Wideband Cavity Filter Utilizing Triple-Mode Resonance

Abstract

The present invention relates to a broadband cavity filter utilizing triple-mode resonance that can realize broadband characteristics by simultaneously utilizing triple modes within a single cavity, and can simultaneously improve skirt characteristics, L-notch formation, and attenuation characteristics while ensuring miniaturization and ease of fabrication using only a single cavity structure. The broadband cavity filter using triple mode resonance of the present invention comprises, within the pocket, an input terminal positioned on one side and an output terminal positioned on the other side, a vertical cylinder that affects TM110 mode resonance, a horizontal cylinder received within the pocket that affects TM120 mode resonance, and a vertical circular plate that affects TM130 mode resonance.

Description

Technology Field

[0001] The present invention relates to a broadband cavity filter utilizing triple-mode resonance, and more specifically, to a filter that implements broadband characteristics using triple-mode resonance within a single cavity. Furthermore, the present invention relates to a broadband cavity filter utilizing triple-mode resonance capable of utilizing triple-mode coupling to improve skirt characteristics and attenuation characteristics. Background Technology

[0002] In general, filter technology is essential in wireless communication systems, radar, satellite communication, and various microwave circuits to selectively pass only signals of specific frequency bands.

[0003] In particular, cavity filters used in the high-frequency range are widely used in mobile communication base stations and satellite repeaters because they have low insertion loss and high selectivity characteristics.

[0004] However, existing single-mode or dual-mode cavity filters have limitations in terms of spurious suppression or prevention of interference between adjacent bands because their bandwidth is limited and their attenuation characteristics outside the passband are insufficient.

[0005] Furthermore, these filters often require a multi-cavity structure to achieve desired characteristics, leading to increased circuit size and complexity in the manufacturing process.

[0006] Therefore, research has been continuously conducted on new filter structures capable of realizing broadband characteristics by utilizing multiple modes within a single cavity, while simultaneously improving skirt and attenuation characteristics.

[0007] For example, Korean Published Patent No. 10-2012-0129240 presents a method for realizing broadband characteristics by placing a coupling element in a groove between a housing and a partition to simultaneously generate E-field and H-field coupling with a resonator. Furthermore, it discloses a multi-mode filter capable of tuning coupling values, which achieves a desired coupling value by adjusting the width and height of the coupling element, compensates for differences in coupling values ​​caused by mechanical errors by installing a tuning element in a position facing the coupling element, and allows for precise tuning of the coupling value as needed.

[0008] However, these conventional methods have the disadvantage of being disadvantageous for miniaturization and high performance due to structural complexity and limited adjustment methods, and failing to provide fundamental characteristic improvements based on triple-mode resonance as in the present invention. Prior art literature

[0009] Korean Published Patent No. 10-2012-0129240 (2012.11.28.) The problem to be solved

[0010] The objective of the present invention is to provide a broadband cavity filter using triple-mode resonance that can realize broadband characteristics by simultaneously utilizing triple modes within a single cavity.

[0011] Another objective of the present invention is to provide a broadband cavity filter using triple-mode resonance that can simultaneously improve skirt characteristics, L-notch formation, and attenuation characteristics while ensuring miniaturization and ease of fabrication with only a single cavity structure. means of solving the problem

[0012] A broadband cavity filter using triple mode resonance according to the present invention may include a vertical cylinder that affects TM110 mode resonance, a horizontal cylinder that is accommodated inside the pocket and affects TM120 mode resonance, and a vertical circular plate that affects TM130 mode resonance, within an input terminal disposed on one side and an output terminal disposed on the other side within the pocket.

[0013] Here, the vertical cylinder is provided in a vertical metal cylinder shape with a shorted shape at the bottom of the pocket, which can affect the resonance frequency characteristics.

[0014] In addition, the horizontal cylinder is fixed at one end to one side of the vertical cylinder and is provided in the shape of a horizontal pin, which can affect the resonance characteristics.

[0015] Here, the vertical circular plate is provided in a shape where the center of the vertical plate is connected to the other end of the horizontal cylinder, which can influence the control of the resonance frequency.

[0016] In addition, the input terminal and the output terminal are symmetrically arranged with respect to each other, and a vertical cylinder, a horizontal cylinder, and a vertical circular plate may be provided in the central part of the input terminal and the output terminal.

