Band-pass filter

Abstract

A band-pass filter comprises a main body, two input and output columns, a plurality of resonant columns and a conductive cage. The input and output columns are located on two opposite sides of the main body in one direction. The plurality of resonant columns are arranged in the main body. Each resonant column has a first end and a second end. The plurality of resonant columns include two input / output resonant columns and at least one intermediary resonant column. The input / output resonant column is adjacent to the input / output column and is electrically connected to the input / output column. The intermediary resonant columns are located between the input and output resonant columns in the direction. The conductive cage surrounds the resonant column and comprises a bottom layer, a top layer and a plurality of side connecting pieces. The side connectors connect the bottom layer and the top layer. The first end of the resonant column is connected to the bottom layer. The second end of the resonant column is arranged to be spaced from the top layer. The minimum distance between each resonant column and the side connecting piece is smaller than the minimum distance between the resonant columns.

Description

Technical Field

[0001] The invention relates to a filter, in particular to a bandpass filter. Background Art

[0002] Among various passive components in electronic components, filters can filter signals with certain frequencies. In this way, noise can be filtered out. In particular, bandpass filters can allow signals with specific frequencies and bandwidths to pass through.

[0003] Current electronic devices usually have a demand for miniaturization. Therefore, bandpass filters also have a demand for miniaturization. Summary of the invention

[0004] In view of the above problems, an object of the present invention is to provide a bandpass filter that can meet the demand of miniaturization.

[0005] One embodiment of the present invention provides a bandpass filter, which includes a main body, two input and output columns, a plurality of resonant columns and a conductive cage. The input and output columns are located on opposite sides of the main body in one direction. A plurality of resonant columns are arranged in the main body. Each resonant column has a first end and a second end. The plurality of resonant columns include two input and output resonant columns and at least one intermediate resonant column. The input and output resonant columns are respectively adjacent to the input and output columns and are respectively electrically connected to the input and output columns. The intermediate resonant column is located between the two input and output resonant columns in the above direction. The conductive cage surrounds the resonant column. The conductive cage includes a bottom layer, a top layer and a plurality of side connectors. The side connector connects the bottom layer and the top layer. The first end of the resonant column is connected to the bottom layer. The second end of the resonant column is arranged to be spaced from the top layer. A minimum distance between each resonant column and the side connector is less than a minimum distance between the resonant columns.

[0006] According to a bandpass filter of an embodiment of the present invention, the first end of the resonant column is connected to the bottom layer and the second end is arranged to be spaced from the top layer, so that the resonant column itself forms an inductor (L), and a capacitor (C) is formed between the resonant column and the top layer, thereby forming an inductor-capacitor (LC) filter in a limited space. In this way, the bandpass filter meets the demand for miniaturization.

[0007] The above description of the content of the present invention and the following description of the implementation modes are used to demonstrate and explain the spirit and principle of the present invention, and to provide a further explanation of the protection scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A three-dimensional schematic diagram of a bandpass filter according to an embodiment of the present invention is shown.

[0009] Figure 2 Shows Figure 1 Schematic diagram of a bandpass filter from top view.

[0010] Figure 3 Shows Figure 1 Schematic diagram of the right side view of the bandpass filter.

[0011] Figure 4 Shows Figure 1 Schematic diagram of the equivalent circuit of a bandpass filter.

[0012] Figure 5 Shows Figure 1 Schematic diagram of the insertion loss and reflection loss of a bandpass filter versus frequency.

[0013] Figure 6 FIG. 4 is a schematic three-dimensional diagram of a bandpass filter according to another embodiment of the present invention.

[0014] Figure 7 Shows Figure 6 Schematic diagram of a bandpass filter from top view.

[0015] Figure 8 Shows Figure 6 Schematic diagram of the right side view of the bandpass filter.

[0016] Fig. 9 Shows Figure 6 Schematic diagram of the equivalent circuit of a bandpass filter.

[0017] Fig.10 Shows Figure 6 Schematic diagram of the insertion loss and reflection loss of a bandpass filter versus frequency.

[0018] Fig.11 FIG. 4 is a schematic three-dimensional diagram of a bandpass filter according to another embodiment of the present invention.

[0019] Fig.12 Shows Fig.11 Schematic diagram of a bandpass filter from top view.

[0020] Fig.13 Shown along Fig.12 Schematic diagram of the front view of the A-A line section.

[0021] Fig.14 Shows Fig.11 Schematic diagram of the equivalent circuit of a bandpass filter.

[0022] Fig.15 Shows Fig.11 Schematic diagram of the insertion loss and reflection loss of a bandpass filter versus frequency.

[0023] Fig.16 FIG. 4 is a schematic three-dimensional diagram of a bandpass filter according to another embodiment of the present invention.

[0024] Fig.17 Shows Fig.16 Schematic diagram of a bandpass filter from top view.

[0025] Fig.18 Shows Fig.16 Schematic diagram of the left side view of the bandpass filter.

[0026] Fig.19 Shows Fig.16 Schematic diagram of the equivalent circuit of a bandpass filter.

[0027] Fig. 20 Shows Fig.16 Schematic diagram of the insertion loss and reflection loss of a bandpass filter versus frequency.

[0028] Fig.21 FIG. 4 is a schematic three-dimensional diagram of a bandpass filter according to another embodiment of the present invention.

[0029] Fig. 22 Shows Fig.21 Schematic diagram of a bandpass filter from top view.

[0030] Fig.23 Shows Fig.21 Schematic diagram of the left side view of the bandpass filter.

[0031] Fig.24 Shows Fig.21 Schematic diagram of the equivalent circuit of a bandpass filter.

[0032] Fig.25 Shows Fig.21 Schematic diagram of the insertion loss and reflection loss of a bandpass filter versus frequency.

