont Corporation and can be subsequently sintered to the surface of the ceramic core 100 as described in detail below. Such a plating pattern 300 preferably covers all of the surfaces of the ceramic core 100 except the top surface 11 to define a ground, wherein the metal patterns 30A, 30B, 30C, 30D,30E, 30F, 30G, 30H, 30I,30J, 30K, and 30L are etched into the top surface 11 of the ceramic core 100, for example, by means of a photolithographic machine. Since such etching processes are well known to those skilled in the art, further description is not provided herein.

[0050] As shown in Fig. 1, the selective plating of the top surface 11 of the ceramic core 100 includes and defines respective RF signal input-output (I / O) transmission lines / pads / patterns, including specifically a first input / output electrode / port / coupling 21 located in the middle of the ceramic core 100, a second input / output electrode / port / coupling 22 located on the left side of the ceramic core 100, and a third input / output electrode / port / coupling 23 located on the right side of the ceramic core 100.

[0051] Here, the first input / output electrode / port / coupling 21 includes a first input / output coupling pattern 21A configured to enable signal connection of the monolithic ceramic band reject band pass hybrid with the shared antenna, wherein the first input / output coupling pattern 21A extends from the front face of the ceramic core 100 by a certain distance and is located in the opening of the plating pattern 300 in the middle of its front face 35 and is insulated from the plating pattern 300 by means of a first non-metallized area 21D. Likewise, the second input / output electrode / port / coupling 22 includes a second input / output coupling pattern 22A configured to enable signal connection of the monolithic ceramic band reject band pass hybrid with the first transmitter, wherein the second input / output coupling pattern 22A extends from the front face of the ceramic core 100 by a certain distance and is located in the opening of the plating pattern 300 on the left side of its front face 35 and is insulated from the plating pattern 300 by means of a second non-metallized area 22D. Finally, the third input / output electrode / port / coupling 23 includes a third input / output coupling pattern 23A configured to enable signal connection of the monolithic ceramic band reject band pass hybrid with the second transmitter, wherein the third input / output coupling pattern 23A extends from the front face of the ceramic core 100 by a certain distance and is located in the opening of the plating pattern 300 on the right side of its front face 35 and is insulated from the plating pattern 300 by means of a third non-metallized area 23D.

[0052] Further, the plating pattern 300 here also includes conductive resonator patterns 30A, 30B, 30C, 30D, 30E, 30F, 30G, 30H, 30I, 30J, 30K and 30L surrounding the respective through holes 10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H, 10I, 10J, 10K, 10L and in combination defining respective resonators (e.g. of the capacitance-inductance type). Each of the resonator patterns 30A, 30B, 30C, 30D, 30E, 30F, 30G, 30H, 30I, 30J, 30K and 30L is isolated by areas not containing conductive material and each defines a respective plate edge opposite and separated from each other, e.g. the areas shown by means of black grey in Fig. 2, identified as non-metallized areas between the patterns 30A, 30B, 30C, 30D, 30E, 30F, 30G, 30H, 30I, 30J, 30K and 30L and the non-metallized areas thereof from the conductive plating pattern 300.

[0053] Finally, the plating pattern 300 here also includes a front face 35 covering a part of the top surface 11 of the ceramic core 100 and side faces 31 and 32 covering both side surfaces of the ceramic core 100 and also includes a bottom face 34 substantially covering the bottom surface of the ceramic core 100 and a back face 33 covering the back surface of the ceramic core 100. Here, as shown in Fig. 1, the plating pattern 300 extends continuously from inside the resonator cavity hole to the top surface 11 and to the bottom surface. The plating pattern 300 here serves to realize grounding.

[0054] An improvement of the present application is that a microstrip line 20 is provided between the first input / output electrode / port / coupling 21 located in the middle of the ceramic core 100 and the second input / output electrode / port / coupling 22 located on the left side of the ceramic core 100, which is realized by coating or printing on the top surface 11 of the ceramic core 100 to realize signal communication between the two.

