Filters and circuit components

Abstract

A filter is disposed on a circuit board and includes a first coupling unit, a second coupling unit, a first ring unit, and at least one ground plane. The first coupling unit is connected to a first feed point, and the second coupling unit is connected to a second feed point. The first ring unit includes at least two signal vias and is located on at least two conductive layers. The first coupling unit and the second coupling unit are coupled to the first ring unit. The at least one ground plane is located on another conductive layer of the circuit board and serves as a reference ground for the first coupling unit, the second coupling unit, and the first ring unit. This saves layout area. This disclosure also relates to a circuit element.

Description

Technical Field

[0001] This disclosure relates to a filter and circuit element, and more particularly to a filter and circuit element disposed on a circuit board. Background Technology

[0002] Driven by humanity's pursuit of a more convenient life, diverse wireless communication systems and radio frequency technologies have been developed. For example, the recent rise of 5G millimeter-wave (mmWave) technology has led to an increasing number of consumer electronics products incorporating this technology, with terminal products constantly being updated. This means that the development and manufacturing costs and design complexity of wireless communication modules and their components will correspondingly increase. For instance, 5G millimeter-wave communication modules typically require a very small size; therefore, some radio frequency circuit elements that occupy significant volume or area in existing technologies (such as filters) will not be suitable for 5G millimeter-wave communication modules.

[0003] In view of this, how to reduce the size, cost and design complexity of circuit components such as filters in wireless communication modules, while meeting the radio frequency characteristics requirements of wireless communication systems, and further making the products more competitive in the market, has become a topic of concern in the market. Summary of the Invention

[0004] This disclosure provides a filter and circuit element disposed on a circuit board. The first ring unit includes at least two signal vias and is located on at least two conductive layers. The first coupling unit and the second coupling unit couple the first ring unit. This facilitates the design of the filter as a vertically arranged three-dimensional filter on the circuit board. In addition to avoiding the yield risk caused by using discrete components, it can also reduce costs and volume.

[0005] According to one embodiment of this disclosure, a filter is provided, disposed on a circuit board and including a first coupling unit, a second coupling unit, a first ring unit, and at least one ground plane. The first coupling unit is connected to a first feed point, and the second coupling unit is connected to a second feed point. The first ring unit includes at least two signal vias and is located on at least two conductive layers. At least a portion of the first coupling unit is parallel to at least a portion of the first coupling portion of the first ring unit, and at least a portion of the second coupling unit is parallel to at least a portion of the second coupling portion of the first ring unit. The first coupling unit and the second coupling unit are coupled to the first ring unit. The at least one ground plane is located on another conductive layer of the circuit board, the other conductive layer being sandwiched between the at least two conductive layers. The at least one ground plane serves as a reference ground for the first coupling unit, the second coupling unit, and the first ring unit.

[0006] According to another embodiment of this disclosure, a circuit element is provided, disposed on a circuit board. The circuit board sequentially includes a first conductive layer, a second conductive layer, and a third conductive layer. The circuit element includes a first coupling unit, a second coupling unit, a first ring unit, and at least one ground plane. The first coupling unit is connected to a first feed point, and the second coupling unit is connected to a second feed point. The first ring unit includes at least two signal vias and is located on the first and third conductive layers. The first coupling unit and the second coupling unit are coupled to the first ring unit. The at least one ground plane is located on the second conductive layer and serves as a reference ground for the first coupling unit, the second coupling unit, and the first ring unit. Attached Figure Description

[0007] Figure 1 A perspective view of a filter according to an embodiment of the present disclosure is shown; Figure 2 Draw Figure 1 Exploded view of the conductive layer of the filter; Figure 3 Draw Figure 1 Exploded view of the signal lines of the intermediate filter; Figure 4 Draw Figure 1 Top view of the signal lines of the intermediate filter; Figure 5 Draw Figure 1 A schematic diagram of the S-parameters of the filter; and Figure 6 Draw Figure 1 A schematic diagram of the surface current density of the filter.

