RF dielectric filter with surface mount RF signal input / output structure

Abstract

An RF dielectric filter comprises: a block of dielectric material including top and bottom outer longitudinal surfaces and side outer surfaces covered with a layer of conductive material. RF signal input / output pads are located at opposite ends of the block. Each of the RF signal input / output pads includes a strip of conductive material bridging between the bottom outer surface and the side outer surface. The strip or region of dielectric material surrounds all sides of the elongated strip of conductive material, except for one end of the strip of conductive material on the side outer surface which is in direct integral coupling relationship with the remainder of the conductive material on the side outer surface. In one embodiment, the strip or region of dielectric material is generally U-shaped and can vary in width.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to and the benefit of U.S. Provisional Patent Application Serial No. 63 / 126,785, filed on December 17, 2020, the disclosure and contents of which are expressly incorporated herein by reference in their entirety. Technical Field

[0003] The present invention relates generally to RF dielectric filters, and more particularly to surface mount RF signal input / output structures for RF dielectric filters, and even more particularly to surface mount RF signal input / output structures for RF dielectric waveguide filters. Background Art

[0004] Various types of RF filters are used to filter RF signals.

[0005] Ceramic monolithic filters are low cost, small size and easy to manufacture. However, they have relatively high insertion loss, slow roll-off and low power handling capability.

[0006] Air cavity filters have low loss, fast roll-off, few spurious signals, and high rejection. However, they are usually large, bulky, and relatively expensive. Although air cavity filters can be made smaller, performance degrades significantly as size decreases.

[0007] Dielectric waveguide filters have good insertion loss, fast roll-off, high rejection and are relatively small.

[0008] The present invention relates to an RF dielectric filter, and more particularly, to an RF dielectric waveguide filter having a novel surface mounted RF signal input / output structure. Summary of the invention

[0009] The present invention generally relates to an RF dielectric filter comprising: a block of dielectric material comprising a plurality of outer surfaces including top and bottom outer longitudinal surfaces, opposite side outer longitudinal surfaces, and opposite outer end surfaces; at least a first RF signal input / output pad extending between the bottom outer surface and one of the opposite side outer longitudinal surfaces or one of the opposite outer end surfaces; wherein at least the first RF signal input / output pad comprises: an elongated conductive material strip extending between the bottom outer surface and one of the opposite side outer longitudinal surfaces or one of the opposite outer end surfaces; and a dielectric material strip or region surrounding all sides of the elongated conductive material strip except for one side of the elongated conductive material strip located on one of the opposite side outer longitudinal surfaces or one of the opposite outer end surfaces.

[0010] In one embodiment, the strip or region of dielectric material is generally U-shaped and surrounds all sides of the strip of elongated conductive material except for the top side of the strip of elongated conductive material on one of the opposing side outer longitudinal surfaces or one of the opposing outer end surfaces.

[0011] In one embodiment, the opposing portion of the strip or region of dielectric material located on one of the opposing side outer longitudinal surfaces or one of the opposing outer end surfaces has a different width than the remaining portion of the strip or region of dielectric material.

[0012] In one embodiment, the opposing portion of the strip or region of dielectric material located on one of the opposing side outer longitudinal surfaces or one of the opposing outer end surfaces has a width greater than the width of the remaining portion of the strip or region of dielectric material.

[0013] In one embodiment, the second RF signal input / output pad extends between the bottom outer surface and one of the opposite side outer longitudinal surfaces or the other of the opposite outer end surfaces.

[0014] In one embodiment, the second RF signal input / output pad includes: an elongated conductive material strip extending between the bottom outer surface and one of the opposite side outer longitudinal surfaces or the other of the opposite outer end surfaces; and a dielectric material strip or area surrounding all sides of the elongated conductive material strip except for one side of the elongated conductive material strip located on one of the opposite side outer longitudinal surfaces or the other of the opposite outer end surfaces.

[0015] In one embodiment, the block of dielectric material defines a longitudinal axis, and the first and second RF signal input / output pads are disposed at opposite ends of the block in diametrically opposed relation and further disposed in co-linear relation with the longitudinal axis of the block of dielectric material.