[0055] As shown in Figs. 1 to 3, the microstrip line 20 is here spaced apart from the metal patterns 30A to 30G of the plated vias 10A, 10B, 10C, 10D, 10E, 10F, 10G in a manner generally parallel to the plated vias 10A to 10L. Here, the microstrip line 20 has a first end 20A extending at least partially adjacent to the via 10A and the metal pattern 30A and a second end 20B extending at least partially adjacent to the via 10G and the metal pattern 30G, here defining a length Dl of the microstrip line 20 between the first end 20A and the second end 20B and having a plurality of protrusions 20C located between a plurality of resonators CX1, CX2,... CX7 along the length Dl. Here, a first input / output coupling 21 is connected to the microstrip line 20 adjacent to the second end 20B and a second input / output coupling 22 is connected to the microstrip line 20 adjacent to the first end 20A. By means of such a manner, the microstrip line 20 and the resonant cavity composed of the vias 10A to 10G and the metal patterns 30A to 30G together form a band-stop filter 101 capable of suppressing signals of a certain frequency band while allowing signals of other frequencies to pass in a manner described in more detail below.

[0056] In particular, a plurality of vias 10A to 10G and corresponding metal patterns 30A to 30G are provided in the top surface 11 of the ceramic core 100 extending in the length L direction of the ceramic core 100 and penetrating the ceramic core 100. Thereby, the vias 10A to 10G and the corresponding metal patterns 30A to 30G equivalently form a plurality of resonators CX1, CX2,... CX7 in a filter circuit of the band-stop filter 101.

[0057] Further, as shown in Figs. 2 to 8, the ceramic core 100 is provided with a first input / output coupling 21 and a second input / output coupling 22, wherein as best shown in Fig. 6, a metal coupling pattern 21A of the first input / output coupling 21 and a metal coupling pattern 22A of the second input / output coupling 22 are electrically isolated from a portion 35 of the front metallized plated layer pattern 300 of the ceramic core 100 by means of a first non-metallized region 21D and a second non-metallized region 22D, respectively. Thereby, the vias 10A and 10B and the metal coupling pattern 22 of the second input / output coupling 22 thereunder and the vias 10F and 10G and the metal coupling pattern 21 of the first input / output coupling 21 thereunder equivalently form two capacitors Cl, C2 in a filter circuit of the band-stop filter 101.

[0058] At the same time, the first input / output coupling part 21 and the second input / output coupling part 22 are connected by the microstrip line 20 printed on the top surface 11. Thus, the microstrip line 20 is equivalent to form an inductance L1 in the filter circuit of the band-stop filter 101. In this way, the through-holes 10A to 10G and the corresponding metal patterns 30A to 30G, the metal coupling patterns 21 of the first input / output coupling part 21 and the metal coupling patterns 22A of the second input / output coupling part 22, and the microstrip line 20 together form the filter circuit of the band-stop filter 101.

[0059] Thus, by changing the length D1 of the microstrip line 20 and the spacing distance between the microstrip line 20 and the metal patterns 30A to 30G, the moving of the attenuation pole of the band-stop filter 101 can be achieved.

[0060] As can be seen from the above, the band-stop filter 101 according to the present application is composed of the first input / output coupling part 21, the microstrip line 20 directly connected between the first input / output coupling part 21 and the second input / output coupling part 22, the plurality of resonant cavities CX1 to CX6 (in the order from left to right, 1-6) and the common cavity CX7 (in the order from left to right, 7). It is known to those skilled in the art that the return loss of the passband of the band-stop filter 101 is determined by adjusting the characteristic impedance of the microstrip line 20 (for example, by changing the length D1 of the microstrip line 20, the height of the protrusion 20C, and the spacing distance between the microstrip line 20 and the metal patterns 30A to 30G), i.e., by adjusting the design parameters of the microstrip line 20 including the position and the width and the like. Further, the Qu of the ceramic core 100 can be used to determine the loss of the band-stop filter 101, where the Qu of the ceramic core 100 is determined by the size of the ceramic core 100, the Qf of the ceramic core 100, and the conductivity of the conductive layer of the plating pattern 300; the stopband frequency of the band-stop filter 101 is determined by adjusting the resonant frequencies of the plurality of resonant cavities CX1 to CX6, which is determined by the mechanical size of the ceramic core 100 and the size of the circuit-to-ground capacitance of the resonant top surface 11; the stopband bandwidth and the size of the attenuation of the band-stop filter 101 are adjusted by adjusting the size of the power absorption of the plurality of resonant cavities CX1 to CX6 to the transmission power of the microstrip line 20, i.e., by adjusting the capacitance value between the microstrip line 20 and the plurality of resonant cavities CX1 to CX6.

