KR101960505B1 - Tunable Cavity Filter For Easy Frequency Tunning Using Snap Dome Switch of Sliding Contact Type - Google Patents

Abstract

The present invention relates to a tunable cavity filter for easy frequency tuning using a snap dome switch of a sliding contact type. According to the present invention, the tunable cavity filter for easy frequency tuning using a snap dome switch of a sliding contact type comprises: a housing in which an input/output connector is installed and a plurality of cavities are partitioned by partition walls; a resonator which is installed in the cavity; a plurality of sub-tuning elements which is mounted around the resonator without being in electrical contact with an upper plate forming the housing, and has different lengths; a plurality of snap dome switches which are formed on the upper plate forming the housing of the cavity by corresponding to the plurality of sub-tuning elements in one-to-one correspondence; and a sliding member which presses one or more of the plurality of snap dome switches while sliding along an upper surface of the housing so as to electrically connect the one or more sub-tuning elements to the housing of the cavity. Therefore, the present invention provides a stable contact structure by pressing the snap dome switch spaced apart from the sub-tuning elements at regular intervals from the upper side of the housing by a sliding method, wherein the sub-tuning elements are disposed around a main tuning bolt in the housing forming the cavity filter and have different lengths, and at the same time and can vary frequency characteristics such as operating frequency and frequency bandwidth.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a tunable cavity filter that can be easily tuned by using a snap contact dome switch.

The present invention relates to a tunable cavity filter which can be tuned easily by using a snap contact type snap dome switch. More specifically, the present invention relates to a tunable cavity filter which is disposed around a main tuning bolt in a housing constituting a cavity filter, And a snap contact dome switch capable of varying frequency characteristics such as operating frequency and frequency bandwidth while providing a stable contact structure by pressing the snap dome switch on the upper side of the housing in a sliding manner To a tunable cavity filter which is easily tuned in frequency.

As the mobile communication technology evolves, the data transmission rate increases exponentially and the transmission power of the base station is increasing to increase the transmission / reception sensitivity due to the increase of the data transmission.

A duplexer, which is used as an essential device to prevent interference between the transmitting and receiving ends in such a base station, is mainly implemented by using an aluminum-made coaxial resonator having high internal power characteristics to withstand high power.

In addition, since the duplexer used in the base station requires a skirt characteristic, the metal tuning screw is applied to the upper cover of the housing constituting the coaxial resonator to adjust the resonance frequency The filter characteristics required by the duplexer can be implemented.

As described above, the filter is implemented in various forms in addition to the duplexer described above as an apparatus for passing only a specific frequency band signal among input frequency signals, and the band pass frequency of the RF filter is determined by the inductance component and the capacitance component of the filter , The operation of adjusting the band pass frequency of the filter as described above is referred to as tuning.

On the other hand, in a communication system such as a mobile communication system, an arbitrary frequency band is allocated to the operators, and the allocated frequency band can be divided into a plurality of channels. Conventional telecommunication carriers have separately created and used a filter for each frequency band.

1 is a view showing the structure of a tunable cavity filter according to the prior art.

As shown in the figure, a conventional cavity filter 1 includes a housing 10, an input connector 11, an output connector 12, a cover 13, a plurality of cavities 14, and a resonator 15, .

2. Description of the Related Art Generally, an RF filter is a device for passing only a specific frequency band signal among input frequency signals, and is implemented in various forms.

As shown in FIG. 1, a plurality of walls are formed in the filter according to the prior art, and a cavity 14 in which each resonator is accommodated by a plurality of walls is defined. The cover 13 is provided with a coupling hole and a tuning bolt 16 for coupling the housing 10 and the cover 13.

Here, the tuning bolt 16 penetrates into the inside of the housing 10 through the coupling hole formed in the cover 13. At this time, the tuning bolt 16 may be disposed on the cover 13 at a position corresponding to the resonator 15 or at a predetermined position inside the cavity 14.

Also, the RF signal is input by the input connector 11 and output to the output connector 12, and the RF signal is transmitted through the coupling window formed in each cavity. At this time, the resonance phenomenon of the RF signal occurs by the cavities 14 and the resonators 15, and the RF signal due to the resonance phenomenon can be filtered.

Thus, the filter according to the prior art shown in Fig. 1 can be tuned for frequency and bandwidth using the tuning bolt 16 described above.

FIG. 2 is a cross-sectional view of one cavity in the tunable filter of the prior art shown in FIG. 1. FIG.

As shown in FIG. 2, the tuning bolt 16 may be positioned above the resonator through the cover 13, and the tuning bolt 16 may be made of a metal material.