[0016] In one embodiment, the block of dielectric material defines a longitudinal axis, and the first and second RF signal input / output pads are disposed at opposite ends of the block in diametrically opposed relation and further disposed in spaced and offset relation to the longitudinal axis of the block of dielectric material.

[0017] In one embodiment, the block of dielectric material defines a plurality of resonators.

[0018] In one embodiment, the block of dielectric material defines a plurality of direct RF signal couplings between the plurality of resonators.

[0019] In one embodiment, the block includes a plurality of slots defined in the block of dielectric material and defining a plurality of dielectric material bridges, the plurality of bridges defining a plurality of direct RF signal couplings between the plurality of resonators.

[0020] The present invention also relates to an RF dielectric filter comprising: a block of dielectric material including top and bottom outer longitudinal surfaces and side outer surfaces covered with a layer of conductive material; first and second RF signal input / output pads located at opposite ends of the block; each of the RF signal input / output pads comprising a strip of conductive material bridged between the bottom outer surface and the side outer surface; and a strip or region of dielectric material surrounding all sides of the elongated strip of conductive material except for one end of the strip of conductive material on the side outer surface which is in direct integral coupling relationship with the remainder of the conductive material on the side outer surface.

[0021] In one embodiment, an RF dielectric waveguide filter comprises: a block of dielectric material including a plurality of outer surfaces including top and bottom outer longitudinal surfaces, opposite side outer longitudinal surfaces, and opposite outer end surfaces; and first and second RF signal input / output pads extending between the bottom outer surface and one of the opposite side outer longitudinal surfaces or one of the opposite outer end surfaces; wherein each of the first and second RF signal input / output pads comprises: an elongated conductive material strip extending between the bottom outer surface and one of the opposite side outer longitudinal surfaces or one of the opposite outer end surfaces; and a generally U-shaped dielectric material strip or region surrounding all sides of the elongated conductive material strip except for one side of the elongated conductive material strip located on one of the opposite side outer longitudinal surfaces or one of the opposite outer end surfaces; wherein an opposite portion of the generally U-shaped dielectric material strip or region located on one of the opposite side outer longitudinal surfaces or one of the opposite outer end surfaces has a different width than a remaining portion of the dielectric material strip or region.

[0022] In one embodiment, the dielectric RF filter further includes a plurality of resonators defined on the dielectric material block between the first and second RF signal input / output pads; and a plurality of slots defined in the dielectric material block and defining a plurality of dielectric material bridges, the plurality of bridges defining a plurality of direct RF signal couplings between the plurality of resonators.

[0023] The present invention further relates to an RF dielectric filter, which includes a block of dielectric material, which includes multiple outer surfaces, including top and bottom outer longitudinal surfaces and an outer side surface; a conductive material layer, which covers the multiple outer surfaces of the dielectric material block; first and second RF signal input / output pads, which bridge the bottom outer surface and the outer side surface of the dielectric material block; wherein each of the first and second RF signal input / output pads includes: a slender conductive material strip, which bridges the bottom outer surface and the outer side surface and includes an end portion integral with the conductive material layer on the outer side surface; and a dielectric material strip or area surrounding the slender conductive material strip, except for the end portion of the slender conductive material strip on the outer side surface that is integral with the conductive material layer on the outer side surface.

[0024] In one embodiment, the strip or region of dielectric material is generally U-shaped.

[0025] In one embodiment, the strip or region of dielectric material on the side outer surface has a different width than the rest of the strip or region of dielectric material.

[0026] In one embodiment, the dielectric material block includes opposite ends and opposite end side outer surfaces, and the first and second RF signal input / output pads are located at the opposite ends of the dielectric material block, and the first and second RF signal input / output pads each include: a slender conductive material strip that bridges the corresponding outer surface of the bottom outer surface and the outer surface of the opposite end and includes an end that is integral with the conductive material layer on the outer end side surface corresponding to the opposite outer end side surface; and a dielectric material strip or area surrounding the slender conductive material strip, except for the end of the slender conductive material strip on the outer end side surface corresponding to the opposite outer end side surface that is integral with the conductive material layer on the outer end side surface corresponding to the opposite outer end side surface.