[0061] In this context, the Qf value (also referred to as the quality factor) of the ceramic refers to the product of the quality factor Qd and the resonant frequency f, where the quality factor Qd is the inverse of the dielectric loss and can be used to reflect the frequency selection characteristics of the ceramic material. In this embodiment, the Qf value is preferably in the range of 6000 to 70000. Further, Qu refers to the unloaded Q value, which is used to represent the maximum Q value that can be achieved by the dielectric resonator under the condition of no loaded coupling loss, and in this embodiment, the value of Qu can be selected from the range of 500 to 3000.

[0062] Another improvement of the application is that the ceramic core 100 is also integrally formed with a band-pass filter 102 connected in parallel with the band-stop filter 101, where the seventh via 10G and its corresponding metal pattern 30G from left to right form a resonant cavity used as a common cavity for the band-stop filter 101 and the band-pass filter 102.

[0063] In particular, as shown in Figs. 2-3, a plurality of vias 10G-L and corresponding metal patterns 30G-L are formed in the top surface 11 of the ceramic core 100 extending along the length L of the ceramic core 100 and through the ceramic core 100. As a result, the vias 10G-L and corresponding metal patterns 30G-L form, in effect, a plurality of resonators CX7, CX10,... CX12 in the filter circuit of the band-pass filter 102.

[0064] Further, as shown in Figs. 2-3, the ceramic core 100 is also provided with a first input / output coupling 21 and a third input / output coupling 23. Preferably, as shown in Fig. 6, the metal coupling pattern 21A of the first input / output coupling 21 and the metal coupling pattern 23A of the third input / output coupling 23 are electrically isolated from the portion 35 of the front metallized plating pattern 300 of the ceramic core 100 by means of a first non-metallized region 21D and a third non-metallized region 23D, respectively. As a result, the vias 10F and 10G and the metal coupling pattern 21A of the first input / output coupling 21 thereunder and the vias 10K and 10L and the metal coupling pattern 23A of the third input / output coupling 23 thereunder form, in effect, two capacitors CI, C3 in the filter circuit of the band-pass filter 102.

[0065] Preferably, the metal coupling pattern 23A of the third input / output coupling 23 is designed to improve the capacitive coupling to ground and, as a result, to enhance the power handling characteristics and capabilities of the band-pass filter 102.

[0066] In particular, as shown in Figs. 3 and 5, the metal coupling pattern 23A of the third input / output coupling 23 is additionally defined with a band of metallized material defining a plurality of fingers 23B and 23C that extend perpendicularly out of the top side and left side of the top portion of the metal coupling pattern 23 that extends between the respective resonators CX11 and CX12. The fingers 23B and 23C interleave, i.e., protrude, into the respective grooves defined in the respective resonators CX11 and CX12. Of course, the grooves define regions that do not contain metallized material. The fingers 23B and 23C are separated from the metallized material of the metal patterns 30K and 30L from each other to achieve capacitive coupling between the metal coupling pattern 23A and the resonators CX11 and CX12.