A thread is formed in the coupling hole of the cover 13 to which the tuning bolt is inserted and the side of the tuning bolt 16 so that the distance from the resonator 15 can be adjusted by rotation. Tuning can be performed by varying the distance from the antenna 16.

Meanwhile, the tuning bolt 16 may be manually rotated, and a separate tuning machine for rotating the tuning bolt may be used. The tuning bolt can be fixed by the nut when the tuning is done at the proper position.

That is, in the conventional cavity filter, the capacitance is changed by changing the distance between the tuning bolt 16 and the resonator 15 due to the rotation of the tuning bolt 16, and the capacitance is changed by one The center frequency of the filter could be changed by changing the capacitance as a parameter.

However, since the conventional cavity filter using the tuning bolt 16 can be tuned only at the time of initial manufacture and can not be tuned during use, the communication environment has changed rapidly in recent years, There has been a problem that it is difficult to actively cope with the case where the antenna characteristics such as the center frequency and the bandwidth are required to be varied.

Therefore, unlike the initial fabrication environment of the filter, there is a need for a practical and applicable technology capable of actively coping with changes in antenna characteristics such as a center frequency and a bandwidth.

Korean Unexamined Patent Application Publication No. 10-2016-0008486 (Jan. 22, 2016)

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems described above, and it is an object of the present invention to provide a sub tuning device which is disposed around a main tuning bolt in a housing constituting a cavity filter and has different lengths, The present invention provides a tunable cavity filter which is easily tuned in frequency by using a sliding contact type snap dome switch capable of pressing a sliding surface to provide a stable contact structure and varying frequency characteristics such as an operating frequency and a frequency bandwidth have.

A tunable cavity filter that can easily perform frequency tuning using a snap contact dome switch according to an embodiment of the present invention includes a housing having a cavity formed therein; A resonator installed in the cavity; A plurality of sub-tuning elements mounted around the resonator in a state in which they are not in electrical contact with the upper plate constituting the housing and having different lengths; A plurality of snap dome switches formed on the upper plate in a one-to-one correspondence with the plurality of sub-tuning elements and electrically connecting the upper plate and the sub-tuning elements when pressed; And a sliding member having one or more pressing means for pressing the snap dome switch while sliding on an upper portion of the upper plate.

The snap dome switch includes: a head receiving a pressure from the pressing means and having an upper side formed to be convex; And a main body part fixedly coupled to the upper plate and supporting and fixing the sub tuning element and the head part such that the head part and the sub tuning element are not in electrical contact with each other, An upper surface of the head portion convex upward when the head receives the pressure from the pressing means is flattened downward and a contact space for contacting the upper end of the sub tuning element may be provided therein.

The tunable cavity filter, which is easily tuned in frequency by using a snap contact dome switch according to an embodiment of the present invention, is disposed outside the upper plate, and presses the pressure transmitted from the pressing means during a sliding operation of the sliding member And a pressure transmitting unit for transmitting the signal to the snap dome switch.

Wherein the pressure transmitting unit includes: a vertical movement protrusion that moves in a downward vertical direction when the upper end is in direct contact with the pressing unit and has a cross-section of a '?' Shape; And a protrusion fixing panel having a guide hole for receiving the vertical movement protrusion and guiding up and down vertical movement and supporting the vertical movement protrusion outside the upper plate of the cavity of the cavity such that the vertical movement protrusion can move only within a predetermined range .

Wherein the pressing means includes: a cylindrical body having an outer diameter threaded to be firmly coupled to the sliding member; A spring formed inside the cylindrical body; And a ball supported at the end of the cylindrical body by the spring.

The tunable cavity filter that can easily perform frequency tuning using a snap contact dome switch according to an embodiment of the present invention includes four snap dome switches arranged in a square around the resonator; And a pair of pressing means arranged corresponding to the arrangement of the four snap dome switches, wherein the snap dome switches are sequentially pressed one by one during the sliding operation of the sliding member to correspond to the lengths of the four sub-tuning elements So that the operating frequency can be changed.

As described above, according to the present invention, the sub tuning elements disposed around the main tuning bolt in the housing constituting the cavity filter and having different lengths, and the snap dome switch spaced apart from each other are pressed by sliding on the upper side of the housing There is an effect of providing a tunable cavity filter which is easily tuned in frequency by using a snap-contact type snap dome switch capable of providing stable contact structure and varying frequency characteristics such as an operating frequency and a frequency bandwidth.