[0008] The reference numerals in the attached figures are explained as follows: 100: Filter 101: First conductive layer 101g, 102g, 103g, 104g, 105g: Grounding plane 102: Second conductive layer 103: Third conductive layer 104: Fourth conductive layer 105: Fifth conductive layer 108: Circuit Board 109, 139: Grounding via 110: First feed line 119: First Feed Point 120: First coupling unit 123, 124, 133, 134, 136, 137, 153, 154, 156, 157, 166, 167: line segments 125, 135, 138, 155, 158, 168: Signal vias 130: First ring unit 131: First coupling part 132: Second coupling section 150: Second ring unit 151: Third Coupling Section 152: Fourth Coupling Section 160: Second coupling unit 170: Second feed line 179: Second Feed Point g23: Spacing h1: Thickness w2, w3, y1: Width x: First direction x1: Length x2: Path length y: Second direction z: Third-party direction Detailed Implementation

[0009] Figure 1 A perspective view of a filter 100 according to one embodiment of the present disclosure is shown. Figure 2 Draw Figure 1 Exploded view of the conductive layer of the intermediate filter 100. Figure 3 Draw Figure 1 Exploded view of the signal lines of filter 100. Figure 4 Draw Figure 1 The diagram shows a top view of the signal lines of the intermediate filter 100. To clearly illustrate the structure of the filter 100, the accompanying diagrams in this disclosure are illustrated in a Cartesian coordinate system with a first direction x, a second direction y, and a third direction z. Figure 1 Illustration omitted Figure 2 The grounding via 109 is shown, and the signal lines located on the inner conductive layer of the circuit board 108 are drawn with solid lines. Please refer to... Figures 1 to 4 According to one embodiment of this disclosure, the circuit element is specifically a filter 100. The filter 100 is disposed on a circuit board 108 and includes a first coupling unit 120, a second coupling unit 160, a first ring unit 130, and at least one ground plane (e.g., at least ground plane 102g). The circuit board 108 specifically includes a fourth conductive layer 104, a first conductive layer 101, a second conductive layer 102, a third conductive layer 103, and a fifth conductive layer 105 in sequence. Furthermore, the circuit element in other embodiments of this disclosure may specifically be a filter or a circuit element containing filtering characteristics. The shape and size of the circuit board are not limited to the figures in this disclosure. The circuit board may be a printed circuit board, a flexible circuit board, or a circuit substrate made of other dielectric materials, and is not limited thereto.

[0010] The first coupling unit 120 is connected to the first feed point 119, and the second coupling unit 160 is connected to the second feed point 179, and so on. Figure 3 As shown. The first ring unit 130 includes signal vias 135 and 138 and is located in the first conductive layer 101 and the third conductive layer 103. At least a portion of the first coupling unit 120 is parallel to at least a portion of the first coupling portion 131 of the first ring unit 130, and at least a portion of the second coupling unit 160 is parallel to at least a portion of the second coupling portion 132 of the first ring unit 130. The first coupling unit 120 and the second coupling unit 160 are coupled to the first ring unit 130. Furthermore, the "connection" described in this disclosure refers to a physical connection between two elements, which can be direct or indirect, while the "coupled" described in this disclosure refers to two elements that are separated from each other and have no physical connection, and the electric field energy generated by the current in one element excites the electric field energy of the other element.

[0011] Ground planes 101g, 102g, 103g, 104g, and 105g are located on the first conductive layer 101, the second conductive layer 102, the third conductive layer 103, the fourth conductive layer 104, and the fifth conductive layer 105, respectively, and are interconnected through multiple grounding vias 109 to maintain system grounding. At least one of each of the ground planes 101g, 102g, 103g, 104g, and 105g is present, with at least one ground plane 102g, 104g, or 105g serving as the reference ground for the first coupling unit 120, the second coupling unit 160, and the first ring unit 130. This facilitates the design of the filter 100 as a vertically arranged three-dimensional bandpass filter (BPF) on the circuit board 108, avoiding yield risks associated with using discrete components and reducing cost and footprint.