[0033] In the above drawings, the meanings of the reference numerals are as follows:

[0034] 1, 2, 3, 4, 5: Bandpass filter

[0035] 11, 21, 31, 41, 51: Main body

[0036] 121, 122, 221, 222, 321, 322, 421, 422, 521, 522: Input and output columns

[0037] 13, 23, 33, 43, 53: Resonance columns

[0038] 13a, 23a, 33a, 43a, 53a: First end

[0039] 13b, 23b, 33b, 43b, 53b: Second end

[0040] 131, 132, 231, 232, 331, 332, 431, 432, 531, 532: Input and output resonance columns

[0041] 133, 233, 333, 433: Intermediate resonance column

[0042] 141, 142, 241, 242, 341, 342, 441, 442, 541, 542: Electrical connectors

[0043] 15, 25, 35, 45, 55: Conductive cage

[0044] 151, 251, 351, 451, 551: bottom layer

[0045] 152, 252, 352, 452, 552: top floor

[0046] 153, 154, 253, 254, 353, 354, 453, 454, 553, 554: Side connectors

[0047] 161, 162, 163, 261, 262, 263, 361, 362, 363, 461, 462, 463: Capacitor conductor

[0048] 37, 481, 482, 582: Floating conductor

[0049] 533: The first intermediate resonance column

[0050] 534: Second intermediate resonance column

[0051] 535: The third intermediate resonance column

[0052] 561: First capacitor conductor

[0053] 562: Second capacitor conductor

[0054] 563: Third capacitor conductor

[0055] 564: Fourth capacitor conductor

[0056] 565: Fifth capacitor conductor

[0057] C1, C2, C3, C4, C5: capacitors

[0058] D1, D2, D3, D4, D5, D6, D7, D21, D22, D23, D24, D33, D61, D62, D63: Distance

[0059] H1, H2: Height

[0060] L1, L2, L3, L4: Connection

[0061] P: Point

[0062] RL: Reflection loss line

[0063] TL: Insertion Loss Line

[0064] θ1, θ2: Angle DETAILED DESCRIPTION

[0065] The following detailed features and advantages of the embodiments of the present invention are described in detail in the embodiments, and the contents are sufficient to enable any person skilled in the art to understand the technical contents of the embodiments of the present invention and implement them accordingly. According to the contents, claims and drawings disclosed in this specification, any person skilled in the art can easily understand the relevant purposes and advantages of the present invention. The following embodiments further illustrate the contents of the present invention in detail, but do not limit the scope of the present invention in any way.

[0066] In the so-called schematic diagrams of this specification, the dimensions, proportions, angles, etc. may be exaggerated for the purpose of illustration, but they are not intended to limit the present invention. Various changes can be made without violating the gist of the present invention. The up, down, front, and back directions mentioned in the description of the embodiments and the drawings are for illustration, not for limiting the present invention.

[0067] Please refer to Figures 1 to 5 . Figure 1 A three-dimensional schematic diagram of a bandpass filter according to an embodiment of the present invention is shown. Figure 2 Shows Figure 1 Schematic diagram of a bandpass filter from top view. Figure 3 Shows Figure 1 Schematic diagram of the right side view of the bandpass filter. Figure 4 Shows Figure 1 Schematic diagram of the equivalent circuit of a bandpass filter. Figure 5 Shows Figure 1 Schematic diagram of the insertion loss and reflection loss of a bandpass filter versus frequency.

[0068] like Figures 1 to 3 As shown, the bandpass filter 1 includes a main body 11 , two input and output columns 121 , 122 , a plurality of resonant columns 13 , two electrical connectors 141 , 142 , a conductive cage 15 , and a plurality of capacitor conductors 161 , 162 , 163 .

[0069] The input-output column 121 and the input-output column 122 are located on opposite sides of the main body 11 in the X direction. The resonant column 13 is disposed in the main body 11. Each resonant column 13 has a first end 13a and a second end 13b. The resonant column 13 includes two input-output resonant columns 131 and 132 and a plurality of intermediate resonant columns 133. The input-output resonant column 131 is adjacent to the input-output column 121. The input-output resonant column 131 is electrically connected to the input-output column 121 through an electrical connector 141. The input-output resonant column 132 is adjacent to the input-output column 122. The input-output resonant column 132 is electrically connected to the input-output column 122 through an electrical connector 142. The material of the main body 11 is an insulating material or a dielectric material. The material of the input-output columns 121, 122 and the resonant column 13 is a conductive material.

[0070] The resonant column 13 is located between the input-output column 121 and the input-output column 122 in the X direction. Specifically, the input-output column 121 is located on the positive X side of the resonant column 13, and the input-output column 122 is located on the negative X side of the resonant column 13. In addition, a plurality of intermediate resonant columns 133 are located between the input-output resonant column 131 and the input-output resonant column 132 in the X direction. Specifically, the input-output resonant column 131 is located on the positive X side of the intermediate resonant column 133, and the input-output resonant column 132 is located on the negative X side of the intermediate resonant column 133.

[0071] The conductive cage 15 surrounds the resonant column 13 with the X direction as the axis. The conductive cage 15 includes a bottom layer 151, a top layer 152, and a plurality of side connectors 153, 154. The two ends of the side connectors 153, 154 are connected to the bottom layer 151 and the top layer 152, respectively. The resonant column 13 is located between the bottom layer 151 and the top layer 152 in the Z direction. Specifically, the bottom layer 151 is located on the negative Z side of the resonant column 13, and the top layer 152 is located on the positive Z side of the resonant column 13. The resonant column 13 is located between the two groups of side connectors 153, 154 in the Y direction. Specifically, the plurality of side connectors 153 are arranged substantially along the X direction and are located on the positive Y side of the resonant column 13. The plurality of side connectors 154 are arranged substantially along the X direction and are located on the negative Y side of the resonant column 13.

[0072] like Figure 2 and Figure 3As shown, the first end 13a of the resonant column 13 is connected to the bottom layer 151. The second end 13b of the resonant column 13 is arranged to be spaced from the top layer 152. The conductive cage 15 is arranged to be grounded. The input-output columns 121 and 122 are closer to the bottom layer 151 and farther from the top layer 152. A height H1 of each input-output column 121 and 122 is one quarter to one half of a height H2 of each input-output resonant column 131 and 132. The electrical connectors 141 and 142 are between the first end 13a and the second end 13b of the resonant column 13. The capacitor conductors 161, 162, and 163 are arranged in the body 11 and are respectively connected to the second end 13b of the resonant column 13. Specifically, the capacitor conductor 161 is connected to the second end 13b of the input-output resonant column 131. The capacitor conductor 162 is connected to the second end 13b of the input-output resonant column 132. The capacitor conductor 163 is connected to the second end 13b of the intermediate resonant column 133. The capacitor conductors 161 , 162 , 163 are disposed to be spaced apart from the top layer 152 , thereby forming a capacitor.

