Dual mode CWG filter design

Abstract

Dual mode ceramic waveguide (CWG) filter designs are disclosed. According to one aspect, a plurality of CWG filter units are provided. The CWG filter units are electromagnetically coupled via one or more first coupling sections through first aligned windows in first parallel facing walls of adjacent CWG filter units. Each CWG filter unit has a pair of dual mode blocks electromagnetically coupled by a second coupling section through second aligned windows in second parallel facing walls of the pair of dual mode blocks. Each CWG filter unit may be formed by ceramic injection molding or dry-pressing to fill a first cavity formed by walls of the pair of dual mode blocks and the second coupling section.

Description

DUAL MODE CWG FILTER DESIGNTechnical Field

[0001] The present disclosure relates to wireless communications, and in particular, to dual mode ceramic waveguide (CWG) filter design.

[0002] In the design of radios for Fourth Generation (4G), Fifth Generation (5G) and Sixth Generation (6G) wireless communication systems, a small high performance radio frequency (RF) front end filter is desired. In recent years, ceramic waveguide (CWG) filters have been of particular interest. In particular, multimode CWG filter technologies have been developed for smaller size, higher Q and / or lower cost.

[0003] For example, FIG. 1 shows a triple mode block 2 which is used to form the CWG filter 4 shown in FIG. 2. The CWG filter 4 includes two triple mode blocks 2 electromagnetically coupled by a waveguide link 6 between the triple mode blocks 2. FIG. 3 illustrates a top view and a bottom view of a printed circuit board (PCB) 8 that includes the CWG filter 4 of FIG. 2. The PCB 8 contains other radio components such as a low pass filter 10 and a roofing filter 12, as well as input / output (I / O) ports 15. The triple mode blocks 2 of FIGS. 1-3 have three comer cuts 14 to couple energy between modes TE011, TE101 and TE110. As shown in FIG. 2, each triple mode block 2 of the CWG filter 4 includes an input / output (I / O) port 16 for coupling energy into and out of the CWG filter 4. Also, one of the triple mode blocks 2 of the CWG filter 4 include frequency tuning screws 18, each frequency tuning screw 18 being configured on a different wall of the triple mode block 2 to tune a different one of the triple modes of the triple mode bock 2.

[0004] FIG. 4 is an example of a hybrid dielectric waveguide filter 20 that includes two triple mode resonators 22 coupled through coupling windows 24 by a single mode resonator 26. Each triple mode resonator 22 includes an I / O port 28, angle cuts 30 for mode coupling and frequency tuning screws 32. FIG. 5 is an example of a hybrid waveguide filter 34 that has step cuts 36 for mode coupling instead of angle cuts 30.

[0005] A problem with the designs of FIGS. 1-5 is difficulty and cost of manufacture to achieve repeatable, high performance.Summary

[0006] An aspect of this disclosure provides a ceramic waveguide, CWG, filter. The CWG filter includes first and second dual mode blocks; and a first coupling section between the first and second dual mode blocks. Each of the first and second dual mode blocks have a mode coupling structure configured to couple electromagnetic energy between a first mode associated with a first electric field direction and a second mode associated with a second electric field direction, the second electric field direction being orthogonal to the first electric field direction. The first coupling section is configured to couple electromagnetic energy of the second mode between the first and second dual mode blocks via first aligned windows in parallel facing walls of the first and second dual mode blocks. The first and second dual mode blocks are in communication through the first aligned windows and the first coupling section. The CWG filter is formed as a unit at least in part by ceramic injection molding or dry-pressing to fill a cavity formed by walls of the first and second dual mode blocks and the first coupling section.

[0007] In some embodiments, the first electric field direction is parallel to the parallel facing walls.

[0008] In some embodiments, the second electric field direction is parallel to the parallel facing walls.

[0009] In some embodiments, the second electric field direction is orthogonal to the parallel facing walls.

[0010] In some embodiments, each of a first wall and a second wall of at least one of the first and second dual mode blocks includes a tuning formation, each tuning formation being configured to tune a frequency response of a different one of the first and second modes.

[0011] In some embodiments, a mode coupling structure of at least one of the first and second dual mode blocks includes a first wall of the dual mode block at an acute angle with respect to a second wall of the dual mode block.