[0067] The monolithic ceramic bandpass bandstop hybrid coupler according to the present application can be manufactured in the following way. First, the length L, width W and height H of the ceramic core 100 and the aperture and pitch of the through holes 10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H, 101, 10J, 10K, 10L are obtained by topological operation and simulation, and then the structure size of the ceramic block is designed based on these parameters, and then the ceramic block is formed by die casting and sintering. Next, the ceramic core 100 can be preferably formed by die casting and sintering, and then the plating layer pattern 300 is sintered by silver plating on the ceramic core 100, and finally the microstrip line 20 and the first to third input / output coupling parts 21 to 23 described in detail above and the metal patterns 30A to 30L described above can be etched by using a photoetching machine, and the bandpass filter 102 and the bandstop filter 101 described above are formed, wherein the bandpass filter 102 and the bandstop filter 101 are both hybrid at the common resonator CX7 (which is composed of the through hole 10G and the corresponding metal pattern 30G) to form a parallel design, and finally the bandpass filter 102 and the bandstop filter 101 pass through the common resonator CX7 and are input or output by means of the first input / output coupling part 21.

[0068] As can be seen from the above, the bandpass filter 102 according to the present application is composed of the first input / output coupling part 21, the third input / output coupling part 23, a plurality of resonant cavities CX8 to CX12 (left to right order 8-12) and a common cavity CX7 (left to right order 7), the resonant frequencies of these resonant cavities CX8 to CX12 being the stopband resonant frequencies of the bandpass filter 102, which are determined by the mechanical size of the ceramic core 100 and the circuit-to-ground capacitance size of the resonant top surface 11; the passband bandwidth of the bandpass filter 102 being determined by the capacitance value and inductance value size between these resonant cavities CX8 to CX12; the return loss of the bandpass filter 102 being determined by the capacitance size between the first input / output coupling part 21 and the common resonant cavity (left to right order 7) and the resonant cavity CX8 (left to right order 8), and the capacitance value size between the third input / output coupling part 23 and the resonant cavity CX11 (left to right order 11); the insertion loss of the bandpass filter 102 being determined by the Qu value of the ceramic core 100, which is determined by the size of the ceramic core 100, the Qf value of the ceramic and the conductivity of the conductive layer; and the out-of-band rejection being determined by the resonant cavity CX12 (left to right order 12) of the bandpass circuit and all the coupling capacitances or inductances between these resonant cavities CX8 to CX12, which are capacitive, with a suppression zero at the low end of the passband, or inductive, with a suppression zero at the high end of the passband.

[0069] Specific embodiments

[0070] A combiner was simulated according to the embodiment shown in FIGS. 1 and 2 with the design parameters specified in Table 1 below.

[0071] Table 1

[0072] The example filters were simulated using Microwave Office, Applied Wave Research, Inc. (El Segundo, CA). In performing the simulation, the passband of the bandstop filter 101 of the ceramic bandstop-bandpass combiner was designed to be a wide frequency passband and the passband of the bandpass filter 102 was designed to be a narrow frequency passband with a narrow isolation band between the passbands of the two. In this context, the scattering parameters are the ratio of the reflected and transmitted traveling waves measured at the specified element junctions.

[0073] FIG. 9 is a simulation plot of the scattering parameters of the passband transmission of the ceramic bandstop-bandpass combiner according to the above-mentioned dimensional parameters of the present application, where it can be seen that the frequency range of the passband of the bandpass filter of the ceramic bandstop-bandpass combiner according to the present application is approximately in the range of the frequency band of 2.001 to 3.1 GHz, where the out-of-band rejection performance thereof is characterized by the portion circled by the line designated 9a and the insertion loss performance thereof is characterized by the portion circled by the line designated 9b. Here, the transmission efficiency from the input coupling 23 to the common output coupling 21 of the bandpass filter is characterized by S21 in FIG. 9. It can be seen from FIG. 9 that the above-mentioned out-of-band rejection performance and insertion loss are satisfactory. Further, FIG. 10 is a simulation plot of the scattering parameters of the passband single port reflection of the ceramic bandstop-bandpass combiner according to the above-mentioned dimensional parameters of the application, where the standing wave performance of the bandpass filter in the ceramic bandstop-bandpass combiner is circled by the elliptical line 10a. Here, the scattering parameters of the single port reflection from the input coupling 23 of the bandpass filter are characterized by S22 in FIG. 10, which describes the reflection condition of the signal.