[0027] In one embodiment, the dielectric material block includes opposite ends and a first outer longitudinal side surface, the first and second RF signal input / output pads are located at the opposite ends and bridged between the bottom outer surface and the first outer longitudinal side surface, and each of the first and second RF signal input / output pads includes: a slender conductive material strip that bridges between the bottom outer surface and the first outer longitudinal side surface and includes an end that is integral with the conductive material layer on the first outer longitudinal side surface, and a dielectric material strip or region surrounding the slender conductive material strip, except for the end of the slender conductive material strip on the first outer longitudinal side surface.

[0028] In one embodiment, a block of dielectric material defines a plurality of resonators, the block of dielectric material defining a plurality of direct RF signal couplings between the plurality of resonators.

[0029] Other advantages and features of the present invention will become more apparent from the following detailed description of the preferred embodiments of the invention, the accompanying drawings and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] These and other features of the present invention may be best understood through the following description of the accompanying drawings, as follows:

[0031] Figure 1 is a top perspective view of an RF dielectric waveguide filter according to the present invention;

[0032] Figure 2 yes Figure 1 A bottom perspective view of the RF dielectric waveguide filter shown in;

[0033] Figure 3 is a depiction of the surface of the printed circuit board mounted on Figure 1 and Figure 2 A perspective view of an RF dielectric waveguide filter;

[0034] Figure 4 yes Figure 1 and Figure 2 A bottom plan view of the RF dielectric waveguide filter shown in;

[0035] Figure 5 yes Figure 1 and Figure 2 Performance curve of RF dielectric waveguide filter;

[0036] Figure 6 is to describe the response to Figure 1 and Figure 2 a graph of the increase in parasitic suppression with adjustment of the resonator width / length ratio of an RF dielectric waveguide filter; and

[0037] Figure 7 is a bottom perspective view of another embodiment of an RF dielectric waveguide filter according to the present invention. DETAILED DESCRIPTION

[0038] Figure 1-4 An RF dielectric filter 100 according to the present invention, and more particularly an RF dielectric filter in an embodiment of an RF dielectric waveguide filter 100 suitable for use, for example, in massive MIMO millimeter wave 5G telecommunication applications, is depicted, which is made of a substantially parallelepiped-shaped solid block or core 101 of dielectric / ceramic material, which includes relative longitudinal horizontal outer top / upper and bottom / lower surfaces 102 and 104, relative longitudinal side vertical outer surfaces 106 and 108, which are arranged in a relationship that is perpendicular to and extends from the horizontal outer top and bottom surfaces 102 and 104, and relative lateral end side vertical outer end surfaces 110 and 112, which are arranged in a relationship that is substantially perpendicular to the longitudinal horizontal outer surfaces 102 and 104 and the longitudinal vertical outer surfaces 106 and 108 and extend therebetween.

[0039] Thus, in the illustrated embodiment, each of the outer surfaces 102 , 104 , 106 and 108 extends in the same direction as the longitudinal axis L1 of the filter 100 and each of the outer end surfaces 110 and 112 extends in a direction transverse or perpendicular to the longitudinal axis L1 of the filter 100 .

[0040] The filter 100 includes a plurality of resonant portions or regions 120 , 122 , 124 , 126 , 128 and 129 extending in spaced-apart and generally parallel relation relative to one another along the length of the block 101 of the filter 100 , and further extending in a relation generally transverse to the longitudinal axis L1 of the filter 100 .

[0041] The plurality of resonant portions 120, 122, 124, 126, 128 and 129 are separated from one another by a plurality of slots or grooves 130, 132, 134, 136 and 138 extending in spaced parallel relation along the length of the block 101 and into the dielectric material of the block 101. In the illustrated embodiment, each of the respective slots or grooves 130, 132, 134, 136 and 138 extends vertically through the body of the block 101 and terminates in an elongated opening in the top and bottom outer surfaces 102 and 104 and the side outer vertical surface 106 of the block 101 of the filter 100. Furthermore, in the illustrated embodiment, each of the slots or grooves 130, 132, 134, 136 and 138 extends inwardly from the outer longitudinal surface 106 into the body of the block 101 and terminates at a point short of the opposing outer longitudinal surface 108.