[0012] In some embodiments, the first wall lies in a plane that is orthogonal to the parallel facing walls.

[0013] In some embodiments, a mode coupling structure of at least one of the first and second dual mode blocks further includes an inward step cut.

[0014] In some embodiments, the inward step cut is one of orthogonal to the parallel facing walls and parallel to the parallel facing walls.

[0015] In some embodiments, a mode coupling structure of at least one of the first and second dual mode blocks further includes a blind via.

[0016] In some embodiments, the blind via is a cylinder having an axis that is one of orthogonal to the parallel facing walls and parallel to the parallel facing walls.

[0017] In some embodiments, the first aligned windows include windows situated in corners of the parallel facing walls.

[0018] Some embodiments further include an input / output, I / O, port in at least one of the first and second dual mode blocks, an I / O port being configured to couple electromagnetic energy of the first mode between an exterior and an interior of a dual mode block that includes the I / O port.

[0019] Some embodiments further include a sequence of at least one single mode block followed by an additional coupling section, the sequence being interposed between the first coupling section and the second dual mode block.

[0020] In some embodiments, the second dual mode block is coupled to a third dual mode block through a second coupling section.

[0021] A further aspect of this disclosure provides a ceramic waveguide, CWG, filter. The CWG filter includes a plurality of CWG filter units electromagnetically coupled via one or more first coupling sections through first aligned windows in first parallel facing walls of adjacent CWG filter units, each CWG filter unit comprising a pair of dual mode blocks electromagnetically coupled by a second coupling section through second aligned windows in second parallel facing walls of the pair of dual mode blocks, each CWG filter unit being formed by ceramic injection molding or dry-pressing to fill a first cavity formed by walls of the pair of dual mode blocks and the second coupling section.

[0022] In some embodiments, the plurality of CWG filter units are formed together by ceramic injection molding or dry-pressing to fill a second cavity formed by walls of each dual mode block of each CWG filter unit and by walls of first and second coupling sections.

[0023] In some embodiments, each dual mode block of the plurality of CWG filter units includes a mode coupling structure configured to couple electromagnetic energybetween a first mode associated with a first modal direction and a second mode associated with a second modal direction, the first and second modal directions being orthogonal.

[0024] In some embodiments, a first set of first coupling sections are configured to couple electromagnetic energy of the first mode between adjacent CWG filter units, and a second set of second coupling sections are configured to couple electromagnetic energy of the second mode between adjacent dual mode blocks of a CWG filter unit.

[0025] In some embodiments, a first dual mode block of a first CWG filter unit of the plurality of CWG filter units includes a first input / output, I / O, port and a second dual mode block of a second CWG filter unit of the plurality of CWG filter units includes a second I / O port, each of the first and second I / O ports being configured to couple electromagnetic energy of one of the first mode and the second mode, into or out of the CWG filter.

[0026] In some embodiments, one second coupling section of a first CWG filter unit of the plurality of CWG filter units couples electromagnetic energy of the first mode between first dual mode blocks of the first CWG filter, and another second coupling section of a second CWG filter unit of the CWG filter units couples electromagnetic energy of the second mode between second dual mode blocks of the second CWG filter unit.

[0027] In some embodiments, a first coupling section between two adjacent CWG filter units includes at least one single mode block.

[0028] In some embodiments, a second coupling section between two dual mode blocks of a CWG filter unit includes at least one single mode block.

[0029] In some embodiments, first parallel facing walls of two adjacent CWG filter units are orthogonal to second parallel facing walls of a pair of dual mode blocks of one of the two adjacent CWG filter units.

[0030] In some embodiments, a first CWG filter unit of the plurality of CWG filter units shares a dual mode block with a second CWG filter unit of the plurality of CWG filter units.

[0031] Some embodiments further include support bars between CWG filter units of the plurality of CWG filter units.