[0017] Here, the TM110 mode can improve the roll-off factor by forming a pole in the lower band.

[0018] In addition, the TM120 mode can resonate at the center of the band to extend the filter bandwidth.

[0019] Here, the TM130 mode resonates in the upper band to form an L-notch and can improve upper attenuation characteristics.

[0020] In addition, the E-Field of the TM110 mode can be distributed throughout the pocket.

[0021] Here, the H-Field of the TM110 mode is concentrated around the input terminal, the output terminal, and the vertical cylinder, so the TM110 mode resonance frequency can be determined.

[0022] In addition, the E-Field of the TM120 mode is concentrated around the input and output terminals, which can extend the resonant bandwidth in the center of the band.

[0023] Here, the H-Field of the TM120 mode is concentrated around the input and output terminals to form an intermediate pole and can ensure the stability of the filter band.

[0024] In addition, the E-Field of the TM130 mode is concentrated at both ends and the center of the pocket, which can improve the upper skirt characteristics.

[0025] Here, the H-Field of the TM130 mode is concentrated around the vertical circular plate to form an L-notch and can improve upper damping characteristics.

[0026] In addition, when the outer diameter of the vertical cylinder is reduced, the resonance frequency of the TM110 mode shifts downward and the upper L-notch frequency also shifts downward, improving skirt characteristics, and when the outer diameter of the vertical cylinder is increased, the resonance frequency of the TM110 mode shifts upward and insertion loss can be reduced. Effects of the invention

[0027] The broadband cavity filter using triple-mode resonance according to the present invention has the advantage of being able to realize broadband characteristics by simultaneously utilizing triple modes within a single cavity.

[0028] In addition, the broadband cavity filter using triple-mode resonance according to the present invention has the advantage of simultaneously improving skirt characteristics, L-notch formation, and attenuation characteristics while ensuring miniaturization and ease of fabrication with only a single cavity structure. Brief explanation of the drawing

[0029] FIG. 1 shows a broadband cavity filter using triple-mode resonance according to one embodiment of the present invention, where FIG. 1(a) is a perspective view, FIG. 1(b) is a top view, FIG. 1(c) is a side view, and FIG. 1(d) is a front view. Figure 2 is a schematic diagram of the triple mode combining inside the pocket of Figure 1. Figure 3 shows the shape of the triple mode electromagnetic waves inside the pocket of Figure 1, where Figure 3(a) is the E-Field distribution of TM110, Figure 1(b) is the H-Field distribution of TM110, Figure 3(c) is the E-Field distribution of TM120, Figure 1(d) is the H-Field distribution of TM120, Figure 3(e) is the E-Field distribution of TM130, and Figure 1(f) is the H-Field distribution of TM130. Figure 4 is a graph showing the change in characteristics of insertion loss and reflection loss according to the change in the outer diameter of the vertical cylinder of Figure 1. Specific details for implementing the invention

[0030] Hereinafter, specific embodiments for carrying out the present invention will be described with reference to the attached drawings.

[0031] In describing the present invention, terms such as first, second, etc. may be used to describe various components, but the components may not be limited by the terms. The terms are intended solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0032] When it is described that a component is connected to or coupled with another component, it may be directly connected to or coupled with that other component, but it can also be understood that there may be other components in between.

[0033] The terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions may include plural expressions unless the context clearly indicates otherwise.

[0034] In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0035] In addition, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

[0036] Hereinafter, a broadband cavity filter using triple-mode resonance according to the present invention will be described in detail with reference to the attached drawings.

[0038] FIG. 1 shows a broadband cavity filter using triple-mode resonance according to an embodiment of the present invention, where FIG. 1(a) is a perspective view, FIG. 1(b) is a top view, FIG. 1(c) is a side view, and FIG. 1(d) is a front view, and FIG. 2 to 4 are detailed schematic diagrams and graphs for explaining FIG. 1 in detail.

[0039] Hereinafter, a broadband cavity filter using triple-mode resonance according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4.

[0040] First, referring to FIG. 1, a broadband cavity filter using triple mode resonance according to one embodiment of the present invention comprises a vertical cylinder (120) that influences TM110 mode resonance, a horizontal cylinder (130) that influences TM120 mode resonance and is housed inside the pocket (100) and an output terminal (150) that influences TM130 mode resonance, and a vertical circular plate (140) that influences TM130 mode resonance, all located within an input terminal (110) positioned on one side and an output terminal (150) positioned on the other side within a pocket (100).