[0073] There is a minimum distance D1, D2, D3 between each resonant column 13 and the side connector 153. Specifically, there is a minimum distance D1 between the input / output resonant column 131 and the side connector 153, there is a minimum distance D2 between the input / output resonant column 132 and the side connector 153, and there is a minimum distance D3 between the intermediate resonant column 133 and the side connector 153. There are minimum distances D4 and D5 between the resonant columns 13. Specifically, there is a minimum distance D4 between the input / output resonant column 131 and the nearest intermediate resonant column 133, and there is a minimum distance D5 between the input / output resonant column 132 and the nearest intermediate resonant column 133. The minimum distance D1 between the input / output resonant column 131 and the side connector 153 is smaller than the minimum distances D4 and D5 between the input / output resonant columns 131, 132 and the nearest intermediate resonant column 133. The minimum distance D2 between the input-output resonant column 132 and the side connector 153 is smaller than the minimum distances D4 and D5 between the input-output resonant columns 131 and 132 and the nearest intermediate resonant column 133. The minimum distance D3 between the intermediate resonant column 133 and the side connector 153 is smaller than the minimum distances D4 and D5 between the input-output resonant columns 131 and 132 and the nearest intermediate resonant column 133.

[0074] There is a minimum distance D6 between two adjacent intermediate resonant columns 133. The minimum distance D4 between the input-output resonant column 131 and the nearest intermediate resonant column 133 is smaller than the minimum distance D6 between the intermediate resonant columns 133. The minimum distance D5 between the input-output resonant column 132 and the nearest intermediate resonant column 133 is smaller than the minimum distance D6 between the intermediate resonant columns 133.

[0075] A distance D7 between the input-output resonant column 131 and the input-output resonant column 132 is greater than the distances D4, D5, and D6 between the other two adjacent resonant columns. Specifically, the distance D7 is greater than the minimum distance D4 between the input-output resonant column 131 and the intermediate resonant column 133. The distance D7 is greater than the minimum distance D5 between the input-output resonant column 132 and the intermediate resonant column 133. The distance D7 is greater than the minimum distance D6 between the intermediate resonant columns 133.

[0076] An angle θ1 between a line L1 from the center of the input-output resonant column 131 to the center of the nearest input-output column 121 and a line L2 from the center of the input-output resonant column 131 to the center of the nearest intermediate resonant column 133 is less than 90 degrees. An angle θ2 between a line L3 from the center of the input-output resonant column 132 to the center of the nearest input-output column 122 and a line L4 from the center of the input-output resonant column 132 to the center of the nearest intermediate resonant column 133 is less than 90 degrees. The bandpass filter 1 can be connected to the bottom layer 151 through the first end 13a of the resonant column 13 and the second end 13b is arranged to be spaced from the top layer 152, so that the resonant column 13 itself forms an inductor (L), and a capacitor (C) is formed between the resonant column 13 and the top layer 152, and an inductor-capacitor (LC) filter is formed in a very small horizontal area and a limited height (i.e., a limited space). In this way, the bandpass filter 1 meets the demand for miniaturization.

[0077] In this embodiment, the arrangement of the resonant columns 13 is trapezoidal, but not limited thereto. In other embodiments, the resonant columns 13 can be arranged in a zigzag shape, or in other polygonal shapes. In this way, the distance required for the resonant columns 13 in the X direction can be reduced.

[0078] In this embodiment, the material of the body 11 is ceramic. For example, the body 11 may be low-temperature co-fired ceramic (LTCC). Thus, the body 11 can fill the space between the resonant column 13 and the conductive cage 15. However, the present invention is not limited thereto. In other embodiments, the body 11 may also be other insulating materials or dielectric materials that can fill the space between the resonant column 13 and the conductive cage 15.

[0079] In this embodiment, the side connection member 153 is a plurality of connection columns, but the present invention is not limited thereto. In other embodiments, the side connection member 153 may also be two side conductive layers, which are respectively located at the positive Y side and the negative Y side of the resonant column 13 .

[0080] In this embodiment, the bandpass filter 1 is bilaterally symmetrical with respect to the YZ plane, and the input-output column 121 and the input-output column 122 can select one input signal and another output signal, but the present invention is not limited thereto. In other embodiments, the bandpass filter may also be asymmetrical.

[0081] like Figure 4 and Figure 5 As shown, the bandpass effect of the bandpass filter 1 is explained. Figure 4 The capacitor C1 is formed by the capacitor conductor 161 and the top layer 152, the capacitor conductor 162 and the top layer 152, and the capacitor conductor 163 and the top layer 152, respectively. Figure 3 In one example, the length of the bandpass filter 1 in the X direction (approximately the distance between the input-output column 121 and the input-output column 122) is approximately 2.0 mm, the length in the Y direction (approximately the distance between the side connector 153 and the side connector 154) is approximately 1.2 mm, and the length in the Z direction (approximately the distance between the bottom layer 151 and the top layer 152) is approximately 0.8 mm. Figure 5 In FIG. 1 , the TL line represents a schematic diagram of insertion loss relative to frequency, and the RL line represents a schematic diagram of reflection loss relative to frequency. A signal of a certain frequency is input from the input-output column 121, and the strength of the signal that can penetrate the bandpass filter 1 and reach the input-output column 122 is recorded. Signals of different frequencies are input by scanning, and the TL line is then drawn. A signal of a certain frequency is input from the input-output column 121, and the strength of the signal reflected by the bandpass filter 1 received at the input-output column 121 is recorded. Signals of different frequencies are input by scanning, and the RL line is then drawn.

[0082] Depend on Figure 5 It can be seen that signals with frequencies below about 22.50 GHz are almost all reflected by the bandpass filter 1 and cannot penetrate the bandpass filter 1. Signals with frequencies between about 22.50 and 24.50 GHz partially penetrate the bandpass filter 1 and are partially reflected by the bandpass filter 1. Signals with frequencies between about 24.50 and 27.50 GHz mostly penetrate the bandpass filter 1. The passband bandwidth of the bandpass filter 1 is about 3.00 GHz, and the center frequency is about 26.00 GHz. Signals with frequencies between about 27.50 and 28.50 GHz partially penetrate the bandpass filter 1 and are partially reflected by the bandpass filter 1. Signals with frequencies above about 28.50 GHz are almost all reflected by the bandpass filter 1 and cannot penetrate the bandpass filter 1. In the RL line, it can be seen that there are four points P where the signal reflection loss drops sharply, and this number matches the number of resonance columns 13 (one input-output resonance column 131, two intermediate resonance columns 133, and one input-output resonance column 132). It is inferred that the greater the number of the resonant columns 13 , the wider the passband bandwidth of the bandpass filter 1 may be.

[0083] In this embodiment, the number of the intermediate resonance column 133 is two, but not limited thereto. In other embodiments, the number of the intermediate resonance column 133 may be one, which may narrow the bandwidth of the bandpass filter 1. The designer of the bandpass filter 1 may design bandpass filters with different bandwidths and center frequencies according to requirements.