[0032] Some embodiments advantageously provide a CWG filter design. Filter structures disclosed herein are manufacturable using existing low-cost ceramic drypressing or ceramic injection molding (CIM) processes. Embodiments disclosed herein include CWG filters of reduced size comparable to half the width of a single mode (SM) CWG filter. Embodiments disclosed herein include a CWG filter having a Q that is more than 30% greater than a single mode CWG filter of the same size. The dual mode CWG filters disclosed herein may be easily tuned for both mode-coupling and for resonator frequency. Also, input / output (VO) ports of the dual mode CWG filters may be configured to be solderable on a printed circuit board (PCB).Brief Description Of The Drawings

[0033] A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

[0034] FIGS. 1-3 show an example of a triple mode monoblock filter assembly;

[0035] FIG. 4 and 5 show an example of a hybrid dielectric waveguide filter;

[0036] FIG. 6 is a perspective view of a CWG filter unit constructed according to principles disclosed herein;

[0037] FIG. 7 is a graph of scattering parameters Sil and S21 for the CWG filter of FIG. 6;

[0038] FIG. 8 is an example of a CWG filter that includes cascaded CWG filter units of FIG. 6;

[0039] FIG. 9 is a graph of scattering parameters Sil and S21 for the CWG filter of FIG. 8;

[0040] FIG. 10 is an example of an n-dual mode block CWG filter having cascaded CWG filter units;

[0041] FIG. 11 is another example of a CWG filter unit having a step cut instead of the angle cut shown in FIG. 6 to achieve mode coupling;

[0042] FIG. 12 is another example of a CWG filter unit having a blind via or through hole instead of the angle cut shown in FIG. 6 to achieve mode coupling;

[0043] FIG. 13 is another example of a CWG filter unit constructed according to principles disclosed herein;

[0044] FIG. 14 is a graph of scattering parameters SI 1 and S21 for the CWG filter of FIG. 13;

[0045] FIG. 15 is another example of a CWG filter unit having a step cut instead of the angle cut shown in FIG. 13 to achieve mode coupling;

[0046] FIG. 16 is another example of a CWG filter unit having a blind via or through hole instead of the angle cut shown in FIG. 13;

[0047] FIGs. 17 and 18 show a perspective view and a top view, respectively, of an example CWG filter constructed according to principles set forth herein;

[0048] FIGs. 19 and 20 show a perspective view and a top view, respectively, of an example CWG filter constructed according to principles set forth herein;

[0049] FIGs. 21 and 22 show a perspective view and a side view, respectively, of an example CWG filter constructed according to principles set forth herein;

[0050] FIG. 23 is another example of a CWG filter unit with an angle cut for mode coupling;

[0051] FIG. 24 is another example of a CWG filter unit with a step cut for mode conversion;

[0052] FIG. 25 is another example of a CWG filter unit with a blind via or through hole for mode coupling;

[0053] FIGs. 26 and 27 are perspective and side views, respectively of an example CWG filter constructed according to principles set forth herein;

[0054] FIGs. 28 and 29 are perspective and side views, respectively of an example CWG filter constructed according to principles set forth herein; and

[0055] FIGs. 30 and 31 are perspective and top views, respectively of an example CWG filter structure including support bars and constructed according to principles set forth herein.Detailed Description

[0056] Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processingsteps related to dual mode ceramic waveguide (CWG) filter design. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0057] As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0058] In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication.

[0059] In some embodiments described herein, the term “coupled,” “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and / or wireless connections.

[0060] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components, and / or groups thereof.

[0061] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0062] Embodiments are directed to CWG filters. Returning now to the drawing figures, in which like elements are similarly numbered, FIG. 6 is a perspective view of a CWG filter unit 40 constructed according to principles disclosed herein. The CWG filter unit 40 includes two dual mode blocks 42a and 42b (referred to collectively as dual mode blocks 42) that are electromagnetically coupled through a coupling section 44. The dual mode blocks 42a and 42b and the coupling section 44 may be filled with ceramic material in an injection molding or dry-press process.

[0063] In the example CWG filter unit 40 of FIG. 6, each dual mode block 42a, 42b includes a single angle cut 46a, 46b (referred to collectively as angle cuts 46). An angle cut 46 is a surface that lies in a plane that is at an acute angle with respect to adjoining walls. Either one or both of the dual mode blocks 42 may include an VO port 48a, 48b (referred to collectively as I / O ports 48), as shown in FIG. 6. I / O ports 48 are configured to couple energy into and out of the CWG filter unit 40. Each dual mode block 42 may include frequency tuning formation 50a, 50b (referred to collectively as tuning formations 50). Note that unlike the known filters of FIGS. 1-5, the tuning formations 50 do not require a screw 18, 32, but rather, can be a shallow pan-like indentation.