[0042] In the illustrated embodiment, slots 130, 132, 134, 136, and 138 are elongated and generally rectangular. Although not shown in any figure, it should be understood that slots 130, 132, 134, 136, and 138 can be any other suitable shape or configuration, including, for example, one or more closed circular openings or slots defined in the interior of block 101.

[0043] In the illustrated embodiment, the slits or slots 130, 132, 134, 136 and 138 extend in a relationship that is generally transverse or perpendicular to and intersecting the longitudinal axis L1 of the filter 100, wherein the slit or slot 130 separates the resonating portions 120 and 122, the slit or slot 132 separates the resonating portions 122 and 124, the slit or slot 134 separates the resonating portions 124 and 126, the slit or slot 136 separates the resonating portions 126 and 128, and the slit or slot 138 separates the resonating portions 128 and 129.

[0044] Each of the slits or slots 130, 132, 134, 136 and 138 defines a respective bridge 131, 133, 135, 137 and 139 of dielectric material in the body of the block 101, which defines a respective inductive direct transmission RF signal transmission path D1, D2, D3, D4 and D5 between the respective resonant portions 120, 122, 124, 126, 128 and 129.

[0045] In the illustrated embodiment, all exterior surfaces 102, 104, 106, 108, 110 and 112 of block 101, including the interior surfaces of respective slots / grooves 130, 132, 134 and 136, are covered with a layer of suitable conductive / metallic material, such as a layer of silver material, except for the exterior surface portions defining the respective input / output pads 200 and 202, as described in more detail below.

[0046] The filter 100 , and more specifically the block 101 thereof, further defines and includes a pair of external RF signal transmission input / output pads 200 and 202 .

[0047] exist Figure 1 and Figure 2 In the embodiment of FIG. 1 , RF signal transmission input / output pads 200 and 202 are located at respective opposite ends of block 101, and more specifically, at respective end resonators 120 and 129. Figure 1 and Figure 2 In the embodiment of the present invention, pads 200 and 202 are arranged in a diametrically opposed and co-linear relationship relative to each other, and are further arranged in a co-linear relationship with the longitudinal axis L1 of the block 101, and more specifically, are arranged between, spaced apart from and parallel to the opposing side outer surfaces 106 and 108.

[0048] The pad 200 consists of an elongated, generally rectangular strip or region 210 of conductive material formed on the outer lower horizontal surface 104 of the block 101, extending and bridging the corner defined between the lower horizontal surface 104 and the side outer lateral end surface 110, terminating on and extending to the conductive material formed on the side outer lateral end surface 110, being integral with the conductive material, and being in direct electrical coupling or coupling relationship with the conductive material.

[0049] In the illustrated embodiment, the strip or region of conductive material 210 is not an isolated island of conductive material, but rather is a strip or region of conductive material that is surrounded by less than all of its sides, and in the illustrated embodiment, is surrounded on only three of its four sides by a generally U-shaped strip or region 220 on the outer surface of the block 101 that is devoid of conductive material (i.e., a generally U-shaped strip or region of exposed dielectric material 220 of the block 101 surrounding all sides of the strip of conductive material 210, except for the top side or end of the strip of conductive material 210 on the side outer surface 110 of the block 101, which is integral with and extends into and is in electrical coupling or coupling relationship with the remainder of the conductive material on the side outer surface 110, and is thereby in direct electrical coupling or coupling relationship with the circuitry of the filter 100).

[0050] More specifically, the strips or regions 220 are comprised of a first region or strip 220a on the lower outer block surface 104 surrounding a portion of the conductive material strip 210 formed on the lower outer horizontal surface 104 of the block 101, and corresponding second regions or strips 220b and 220c of dielectric material extending integrally from opposite ends of the first region or strip 220a of dielectric material on the lower outer block surface 104, formed on the side outer vertical end surface 110, and located on opposite sides of the portion of the conductive material strip 210 formed on the side outer vertical end block surface 110.

[0051] In a manner similar to the RF signal input / output pad 200, the RF signal input / output pad 202 at the opposite end of the block 101 is composed of an elongated rectangular strip or area 210 of conductive material formed on the outer lower horizontal surface 104 of the block 101, extending around and bridging the corner defined between the lower horizontal surface 104 and the side outer lateral end surface 112, and terminating on and extending into the conductive material formed on the side outer lateral end surface 112 and being in direct integral coupling or coupling relationship with the conductive material.