[0041] Here, the pocket (100) is a pocket structure formed to implement triple-mode resonance within a single cavity and is designed to have a relatively simple yet stable mechanical shape.

[0042] These pockets (100) have metal structures arranged inside to induce different electromagnetic modes to resonate simultaneously, thereby providing the advantage of being able to replace complex structures that previously required multiple cavities.

[0043] First, an input terminal (110) is provided on one side of the pocket (100), and an output terminal (150) is provided on the other side.

[0044] The input terminal (110) serves to introduce a high-frequency signal from the outside into the pocket (100), and the output terminal (150) serves to transmit a signal that has undergone a filtering process inside the pocket (100) to an external circuit.

[0045] These two terminals are arranged symmetrically with respect to each other so that the distribution of the electromagnetic field generated inside the pocket (100) is balanced left and right, and the coupling between modes is stably formed.

[0046] The present invention allows TM110, TM120, and TM130 modes to be induced simultaneously inside the pocket (100) without unnecessary distortion when an input signal is applied through the input terminal (110), and as a result, an output signal is stably emitted through the output terminal (150).

[0047] In addition, metal structures for inducing triple mode resonance are arranged inside the pocket (100), and first, a vertical cylinder (120) that has a major influence on the TM110 mode resonance is provided.

[0048] Here, the vertical cylinder (120) has a structure that is shorted to the lower part of the pocket (100) in the shape of a vertical metal cylinder, and strongly controls the resonance characteristics of the TM110 mode by concentrating the electric field in the vertical direction.

[0049] In particular, when the outer diameter of the vertical cylinder (120) changes, the resonant frequency of the TM110 mode shifts sensitively, and as a result, the lower band characteristics of the entire filter change. Therefore, the vertical cylinder (120) acts as a key structure forming the lower pole of the filter.

[0050] Next, the present invention is provided with a horizontal cylinder (130) that influences the resonance of the TM120 mode, which is formed in the shape of a horizontal pin, and one end thereof is fixed to one surface of the vertical cylinder (120).

[0051] Through this horizontal coupling structure, the electromagnetic field is cross-coupled between the vertical cylinder (120) and the horizontal cylinder (130), thereby stably generating the TM120 mode.

[0052] Additionally, the horizontal cylinder (130) is positioned near the center of the cavity and, due to this positional characteristic, forms a resonant pole at the center of the band, playing an important role in expanding the filter bandwidth.

[0053] Finally, the present invention is provided with a vertical circular plate (140) that controls the resonance of the TM130 mode, which is formed as a vertical disc structure connected to the other end of the horizontal cylinder (130) and induces the electric field to be concentrated around the disc.

[0054] This structural arrangement of the present invention generates a strong electric field distribution at both ends of the cavity, and consequently causes the TM130 mode to occur in the upper frequency region.

[0055] Here, the TM130 mode is a component that directly participates in controlling the upper characteristics of the filter, as it significantly improves the attenuation characteristics of the filter by contributing to the upper skirt characteristics and L-notch formation.

[0056] Meanwhile, the input terminal (110) and the output terminal (150) are symmetrically arranged facing each other, and a vertical cylinder (120), a horizontal cylinder (130), and a vertical circular plate (140) are arranged in a line in the center of them. In the present invention, based on such symmetrical arrangement, the coupling between modes is uniformly formed, thereby preventing the phenomenon where a specific mode is excessively strengthened or weakened.

[0057] Ultimately, when an input signal is applied through the input terminal (110), the TM110, TM120, and TM130 modes are simultaneously induced inside the pocket (100) to achieve triple-mode resonance, and this combined response is converted into an output signal and transmitted to the output terminal (150).

[0058] Therefore, the broadband cavity filter using triple-mode resonance according to the present invention enables triple-mode resonance within a single pocket, thereby enabling superior broadband characteristics that are much simpler than conventional multi-cavity structures.

[0059] In particular, in the present invention, the desired center frequency and bandwidth can be easily controlled by adjusting the geometric size and arrangement of the vertical cylinder (120), horizontal cylinder (130), and vertical circular plate (140), so that it can be effectively applied to high-performance wireless communication systems, radar, and satellite communication devices.