[0064] As shown in FIG. 6, each dual mode block 42 supports three orthogonal modes. For example, each dual mode block 42 supports a first TE mode, a second TE mode and a third TE mode. The first TE mode is associated with an electric field in an x- direction (referred to herein as an x-directed mode). For an x-directed mode, the majority of the electric field of the mode is in the x-direction . The second TE mode is associated with an electric field in the z-direction (referred to herein as a z-directed mode) For a z-directed mode, the majority of the electric field of the mode is in the z- direction. The third TE mode is associated with an electric field in the y-direction (referred to herein as a y-directed mode). For a y-directed mode, the majority of theelectric field of the mode is in the y-direction. In the example CWG filter unit 40 of FIGS. 6 and 7, the y-directed mode is not used. The x-directed mode may be used for coupling energy into and out of the CWG filter unit 40 via the I / O ports 48 and the z- directed mode may be used for coupling energy between the two dual mode blocks 42a, 42b through aligned windows in parallel facing walls of the two dual mode blocks 42 via a coupling section 44

[0065] The angle cuts 46a, 46b, are configured to couple energy between the x- directed mode and the z-directed mode, and are configured to avoid coupling energy into the y-directed mode.

[0066] FIG. 7 is a graph of scattering parameters SI 1 and S21 for the CWG filter unit 40 of FIG. 6.

[0067] FIG. 8 is an example of a CWG filter that includes first and second dual mode blocks 52a, 52b forming a first CWG filter unit 56, and includes first and second dual mode blocks 52c, 52d forming a second CWG filter unit 58. The first and second dual mode blocks 52a, 52b of the first CWG filter unit 56 are electromagnetically coupled by a first coupling section 60a. The first and second dual mode blocks 52c, 52d of the second CWG filter unit 58 are electromagnetically coupled by a first coupling section 60b. The dual mode block 52b of the first CWG filter unit 56 is electromagnetically coupled to the dual mode block 52c of the second CWG filter unit 58, via a third coupling section 62. Note that the mode coupled by coupling sections 60a and 60b is orthogonal to the mode coupled by coupling section 62.

[0068] FIG. 9 is a graph of scattering parameters SI 1 and S21 for the CWG filter unit 40 of FIG. 8. FIG. 10 is an example of an n-dual mode block CWG filter 64 having dual mode blocks 52a through 52n.

[0069] FIG. 11 is an example CWG filter unit 66 that is similar to the CWG filter unit 40 of FIG. 6, except that instead of angle cuts 46, the dual mode blocks 68a, 68b of FIG. 11 each have a step cut 70 configured to couple electromagnetic energy between the x-directed mode and the z-directed mode in the respect dual mode block. FIG. 12 is an example of a CWG filter unit 72 that is similar to the CWG filter unit 40 or 66, but instead of having an angle cut 46 or a step cut 70, the CWG filter unit 72 has a blind via 74 in each of the dual mode blocks 76, 76b to perform the function coupling electromagnetic energy between the x-directed and z-directed modes. The blind via 74 may be filled with a dielectric such as air and may be metallic on all sides. The blind via74 may extend from a first wall of the respective dual mode block 76 to a second wall opposite the first wall of the dual mode block 76, where the first and second walls are in parallel x-z planes that are parallel to the aligned windows through which energy is coupled between the dual mode blocks 76a, 76b via the coupling section 78.

[0070] FIG. 13 is another example CWG filter unit 80 that includes two dual mode blocks 82a, 82b. Each dual mode block 82a, 82b has an angle cut 84 configured to couple energy between a y-directed mode (i.e., electric field vector in the y-direction) and a z-directed mode (i.e., electric field vector in the z-direction). In the CWG filter unit 80, energy is coupled between the dual mode blocks 82a and 82b via aligned windows through coupling sections 86 at each of four corners of first and second parallel facing walls of the dual mode blocks 82a, 82b, where the first and second parallel facing walls contain a z-axis and are perpendicular to the y-axis. The spacing between coupling sections 86 may be filled with air or other dielectric. The walls of the coupling sections 86 may be metallized. The angle cuts 84 are configured to avoid coupling of energy into the x-directed mode. A model of the CWG filter unit 80 for simulation purposes is shown in FIG. 13 with VO ports 88a, 88b configured to couple energy into and out of the CWG filter unit 80. FIG. 14 is a graph of scattering parameters Si l and S21 for the CWG filter unit 80 of FIG. 13.

