KR101237227B1 - Frequency Tunable Filter Using Sliding - Google Patents

Abstract

A frequency tunable filter using a sliding method is disclosed. The disclosed filter comprises a housing in which a plurality of cavities are defined by partitions; A sub cover coupled to an upper portion of the housing and having a guide groove formed therein; At least one sliding member installed in the guide groove; A main cover coupled to an upper portion of the sub cover. A resonator accommodated in the cavity; At least one tuning element coupled to a lower portion of the sliding member and inserted into the housing and made of a dielectric material, the tuning is performed by a sliding operation of the sliding member, and at least one side of the sliding member At least one first guide member is coupled to the side of the groove to guide the sliding motion. According to the disclosed filter, the tuning operation can be easily performed by the user, the sliding operation can be made more stable, and the height of the tuning element can be adjusted with the resonator of the tuning element, thereby providing a wide tuning range. .

Description

Frequency Tunable Filter Using Sliding

The present invention relates to a filter, and more particularly, to a tunable filter capable of varying filter characteristics such as the center frequency and bandwidth of the filter by a sliding method.

A filter is a device for passing only a signal of a specific frequency band among input frequency signals, and has been implemented in various forms. The band pass frequency of the RF filter is determined by the inductance component and the capacitance component of the filter, and the operation of adjusting the band pass frequency of the filter is called tuning.

In a communication system such as a mobile communication system, operators are allocated an arbitrary frequency band and divide the allocated frequency band into several channels. In the conventional case, telecommunication operators used to separately prepare filters for each frequency band.

However, in recent years, as the communication environment changes rapidly, it is necessary to change characteristics such as the center frequency and the bandwidth, unlike the initial environment in which the filter is mounted. Tunable filters are used to vary these characteristics.

1 is a view showing the structure of a conventional filter.

Referring to FIG. 1, a conventional filter includes a housing 100, an input connector 102, an output connector 104, a cover 106, a plurality of cavities 108 and a resonator 110.

The RF filter is a device for passing only a signal of a specific frequency band among input frequency signals, and has been implemented in various formats.

A plurality of walls are formed inside the filter, and the cavity 108 defines a cavity 108 in which each resonator is accommodated. The cover 106 is provided with a coupling hole and a tuning bolt 112 for coupling the housing 100 and the cover 106.

The tuning bolt 112 is coupled to the cover 106 and penetrates into the housing. The tuning bolt 112 is disposed in the cover 106 corresponding to a position corresponding to the resonator or a predetermined position inside the cavity.

The RF signal is input by the input connector 102 and output to the output connector 104, and the RF signal proceeds through coupling windows formed in each cavity. A resonance phenomenon of the RF signal is generated by each cavity 108 and the resonator 110, and the RF signal is filtered by the resonance phenomenon.

In the conventional filter as shown in FIG. 1, tuning for frequency and bandwidth is performed by a tuning bolt.

2 is a cross-sectional view of one cavity in a conventional tunable filter.

2, the tuning bolt 112 is penetrated from the cover 106 and positioned above the resonator. The tuning bolt 112 is made of a metal material and is fixed by screwing the cover.

Therefore, the tuning bolt 112 may be adjusted by the distance between the resonator and the tuning by varying the distance between the resonator 110 and the tuning bolt 112. The tuning bolts 112 may be rotated by hand, or a separate tuning machine for the rotation of the tuning bolts may be used. The tuning bolts are held by the nuts if the tuning is done in the proper position.

3 is a view for explaining the principle that tuning is performed by the rotation of the tuning bolt.

Referring to FIG. 3, a capacitance C is formed between the tuning bolt and the resonator. Capacitance is a physical quantity that varies by permittivity, cross-sectional area, and distance between two metals, the distance corresponding to the distance between the tuning bolt and the resonator.

That is, the capacitance is also changed by changing the distance between the tuning bolt and the resonator by the rotation of the tuning bolt. Capacitance is one parameter that determines the frequency of the filter, and the center frequency of the filter may be changed by changing the capacitance.

The conventional filter is a structure that can be tuned by a tuning bolt, but there is a considerable difficulty in the user to tune the characteristics of the filter using the tuning bolt. Substantially, tuning by the tuning bolt was performed by the filter manufacturer in order to match the detailed characteristics after the manufacture of the filter, but it was difficult for the user to tune.

The present invention proposes a sliding frequency tunable filter which can be easily tuned by a user in order to solve the problems of the prior art as described above.