[0074] Figure 11 is a schematic diagram of the scattering parameters of the band-stop transmission of the ceramic band-stop bandpass combiner according to the above-described dimensional parameters of the present invention. It can be seen that the frequency range of the stopband of the band-stop filter of the ceramic band-stop bandpass combiner according to the present invention is also approximately in the range of 2.001 to 3.1 GHz, and the frequency range of the stopband of the band-stop filter is indicated by the coil labeled 11a in Figure 11. Here, S31 is used in Figure 11 to characterize the transmission efficiency from the input coupling section 22 to the common output coupling section 21, which serves as the band-stop filter. Furthermore, the frequency range of the passband of the band-stop filter of the ceramic band-stop bandpass combiner is also indicated by the coil labeled 11b, and it can be seen that this frequency range is approximately in the range of 0.001 GHz to 2.0 GHz. Furthermore, in Figure 12, S33 is used to characterize the scattering parameter of the single-port reflection of the input coupling section 22 used as a band-stop filter, in order to describe the signal reflection situation, and in Figure 13, S11 is used to characterize the scattering parameter of the single-port reflection of the common output coupling section 21 used as a combiner, in order to describe the signal reflection situation.

[0075] As can be seen from Figures 11 and 13-14, compared to cavity-type low-pass bandpass combiners, the in-band attenuation of the bandstop filter in the ceramic bandstop bandpass combiner according to the present invention is significantly smaller in the transmission passband of the bandstop filter and the sideband adjacent to the bandpass filter. Furthermore, regarding out-of-band attenuation, the ceramic bandstop bandpass combiner of the present invention achieves faster or steeper out-of-band attenuation compared to low-pass bandpass combiners. In other words, the ceramic bandstop bandpass combiner of the present invention has significant advantages over existing low-pass bandpass combiners, at least in terms of performance indicators such as insertion loss and near-end rejection.

[0076] As a result, in application scenarios requiring the coexistence of multiple communication networks such as 3G, 4G, and 5G, multiple system signals located in different frequency bands can be combined into a single transmission stream without switching antennas. Based on the superior insertion loss, out-of-band rejection, lower in-band attenuation, and faster out-of-band attenuation of this invention, it can effectively accommodate the coexistence of multiple communication networks such as 3G, 4G, and 5G in the same area, thereby improving the utilization rate of existing resources.

[0077] Furthermore, Figure 12 is a schematic diagram of the scattering parameters of the band-stop single-port reflection of the ceramic band-stop bandpass combiner according to the above-described dimensional parameters of the present invention, wherein the standing wave in the passband of the band-stop filter is indicated by a red coil (labeled 12a).

[0078] Figures 13 and 14 are schematic diagrams of the scattering parameters reflected from the common port of the ceramic bandstop bandpass combiner according to the above-described dimensional parameters of the present invention, and schematic diagrams of the scattering parameters reflected and transmitted after combining. The standing wave in the passband of the bandstop filter emanating from the red coil (labeled 13a) and the standing wave of the bandpass filter in the ceramic bandstop bandpass combiner emanating from the green coil (labeled 13b) are clearly visible.

[0079] As can be seen from the above, the simulation results show that the bandstop-bandpass combiner exhibits a significant improvement in attenuation at the target frequency and minimal signal loss in both the transmit and receive passbands. This indicates that the ceramic bandstop-bandpass combiner according to the present invention can solve the technical requirement of combining wideband and narrowband outputs or inputs. Simultaneously, it also addresses the problem of wideband and narrowband frequencies being close together while requiring low passband loss and high mutual suppression between the two passbands.