[0012] In detail, the first coupling portion 131 and the second coupling portion 132 of the first annular unit 130 specifically include signal vias 135 and 138 respectively and are both located in the first conductive layer 101 and the third conductive layer 103. The first coupling portion 131 is formed by sequentially connecting the line segment 133 located in the first conductive layer 101, the signal via 135 and the line segment 134 located in the third conductive layer 103. The second coupling portion 132 is formed by sequentially connecting the line segment 136 located in the first conductive layer 101, the signal via 138 and the line segment 137 located in the third conductive layer 103. The first coupling unit 120 and the second coupling unit 160 respectively include signal vias 125 and 168 and are located in the first conductive layer 101 and the third conductive layer 103. The first coupling unit 120 is formed by sequentially connecting a line segment 123 in the first conductive layer 101, a signal via 125, and a line segment 124 in the third conductive layer 103. The second coupling unit 160 is formed by sequentially connecting a line segment 166 in the first conductive layer 101, a signal via 168, and a line segment 167 in the third conductive layer 103. According to this disclosure, the line segments of the filter can be straight lines, arcs, or curves. This helps the vertical ring structure filter 100 simultaneously meet the requirements of signal feed coupling and reduced layout area.

[0013] The ratio of the path length of the first ring unit 130 in the first conductive layer 101 to the path length x2 of the first coupling unit 120 in the first conductive layer 101 can be between 2.5 and 8, and the ratio of the path length of the first ring unit 130 in the third conductive layer 103 to the path length of the first coupling unit 120 in the third conductive layer 103 can also be between 2.5 and 8. The path lengths mentioned in this disclosure refer to the center path length. Furthermore, the ratio can be between 3 and 4.5. This facilitates a balance between signal coupling and layout design flexibility. In this embodiment, the path lengths of the first ring unit 130 in the first conductive layer 101 and the third conductive layer 103 are both 1690 μm (micrometer), and the path length x2 of the first coupling unit 120 in the first conductive layer 101 and the third conductive layer 103 are both 450 μm; therefore, the ratio is 3.76.

[0014] The filter 100 may further include a first feed line 110 and a second feed line 170. The first feed point 119 is connected between the first feed line 110 and the signal via 125 of the first coupling unit 120, and the second feed point 179 is connected between the second feed line 170 and the signal via 168 of the second coupling unit 160. In this way, a suitable feed method can effectively excite the dual-mode resonance of the filter 100, while avoiding the complex structure, large size, and high cost of filters using multiple cascaded structures or discrete components in the prior art.

[0015] The first feed line 110 and the second feed line 170 are both located on the second conductive layer 102 of the circuit board 108, which is sandwiched between the first conductive layer 101 and the third conductive layer 103. Thus, the first feed line 110, the first feed point 119, and the first coupling unit 120 are specifically formed in a tuning fork shape, and the second feed line 170, the second feed point 179, and the second coupling unit 160 are also specifically formed in a tuning fork shape. This creates two sets of tuning fork structures containing striplines and feed arm-type coupling units, enabling energy coupling to the filter 100 and satisfying the signal coupling requirements of the vertically arranged ring structure filter 100.

[0016] The filter 100 specifically includes a second ring unit 150 and a grounding via 139. The second ring unit 150 includes signal vias 155 and 158 and is located in the first conductive layer 101 and the third conductive layer 103. At least a portion of the first coupling unit 120 is parallel to at least a portion of the third coupling portion 151 of the second ring unit 150, and at least a portion of the second coupling unit 160 is parallel to at least a portion of the fourth coupling portion 152 of the second ring unit 150. The first coupling unit 120 and the second coupling unit 160 couple the second ring unit 150. Furthermore, each of the first feed line 110, the second feed line 170, the first coupling unit 120, the second coupling unit 160, the first ring unit 130, and the second ring unit 150 is specifically a stripline. It should be understood that some transmission lines in the filter according to this disclosure may be microstrip lines, and are not limited to this embodiment. In addition, both the first feed line 110 and the second feed line 170 have a impedance of 50 ohms and a width of 62 μm.