Another object of the present invention is to propose a sliding frequency tunable filter in which a sliding operation for tuning can be made more stably.

Another object of the present invention is to propose a sliding frequency tunable filter capable of adjusting the height of a tuning element with a resonator.

Still another object of the present invention is to propose a slidable tunable filter having a wider tuning range.

According to an aspect of the present invention, a plurality of cavities are defined by the partition walls in order to achieve the object as described above; A sub cover coupled to an upper portion of the housing and having a guide groove formed therein; At least one sliding member installed in the guide groove; A main cover coupled to an upper portion of the sub cover. A resonator accommodated in the cavity; At least one tuning element coupled to a lower portion of the sliding member and inserted into the housing and made of a dielectric material, the tuning is performed by a sliding operation of the sliding member, and at least one side of the sliding member A frequency tunable filter is provided using a sliding method in which at least one first guide member which contacts a side surface of a groove and guides a sliding operation is coupled.

The tunable filter described above may further include at least one second guide member coupled to an upper portion of the sliding member and contacting a lower portion of the main cover to guide the sliding operation.

The first guide member and the second guide member may be elastic bodies, and the elastic bodies may include leaf springs.

In the guide groove of the sub cover, it is preferable that a long hole is formed so that the tuning element is inserted into the housing and freely slides.

The server cover is formed with a bolt hole for inserting the tuning bolt into the housing.

The sliding member is preferably made of Ultem material which is an amorphous thermoplastic polyether amide.

A threaded hole is formed in the sliding member, and an adjustment bolt capable of adjusting a depth to be inserted by rotation is inserted into the threaded hole, and the tuning element is coupled to a lower portion of the adjustment bolt.

The adjusting bolt may be made of the same material as the sliding member.

The tunable filter may further include a driving unit that provides a driving force for sliding the sliding member, and the sliding member may include a coupling hole for coupling with the driving unit.

According to another aspect of the present invention, there is provided a housing comprising: a housing in which a plurality of cavities are defined by partitions; A resonator accommodated in the cavity; At least one sliding member mounted on the resonator; And a tuning element made of a dielectric material coupled to the lower portion of the sliding member, wherein the sliding member has a threaded hole formed therein, and an adjustment bolt capable of adjusting a depth inserted by rotation is inserted into the sliding member. The element is provided with a frequency tunable filter using a sliding method coupled to the bottom of the adjustment bolt.

The present invention has the advantage that the user can easily tune and the sliding operation can be made more stable.

In addition, the present invention has the advantage that it is possible to secure a wide tuning range by allowing the height adjustment of the tuning element of the tuning element for tuning.

1 is a view showing the structure of a conventional tunable filter.
2 is a cross-sectional view of one cavity in a conventional tunable filter.
3 is a view for explaining the principle that tuning is performed by the rotation of the tuning bolt.
Figure 4 is an exploded perspective view of a sliding frequency tunable filter according to an embodiment of the present invention.
5 is a perspective view of a sliding member according to an embodiment of the present invention.
6 is a top plan view of the sliding member according to an embodiment of the present invention.
7 is a cross-sectional view of the sliding member according to an embodiment of the present invention.
8 is a diagram illustrating a structure of a sub cover of a tunable filter according to an embodiment of the present invention.
9 is a cross-sectional view illustrating an installation state of a sliding member installed between an upper cover and a sub cover according to an embodiment of the present invention, and FIG. 10 is a guide groove of a sub cover of a sliding member according to an embodiment of the present invention. Top view showing the state attached to the.
11 illustrates a cross-sectional view of a cavity of one of the tunable filters in accordance with one embodiment of the present invention.
12 and 13 illustrate a coupling relationship between a sliding member and a driving unit sliding the sliding member according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the frequency tunable filter of the sliding method according to the present invention.

4 is an exploded perspective view of a sliding type tunable filter according to an embodiment of the present invention.

Referring to FIG. 4, the frequency tunable filter according to an embodiment of the present invention includes a housing 400, a main cover 402, a sliding member 404, a sub cover 406, a plurality of cavities 408, and a plurality of tunable filters. May include a resonator 410, an input connector 412, and an output connector 414.

The housing 400 protects components such as a resonator inside the filter and serves as a shield for electromagnetic waves. The housing 400 may be a housing in which a base is formed of aluminum and plated thereto. RF equipment such as filters and waveguides typically use silver plating with excellent electrical conductivity to minimize losses. In recent years, a plating method other than silver plating may be used to improve properties such as corrosion resistance, and a housing using such plating method may be used.