[0080] Furthermore, since the ceramic bandstop bandpass combiner of the present invention uses a ceramic dielectric substrate and is designed as a single unit, it meets the technical requirements of small size, simplified process and reduced cost of existing radio frequency components.

[0081] It is particularly noteworthy that the ceramic bandstop bandpass combiner of the present invention can not only achieve low-frequency broadband and narrowband combining, but also high-frequency broadband and narrowband combining, thereby effectively meeting the technical requirements for combining high and low frequency broadband and narrowband.

[0082] It should be understood that although this specification describes various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0083] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A single-unit ceramic bandstop-bandpass combiner, configured to be installed between a shared antenna and multiple transmitters, characterized in that, include: A ceramic core defined by a top surface, a bottom surface and side surfaces, wherein the top surface of the ceramic core defines opposing upper peripheral longitudinal edges and lower peripheral longitudinal edges and is provided with a plurality of separate through holes along its length direction, the through holes extending through the ceramic core between the top surface and the bottom surface and being surrounded by a conductive metal pattern on the top surface to form a plurality of resonators; The plating pattern has an inner surface conforming to the upper peripheral longitudinal edge and the lower peripheral side edge of the ceramic core and is configured to substantially cover the side and bottom surfaces of the ceramic core to define grounding. The first input / output coupling section located in the middle of the ceramic core and connected to the common antenna signal; A second input / output coupling section and a third input / output coupling section located on both sides of the first input / output coupling section and respectively connected to the signals of the first transmitter and the second transmitter, wherein the third input / output coupling section and the first input / output coupling section form a bandpass filter via a plurality of resonators located therebetween; as well as A microstrip line located on the top surface of a ceramic core for signal connection to a first input / output coupling section and a second input / output coupling section, wherein the microstrip line is generally parallel to and spaced apart from a plurality of vias, such that it and a plurality of resonators located therebetween together form a band-stop filter located between the first input / output coupling section and the second input / output coupling section, wherein the band-stop filter and the band-pass filter are connected in parallel via a shared at least one resonator.

2. The single-unit ceramic band stop and band continueer as described in claim 1, characterized in that, The ceramic core includes twelve through holes arranged generally collinearly in sequence, wherein at least the seventh through hole is designed as part of a resonator shared by a band-stop filter and a band-pass filter.

3. The single-unit ceramic band stop and band continueer as described in claim 2, characterized in that, The microstrip line has a first end that extends at least partially intersecting with a first via and its metal pattern, and a second end that extends at least partially intersecting with a seventh via and its metal pattern, wherein the first end and the second end define the length of the microstrip line.

4. The single-unit ceramic band stop and band continueer as described in claim 3, characterized in that, The microstrip line has multiple protrusions along its length that extend toward the resonators, with the multiple protrusions protruding between adjacent resonators.

5. The single-unit ceramic band stop and band continueer as described in claim 1, characterized in that, The third input / output coupling section has a plurality of fingers interleaved with the resonators, wherein at least one finger protrudes between two adjacent resonators.

6. The single-unit ceramic band stop and band pass combiner as described in claim 1, characterized in that, The length and width of the microstrip line are proportional to its equivalent inductance in the band-stop filter.

7. The single-unit ceramic band stop and band continueer as described in claim 6, characterized in that, The length of the microstrip line and its spacing from the resonator are related to the attenuation poles of the bandstop filter.

8. The single-unit ceramic band stop and band pass combiner as described in claim 1, characterized in that, The ceramic core is designed to be approximately 55 to 70 mm long, 6 to 10 mm high, and 8 to 12 mm wide.

9. The single-unit ceramic band stop and band continueer as described in claim 1, characterized in that, The plating pattern is designed as a silver-containing conductive layer, which is sintered onto the surface of the ceramic core via a silver-containing thick-film conductive paste.

10. The single-unit ceramic band stop and band pass combiner as described in claim 1, characterized in that, It also includes a shielding cover for signal shielding, wherein the shielding cover is snapped onto the front of the ceramic core.

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