1 is a view showing the structure of a tunable cavity filter according to the prior art.
FIG. 2 is a cross-sectional view of one cavity in the tunable filter of the prior art shown in FIG. 1. FIG.
FIG. 3 is a view schematically showing the overall configuration of a tunable cavity filter that can easily perform frequency tuning using a snap contact dome switch according to an embodiment of the present invention. Referring to FIG.
FIG. 4 is a cross-sectional view of one of the cavity resonators constituting the tunable cavity filter shown in FIG. 3. FIG.
FIG. 5 is a view for explaining an embodiment in which a snap contact type snap dome switch constituting the tunable cavity filter shown in FIG. 3 is disposed at the top of the tuning element.
6 is a diagram showing simulation results of a variable state of the operating frequency according to the embodiment shown in FIG.
FIG. 7 is a view showing an equivalent circuit of a tunable cavity filter which can easily be tuned in frequency by using a snap contact dome switch according to an embodiment of the present invention.

The description of the present invention is merely an example for structural or functional explanation, and the scope of the present invention should not be construed as being limited by the embodiments described in the text. That is, the embodiments are to be construed as being variously embodied and having various forms, so that the scope of the present invention should be understood to include equivalents capable of realizing technical ideas.

Meanwhile, the meaning of the terms described in the present invention should be understood as follows.

The terms "first "," second ", and the like are intended to distinguish one element from another, and the scope of the right should not be limited by these terms. For example, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

It is to be understood that when an element is referred to as being "connected" to another element, it may be directly connected to the other element, but there may be other elements in between. On the other hand, when an element is referred to as being "directly connected" to another element, it should be understood that there are no other elements in between. On the other hand, other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

It should be understood that the singular " include "or" have "are to be construed as including a stated feature, number, step, operation, component, It is to be understood that the combination is intended to specify that it does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

In each step, the identification code (e.g., a, b, c, etc.) is used for convenience of explanation, the identification code does not describe the order of each step, Unless otherwise stated, it may occur differently from the stated order. That is, each step may occur in the same order as described, may be performed substantially concurrently, or may be performed in reverse order.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used predefined terms should be interpreted to be consistent with the meanings in the context of the related art and can not be interpreted as having ideal or overly formal meaning unless explicitly defined in the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a view schematically showing the overall configuration of a tunable cavity filter which can easily be tuned in frequency by using a snap contact dome switch according to an embodiment of the present invention. FIG. 4 is a cross- Sectional view of a cavity of one of the cavity resonators constituting the filter.

As shown in the figure, a tunable cavity filter that can easily perform frequency tuning using a snap contact dome switch according to an embodiment of the present invention includes a housing 100, a resonator 200, a main tuning bolt 300 , A sub tuning element 400, a snap dome switch 500, and a sliding member 600.

The cavity filter according to an embodiment of the present invention will now be described in detail with reference to the drawings.

In the present embodiment, the housing 100 is provided with input / output connectors 101 and 102 on one side of the main body, a plurality of cavities 110 are partitioned by barrier ribs, Can be formed.

In addition, the resonator 200 is installed at a lower center of the cavity 110, and may be formed in a cylindrical shape, though not shown in detail, but having a hollow portion formed at the center thereof.

The main tuning bolt 300 may be installed vertically downward from the upper plate in the housing 110 of the cavity 110 while maintaining a constant distance from the resonator 200 in a one-to-one correspondence.

The sub tuning elements 400 are spaced apart from each other around the main tuning bolt 300 in a state in which they are not in electrical contact with the upper plate 120 constituting the housing 100 of the cavity And may be formed of a plurality of sub-tuning elements having different lengths.

In addition, the snap dome switch 500 may be formed in a plurality of the upper plates 120 that correspond to the plurality of sub-tuning elements 400 in one-to-one correspondence with the housing 100 of the cavity.

The sliding member 600 slides along the upper surface of the housing 100 to press one or more of the plurality of snap dome switches 500 to move the housing 100 of the cavity and the one or more sub- Since the housing 100 corresponds to GND, the sub-tuning device 400 can be electrically connected to the corresponding sub-tuning device 400 in accordance with the length of the sub- So that it can be changed and operated.

In addition, the sliding member 600 may include a pressing means 700 for pressing one or more of the plurality of snap dome switches 500 during the sliding operation.

As shown in the figure, the pressing means 700 includes a cylindrical body 710 having an outer diameter threaded to be tightly coupled to the sliding member 600 in a screwing manner, a cylindrical body 710 And a ball 720 supported at the end of the cylindrical body 710 by the spring.