The sub cover 406 is coupled to the housing at the upper portion of the housing, and may be coupled to the housing and the bolt through a plurality of fastening holes. A guide groove 420 is formed in the sub cover 406 so that the sliding member 404 can be slidably operated.

A plurality of partitions are formed inside the filter, which define the cavity 408 in which the resonators 410 are accommodated together with the housing 400 of the filter. The number of cavities and resonators is associated with the order of the filter, and FIG. 4 shows the case of order 8, i.e., eight resonators. The order of the filter is associated with insertion loss and skirt characteristics. The higher the order of the filter, the higher the skirt characteristics but the lower the insertion loss trade-off relationship. The order of the filter is set by the required insertion loss and skirt characteristics. Although a cylindrical resonator is illustrated in FIG. 4, various types of resonators, such as a disk type resonator, may be used.

Some of the barrier ribs have coupling windows corresponding to the propagation directions of the RF signal. The RF signal resonating by the cavity and the resonator proceeds through the coupling window to the next cavity.

The main cover 402 is coupled to the upper portion of the sub cover 406 and may be fastened by bolt coupling.

The sliding member 404 is provided to be slidable in a direction perpendicular to the direction in which the resonator stands, that is, in a horizontal direction. The sliding member 404 is installed in the guide groove formed on the upper part of the sub cover, and may be slid in an automated manner by using a motor or may be slid by a user by hand. The installation structure of the sliding member 404 will be described in detail with reference to the separate drawings.

The number of sliding members 404 may correspond to the number of resonator lines formed in the filter. 4 shows a filter having two resonator lines in which four resonators are distributed in each line, and the number of sliding members 404 is correspondingly two.

The tuning element 430 is coupled to the lower portion of each sliding member. The tuning element 430 penetrates into the filter through a hole formed in the sub cover 406, and the tuning element 430 may be a dielectric material, and preferably, a ceramic material.

The tuning element 430 is coupled to the lower portion of the sliding member 404 corresponding to the resonator 410 provided in the filter, and the corresponding tuning element is provided for each resonator. There are four resonators under each sliding member 404, so four tuning elements 430 are coupled to the sliding member 404. Also, the spacing of the tuning elements to be joined corresponds to the spacing of the resonators.

The sliding member 414 to which the tuning element is coupled is used to tune the filter of the user. The tuning of the rotation method by the tuning bolt is not only troublesome to tune, but also requires a lot of time due to individual tuning.

According to the exemplary embodiment of the present invention, the tuning is performed by the sliding member 404 to which the tuning element 430 is coupled, so that simple and collective tuning is possible.

The position of the tuning element 430 coupled corresponding to the sliding of the sliding member 404 is also varied. The tuning element 430 forms capacitance by interaction with the resonator 410, and when the position of the tuning element 430 is changed, the capacitance is changed.

The capacitance is determined by the distance between the two metal bodies and the dielectric constant between the two metal bodies. As the position of the tuning element of the dielectric material is changed, the capacitance is varied and tuning of the filter characteristics is possible.

When there are a plurality of sliding members, the sliding members may be independently slid and may be collectively slid by one motor. In case of sliding in a lump, all the resonators of the filter can be tuned in a lump, and even if they are slid independently, the tuning efficiency is significantly increased compared to the tuning by a conventional tuning bolt.

Although not shown in FIG. 4, a tuning bolt for tuning at the time of manufacture of a filter may be inserted into the filter from the sub cover 406, and the role of the inserted tuning bolt may be the same as that of a conventional filter.

5 is a perspective view of a sliding member according to an embodiment of the present invention, FIG. 6 is a top plan view of the sliding member according to an embodiment of the present invention, and FIG. 7 is a cross-sectional view of the sliding member according to an embodiment of the present invention. to be.

5 to 7, the tuning elements 430 are coupled to the sliding member at predetermined intervals, and as described above, the intervals of the tuning elements 430 correspond to the intervals between the resonators.

Referring to FIG. 7, the tuning element 430 has a cylindrical rod shape. However, the shape of the tuning element 430 of the present invention is not limited thereto, and it will be apparent to those skilled in the art that the tuning element 430 may be implemented in various shapes capable of varying capacitance.

5 to 7, a plurality of first guide members 500 are coupled to one side of the sliding member 404, and a plurality of second guide members 502 are coupled to an upper portion of the sliding member. 5 to 7 illustrate a case in which the first guide member 500 is coupled to only one side, but the first guide member 500 may be coupled to both sides of the sliding member 404.