[0052] In the illustrated embodiment, the strip or region of conductive material 210 is surrounded on three sides by a generally U-shaped strip or region 220 on the outer surface of the block 101 that is devoid of conductive material (i.e., a generally U-shaped strip or region of exposed dielectric material of the block 101 that surrounds all sides of the strip of conductive material 210, except for the top side or end of the strip of conductive material 210 on the side outer surface 112 of the block 101, which top side or end of the strip of conductive material 210 is integral with and extends into and is in direct electrical coupling or coupling relationship with the remainder of the conductive material on the side outer surface 112, and is therefore in direct electrical coupling or coupling relationship with the circuitry of the filter 100).

[0053] More specifically, the strip or region 220 is comprised of a first region or strip 220a on the lower outer block surface 104 surrounding a portion of the conductive material strip 210 formed on the lower outer horizontal surface 104 of the block 101, and corresponding second regions or strips 220b and 220c of dielectric material extending integrally from opposite ends of the first region or strip 220a of dielectric material on the lower outer block surface 104, formed on the side outer vertical end surface 112, and located on opposite sides of the portion of the conductive material strip 210 formed on the side outer vertical end block surface 112.

[0054] In the filter embodiment 100 , each of the second regions or strips 220 b and 220 c of the respective dielectric material of each of the respective RF signal input / output pads 200 and 202 has a width greater than the width of the first region or strip 220 a of the dielectric material located at the bottom outer surface 104 .

[0055] According to the present invention, in the filter embodiment 100, the length and / or width of the dielectric material strips or regions 220 (including, for example, the length and / or width of the corresponding second regions or strips 220b and 220c of the dielectric material strips 220 and / or the length and / or width of the conductive material strips 210 of each RF signal input / output pad of the corresponding RF signal input / output pads 200 and 202) and more specifically the length and / or width of the portions or ends of the conductive material strips on the corresponding block outer end surfaces 110 and 112 can be adjusted to allow adjustment of the RF signal input / output coupling to the external circuit, for example, including reduction of the insertion loss of the filter 100.

[0056] The filter 100 is suitable for surface mounting on the top outer surface 302 of the mother printed circuit board 300, such as Figure 3 . In the illustrated embodiment, the top outer surface 302 of the mother printed circuit board 300 includes a generally centrally located elongated conductive material strip 304 formed thereon. The filter 100 is located on the top outer surface 302 of the mother printed circuit board 300 in the following relationship: the portions of the corresponding conductive material strips 210 of the corresponding RF signal input / output pads 200 and 202 of the filter 100 located on the bottom outer surface 104 sit on and contact the conductive material strips 304 formed on the top outer surface 302 of the mother printed circuit board 300.

[0057] Figure 4 The path of the RF signal from the RF signal input / output pad 200 through the block 101 of the filter 100, through each of the corresponding resonators 120, 122, 124, 126, 128 and 129, and out through the RF signal input / output pad 202 is depicted.

[0058] Figure 5 and Figure 6 is a graph depicting the performance of the filter 100 of the present invention, wherein Figure 6 The performance of filter 100 is depicted in response to the RF input / output coupling adjustments described in more detail above.

[0059] Figure 7 Another embodiment of a filter 1000 according to the present invention is depicted, wherein respective RF signal input / output pads 200 and 202 of the filter 100 are located on respective end resonators 120 and 129 of the block 101 of the filter 100 in an orientation in which the respective signal input / output pads 200 and 202 extend and bridge between the bottom outer horizontal block surface 104 and the side outer vertical longitudinal block surface 106, rather than as in FIG. Figure 1 and Figure 2The filter embodiment 100 of the present invention bridges the bottom outer horizontal block surface 104 and the side outer vertical lateral end block surfaces 110 and 112.

[0060] Figure 7 The RF signal input / output pads 200 and 202 in the filter embodiment 1000 are otherwise identical in structure to the RF signal input / output pads 200 and 202 of the filter embodiment 100, and thus the previous description and elements of the RF signal input / output pads 200 and 202 of the filter embodiment 100 are incorporated herein by reference with respect to the filter embodiment 1000.