Therefore, according to the embodiment of the present invention, when the sliding member 600 slides on the upper side of the housing 100 of the cavity filter, the tip of the ball 720 contacts the snap dome switch A part of the ball 720 is inserted into the body 710 and then comes out again by receiving the repulsive force by the spring while pressing the ball 500.

The cavity filter according to the embodiment of the present invention further includes a driving motor 800 capable of driving the sliding member 600 in a linear reciprocating manner so that the snap dome switch 500 The sliding operation can be performed.

As shown in the drawing, the cavity filter according to the embodiment of the present invention is disposed outside the upper plate 120 of the housing 100 of the cavity so that when the sliding member 600 is in the sliding operation of the sliding member 600, And a pressure transmitting unit 900 for transmitting the pressure transmitted from the snap dome switch 500 to the snap dome switch 500.

At this time, the pressure transmission unit 900 may include a vertical movement projection 910 and a projection fixing panel 920.

More specifically, the vertical movement protrusion 910 can move in the lower vertical direction when the upper end thereof is in direct contact with the pressing means 700. As shown in the drawing, the lower surface can be formed convexly with a curved surface, so that the pressure received from the pressing means 700 can be reduced to a desired value by the snap dome switch 500, It is possible to stably support the contact structure while transmitting the necessary amount of force.

The protrusion fixing panel 920 includes a guide hole 921 for receiving the vertical movement protrusion 910 and guiding up and down vertical movement of the protrusion fixing panel 920. The protrusion fixing panel 920 is provided outside the upper plate 120 of the housing 100 of the cavity The vertical movement protrusion 910 can be supported so as to be movable only within a certain range.

4, the upper plate 120 of the housing 100 constituting the cavity filter is connected to the guide holes 921 of the pressure transmitting unit 900 And a snap dome switch 500 at a corresponding point.

More specifically, the snap dome switch 500 includes a head 510 receiving pressure from the lower surface of the vertical movement projection 910 and a lower portion 510 disposed below the head 510, And a main body 520 for fixing the tuning element 400 so as not to move.

Here, the head 510 may be formed such that the upper surface thereof is convex to receive pressure when the vertical movement projection 910 of the pressure transmission unit 900 moves in the downward vertical direction.

The main body 520 is fixed to the upper plate 120 constituting the housing 100 of the cavity so that the head 510 and the sub tuning device 400 are not in electrical contact with each other The sub-tuning element 400 and the head 510 can be supported and fixed at the same time.

In this case, when the head 510 receives pressure from the pressure transmission unit 900, the top surface of the head 510, which is convex upward, is flattened downward The sub-tuning element 400 may be provided with a contact space in contact with the upper end of the sub-tuning element 400.

The cavity filter according to the embodiment of the present invention may be configured such that the head 510 of the snap dome switch 500 does not come into direct contact with the vertical movement projection 910, 121 may be formed on the outer surface.

FIG. 5 is a view for explaining an embodiment in which a snap contact type snap dome switch constituting the tunable cavity filter shown in FIG. 3 is disposed at the top of the tuning element.

As shown in the drawing, a snap dome switch constituting a tunable cavity filter according to an embodiment of the present invention includes four main tuning bolts 300 arranged vertically and vertically with a square structure, The first to fourth snap dome switches 501, 502, 503, and 504 connected in correspondence with the sub-tuning elements 400.

In addition, according to the embodiment of the present invention, a pair of pressing means 700 formed on the sliding member 600 and corresponding to the four snap dome switches, It can be seen that the snap dome switches 501 are vertically crossed and sequentially pressed one by one.

That is, when the sliding member 600 linearly moves in the advancing direction corresponding to the driving of the motor at the upper side of the housing 100, the upper pressing means 701 moves in a direction The snap dome switch 500 can be pressed in turn by a pair of pressing means 701, 702 which are constantly spaced apart.

More specifically, first, the first snap dome switch 501 is pressed by the upper pressing means 701, the second snap dome switch 502 is pressed by the lower pressing means 702, and then, The third snap dome switch 503 can be pressed by the means 701 and finally the fourth snap dome switch 504 can be pressed by the lower pressing means 702. [

Accordingly, in the cavity filter according to the embodiment of the present invention, the four snap dome switches 501, 502, 503, and 504 contact the four sub tuning elements 400 having different lengths, resulting in a housing 100 having GND It can be seen that the operating frequency can be changed to an operating frequency corresponding to the length of the four sub tuning elements by electrically connecting the sub tuning elements to each other, and the operating frequency band can be adjusted by adjusting the lengths of the four sub tuning elements.