The first guide member 500 and the second guide member 502 function to guide sliding so that the sliding member 404 slides stably. The sliding member 404 should be slid only in the length (vertical) direction, and the vertical movement or the horizontal movement should be eliminated when sliding.

The first guide member 500 and the second guide member 502 remove unnecessary movement in the vertical direction or the horizontal direction, and allow the sliding member to slide only in a predetermined direction.

According to a preferred embodiment of the present invention, the first guide member 500 and the second guide member 502 are made of an elastic material, preferably may be implemented as a leaf spring.

5 to 7, the first guide member 500 and the second guide member 502 have a leaf spring structure in which a plurality of wing portions 500a and 502a having elastic force are formed. The elastic force of the elastic body has an advantage of preventing the sliding member from moving in a direction other than the sliding direction and minimizing frictional force when sliding.

The wing parts 500a and 502a come in contact with the side surfaces of the guide grooves formed in the sub cover and the main cover, and allow stable guide operation by the elastic force.

In addition to the structure illustrated in FIGS. 5 to 7, the elastic body may be used as the guide member in various forms, and it will be apparent to those skilled in the art that such deformation is included in the scope of the present invention.

According to a preferred embodiment of the present invention, means are provided for adjusting the depth at which the tuning element 430 is inserted into the filter. Therefore, according to the present invention, the tuning to adjust the insertion depth of the tuning element can be performed simultaneously with the tuning by sliding, thereby ensuring a wider tuning range.

Hereinafter, a structure for adjusting the insertion depth of the tuning element 430 will be described with reference to FIG. 7.

The material of the sliding member 404 may be selected from one of various dielectric materials, and preferably, may be formed of a plastic material.

A plurality of adjustment bolts 700 are coupled to the sliding member 404 corresponding to each tuning element 430. The sliding member 404 is formed with a threaded hole 702 for the insertion of the adjustment bolt 700.

According to a preferred embodiment of the present invention, the adjustment bolt 700 is preferably made of the same material as the sliding member 404.

The tuning element is coupled to the bottom of the adjustment bolt 700, and preferably the tuning element is coupled by means of an adhesive method. The sliding member 404 and the adjusting bolt 700 are preferably made of Ultem material, which is an amorphous thermoplastic polyamide amide, for stable adhesion between the plastic-based adjusting bolt 700 and the ceramic-based tuning element 430. .

When the common adhesive 3M Scotch-weld or Epoxy DP-460 off-white is used, the most stable adhesion can be obtained if the material of the adjusting bolt is Ultem.

The user may adjust the depth at which the tuning element 430 is inserted into the filter by adjusting the depth at which the adjusting bolt 700 is inserted by rotating the adjusting bolt 700. When the adjustment of the depth in which the bolt is inserted can be adjusted by the nut 704 the insertion depth of the bolt.

5 to 7, two coupling holes 520 and 522 are formed at one end of the sliding member. The coupling holes 520 and 522 are holes for engaging with the driving unit that is slid by the motor when the sliding member 414 is slid by the driving unit such as a motor. Coupling relationship between the sliding member and the motor will be described later through separate drawings, and the driving unit and the sliding member may be coupled through the coupling holes 520 and 522. According to one embodiment of the present invention, the coupling holes 520 and 522 are formed with threads, and the sliding member may be coupled by screw coupling.

The other end of the sliding member 404 does not have to be formed with a hole, and can be installed only on the filter so as to be able to hang on a specific structure to be freely slidable. For example, a method of forming a jaw to which the sliding member can be worn at the end of the filter can be used.

8 illustrates a structure of a sub cover of a tunable filter according to an embodiment of the present invention.

Referring to FIG. 8, a guide groove 420 for guiding the sliding member operation is formed in the sub cover, and a plurality of long holes 802, 804, 806, and 808 are formed in the guide groove. In addition, a plurality of bolt holes 810 may be formed in the sub cover so that the tuning bolts may be inserted into the filter. As mentioned above, the tuning bolts can be used for initial tuning in filter manufacture.

A number of long holes 802, 804, 806, and 808 are formed. The long holes 802, 804, 806, 808 are holes formed for free movement of the tuning element 430 inserted into the filter. This is because if the hole is not formed long, it may interfere with the sliding operation.

The plurality of long holes 802, 804, 806, 808 are set at positions formed corresponding to the positions of the tuning elements 430 penetrating from the cover. Since the spacing of the tuning elements corresponds to the spacing between the resonators, the spacing of the long holes corresponds to the spacing of the resonators and the tuning element 430.