[0017] The first coupling portion 131 and the third coupling portion 151 are located on both sides of the first coupling unit 120 (i.e., on the positive and negative directions of the second direction y of the first coupling unit 120, respectively). At least a portion of the first coupling unit 120, at least a portion of the first coupling portion 131, and at least a portion of the third coupling portion 151 are parallel to each other, i.e., at least a portion of the first coupling unit 120 and at least a portion of the first coupling portion 131 maintain the same distance, and the at least a portion of the first coupling unit 120 and at least a portion of the third coupling portion 151 maintain the same distance. Specifically, a portion of line segment 123 of the first coupling unit 120, a portion of line segment 133 of the first coupling part 131, and a portion of line segment 153 of the third coupling part 151 are parallel to each other. Signal vias 125, 135, and 155 are parallel to each other. A portion of line segment 124 of the first coupling unit 120, a portion of line segment 134 of the first coupling part 131, and a portion of line segment 154 of the third coupling part 151 are parallel to each other. Thus, both the first ring unit 130 and the second ring unit 150 are coupled to the first coupling unit 120.

[0018] The second coupling portion 132 and the fourth coupling portion 152 are located on both sides of the second coupling unit 160, and at least a portion of the second coupling unit 160, at least a portion of the second coupling portion 132, and at least a portion of the fourth coupling portion 152 are parallel to each other. Specifically, a portion of line segment 166 of the second coupling unit 160, a portion of line segment 136 of the second coupling portion 132, and a portion of line segment 156 of the fourth coupling portion 152 are parallel to each other, signal vias 138, 158, and 168 are parallel to each other, and a portion of line segment 167 of the second coupling unit 160, a portion of line segment 137 of the second coupling portion 132, and a portion of line segment 157 of the fourth coupling portion 152 are parallel to each other, so that both the first ring unit 130 and the second ring unit 150 are coupled to the second coupling unit 160.

[0019] The grounding via 139 connects the line segments (unlabeled) of the first ring unit 130 located in the first conductive layer 101 and the third conductive layer 103, the line segments (unlabeled) of the second ring unit 150 located in the first conductive layer 101 and the third conductive layer 103, and the grounding plane 102g. By utilizing the grounding via 139 to create a grounding path, low-frequency modes are generated at the adjacent resonant frequencies of the first ring unit 130 and the second ring unit 150 (especially the first ring unit 130 with the longer path length). This achieves a dual-mode effect without requiring multiple structures to be connected in series, thereby expanding the operating (application) bandwidth.

[0020] The ratio of the path length of the first annular unit 130 on the first conductive layer 101 to the path length of the second annular unit 150 on the first conductive layer 101 can be greater than 1 and less than 1.1. The ratio of the path length of the first annular unit 130 on the third conductive layer 103 to the path length of the second annular unit 150 on the third conductive layer 103 can be greater than 1 and less than 1.1. Furthermore, the ratio can be greater than 1 and less than 1.05. Thus, there are slight differences in the loop path lengths of the first annular unit 130 and the second annular unit 150, which helps the feeding signals of different wavelengths to match the loop path lengths of the first annular unit 130 and the second annular unit 150 respectively, so as to achieve a broadband effect through two corresponding resonance frequencies (for example Figure 5 the two resonance frequencies of 37.10 GHz and 41.90 GHz indicated by the marked points m1 and m2 in the figure). In this embodiment, the path length of the first annular unit 130 on the first conductive layer 101 or the third conductive layer 103 is the path length on the conductive layer from the signal through-hole 135 via the grounding through-hole 139 to the signal through-hole 138. The path length of the second annular unit 150 on the first conductive layer 101 or the third conductive layer 103 is the path length on the conductive layer from the signal through-hole 155 via the grounding through-hole 139 to the signal through-hole 158. The ratio of the path length of the first annular unit 130 on the first conductive layer 101 (1690 um) to the path length of the second annular unit 150 on the first conductive layer 101 (1660 um) is 1.02. The ratio of the path length of the first annular unit 130 on the third conductive layer 103 (1690 um) to the path length of the second annular unit 150 on the third conductive layer 103 (1660 um) is 1.02.