[0084] Please refer to Figures 6 to 10 . Figure 6 FIG. 4 is a schematic three-dimensional diagram of a bandpass filter according to another embodiment of the present invention. Figure 7 Shows Figure 6 Schematic diagram of a bandpass filter from top view. Figure 8 Shows Figure 6 Schematic diagram of the right side view of the bandpass filter. Fig. 9 Shows Figure 6 Schematic diagram of the equivalent circuit of a bandpass filter. Fig.10 Shows Figure 6 Schematic diagram of the insertion loss and reflection loss of a bandpass filter versus frequency.

[0085] like Figures 6 to 8 As shown, the bandpass filter 2 and Figures 1 to 3 The bandpass filter 2 is similar to the bandpass filter 1 shown. The bandpass filter 2 includes a main body 21 , two input and output columns 221 , 222 , a plurality of resonant columns 23 , two electrical connectors 241 , 242 , a conductive cage 25 , and a plurality of capacitor conductors 261 , 262 , 263 .

[0086] The input-output column 221 and the input-output column 222 are located on opposite sides of the main body 21 in the X direction. The resonant column 23 is disposed in the main body 21. Each resonant column 23 has a first end 23a and a second end 23b. The resonant column 23 includes two input-output resonant columns 231 and 232 and a plurality of intermediate resonant columns 233. The input-output resonant column 231 is electrically connected to the input-output column 221 through an electrical connector 241. The input-output resonant column 232 is electrically connected to the input-output column 222 through an electrical connector 242. The resonant column 23 is located between the input-output column 221 and the input-output column 222 in the X direction. The conductive cage 25 surrounds the resonant column 23 with the X direction as the axis. The conductive cage 25 includes a bottom layer 251, a top layer 252 and a plurality of side connectors 253 and 254. The two ends of the side connectors 253 and 254 are respectively connected to the bottom layer 251 and the top layer 252. The resonant column 23 is located between the bottom layer 251 and the top layer 252 , and between the side connecting member 253 and the side connecting member 254 .

[0087] like Figure 7 and Figure 8As shown, the first end 23a of the resonant column 23 is connected to the bottom layer 251. The second end 23b of the resonant column 23 is arranged to be spaced from the top layer 252. The conductive cage 25 is arranged to be grounded. Capacitor conductors 261, 262, 263 are arranged in the body 21 and are respectively connected to the second end 23b of the resonant column 23. The capacitor conductors 261, 262, 263 are arranged to be spaced from the top layer 252, thereby forming a capacitor. The minimum distance D1 from the input-output resonant column 231 to the side connector 253, the minimum distance D2 from the input-output resonant column 232 to the side connector 253, and the minimum distance D3 from the intermediate resonant column 233 to the side connector 253 are all smaller than the minimum distances D4 and D5 between the resonant columns 23.

[0088] The bandpass filter 2 of the present embodiment further has the following features. Among the capacitor conductors 261, 262, and 263, a distance D21 between the capacitor conductor 261 connected to the input-output resonance column 231 and the capacitor conductor 262 connected to the input-output resonance column 232 is smaller than the minimum distances D4 and D5 between the resonance columns 23. In addition, the distance D21 is also smaller than a distance D22 between the capacitor conductor 261 connected to the input-output resonance column 231 and the capacitor conductor 263 connected to the intermediate resonance column 233. The distance D21 is also smaller than a distance D23 between the capacitor conductor 262 connected to the input-output resonance column 232 and the capacitor conductor 263 connected to the intermediate resonance column 233. The distance D21 is also smaller than a distance D24 between the capacitor conductors 263 connected to the intermediate resonance column 233. Thus, a capacitor can be formed between the capacitor conductor 261 and the capacitor conductor 262. Since the distance D22 between the capacitor conductor 261 and the capacitor conductor 263 is farther than the distance D21, no capacitor is formed. Since the distance D23 between the capacitor conductor 262 and the capacitor conductor 263 is greater than the distance D21, no capacitor is formed. Since the distance D24 between the capacitor conductors 263 is greater than the distance D21, no capacitor is formed.

[0089] like Fig. 9 and Fig.10 As shown, the bandpass effect of the bandpass filter 2 is explained. Fig. 9 The capacitor C1 is formed by the capacitor conductor 261 and the top layer 252, the capacitor conductor 262 and the top layer 252, and the capacitor conductor 263 and the top layer 252, respectively. Figure 8 ), capacitor C2 is formed by capacitor conductor 261 and capacitor conductor 262 ( Figure 7 ).

[0090] Fig.10 In the diagram, the TL line represents the insertion loss versus frequency, and the RL line represents the reflection loss versus frequency. Fig.10It can be seen that signals with frequencies below approximately 24.0 GHz will almost all be reflected by bandpass filter 2 and will not be able to penetrate bandpass filter 2. Signals with frequencies between approximately 24.0 and 26.0 GHz will partially penetrate bandpass filter 2 and will be partially reflected by bandpass filter 2. Signals with frequencies between approximately 26.0 and 29.0 GHz will mostly penetrate bandpass filter 2, and the passband bandwidth of bandpass filter 2 is approximately 3.00 GHz, with a center frequency of approximately 27.5 GHz. Signals with frequencies between approximately 29.0 and 29.50 GHz will partially penetrate bandpass filter 2 and will be partially reflected by bandpass filter 2. Signals with frequencies above approximately 29.50 GHz will almost all be reflected by bandpass filter 2 and will not be able to penetrate bandpass filter 2. It can be seen that in the higher frequency band (29.0 to 29.50 GHz) where "signals partially penetrate bandpass filter 2 and are partially reflected by bandpass filter 2", the bandwidth is approximately 0.5 GHz. Compared to Figure 5 In the relatively high frequency band where "the signal partially penetrates the bandpass filter 1 and is partially reflected by the bandpass filter 1", the bandwidth is about 1.00 GHz. Therefore, the bandpass filter 2 of this embodiment has a narrower "band where it is difficult to distinguish whether the signal penetrates or not" such as "the signal partially penetrates the bandpass filter 2 and is partially reflected by the bandpass filter 2".

[0091] Please refer to Figures 11 to 15 . Fig.11 FIG. 4 is a schematic three-dimensional diagram of a bandpass filter according to another embodiment of the present invention. Fig.12 Shows Fig.11 Schematic diagram of a bandpass filter from top view. Fig.13 Shown along Fig.12 Schematic diagram of the front view of the A-A line section. Fig.14 Shows Fig.11 Schematic diagram of the equivalent circuit of a bandpass filter. Fig.15 Shows Fig.11 Schematic diagram of the insertion loss and reflection loss of a bandpass filter versus frequency.