The long holes 802, 804, 806, and 808 are formed so as not to affect the sliding motion, and the length of the long holes 802, 804, 806, and 808 may be determined by the sliding range of the sliding member 404. .

9 is a cross-sectional view illustrating an installation state of a sliding member installed between an upper cover and a sub cover according to an embodiment of the present invention, and FIG. 10 is a guide groove of a sub cover of a sliding member according to an embodiment of the present invention. It is a top view which shows the state mounted in the.

9 and 10, the end of the wing portion of the first guide member 500 having elastic force is in contact with the side surface of the guide groove 800, and the wing portion 502a of the second guide member 502 having elastic force. The end of) contacts the top cover.

 Since only the ends of the wing parts 500a and 502a contact the side surfaces of the guide grooves and the lower part of the main cover, frictional forces generated during the sliding process can be minimized. In addition, since the wing portions 500a and 502a have an elastic force, a stable contact state can be maintained to prevent the sliding member from moving in a direction other than the sliding direction.

11 illustrates a cross-sectional view of one cavity of a tunable filter according to an embodiment of the present invention.

Referring to FIG. 11, a cavity is provided with a resonator 410. The resonator may be fixed to the lower part of the filter by screwing, and may be formed integrally with the housing of the filter. As described above, a resonator having a cylindrical shape is illustrated in FIG. 11, but the shape of the resonator is variously changed. Can be.

Above the resonator is a tuning element 430 inserted from the sliding member through the long hole of the sub-cover. Also, the tuning bolt 1100 inserted through the bolt hole of the sub cover is positioned on the resonator.

As the sliding member 404 slides, the tuning element 430 coupled thereto also slides. The permittivity changes as the tuning element 430 moves, and thus the capacitance value changes.

12 and 13 are views illustrating a coupling relationship between a sliding member and a driving unit sliding the sliding member according to an embodiment of the present invention.

Referring to FIG. 12, the driving unit includes a motor 1200, a screw 1202 coupled to the motor, and an intermediate member 1204 coupled to the screw 1202.

The motor 1200 provides a rotational force, and the rotational force of the motor 1200 is provided to the screw 1202. The screw 1202 converts the rotational movement of the motor 1200 into a horizontal movement. The intermediate member 1204 is formed with a screw hole for coupling the screw 1202, the intermediate member 1204 moves in the horizontal direction of the left and right corresponding to the rotation of the screw 1202.

An upper portion of the intermediate member 1204 is formed with a coupling hole 1206 for engaging with the sliding member 414. The coupling hole 1206 formed on the upper portion of the intermediate member corresponds to the coupling hole formed at one end of the sliding member, and two holes are formed with threads so that the intermediate member 1204 and the sliding member 414 are formed by screwing. Can be combined. Of course, the coupling method is not limited to screw coupling, and various coupling methods may be used.

The driving unit as described above may be built in the filter, or may be provided outside. When provided on the outside, a part of the sliding member may protrude to the outside and be coupled with the intermediate member of the driving unit.

Claims (6)

A housing in which a plurality of cavities are formed;
A resonator accommodated in the cavity;
At least one sliding member mounted on the resonator;
A sub cover coupled to an upper portion of the resonator and a lower portion of the sliding member ;
A main cover coupled to the sub cover and the sliding member; And
Comprising a tuning element of the dielectric material coupled to the lower sliding member,
A threaded hole is formed in the sliding member, and an adjustment bolt capable of adjusting a depth to be inserted by rotation is inserted into the hole, and the tuning element is coupled to a lower portion of the adjustment bolt, and the sub cover includes the A frequency tunable filter using a sliding method, characterized in that a guide groove for guiding the sliding operation of the sliding member is formed. The method of claim 1,
And a long hole is formed in the guide groove of the sub cover to allow the tuning element to be inserted into the housing and to be freely slidable. The method of claim 2,
And at least one first guide member coupled to at least one side of the sliding member and at least one second guide member coupled to an upper portion of the sliding member. The method of claim 3,
The frequency tunable filter using the sliding method, characterized in that the first guide member and the second guide member is an elastic body. 5. The method of claim 4,
The elastic body is a frequency tunable filter using a sliding method characterized in that it comprises a leaf spring. The method of claim 1,
The sliding member and the adjustment bolt is a frequency tunable filter using a sliding method, characterized in that made of Ultem material which is an amorphous thermoplastic polyamide amide.

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