[0061] FIG. 2 is a schematic diagram of a triple mode combined inside the pocket (100) of FIG. 1.

[0062] As can be seen in FIG. 2, inside the pocket (100), between the input terminal (110) acting as a source and the output terminal (150) acting as a load, there is provided a vertical cylinder (120) involved in the TM110 mode, a horizontal cylinder (130) involved in the TM120 mode, and a vertical circular plate (140) involved in the TM130 mode, and electromagnetic fields of different modes are generated by these, and triple mode resonance is achieved by combining the three modes simultaneously.

[0063] First, the TM110 mode is mainly formed by the vertical cylinder (120). Here, the vertical cylinder (120) is configured as a vertical metal cylinder as in FIG. 1 so that the electric field is strongly concentrated in the vertical direction, and as a result, the TM110 mode is stably generated in the lower frequency region of the cavity.

[0064] This mode forms a pole located at the lower end of the filter response band, causing the input signal to be rapidly attenuated when it moves out of the passband and into the lower end. In other words, the TM110 mode improves the roll-off factor and strengthens the lower skirt characteristics.

[0065] Next, the TM120 mode is mainly formed by a horizontal cylinder (130). Here, the horizontal cylinder (130) is a horizontal pin structure as in FIG. 1, with one end fixed to one side of the vertical cylinder (120) and positioned in the center of the cavity.

[0066] This results in an electromagnetic field with a distribution different from that of the TM110 mode, and a new resonant pole is formed in the center of the band.

[0067] Meanwhile, the TM120 mode plays a key role in widening the filter's passband and, in particular, has the effect of stabilizing the overall filter response by minimizing insertion loss in the center of the band. Therefore, the TM120 mode acts as an intermediate mode that balances the triple-mode coupling.

[0068] Finally, the TM130 mode is formed by a vertical circular plate (140). Here, the vertical circular plate (140) is connected to the other end of the horizontal cylinder (130) as a vertical circular plate structure as in FIG. 1, and a strong electric field is formed at both ends of the cavity by this structure.

[0069] Consequently, the TM130 mode resonates in the upper frequency range and generates an L-notch at the top of the filter response. This L-notch suppresses unwanted signal components in the upper passband and provides the effect of significantly improving upper attenuation characteristics. In other words, the TM130 mode serves to improve skirt characteristics and increase the overall selectivity of the filter.

[0070] In this way, in the present invention, the TM110, TM120, and TM130 modes each form a lower pole, a middle pole, and an upper pole, respectively, and by combining these three modes, broadband characteristics equivalent to a multi-cavity structure can be realized even in a single cavity structure.

[0071] In particular, the lower skirt is reinforced by the TM110 mode, the upper skirt and attenuation characteristics are improved by the TM130 mode, and the bandwidth is expanded by the TM120 mode, so as a result, the entire filter can simultaneously achieve broadband operation and excellent cutoff characteristics.

[0072] Accordingly, the broadband cavity filter using triple-mode resonance according to the present invention has the advantage of obtaining an excellent frequency response with a simpler structure than the prior art, as the three modes occurring inside the pocket (100) act complementarily to each other.

[0074] FIG. 3 shows the shape of a triple mode electromagnetic wave inside the pocket (100) of FIG. 1, where FIG. 3(a) shows the E-Field distribution of TM110, FIG. 1(b) shows the H-Field distribution of TM110, FIG. 3(c) shows the E-Field distribution of TM120, FIG. 1(d) shows the H-Field distribution of TM120, FIG. 3(e) shows the E-Field distribution of TM130, and FIG. 1(f) shows the H-Field distribution of TM130.

[0075] First, the E-Field of the TM110 mode shown in FIG. 3(a) is distributed throughout the pocket (100) and is induced by a structural arrangement around the vertical cylinder (120).

[0076] This electric field distribution forms a lower pole, enhancing the roll-off coefficient in the lower passband and enabling rapid attenuation characteristics.

[0077] The H-Field of the TM110 mode shown in Fig. 3(b) is concentrated around the input terminal (110), the output terminal (150), and the vertical cylinder (120), which shows that the resonant frequency of the TM110 mode responds sensitively to the diameter and length of the vertical cylinder (120).

[0078] That is, it means that the frequency of the TM110 mode can be finely controlled by adjusting the geometric parameters of the vertical cylinder (120).