[0092] like Figures 11 to 13 As shown, the bandpass filter 3 and Figures 1 to 3 The bandpass filter 3 is similar to the bandpass filter 1 shown. The bandpass filter 3 includes a main body 31 , two input and output columns 321 , 322 , a plurality of resonant columns 33 , two electrical connectors 341 , 342 , a conductive cage 35 , and a plurality of capacitor conductors 361 , 362 , 363 .

[0093] The input-output column 321 and the input-output column 322 are located at opposite sides of the main body 31 in the X direction. The resonant column 33 is disposed in the main body 31. Each resonant column 33 has a first end 33a and a second end 33b. The resonant column 33 includes two input-output resonant columns 331 and 332 and a plurality of intermediate resonant columns 333. The input-output resonant column 331 is electrically connected to the input-output column 321 through an electrical connector 341. The input-output resonant column 332 is electrically connected to the input-output column 322 through an electrical connector 342. The resonant column 33 is located between the input-output column 321 and the input-output column 322 in the X direction. The conductive cage 35 surrounds the resonant column 33 with the X direction as the axis. The conductive cage 35 includes a bottom layer 351, a top layer 352 and a plurality of side connectors 353 and 354. The two ends of the side connectors 353 and 354 are respectively connected to the bottom layer 351 and the top layer 352. The resonant column 33 is located between the bottom layer 351 and the top layer 352 , and between the side connecting member 353 and the side connecting member 354 .

[0094] like Fig.12 and Fig.13 As shown, the first end 33a of the resonant column 33 is connected to the bottom layer 351. The second end 33b of the resonant column 33 is arranged to be spaced from the top layer 352. The conductive cage 35 is arranged to be grounded. Capacitor conductors 361, 362, 363 are arranged in the body 31 and are respectively connected to the second end 33b of the resonant column 33. The capacitor conductors 361, 362, 363 are arranged to be spaced from the top layer 352, thereby forming a capacitor. The minimum distance D1 from the input-output resonant column 331 to the side connector 353, the minimum distance D2 from the input-output resonant column 332 to the side connector 353, and the minimum distance D3 from the intermediate resonant column 333 to the side connector 353 are all smaller than the minimum distances D4 and D5 between the resonant columns 33.

[0095] The bandpass filter 3 of the present embodiment further has the following features. The bandpass filter 3 also includes a floating conductor 37. The capacitor conductors 363 connected to the intermediate resonance column 333 are adjacent to each other. The floating conductor 37 is arranged to overlap with two adjacent capacitor conductors 363 and to be spaced apart from each other. The floating conductor 37 is arranged between the first end 33a and the second end 33b of the resonance column 33. The floating conductor 37 is arranged to be closer to the second end 33b and farther away from the first end 33a. The floating conductor 37 is not electrically connected to any element and electrically floats. Thereby, the capacitor conductor 363, the floating conductor 37 and the capacitor conductor 363 can form a capacitor.

[0096] like Fig.14 and Fig.15 , the bandpass effect of the bandpass filter 3 is explained. Fig.14 The capacitor C1 is formed by the capacitor conductor 361 and the top layer 352, the capacitor conductor 362 and the top layer 352, and the capacitor conductor 363 and the top layer 352, respectively. Fig.13 ), capacitor C3 is formed by capacitor conductor 363, floating conductor 37 and capacitor conductor 363 ( Fig.13 ).

[0097] Fig.15 In the diagram, the TL line represents the insertion loss versus frequency, and the RL line represents the reflection loss versus frequency. Fig.15 It can be seen that signals with frequencies below approximately 25.75 GHz will almost all be reflected by the bandpass filter 3 and will not be able to penetrate the bandpass filter 3. Signals with frequencies between approximately 25.75 and 26.25 GHz will partially penetrate the bandpass filter 3 and will also be partially reflected by the bandpass filter 3. Signals with frequencies between approximately 26.25 and 29.75 GHz will mostly penetrate the bandpass filter 3, and the passband bandwidth of the bandpass filter 3 is approximately 3.50 GHz, with a center frequency of approximately 28.00 GHz. Signals with frequencies between approximately 29.75 and 31.25 GHz will partially penetrate the bandpass filter 3 and will also be partially reflected by the bandpass filter 3. Signals with frequencies above approximately 31.25 GHz will almost all be reflected by the bandpass filter 3 and will not be able to penetrate the bandpass filter 3. It can be seen that in the lower frequency band (25.75 to 26.25 GHz) where "signals partially penetrate the bandpass filter 3 and are partially reflected by the bandpass filter 3", the bandwidth is approximately 0.5 GHz. Compared to Figure 5 In the relatively high frequency band where "the signal partially penetrates the bandpass filter 1 and is partially reflected by the bandpass filter 1", the bandwidth is about 1.00 GHz. Therefore, the bandpass filter 3 of this embodiment has a narrowed "band where it is difficult to distinguish whether the signal penetrates or not" such as "the signal partially penetrates the bandpass filter 3 and is partially reflected by the bandpass filter 3".

[0098] Please refer to Figures 16 to 20 . Fig.16 FIG. 4 is a schematic three-dimensional diagram of a bandpass filter according to another embodiment of the present invention. Fig.17 Shows Fig.16 Schematic diagram of a bandpass filter from top view. Fig.18 Shows Fig.16 Schematic diagram of the left side view of the bandpass filter. Fig.19 Shows Fig.16 Schematic diagram of the equivalent circuit of a bandpass filter. Fig. 20 Shows Fig.16 Schematic diagram of the insertion loss and reflection loss of a bandpass filter versus frequency.

[0099] like Figures 16 to 18 As shown, the bandpass filter 4 and Figures 1 to 3The bandpass filter 4 is similar to the bandpass filter 1 shown. The bandpass filter 4 comprises a main body 41 , two input and output columns 421 , 422 , a plurality of resonant columns 43 , two electrical connectors 441 , 442 , a conductive cage 45 , and a plurality of capacitor conductors 461 , 462 , 463 .

[0100] The input-output column 421 and the input-output column 422 are located on opposite sides of the main body 41 in the X direction. The resonant column 43 is disposed in the main body 41. Each resonant column 43 has a first end 43a and a second end 43b. The resonant column 43 includes two input-output resonant columns 431 and 432 and a plurality of intermediate resonant columns 433. The input-output resonant column 431 is electrically connected to the input-output column 421 through an electrical connector 441. The input-output resonant column 432 is electrically connected to the input-output column 422 through an electrical connector 442. The resonant column 43 is located between the input-output column 421 and the input-output column 422 in the X direction. The conductive cage 45 surrounds the resonant column 43 with the X direction as the axis. The conductive cage 45 includes a bottom layer 451, a top layer 452 and a plurality of side connectors 453 and 454. The two ends of the side connectors 453 and 454 are respectively connected to the bottom layer 451 and the top layer 452. The resonant columns 43 are located between the bottom layer 451 and the top layer 452, and between the side connecting members 453 and 454. In this embodiment, the resonant columns 43 are arranged in a zigzag shape.