[0061] More specifically, in Figure 7 In the embodiment of FIG. 1 , the RF signal input / output pads 200 and 202 are disposed in a diametrically opposed and co-linear relationship with respect to each other, and are further disposed in a spaced-apart and offset relationship with respect to the longitudinal axis L1 of the block 101 .

[0062] More specifically, the RF signal input / output pad 200 on the filter 1000 is formed on the end resonator 120 and is composed of an elongated, generally rectangular conductive material strip or area 210, which is formed on the outer lower horizontal surface 104 of the block 101, extends around and bridges the corner defined between the lower horizontal surface 104 and the side outer vertical longitudinal surface 106, and terminates on and extends into the conductive material formed on the side outer vertical longitudinal surface 106, and is integral with and in direct electrical coupling relationship with the conductive material.

[0063] In the illustrated embodiment, the strip or area of ​​conductive material 210 is surrounded on three sides by a generally U-shaped strip or area 220 on the outer surface of the block 101 that is devoid of conductive material (i.e., a generally U-shaped strip or area of ​​exposed dielectric material 220 of the block 101 that surrounds all sides of the strip of conductive material 210, except for the top side or end of the strip of conductive material 210 on the side outer vertical longitudinal surface 106 of the block 101, which is integral with and in direct electrical coupling or coupling relationship with the remainder of the conductive material on the outer surface 106, and thereby in direct electrical coupling or coupling relationship with the block circuitry).

[0064] More specifically, the strip or region 220 consists of a first region or strip 220a on the lower outer block surface 104, which surrounds the portion of the conductive material strip 210 formed on the lower outer horizontal surface 104 of the block 101, and corresponding second regions or strips 220b and 220c of dielectric material that extend integrally from opposite ends of the first region or strip 220a of dielectric material on the lower outer block surface 104, are formed on the side outer vertical longitudinal surface 106, and are located on opposite sides of the portion of the conductive material strip 210 formed on the side outer vertical longitudinal block surface 106.

[0065] In a manner similar to the RF signal input / output pad 200, the RF signal input / output pad 202 on the filter 1000 is formed on the opposite end resonator 129 and is composed of an elongated strip or region of conductive material 210 formed on the outer lower horizontal surface 104 of the block 101, extending around the corner defined between the lower horizontal surface 104 and the side outer vertical longitudinal surface 106, and terminating on and extending into the conductive material formed on the side outer vertical longitudinal surface 106 and being integral with the conductive material.

[0066] In the illustrated embodiment, the strip or region of conductive material 210 is surrounded on three sides by a generally U-shaped strip or region 220 on the outer surface of the block 101 that is devoid of conductive material (i.e., a generally U-shaped strip or region of exposed dielectric material of the block 101 that surrounds all sides of the strip of conductive material 210, except for the top side or end of the strip of conductive material 210 on the side outer vertical longitudinal surface 106 of the block 101, which is integral with and in direct electrical coupling or coupling relationship with the remainder of the conductive material of the side outer surface 106, and is therefore in direct electrical coupling or coupling relationship with the remainder of the filter circuit).

[0067] More specifically, the strip or region 220 consists of a first region or strip 220a on the lower outer block surface 104, which surrounds the portion of the conductive material strip 210 formed on the lower outer horizontal surface 104 of the block 101, and corresponding second regions or strips 220b and 220c of dielectric material that extend integrally from opposite ends of the first region or strip 220a of dielectric material on the lower outer block surface 104, are formed on the side outer vertical longitudinal surface 106, and are located on opposite sides of the portion of the conductive material strip 210 formed on the side outer vertical longitudinal block surface 106.

[0068] In the filter embodiment 1000 , each of the second regions or strips 220 b and 220 c of the respective dielectric material of each of the respective RF signal input / output pads 200 and 202 has a width greater than the width of the first region or strip 220 a of the dielectric material on the bottom outer surface 104 .