[0021] The total number of signal through-holes 135 and 138 included in the first annular unit 130 is two. The total number of signal through-holes 155 and 158 included in the second annular unit 150 is two. Each of the first annular unit 130 and the second annular unit 150 is a vertical figure-eight (or "day" shape), and the grounding through-hole 139 is the center of the vertical figure-eight of the first annular unit 130, and the grounding through-hole 139 is also the center of the vertical figure-eight of the second annular unit 150. On each of the first conductive layer 101 and the third conductive layer 103, the path lengths from the grounding through-hole 139 to the signal through-holes 135 and 138 of the first annular unit 130 are equal, and the path lengths from the grounding through-hole 139 to the signal through-holes 155 and 158 of the second annular unit 150 are equal. Thus, the grounding through-hole 139 at the center of the vertical figure-eight loop path can generate a low-frequency mode at the adjacent positions of the resonance frequencies, and at the same time helps to achieve an expanded operating bandwidth and a reduced layout area. Furthermore, the line segments other than the coupling parts of each annular unit in the filter according to the present disclosure can be located on conductive layers different from the coupling parts.

[0022] The filter 100 is specifically mirror-symmetric to the second conductive layer 102. This reduces the design complexity of the broadband filter 100. Furthermore, as in this embodiment… Figure 4 As shown, the width w2 of line segment 123 of the first coupling unit 120 and the width of line segment 166 of the second coupling unit 160 are both 40 μm. The width w3 of wire of the first ring unit 130 and the width of wire of the second ring unit 150 are both 62 μm. The spacing g23 between the line segments of each parallel and adjacent coupling unit and the line segments of each ring unit is 42 μm. The length x1 of the coupling and filtering structure of the filter 100 is 1705 μm and the width y1 is 460 μm. The thickness h1 of the circuit board 108 is 400 μm. Therefore, the filter 100 has sufficiently small length and width dimensions to be suitable for 5G millimeter wave products.

[0023] Figure 5 Draw Figure 1 The diagram shows the S-parameters of the intermediate filter 100. The first and second measurement terminals used to measure the S-parameters in the diagram can be respectively located at the edges of the first feed line 110 and the second feed line 170 on the circuit board 108. Please refer to... Figure 5 The 3dB band of filter 100, defined by parameter S21, is from 35.13 GHz to 44.40 GHz, meaning its 3dB bandwidth exceeds 9.2 GHz. The minimum loss within this 3dB band is approximately 1.2 dB, indicating very low insertion loss (IL), making it suitable for current 5G millimeter-wave bands. Furthermore, the S22 parameter has a reference point m1 of 37.10 GHz and a reference point m2 of 41.90 GHz and a reference point m2 of -24.05 dB. This indicates that filter 100 has two resonant frequencies: 37.10 GHz and 41.90 GHz, generated by the longer first ring unit 130 and the shorter second ring unit 150, respectively. The frequencies corresponding to the extreme values ​​of the S-parameters within the 3dB band of filter 100 can be defined as the resonant frequencies. In addition, the S21 parameter is indicated at m3 of 37.00 GHz and -1.38 dB, m4 of 40.00 GHz and -1.22 dB, and m5 of 43.50 GHz and -2.11 dB.

[0024] Figure 6 Draw Figure 1 A schematic diagram of the surface current density of the intermediate filter 100, wherein... Figure 6The color variations of the edge lines of the intermediate filter 100 are only for illustrative purposes and do not represent the magnitude of the surface current density. Please refer to... Figure 3 , Figure 5 and Figure 6 The surface current densities of the filter 100 according to this disclosure at 37.10 GHz and 41.90 GHz are as follows: Figure 6 As shown in (a) and (b), after the signal is fed into the filter 100 from the first feed line 110 or the second feed line 170, the signal near 41.90 GHz will resonate through the loop path of the second loop unit 150, and the signal near 37.10 GHz will resonate through the loop path of the first loop unit 130, and compared to Figure 6 (b) Current distribution in high-frequency modes, Figure 6 (a) The excitation current of the low-frequency resonant mode will concentrate in the grounding via 139 and generate a grounding path, thereby exciting another adjacent mode at a slightly lower frequency, enabling the filter 100 to achieve a dual bandwidth expansion effect, and as... Figure 5 As shown in the S-parameters, filter 100 is specifically suitable for today's 5G millimeter-wave products and can expand the operating bandwidth.