[0101] like Fig.17 and Fig.18 As shown, the first end 43a of the resonant column 43 is connected to the bottom layer 451. The second end 43b of the resonant column 43 is arranged to be spaced from the top layer 452. The conductive cage 45 is arranged to be grounded. Capacitor conductors 461, 462, 463 are arranged in the body 41 and are respectively connected to the second end 43b of the resonant column 43. The capacitor conductors 461, 462, 463 are arranged to be spaced from the top layer 452, thereby forming a capacitor. The minimum distance D1 from the input-output resonant column 431 to the side connector 453, the minimum distance D2 from the input-output resonant column 432 to the side connector 453, and the minimum distances D3 and D33 from the intermediate resonant column 433 to the side connector 453 are all smaller than the minimum distances D4 and D5 between the resonant columns 43.

[0102] The bandpass filter 4 of the present embodiment further has the following features. The bandpass filter 4 further includes two floating conductors 481, 482. The capacitor conductor 461 connected to the input-output resonance column 431 and one of the capacitor conductors 463 connected to the intermediate resonance column 433 are adjacent to each other. The floating conductor 481 is arranged to overlap with the capacitor conductor 461 and the nearest capacitor conductor 463 and to be spaced apart from each other. The capacitor conductor 462 connected to the input-output resonance column 432 and one of the capacitor conductors 463 connected to the intermediate resonance column 433 are adjacent to each other. The floating conductor 482 is arranged to overlap with the capacitor conductor 462 and the nearest capacitor conductor 463 and to be spaced apart from each other. The floating conductors 481, 482 are arranged between the first end 43a and the second end 43b of the resonance column 43. The floating conductors 481, 482 are arranged to be closer to the second end 43b and farther away from the first end 43a. The floating conductors 481, 482 are not electrically connected to any element and are electrically floating. Thus, the capacitor conductor 461, the floating conductor 481 and the nearest capacitor conductor 463 can form a capacitor. The capacitor conductor 462, the floating conductor 482 and the nearest capacitor conductor 463 can form a capacitor.

[0103] like Fig.19 and Fig. 20 As shown, the bandpass effect of the bandpass filter 4 is explained. Fig.19 The capacitor C1 is formed by the capacitor conductor 461 and the top layer 452, the capacitor conductor 462 and the top layer 452, and the capacitor conductor 463 and the top layer 452, respectively. Fig.18 ), capacitor C4 is formed by capacitor conductor 461, floating conductor 481 and capacitor conductor 463 ( Fig.18 ). Capacitor C5 is formed by capacitor conductor 462, floating conductor 482 and capacitor conductor 463 ( Fig.18 ).

[0104] Fig. 20 In the diagram, the TL line represents the insertion loss versus frequency, and the RL line represents the reflection loss versus frequency. Fig. 20It can be seen that signals with frequencies below approximately 24.90 GHz will almost certainly be reflected by the bandpass filter 4 and will not be able to penetrate the bandpass filter 4. Signals with frequencies between approximately 24.90 and 25.50 GHz will partially penetrate the bandpass filter 4 and will also be partially reflected by the bandpass filter 4. Signals with frequencies between approximately 25.50 and 29.50 GHz will mostly penetrate the bandpass filter 4, and the passband bandwidth of the bandpass filter 4 is approximately 4.00 GHz, with a center frequency of approximately 27.50 GHz. Signals with frequencies between approximately 29.50 and 31.25 GHz will partially penetrate the bandpass filter 4 and will also be partially reflected by the bandpass filter 4. Signals with frequencies above approximately 31.25 GHz will almost certainly be reflected by the bandpass filter 4 and will not be able to penetrate the bandpass filter 4. It can be seen that the passband bandwidth of the bandpass filter 4 is approximately 4.00 GHz. Compared to Figure 5 The bandwidth of the bandpass filter 1 is about 3.00 GHz. Therefore, the bandwidth of the bandpass filter 4 of this embodiment is widened. In the RL line, there are five points P where the signal reflection loss drops sharply, and this number is consistent with the number of resonance columns 43 (one input-output resonance column 431, three intermediate resonance columns 433 and one input-output resonance column 432). It is inferred that the more the number of resonance columns 43, the wider the bandwidth of the bandpass filter 4 may be.

[0105] Please refer to Figure 21 to Figure 25 . Fig.21 FIG. 4 is a schematic three-dimensional diagram of a bandpass filter according to another embodiment of the present invention. Fig. 22 Shows Fig.21 Schematic diagram of a bandpass filter from top view. Fig.23 Shows Fig.21 Schematic diagram of the left side view of the bandpass filter. Fig.24 Shows Fig.21 Schematic diagram of the equivalent circuit of a bandpass filter. Fig.25 Shows Fig.21 Schematic diagram of the insertion loss and reflection loss of a bandpass filter versus frequency.

[0106] like Figure 21 to Figure 23 As shown, the bandpass filter 5 and Figures 16 to 20 The bandpass filter 5 is similar to the bandpass filter 4 shown. The bandpass filter 5 includes a main body 51, two input and output columns 521, 522, a plurality of resonant columns 53, two electrical connectors 541, 542, a conductive cage 55, a first capacitor conductor 561, a second capacitor conductor 562, a third capacitor conductor 563, a fourth capacitor conductor 564 and a fifth capacitor conductor 565.

[0107] The input-output column 521 and the input-output column 522 are located on opposite sides of the main body 51 in the X direction. The resonant column 53 is disposed in the main body 51. Each resonant column 53 has a first end 53a and a second end 53b. The resonant column 53 includes two input-output resonant columns 531 and 532, a first intermediate resonant column 533, a second intermediate resonant column 534 and a third intermediate resonant column 535. The input-output resonant column 531 is adjacent to the input-output column 521. The input-output resonant column 531 is electrically connected to the input-output column 521 through an electrical connector 541. The input-output resonant column 532 is adjacent to the input-output column 522. The input-output resonant column 532 is electrically connected to the input-output column 522 through an electrical connector 542. The material of the main body 51 is an insulating material or a dielectric material. The materials of the input-output columns 521, 522 and the resonant column 53 are conductive materials.