FIG. 6 is a diagram showing a simulation result of a variable state of the operating frequency according to the embodiment shown in FIG. 5, and FIG. 7 is a graph showing a result of simulation of the frequency tuning using a snap contact dome switch according to an embodiment of the present invention. 1 is a diagram showing an equivalent circuit of a tunable cavity filter.

The simulation results shown in FIG. 6 are shown in Table 1 below.

channel Switch position 504 503 502 501 Insertion loss Operating frequency One (a) no no no no 1.2dB 2020MHz 2 (b) 501 no no no ok 1.3dB 2010MHz 3 (c) 502 no no ok no 1.4dB 2000 MHz 4 (d) 503 no ok no no 1.5dB 1990MHz 5 (e) 504 ok no no no 1.6dB 1980MHz

As shown in Table 1, the tunable cavity filter according to the embodiment of the present invention can have an operating frequency band that operates in five frequency bands as a whole.

The equivalent circuit of FIG. 6 is a circuit added with a pin and switches SW1, SW2, SW3, and SW4 for implementing a capacitance added in parallel to the resonator of the filter according to the related art.

In this case, the Pin corresponds to four sub-tuning elements 400 in the embodiment of the present invention, and the switches SW1, SW2, SW3, and SW4 may be implemented by the respective snap dome switches 501, 502, 503, and 504.

As described above, according to the present invention, the sub tuning element and the snap dome switch, which are disposed around the main tuning bolt in the housing constituting the cavity filter and have different lengths, are slidably pressed on the upper side of the housing to form a stable contact structure The present invention provides a tunable cavity filter that can easily be tuned in frequency by using a snap contact dome switch capable of varying frequency characteristics such as an operating frequency and a frequency bandwidth.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, It is within the scope of the present invention that component changes to such an extent that they can be coped evenly within a range that does not deviate from the scope of the present invention.

100: housing 110: cavity
120: upper plate 121: tape
200: Resonator
300: main tuning bolt 400: sub tuning element
500 (501,502,503,504): Snap dome switch
510: head part 520:
600: sliding member 700 (701, 702): pressing means
710: Body 720: Ball
800: driving motor 900: pressure transmitting unit
910: Vertical movement projection 920: Projection fixing panel

Claims (6)

A housing having a cavity formed therein;
A resonator installed in the cavity;
A plurality of sub-tuning elements mounted around the resonator in electrical contact with the upper plate forming the housing and having different lengths;
A plurality of snap dome switches formed on the upper plate in a one-to-one correspondence with the plurality of sub-tuning elements and electrically connecting the upper plate and the sub-tuning elements when pressed; And
And a sliding member slidably mounted on the upper plate and having at least one pressing means for pressing the snap dome switch. The sliding contact type snap dome switch according to claim 1, filter
The apparatus of claim 1, wherein the snap dome switch comprises:
A head portion receiving pressure from the pressing means and having an upper side convexly formed; And
And a main body fixedly coupled to the upper plate and supporting and fixing the sub-tuning element and the head so that the head and the sub-tuning element are not in electrical contact with each other,
Wherein,
Wherein the top portion of the head portion, which is convex upward when the head receives the pressure from the pressing means, is in contact with the top of the sub-tuning element while being flattened downward. Tunable cavity filter for easy frequency tuning using a snap dome switch
The method according to claim 1,
A pressure transmitting unit disposed outside the upper plate and transmitting a pressure transmitted from the pressing unit to the snap dome switch during a sliding operation of the sliding member; And a tuning cavity filter for easily tuning the frequency by using a snap contact type snap dome switch.
4. The apparatus according to claim 3,
A vertical movement protrusion which moves in a lower vertical direction when the upper end is in direct contact with the pressing means and has a cross-section of a '?'Shape; And
And a protrusion fixing panel having a guide hole for receiving the vertical movement protrusion and guiding up and down vertical movement and supporting the vertical movement protrusion outside the upper plate of the cavity of the cavity such that the vertical movement protrusion can move only within a predetermined range Tunable cavity filter for easy frequency tuning using snap-dome switch with sliding contact The apparatus according to claim 1,
A cylindrical body having an outer diameter threaded to securely engage the sliding member;
A spring formed inside the cylindrical body; And
A ball supported at the end of the cylindrical body by the spring; And a tuning cavity filter which is easily tuned in frequency by using a snap contact dome switch.
The method according to claim 1,
Four snap dome switches arranged in a square around the resonator;
And a pair of pressing means arranged corresponding to the arrangement of the four snap dome switches,
The snap dome switches are sequentially pressed one by one during the sliding operation of the sliding member to change the operating frequency corresponding to the lengths of the four sub tuning elements. One Tunable Cavity Filter

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