[0025] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A filter, characterized in that, It is disposed on a circuit board and includes: A first coupling unit is connected to a first feed point; A second coupling unit is connected to a second feed point; A first ring unit includes at least two signal vias and is located in at least two conductive layers. At least a portion of the first coupling unit is parallel to at least a portion of a first coupling portion of the first ring unit. At least a portion of the second coupling unit is parallel to at least a portion of a second coupling portion of the first ring unit. The first coupling unit and the second coupling unit are coupled to the first ring unit. as well as At least one ground plane is located on another conductive layer of the circuit board, wherein the other conductive layer is sandwiched between the at least two conductive layers, and the at least one ground plane is the reference ground of the first coupling unit, the second coupling unit and the first ring unit.

2. The filter as described in claim 1, characterized in that, The first coupling portion and the second coupling portion of the first annular unit each include at least two signal vias and are both located in the at least two conductive layers. Each of the first coupling unit and the second coupling unit includes at least one signal via and is located in the at least two conductive layers.

3. The filter as described in claim 2, characterized in that, The ratio of the path length of the first ring unit located in one of the at least two conductive layers to the path length of the first coupling unit located in the conductive layer is between 2.5 and 8.

4. The filter as described in claim 2, characterized in that, It also includes: A first feed line, wherein the first feed point is connected between the first feed line and the at least one signal via of the first coupling unit; and A second feed line, wherein the second feed point is connected between the second feed line and the at least one signal via of the second coupling unit.

5. The filter as described in claim 4, characterized in that, Both the first feed line and the second feed line are located on the other conductive layer of the circuit board.

6. The filter as described in claim 1, characterized in that, It also includes: A second ring unit, comprising at least two signal vias and located in the at least two conductive layers, wherein at least a portion of the first coupling unit is parallel to at least a portion of a third coupling portion of the second ring unit, and at least a portion of the second coupling unit is parallel to at least a portion of a fourth coupling portion of the second ring unit; the first coupling unit and the second coupling unit are coupled to the second ring unit; and A grounding through hole connects the first ring unit, the second ring unit, and the at least one grounding plane; The first coupling part and the third coupling part are respectively located on both sides of the first coupling unit, and the second coupling part and the fourth coupling part are respectively located on both sides of the second coupling unit.

7. The filter as described in claim 6, characterized in that, The ratio of the path length of the first ring unit in one of the at least two conductive layers to the path length of the second ring unit in the conductive layer is greater than 1 and less than 1.

1.

8. The filter as described in claim 6, characterized in that, The number of at least two signal vias in each of the first ring unit and the second ring unit is two, and each of the first ring unit and the second ring unit is in the shape of an 8. Wherein, on one of the at least two conductive layers, the path lengths from the grounding via to the two signal vias of the first annular unit are equal, and the path lengths from the grounding via to the two signal vias of the second annular unit are equal.

9. The filter as described in claim 1, characterized in that, The filter is mirror-symmetric to the other conductive layer.

10. A circuit element, characterized in that, Distributed on a circuit board, wherein the circuit board sequentially includes a first conductive layer, a second conductive layer, and a third conductive layer, the circuit element includes: A first coupling unit is connected to a first feed point; A second coupling unit is connected to a second feed point; A first ring unit, comprising at least two signal vias and located on the first conductive layer and the third conductive layer, wherein a first coupling unit and a second coupling unit are coupled to the first ring unit; and At least one ground plane is located in the second conductive layer, wherein the at least one ground plane is the reference ground of the first coupling unit, the second coupling unit and the first ring unit.

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