[0108] The resonant column 53 is located between the input-output column 521 and the input-output column 522 in the X direction. That is, the projection of the resonant column 53 in the X direction is located between the projection of the input-output column 521 in the X direction and the projection of the input-output column 522 in the X direction. Specifically, the input-output column 521 is located at the positive X side of the resonant column 53, and the input-output column 522 is located at the negative X side of the resonant column 53. In addition, the first intermediate resonant column 533, the second intermediate resonant column 534, and the third intermediate resonant column 535 are located between the input-output resonant column 531 and the input-output resonant column 532 in the X direction. Specifically, the input-output resonant column 531 is located at the positive X side of the first intermediate resonant column 533, the second intermediate resonant column 534, and the third intermediate resonant column 535, and the input-output resonant column 532 is located at the negative X side of the first intermediate resonant column 533, the second intermediate resonant column 534, and the third intermediate resonant column 535.

[0109] The conductive cage 55 surrounds the resonant column 53 with the X direction as the axis. The conductive cage 55 includes a bottom layer 551, a top layer 552, and a plurality of side connectors 553, 554. The two ends of the side connectors 553, 554 are respectively connected to the bottom layer 551 and the top layer 552. The resonant column 53 is located between the bottom layer 551 and the top layer 552 in the Z direction. Specifically, the bottom layer 551 is located at the negative Z side of the resonant column 53, and the top layer 552 is located at the positive Z side of the resonant column 53. The resonant column 53 is located between the side connector 553 and the side connector 554 in the Y direction. In the present embodiment, the resonant columns 53 are arranged in a zigzag shape.

[0110] like Fig. 22 and Fig.23As shown, the first end 53a of the resonant column 53 is connected to the bottom layer 551. The second end 53b of the resonant column 53 is arranged to be spaced from the top layer 552. The conductive cage 55 is arranged to be grounded. The input-output columns 521 and 522 are closer to the bottom layer 551 and farther from the top layer 552. A height H1 of each input-output column 521 and 522 is one quarter to one half of a height H2 of each input-output resonant column 531 and 532. The electrical connectors 541 and 542 are between the first end 53a and the second end 53b of the resonant column 53.

[0111] The first capacitor conductor 561, the second capacitor conductor 562, the third capacitor conductor 563, the fourth capacitor conductor 564 and the fifth capacitor conductor 565 are disposed in the body 51 and are respectively connected to the second end 53b of the resonance column 53. Specifically, the first capacitor conductor 561 is connected to the second end 53b of the input-output resonance column 531. The second capacitor conductor 562 is connected to the second end 53b of the first intermediate resonance column 533. The third capacitor conductor 563 is connected to the second end 53b of the second intermediate resonance column 534. The fourth capacitor conductor 564 is connected to the second end 53b of the third intermediate resonance column 535. The fifth capacitor conductor 565 is connected to the second end 53b of the input-output resonance column 532. The first capacitor conductor 561, the second capacitor conductor 562, the third capacitor conductor 563, the fourth capacitor conductor 564 and the fifth capacitor conductor 565 are disposed to be spaced from the top layer 552, thereby forming a capacitor.

[0112] The minimum distance D1 from the input / output resonant column 531 to the side connector 553, the minimum distance D2 from the input / output resonant column 532 to the side connector 553, the minimum distance D3 from the first intermediate resonant column 533 to the side connector 553, the minimum distance D33 from the second intermediate resonant column 534 to the side connector 554, and the minimum distance D3 from the third intermediate resonant column 535 to the side connector 553 are all smaller than the minimum distances D4 and D5 between the resonant columns 53.

[0113] There is a minimum distance D61 between the first intermediate resonance column 533 and the second intermediate resonance column 534, there is a minimum distance D62 between the second intermediate resonance column 534 and the third intermediate resonance column 535, and there is a minimum distance D63 between the first intermediate resonance column 533 and the third intermediate resonance column 535. The minimum distance D4 between the input-output resonance column 531 and the first intermediate resonance column 533 is smaller than the minimum distances D61, D62, and D63. The minimum distance D5 between the input-output resonance column 532 and the third intermediate resonance column 535 is smaller than the minimum distances D61, D62, and D63.

[0114] A distance D7 between the input-output resonant column 531 and the input-output resonant column 532 is greater than the distances D4 , D5 , D61 , D62 , and D63 .

[0115] An angle θ1 between a line L1 connecting the center of the input-output resonant column 531 to the center of the nearest input-output column 521 and a line L2 connecting the center of the input-output resonant column 531 to the center of the first intermediate resonant column 533 is less than 90 degrees. An angle θ2 between a line L3 connecting the center of the input-output resonant column 532 to the center of the nearest input-output column 522 and a line L4 connecting the center of the input-output resonant column 532 to the center of the third intermediate resonant column 535 is less than 90 degrees.

[0116] The bandpass filter 5 of the present embodiment further has the following features. The bandpass filter 5 also includes a floating conductor 582. The fifth capacitor conductor 565 connected to the input-output resonance column 532 and the fourth capacitor conductor 564 connected to the third intermediate resonance column 535 are adjacent to each other. The floating conductor 582 is arranged to overlap with the fifth capacitor conductor 565 and the fourth capacitor conductor 564 and to be spaced apart from each other. The floating conductor 582 is arranged between the first end 53a and the second end 53b of the resonance column 53. The floating conductors 581 and 582 are arranged to be closer to the second end 53b and farther away from the first end 53a. The floating conductor 582 is not electrically connected to any element and electrically floats. Thereby, the fourth capacitor conductor 564, the floating conductor 582 and the fifth capacitor conductor 565 can form a capacitor.

[0117] like Fig.24 and Fig.25 As shown, the bandpass effect of the bandpass filter 5 is explained. Fig.24 The capacitor C1 in the figure is formed by the first capacitor conductor 561 and the top layer 552, the second capacitor conductor 562 and the top layer 552, the third capacitor conductor 563 and the top layer 552, the fourth capacitor conductor 564 and the top layer 552, and the fifth capacitor conductor 565 and the top layer 552, respectively ( Fig.23 ), capacitor C5 is formed by the fourth capacitor conductor 564, the floating conductor 582 and the fifth capacitor conductor 565 ( Fig.23 ).