[0071] FIG. 15 is another example CWG filter unit 90 that includes two dual mode blocks 92a, 92b. Each dual mode block 92a, 92b has an step cut 94 configured to couple energy between a y-directed mode (i.e., electric field vector in the y-direction) and a z-directed mode (i.e., electric field vector in the z-direction). In the CWG filter unit 90, energy is coupled between the dual mode blocks 92a and 92b via aligned windows through coupling sections 96 at each of four corners of first and second parallel facing walls of the dual mode blocks 92a and 92b, where the first and second parallel facing walls contain a z-axis and are perpendicular to the y-axis. The step cuts 94 are configured to avoid coupling of energy into the x-directed mode.

[0072] FIG. 16 is another example CWG filter unit 98 that includes two dual mode blocks 100a, 100b. Each dual mode block 100a, 100b has a blind via 102 configured to couple energy between a y-directed mode (i.e., electric field vector in the y-direction) and a z-directed mode (i.e., electric field vector in the z-direction). In the CWG filter unit 98, energy is coupled between the dual mode blocks 100a and 100b via aligned windows through coupling sections 104 at each of four corners of first and secondparallel facing walls of the dual mode blocks 100a, 100b, where the first and second parallel facing walls contain a z-axis and are perpendicular to the y-axis. The blind vias 102 are configured to avoid coupling of energy into the x-directed mode.

[0073] FIGs. 17 and 18 show a perspective view and a top view, respectively, of an example CWG filter 105 that includes I / O ports 106 and multiple dual mode blocks 108. Referring to FIG. 20, the CWG filter 105 may be seen as including three CWG filter units. Two of the CWG filter units 40 are of the type shown in FIG. 6, and one of the CWG filter units 80 is of the type shown in FIG. 13. Note that the CWG filter unit 80 may be substituted by the CWG filter unit 90 or 98. As noted above, a difference between the CWG filter unit 40 and the CWG filter unit 80 is that the direction of the electric field of the mode that is coupled between the dual mode blocks of the CWG filter unit.

[0074] FIGs. 19 and 20 show perspective and top views, respectively, of another example CWG filter 110 with dual mode blocks 109 and VO ports 112a and 112b.A first pair of dual mode blocks 109a and 109b form a first CWG filter unit 114a and a second pair of dual mode blocks 109a and 109c form a second CWG filter unit 114b. The first CWG filter unit 114a and the second CWG filter unit 114b share a common dual mode block 108. In operation, a first mode in the dual mode block 109c may be excited the I / O port 112a. This first mode may be coupled to a second mode. Energy of the second mode of the dual mode block 109c may be coupled to the same second mode of the dual mode block 109a. Energy of this second mode of the dual mode block 109a may be coupled to a first mode of the dual mode block 109a. Energy of this first mode of the dual mode block 109a may be coupled to this same first mode of the dual mode block 109b.

[0075] FIGs. 21 and 22 show a perspective view and a side view, respectively, of an example CWG filter 116 that includes two dual mode blocks 118a, 118b and multiple single mode blocks 120a, 120b... 120n. In the example of FIGs. 19 and 20, the dual mode blocks 118a and 118b may be of the type 82a and 82b shown in FIG. 13.

[0076] FIG. 23 shows another example of a CWG filter unit 122 having dual mode blocks 124a and 124b coupled by a coupling section 126. The dual mode blocks 124a and 124b each have an angle cut 128. Compare the CWG filter unit 122, which couples energy between the dual mode blocks 124a, 124b via a z-directed mode (which may be called a vertical mode) to the CWG filter unit 80 of FIG. 13, which couplesenergy between the dual mode blocks 82a and 82b via a y-directed mode (which may be called a horizontal mode). FIG. 24 is an example CWG filter unit 130 that is similar to the CWG filter unit 122, except for the step cut 134 in the dual mode blocks 132a, 132b of the CWG filter unit 130. FIG. 25 is an example CWG filter unit 136 that is similar to the CWG filter unit 122, except for the blind via 140 in the dual mode blocks 138a, 138b of the CWG filter unit 136.