[0069] According to the present invention, in the filter embodiment 1000, the length and / or width of the dielectric material strip or region 220 (including, for example, the length and / or width of the corresponding second regions or strips 220b and 220c of the dielectric material strip 220 and the length and / or width of the conductive material strip 210 of each RF signal input / output pad 200 and 202) and the length and / or width of the portion or end of the conductive material strip 210 located on the block side surface 106, in particular, can be adjusted to allow adjustment of the RF signal input / output coupling to the external circuit, including, for example, reduction of the insertion loss of the filter 1000.

[0070] Furthermore, in both filter embodiments 100 and 1000, the second harmonic frequency can be adjusted by adjusting the width and / or length of the respective resonators 120 and 129 including the respective input / output pads 200 and 202 while keeping the fundamental frequency the same, and the same second harmonic resonance becomes a transmission zero due to the coupling paths and connections of the respective input / output pads 200 and 202 on the respective block side surfaces 110, 112, and 106.

[0071] Although the present invention has been specifically taught with reference to the illustrated embodiments, it is to be understood that those skilled in the art will recognize that changes in form and detail may be made without departing from the spirit and scope of the present invention. The described embodiments are to be considered in all respects as illustrative only and not restrictive.

[0072] For example, it should be understood that the corresponding RF signal input / output pads 200 and 202 can be positioned and oriented on the bottom horizontal longitudinal outer surface 104 of the corresponding filter embodiments 100 and 1000 in a relationship and orientation similar to the filter embodiment 1000, except that the RF signal input / output pads 200 and 202 extend between the bottom horizontal longitudinal outer surface 104 and the opposite side vertical longitudinal outer surface 108.

[0073] It should further be understood that the present invention encompasses any one or more of several different embodiments in which the respective RF signal input / output pads 200 and 202 extend or bridge between the bottom horizontal longitudinal outer surface and one of the outer side surfaces 106, 108, 110 or 112, depending on the particular or desired direct PCB mounting application.

Claims

1. An RF dielectric filter, comprising: a block of dielectric material comprising a plurality of exterior surfaces including top and bottom exterior longitudinal surfaces, opposing side exterior longitudinal surfaces, and opposing exterior end surfaces; at least a first RF signal input / output pad extending between said bottom outer longitudinal surface and one of said opposing side outer longitudinal surfaces or one of said opposing outer end surfaces; Wherein, the at least first RF signal input / output pad comprises: an elongated strip of conductive material extending between said bottom outer longitudinal surface and one of said opposing side outer longitudinal surfaces or one of said opposing outer end surfaces; and a generally U-shaped strip of dielectric material surrounding all sides of the elongated strip of conductive material except for a top side of the elongated strip of conductive material located on one of the opposed side outer longitudinal surfaces or one of the opposed outer end surfaces; and Wherein, the width of each opposing portion of the dielectric material strip located on one of the opposing side outer longitudinal surfaces or one of the opposing outer end surfaces is greater than the width of the dielectric material strip located on the bottom outer longitudinal surface and extending to the opposing portion.

2. The RF dielectric filter according to claim 1, further comprising a second RF signal input / output pad extending between the bottom outer longitudinal surface and one of the opposite side outer longitudinal surfaces or the other of the opposite outer end surfaces.

3. The RF dielectric filter according to claim 2, wherein: The second RF signal input / output pad comprises: an elongated strip of conductive material extending between said bottom outer longitudinal surface and one of said opposing side outer longitudinal surfaces or the other of said opposing outer end surfaces; and A strip of dielectric material surrounds all sides of the elongated strip of conductive material except one side of the elongated strip of conductive material located on the other of one of the opposed side outer longitudinal surfaces or the opposed outer end surfaces.

4. The RF dielectric filter according to claim 2, wherein: The block of dielectric material defines a longitudinal axis, the first and second RF signal input / output pads being disposed at opposite ends of the block in diametrically opposed relation and further disposed in a co-linear relation with the longitudinal axis of the block of dielectric material.

5. The RF dielectric filter according to claim 2, wherein: The block of dielectric material defines a longitudinal axis, and the first and second RF signal input / output pads are disposed at opposite ends of the block in diametrically opposed relation and further disposed in spaced and offset relation to the longitudinal axis of the block of dielectric material.