[0118] Fig.25 In the diagram, the TL line represents the insertion loss versus frequency, and the RL line represents the reflection loss versus frequency. Fig.25It can be seen that signals with frequencies below approximately 24.50 GHz will almost always be reflected by the band-pass filter 5 and will not be able to penetrate the band-pass filter 5. Signals with frequencies between approximately 24.50 and 25.50 GHz will partially penetrate the band-pass filter 5 and will also be partially reflected by the band-pass filter 5. Signals with frequencies between approximately 25.50 and 29.00 GHz will mostly penetrate the band-pass filter 5, and the passband bandwidth of the band-pass filter 5 is approximately 3.50 GHz, with a center frequency of approximately 27.25 GHz. Signals with frequencies between approximately 29.00 and 29.50 GHz will partially penetrate the band-pass filter 5 and will also be partially reflected by the band-pass filter 5. Signals with frequencies above approximately 29.50 GHz will almost always be reflected by the band-pass filter 5 and will not be able to penetrate the band-pass filter 5. Compared to Figure 5 The passband bandwidth of the middle pass filter 1 is about 3.00 GHz. Therefore, the passband bandwidth of the pass filter 5 of this embodiment is widened.

[0119] It can be seen that in the higher frequency band (29.0-29.50 GHz) where "the signal partially penetrates the bandpass filter 5 and is partially reflected by the bandpass filter 5", the bandwidth is about 0.5 GHz. Fig. 20 In the higher frequency band (29.50-31.25 GHz) where "signals partially penetrate the bandpass filter 4 and are partially reflected by the bandpass filter 4", the bandwidth is about 1.75 GHz. Therefore, the bandpass filter 5 of this embodiment has a narrower "band where it is difficult to distinguish whether the signal penetrates or not" such as "signals partially penetrate the bandpass filter 5 and are partially reflected by the bandpass filter 5". In addition, the bandwidth of the bandpass of the bandpass filter 5 drops more sharply at the high-frequency boundary than the bandwidth of the bandpass filter 4 at the high-frequency boundary.

[0120] In summary, in a bandpass filter of one embodiment of the present invention, the first end of the resonance column is connected to the bottom layer and the second end is set to be spaced from the top layer, so that the resonance column itself forms an inductor (L), and a capacitor (C) is formed between the resonance column and the top layer, thereby forming an inductor-capacitor (LC) filter in a limited space. In this way, the bandpass filter meets the demand for miniaturization. By setting the capacitor conductor, the size of the capacitor can be increased, and the bandpass state of the bandpass filter can be adjusted. By setting the floating conductor, the setting method of the capacitor in the equivalent circuit can be increased, and the bandpass state of the bandpass filter can be adjusted, such as the bandwidth of the bandpass, the bandwidth of the "frequency band where it is difficult to distinguish whether the signal penetrates or not", etc.

Claims

1. A bandpass filter, comprising: One subject; Two input and output posts are located on opposite sides of the main body in one direction; A plurality of resonant columns are disposed in the main body, each of the resonant columns having a first end and a second end, and the resonant columns include: Two input-output resonant columns, respectively adjacent to the two input-output columns and respectively electrically connected to the two input-output columns; as well as At least one intermediate resonance column is located between the two input and output resonance columns in the direction; a conductive cage surrounding the resonant columns, the conductive cage comprising a bottom layer, a top layer and a plurality of side connecting members, the side connecting members connecting the bottom layer and the top layer, the first ends of the resonant columns connected to the bottom layer, the second ends of the resonant columns arranged to be spaced from the top layer, and a minimum distance between each of the resonant columns and the side connecting members being smaller than a minimum distance between the resonant columns; as well as A plurality of capacitor conductors are arranged in the main body and respectively connected to the second ends of the resonance columns. The capacitor conductors are arranged to be spaced apart from the top layer. 2 . The bandpass filter according to claim 1 , wherein the main body is made of ceramic. The bandpass filter according to claim 1 , wherein the conductive cage is arranged to be grounded. 4 . The bandpass filter according to claim 1 , wherein a distance between the two input-output resonant columns is greater than distances between other two adjacent resonant columns. 5 . The bandpass filter according to claim 1 , wherein the side connecting members are a plurality of connecting posts, and two ends of the connecting posts are respectively connected to the bottom layer and the top layer. 6 . The bandpass filter according to claim 1 , wherein the at least one intermediate resonance column is in plurality, and a minimum distance between each of the input / output resonance columns and the intermediate resonance columns is smaller than a minimum distance between two adjacent intermediate resonance columns. 7 . The bandpass filter according to claim 1 , wherein the two input-output columns are closer to the bottom layer and farther from the top layer, and a height of each of the input-output columns is one quarter to one half of a height of each of the input-output resonance columns. 8 . The bandpass filter according to claim 1 , wherein an angle between a line connecting each of the input / output resonant columns to the nearest input / output column and a line connecting each of the input / output resonant columns to the nearest intermediate resonant column is less than 90 degrees. 9 . The bandpass filter according to claim 1 , wherein a distance between the two capacitor conductors connected to the two input-output resonant columns is smaller than the minimum distance between the resonant columns. 10 . The bandpass filter according to claim 1 , further comprising at least one floating conductor, arranged to overlap with two adjacent ones of the capacitor conductors and to be spaced apart from each other. 11 . The bandpass filter according to claim 10 , wherein the at least one floating conductor is disposed between the first ends and the second ends of the resonant columns, and the at least one floating conductor is disposed closer to the second ends and farther from the first ends. 12 . The bandpass filter according to claim 10 , wherein the at least one floating conductor is in plurality, and each of the floating conductors is arranged to overlap with the plurality of capacitor conductors connected to each of the input and output resonant columns and to be spaced apart from each other.

13. The bandpass filter according to claim 1, wherein The at least one intermediate resonance column is in a plurality of numbers, and the intermediate resonance columns include a first intermediate resonance column, a second intermediate resonance column, and a third intermediate resonance column. The first intermediate resonance column and the third intermediate resonance column are adjacent to the two input and output resonance columns respectively. The bandpass filter also includes a plurality of capacitive conductors and a floating conductor; The capacitor conductors are disposed in the main body and are respectively connected to the second ends of the resonant columns, and the capacitor conductors are disposed to be spaced apart from the top layer; The capacitor conductors include a first capacitor conductor, a second capacitor conductor, a third capacitor conductor, a fourth capacitor conductor and a fifth capacitor conductor, wherein the first capacitor conductor and the fifth capacitor conductor are connected to the two input-output resonant columns respectively, and the second capacitor conductor, the third capacitor conductor and the fourth capacitor conductor are connected to the first intermediate resonant column, the second intermediate resonant column and the third intermediate resonant column respectively; The floating conductor is arranged to overlap with the fourth capacitor conductor and the fifth capacitor conductor and to be spaced apart from each other.

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