[0077] FIGs. 26 and 27 are perspective and side views, respectively of an example CWG filter 142 being constructed with CWG filter units 144 and 146. CWG filter unit 144 is constructed from dual mode blocks 148a-148f. In the example of FIGs. 26 and 27, the dual mode blocks 148a and 148 may be like the dual mode blocks 82a and 82b shown in FIG. 13. Dual mode block 148a is coupled to the I / O port 150a and dual mode block 148f is coupled to the VO port 150b. The dual mode blocks 148c and 148d may be coupled by a coupling section 152, which may be similar to the coupling section 126 shown in FIG. 23.

[0078] FIGs. 28 and 29 are perspective and side views, respectively, of an example CWG filter 154 being constructed with the dual mode blocks 118a, 118b and single mode blocks 120a, 120b (see FIGs. 21 and 22) to form first and second CWG filter unit 156, 158. The CWG filter 154 also includes dual mode blocks 148b and 148c to form the second CWG filter unit 146 (see FIG. 29).

[0079] FIGs. 30 and 31 are perspective and top views, respectively of an example CWG filter structure 160 constructed according to principles disclosed above with the added feature of support bars 162 between dual mode blocks and / or between CWG filter units 164a and 164b that are coupled by a coupling section 166. The support bars 162 may preferably be of the same ceramic and from the same mold as the remainder of the CWG filter structure 160. The support bars 162 may be provided to increase mechanical strength and reliability of a CWG filter designed and manufactured according to principles disclosed herein. One example of the filter structure 160 is provided with reference to the filter unit shown in FIG. 22. With reference to FIG. 22, filter structure 160 may include the dual mode blocks 109a, 109b to form CWG filter sections 164a and includes the dual mode blocks 109c and 109d to form CWG filter sections 164b, with the addition of the support bars 162 between dual mode blocks 109c and 109d. Then entire structure of FIG. 32 can be formed in one ceramic injection molding or dry-pressprocess. Note that in some embodiments, the size and position of the support bars 162 may be selected to minimize impact on filter performance or to alter filter performance.

[0080] Note that a variety of CWG filter configurations can be constructed with various combinations of the CWG filter units disclosed herein, and the principles disclosed herein extend to these various combinations.

[0081] Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments can be combined in any way and / or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination.

[0082] Abbreviations that may be used in the preceding description include:Abbreviation ExplanationCWG Ceramics WaveguideCIM Ceramics Injection MoldingDM Dual ModeSM Single ModeTE Transverse electric

[0083] It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings.

Claims

ClaimsWhat is claimed is:

1. A ceramic waveguide, CWG, filter, the CWG filter comprising: a first dual mode block; a second dual mode block, each of the first and second dual mode blocks having a mode coupling structure configured to couple electromagnetic energy between a first mode associated with a first electric field direction and a second mode associated with a second electric field direction, the second electric field direction being orthogonal to the first electric field direction; a first coupling section between the first and second dual mode blocks, the first coupling section being configured to couple electromagnetic energy of the second mode between the first and second dual mode blocks via first aligned windows in parallel facing walls of the first and second dual mode blocks; and the first and second dual mode blocks being in communication through the first aligned windows and the first coupling section, the CWG filter being formed as a unit at least in part by ceramic injection molding or dry-pressing to fill a cavity formed by walls of the first and second dual mode blocks and the first coupling section.

2. The CWG filter of Claim 1, wherein the first electric field direction is parallel to the parallel facing walls.

3. The CWG filter any of Claims 1 and 2, wherein the second electric field direction is parallel to the parallel facing walls.

4. The CWG filter of any of Claims 1 and 2, wherein the second electric field direction is orthogonal to the parallel facing walls.

5. The CWG filter of any of Claims 1 and 2, wherein each of a first wall and a second wall of at least one of the first and second dual mode blocks includes a tuning formation, each tuning formation being configured to tune a frequency response of a different one of the first and second modes.

6. The CWG filter of any of Claims 1 and 2, wherein a mode coupling structure of at least one of the first and second dual mode blocks includes a first wall of the dual mode block at an acute angle with respect to a second wall of the dual mode block.