[0079] Next, the E-Field of the TM120 mode shown in FIG. 3(c) is concentrated around the input terminal (110) and the output terminal (150) and serves to expand the passband of the filter.

[0080] Meanwhile, the H-Field of the TM120 mode shown in FIG. 3(d) is also concentrated and distributed around the input terminal (110) and the output terminal (150), ensuring the flatness of the filter response.

[0081] Next, the E-Field of the TM130 mode shown in FIG. 3(e) is strongly concentrated at both ends and the center of the pocket (100), which causes the TM130 mode to form a pole in the upper band and plays a major role in improving the skirt characteristics. That is, it induces abrupt attenuation in the upper frequency region to suppress the passage of unnecessary high-frequency components.

[0082] Finally, the H-Field of the TM130 mode shown in FIG. 3(f) is concentrated around the vertical circular plate (140), which shows that the disc structure of the vertical circular plate (140) is a key element in controlling the resonance of the upper mode, and in particular enables the formation of an L-notch.

[0083] This L-notch selectively removes unwanted signals in the upper part of the passband, significantly improving upper attenuation characteristics.

[0084] Accordingly, as shown in Fig. 3, the E-Field and H-Field distributions of the TM110, TM120, and TM130 modes contribute to pole formation and improved damping characteristics in the lower, middle, and upper regions, respectively.

[0085] In particular, an important feature of the present invention is that each mode is generated by different structures (vertical cylinder (120), horizontal cylinder (130), vertical circular plate (140)) and combined with each other to enable triple-mode resonance in a single cavity.

[0086] As described above, the broadband cavity filter using triple-mode resonance according to the present invention has the advantage of being able to achieve a broadband and high-selectivity filter response in a single cavity without the complex filter structure that conventionally relied on multiple cavities.

[0088] FIG. 4 shows the change in characteristics of insertion loss and reflection loss according to the change in the outer diameter of the vertical cylinder (120) of FIG. 1, and is a graph illustrating the effect of the change in the outer diameter of the vertical cylinder (120) on the characteristics of reflection loss (first reflection loss (S110), second reflection loss (S120), third reflection loss (S130)) and insertion loss (first insertion loss (S210), second insertion loss (S220), third insertion loss (S230)).

[0089] First, when the outer diameter of the vertical cylinder (120) is the median value (RBR (Radius of Base Resonator) = 14.4 mm), the reflection loss curve (S120) exhibits a deep cutoff characteristic of approximately -57 dB at around 4.05 GHz, and the insertion loss curve (S220) shows a loss of approximately -0.7 dB at the center of the passband.

[0090] This condition serves as the reference response of the present invention and provides a state in which bandwidth and attenuation characteristics are maintained in balance.

[0091] Meanwhile, when the outer diameter of the vertical cylinder (120) decreases (RBR=13.6 mm), the reflection loss curve (S110) shifts downward to -34 dB at around 3.01 to 3.05 GHz, and the insertion loss curve (S210) also shifts to a lower side along the frequency axis.

[0092] In addition, as the notch position of the upper cutoff band shifts to approximately 4.10 GHz, it exhibits deep attenuation characteristics of -64 dB or more.

[0093] Therefore, when the outer diameter is small, the skirt characteristics are enhanced, and unwanted signals in the high-frequency range are blocked more effectively.

[0094] Conversely, when the outer diameter of the vertical cylinder (120) increases (RBR=15.2 mm), the reflection loss curve (S130) shifts upward to around 3.09 GHz while maintaining a level of -33 dB.

[0095] The insertion loss curve (S230) drops to around -0.5 dB at the center of the passband, showing the flattest passband response.

[0096] In addition, in the upper cutoff band, a notch of -77 dB or more is formed around 4.02 GHz, further improving the upper attenuation characteristics.

[0097] Accordingly, the outer diameter of the vertical cylinder (120) according to the present invention has a significant influence on the filter characteristics. When the outer diameter is reduced, the skirt characteristics are strengthened, and when the outer diameter is increased, the insertion loss is reduced and the passband response is improved. Thus, it can be seen that the outer diameter of the vertical cylinder (120) is a key design variable for adjusting the triple mode frequency response within a single pocket (100).