6. The RF dielectric filter according to claim 1, wherein: The block of dielectric material defines a plurality of resonators.

7. The RF dielectric filter according to claim 6, wherein: The block of dielectric material defines a plurality of direct RF signal couplings between the plurality of resonators.

8. The RF dielectric filter according to claim 7, wherein: The block includes a plurality of slots defined in the block of dielectric material and defining a plurality of dielectric material bridges, the plurality of dielectric material bridges defining the plurality of direct RF signal couplings between the plurality of resonators.

9. The RF dielectric filter according to claim 1, wherein: The block of dielectric material defines a plurality of resonators, the block of dielectric material defining a plurality of direct RF signal couplings between the plurality of resonators.

10. The RF dielectric filter according to claim 1, wherein: The width of each of the opposing portions of the dielectric material strip at an edge of one of the opposing side outer longitudinal surfaces or one of the opposing outer end surfaces is greater than the width of the dielectric material strip at an edge of the bottom outer longitudinal surface.

11. The RF dielectric filter according to claim 10, wherein: The opposing portions of the dielectric material strip have a rectangular shape on one of the opposing side outer longitudinal surfaces or one of the opposing outer end surfaces.

12. An RF dielectric filter comprising: a block of dielectric material including top and bottom outer longitudinal surfaces, opposing outer end surfaces, and opposing side outer surfaces covered with a layer of conductive material; a first RF signal input / output pad and a second RF signal input / output pad located at opposite ends of the block; Each of said RF signal input / output pads comprises a strip of conductive material bridging between said bottom outer longitudinal surface and a corresponding said outer end surface; and a strip of dielectric material surrounding said strip of conductive material on all sides except for an end of said strip of conductive material on said outer end surface in direct integrally coupled relationship with the remainder of said conductive material on said outer end surface; wherein each opposing portion of the dielectric material strip at the opposing outer end surfaces has a width greater than a width of the dielectric material strip at the bottom outer longitudinal surface extending to the opposing portion.

13. The RF dielectric filter of claim 12, further comprising: a plurality of resonators defined on the block of dielectric material between the first RF signal input / output pad and the second RF signal input / output pad; as well as A plurality of slots are defined in the block of dielectric material and define a plurality of bridges of dielectric material, the plurality of bridges of dielectric material defining a plurality of direct RF signal couplings between the plurality of resonators.

14. The RF dielectric filter according to claim 12, wherein: The width of each opposing portion of the strip of dielectric material at the outer end surface edge is greater than the width of the strip of dielectric material at the bottom outer longitudinal surface edge extending to the opposing portion.

15. The RF dielectric filter according to claim 14, wherein: The opposing portions of the strip of dielectric material have a rectangular shape at the outer end surface.

16. An RF dielectric filter comprising: a block of dielectric material comprising a plurality of exterior surfaces including a top exterior longitudinal surface and a bottom exterior longitudinal surface and an exterior side surface; a layer of conductive material covering the plurality of outer surfaces of the block of dielectric material; a first RF signal input / output pad and a second RF signal input / output pad bridging the bottom outer longitudinal surface and the outer side surface of the dielectric material block; Wherein, each of the first RF signal input / output pad and the second RF signal input / output pad comprises: an elongated strip of conductive material bridging said bottom outer longitudinal surface and one of said outer side surfaces and including an end portion integral with said conductive material layer on said outer side surface; and a strip of dielectric material surrounding said elongated strip of conductive material, excluding said end of said elongated strip of conductive material on said one outer surface integral with said conductive material layer on said one outer surface; wherein the width of an opposing portion of said strip of dielectric material on one of said outer surfaces is greater than the width of said strip of dielectric material on said bottom outer longitudinal surface extending to said opposing portion.

17. The RF dielectric filter according to claim 16, wherein: The strip of dielectric material is generally U-shaped.

18. The RF dielectric filter of claim 16, wherein: The width of each opposing portion of the strip of dielectric material at an edge of one of the outer side surfaces is greater than the width of the strip of dielectric material at an edge of the bottom outer longitudinal surface.

19. The RF dielectric filter of claim 18, wherein: The opposing portions of the strip of dielectric material have a rectangular shape on one of the outer side surfaces.

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