7. The CWG filter of Claim 6, wherein the first wall lies in a plane that is orthogonal to the parallel facing walls.

8. The CWG filter of any of Claims 1 and 2, wherein a mode coupling structure of at least one of the first and second dual mode blocks further includes an inward step cut.

9. The CWG filter of Claim 8, wherein the inward step cut is one of orthogonal to the parallel facing walls and parallel to the parallel facing walls.

10. The CWG filter of any of Claims 1 and 2, wherein a mode coupling structure of at least one of the first and second dual mode blocks further includes a blind via.

11. The CWG of Claim 10, wherein the blind via is a cylinder having an axis that is one of orthogonal to the parallel facing walls and parallel to the parallel facing walls..

12. The CWG filter of any one of Claims 1-11, wherein the first aligned windows include windows situated in comers of the parallel facing walls.

13. The CWG filter of any one of Claims 1-12, further comprising an input / output, I / O, port in at least one of the first and second dual mode blocks, an I / O port being configured to couple electromagnetic energy of the first mode between an exterior and an interior of a dual mode block that includes the I / O port.

14. The CWG of any one of Claims 1-13, further comprising a sequence of at least one single mode block followed by an additional coupling section, the sequence being interposed between the first coupling section and the second dual mode block.

15. The CWG of any one of Claim 1-14, wherein the second dual mode block is coupled to a third dual mode block through a second coupling section.

16. A ceramic waveguide, CWG, filter, the CWG filter comprising: a plurality of CWG filter units electromagnetically coupled via one or more first coupling sections through first aligned windows in first parallel facing walls of adjacent CWG filter units, each CWG filter unit comprising a pair of dual mode blocks electromagnetically coupled by a second coupling section through second aligned windows in second parallel facing walls of the pair of dual mode blocks, each CWG filter unit being formed by ceramic injection molding or dry-pressing to fill a first cavity formed by walls of the pair of dual mode blocks and the second coupling section.

17. The CWG filter of Claim 16, wherein the plurality of CWG filter units are formed together by ceramic injection molding or dry-pressing to fill a second cavity formed by walls of each dual mode block of each CWG filter unit and by walls of first and second coupling sections.

18. The CWG filter of any of Claims 16 and 17, wherein each dual mode block of the plurality of CWG filter units includes a mode coupling structure configured to couple electromagnetic energy between a first mode associated with a first modal direction and a second mode associated with a second modal direction, the first and second modal directions being orthogonal.

19. The CWG filter of Claim 18, wherein a first set of first coupling sections are configured to couple electromagnetic energy of the first mode between adjacent CWG filter units, and a second set of second coupling sections are configured to couple electromagnetic energy of the second mode between adjacent dual mode blocks of a CWG filter unit.

20. The CWG filter of any of Claims 18-19, wherein a first dual mode block of a first CWG filter unit of the plurality of CWG filter units includes a first input / output, I / O, port and a second dual mode block of a second CWG filter unit of the plurality of CWG filter units includes a second I / O port, each of the first and second I / O ports being configured to couple electromagnetic energy of one of the first mode and the second mode, into or out of the CWG filter.

21. The CWG filter of any one of Claims 18-20, wherein one second coupling section of a first CWG filter unit of the plurality of CWG filter units couples electromagnetic energy of the first mode between first dual mode blocks of the first CWG filter, and another second coupling section of a second CWG filter unit of the CWG filter units couples electromagnetic energy of the second mode between second dual mode blocks of the second CWG filter unit.

22. The CWG filter of any one of Claims 16-21, wherein a first coupling section between two adjacent CWG filter units includes at least one single mode block.

23. The CWG filter of any one of Claims 16-22, wherein a second coupling section between two dual mode blocks of a CWG filter unit includes at least one single mode block.

24. The CWG filter of any one of Claims 16-23, wherein first parallel facing walls of two adjacent CWG filter units are orthogonal to second parallel facing walls of a pair of dual mode blocks of one of the two adjacent CWG filter units.

25. The CWG filter of any one of Claims 16-24, wherein a first CWG filter unit of the plurality of CWG filter units shares a dual mode block with a second CWG filter unit of the plurality of CWG filter units.

26. The CWG filter of any one of Claims 16-25, further comprising support bars between CWG filter units of the plurality of CWG filter units.

Images