[0099] As described above, the broadband cavity filter using triple-mode resonance according to the present invention has the advantage of being able to realize broadband characteristics by simultaneously utilizing triple modes within a single cavity, and has the advantage of simultaneously improving skirt characteristics, L-notch formation, and attenuation characteristics while ensuring miniaturization and ease of manufacturing with only a single cavity structure.

[0101] The description of the presented embodiments is provided so that any person skilled in the art may use or practice the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the scope of the present invention. Thus, the present invention is not limited to the embodiments presented herein, but should be interpreted in the broadest possible scope consistent with the principles and novel features presented herein.

Claims

Claim 1 A broadband cavity filter utilizing triple mode resonance, comprising: a vertical cylinder that influences TM110 mode resonance within an input terminal positioned on one side and an output terminal positioned on the other side within a pocket; a horizontal cylinder accommodated within the pocket that influences TM120 mode resonance; and a vertical circular plate that influences TM130 mode resonance; wherein the TM110 mode resonance is controlled by concentrating the electric field in a vertical direction in the vertical cylinder, the TM120 mode is generated by cross-coupled electromagnetic fields between the vertical cylinder and the horizontal cylinder, and the TM130 mode resonance is controlled by inducing the electric field to concentrate on the vertical circular plate. Claim 2 A broadband cavity filter using triple mode resonance according to claim 1, characterized in that the vertical cylinder is provided in a vertical metal cylinder shape and is shorted at the bottom of the pocket to affect the resonance frequency characteristics. Claim 3 A broadband cavity filter using triple-mode resonance according to claim 2, characterized in that one end of the horizontal cylinder is fixed to one surface of the vertical cylinder and is provided in a horizontal pin shape to affect the resonance characteristics. Claim 4 A broadband cavity filter using triple-mode resonance, characterized in that, in claim 3, the vertical circular plate is provided in a shape in which the center of the vertical plate is connected to the other end of the horizontal cylinder and influences the control of the resonance frequency. Claim 5 A broadband cavity filter using triple-mode resonance according to claim 1, characterized in that the input terminal and the output terminal are symmetrically arranged with respect to each other, and the vertical cylinder, the horizontal cylinder, and the vertical circular plate are provided in the central portion of the input terminal and the output terminal. Claim 6 A broadband cavity filter using triple-mode resonance according to claim 1, characterized in that the TM110 mode forms a pole in the lower band to improve the roll-off coefficient. Claim 7 A broadband cavity filter using triple-mode resonance according to claim 1, characterized in that the TM120 mode resonates at the center of the band to expand the filter bandwidth. Claim 8 A broadband cavity filter using triple-mode resonance according to claim 1, characterized in that the TM130 mode resonates at the upper band to form an L-notch and improves upper attenuation characteristics. Claim 9 A broadband cavity filter using triple-mode resonance according to claim 1, characterized in that the E-Field of the TM110 mode is distributed throughout the pocket. Claim 10 A broadband cavity filter using triple-mode resonance, characterized in that, in claim 1, the H-Field of the TM110 mode is concentratedly distributed around the input terminal, the output terminal, and the vertical cylinder to determine the TM110 mode resonance frequency. Claim 11 A broadband cavity filter using triple-mode resonance according to claim 1, characterized in that the E-Field of the TM120 mode is concentratedly distributed around the input terminal and the output terminal to expand the resonance bandwidth. Claim 12 A broadband cavity filter using triple-mode resonance according to claim 1, characterized in that the H-Field of the TM120 mode is concentratedly distributed around the input terminal and the output terminal to form an intermediate pole and secure the stability of the filter band. Claim 13 A broadband cavity filter using triple-mode resonance according to claim 1, characterized in that the E-Field of the TM130 mode is concentratedly distributed at both ends and the center of the pocket to improve upper skirt characteristics. Claim 14 A broadband cavity filter using triple-mode resonance according to claim 1, characterized in that the H-Field of the TM130 mode is concentrated around the vertical circular plate to form a notch and improve upper attenuation characteristics. Claim 15 A broadband cavity filter using triple-mode resonance according to claim 1, characterized in that when the outer diameter of the vertical cylinder decreases, the resonance frequency of the TM110 mode shifts downward and the upper L-notch frequency also shifts downward, thereby improving skirt characteristics, and when the outer diameter of the vertical cylinder increases, the resonance frequency of the TM110 mode shifts upward and the insertion loss decreases.

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