KR101818109B1 - The frequency-variable filter improving insertion loss - Google Patents

Abstract

A frequency variable filter excellent in insertion loss characteristics is disclosed. The disclosed filter includes a housing 300 forming one or more cavities in a metallic material of arbitrary shape and defining a predetermined window between the cavity and the cavity; A resonator received in the at least one cavity; A cover capable of covering the housing in which at least one arbitrary-shaped through-hole is formed; A tuning skew capable of passing through the through hole of the cover; A driving unit connected to the tuning screw and capable of feeding the tuning screw straight up and down; A frequency variable filter including a control unit capable of controlling the driving unit is disclosed. Particularly, a metal material having a predetermined tube shape is inserted between the through hole formed in the cover and the clearance between the tuning skew, thereby securing a contact point between the cover and the tuning screw, thereby providing a tunable filter having excellent insertion loss characteristics.

Description

TECHNICAL FIELD [0001] The present invention relates to a variable frequency filter capable of improving insertion loss characteristics,

The present invention relates to a filter, and more particularly, to a variable frequency filter for reducing insertion loss by changing a center frequency of a filter and improving contact characteristics between a cover and a tuning screw.

The filter is implemented in various ways as a device that passes only a signal of a specific frequency band among input frequency signals and does not pass the remaining frequency signals. As the communication system is diversified, a communication system appears in various frequency bands, and in order to achieve system integration and operation efficiency, there is a need for a variable frequency filter capable of varying the operating frequency. The present invention has been proposed by the diversification of such a communication system and the necessity of a frequency variable filter of an operator.

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

Referring to FIG. 1, a conventional cavity structure filter includes a housing 100 having a plurality of cavities 105 formed in a metallic material having an arbitrary shape and a predetermined window 107 formed between the cavity and the cavities. A resonator 104 accommodated in the housing, an input connector 102 and an output connector 103, a cover 101 covering the housing in which a predetermined screw tab is formed, a tuning screw 106).

2 is a sectional view taken along the line F-F in which a tuning tuning screw 106 passing through a lid 101 and a resonator 104 formed inside a cavity is formed at a predetermined position inside the resonator 104. As shown in Fig. That is, since the resonator 104 having a predetermined length is connected to the bottom surface of the space in which the predetermined cavity is formed, a cover for covering the cavity is formed on the upper surface, and a predetermined clearance is formed between the air end and the cover. Resonator 104 resonates at a specific frequency. Further, the resonance frequency is changed according to the depth of the tuning screw 106 which is pinched into the resonator. That is, when the tuning screw 106 is inserted into the resonator, an electromagnetic field coupling capacitance between the resonator and the tuning screw is generated, and the generated coupling amount is determined by the resonance frequency of the tuning screw, As you dig deeper into the inside, c becomes larger and the resonant frequency moves to a lower frequency. Therefore, in the conventional RF filter, by adjusting the length of the resonator formed in the cavity and the depth of the tuning screw inserted into the resonator, the position of the tuning screw is fixed by the nut at the center frequency desired by the user, have.

In Korean Patent No. 10-1009276 (Jan. 18, 2011), a filter includes a housing in which a plurality of cavities are defined by barrier ribs; A resonator accommodated in the cavity; A cover coupled to the upper portion of the housing; And a sliding member which is slidably disposed in the first direction on the cover and to which a plurality of tuning elements are coupled, wherein the tuning element is inserted into the filter through the hole formed in the cover and positioned on the resonator, At least one guide hole is formed in the sliding member, and at least one guide protrusion protruding through the guide hole is formed in the cover, and the side portion of the guide protrusion is formed with a guide, which is opposite to the guide in the second direction, There is provided a tunable filter having a stable sliding structure that contacts the inner surface of the hole. According to the disclosed filter, there is an advantage that more stable sliding is possible,

A variable filter device capable of changing a center frequency and a bandwidth is disclosed in Korean Patent Laid-Open No. 10-2015-0016069 (Feb. 11, 2015), wherein the variable filter device comprises a casing forming a cavity therein by coupling a cover and a body; A resonator attached or integrally formed on the lower surface of the cavity; A tuning element including a head and a rod, the rod penetrating the cover and being insertable into the resonator; And a cam disposed on the head and in contact with the head, wherein the degree of insertion of the rod is adjusted by the cam, and the degree of insertion of the rod is adjusted by the cam so that the center frequency of the resonators as well as the coupling amount between the resonators , Which allows the filter performance to be maintained despite a wide range of center frequency shifts.

A filter unit having a sliding member for tuning a frequency band of a frequency signal to be filtered; A communication module for receiving a control signal for controlling tuning of the frequency band; And a control unit for controlling the tuning of the frequency band while moving the sliding member based on the control signal, wherein the control unit controls the sliding member to move the sliding member by a preset reference distance when receiving the control signal A processor; An RF signal generator for generating a frequency signal to be tuned under the control of the processor; And an RF signal detector for detecting an output signal power of the filter unit with respect to the frequency signal generated by the RF signal generator, wherein the processor compares the detected power of the RF signal detector with a predetermined threshold value, Wherein the sliding member repeatedly performs a comparison operation of the detection power and the boundary value while moving the sliding member by the reference distance until it becomes larger than the preset boundary value, is slid corresponding to the rotation of the motor, The processor controls the driving of the motor to move the sliding member by a reference distance and automatically performs tuning of the filter using a control signal transmitted from a remote place.

However, in such conventional techniques, there is a problem that not only a specific frequency is fixed but also a member for varying the center frequency is not in contact with each other and insertion loss is high. Therefore, it is necessary to reduce the insertion loss to vary the center frequency.

Korean Patent No. 10-1009276 Korean Patent Publication No. 10-2015-0016069 International Patent Publication No. W02012 / 138777 A1

In the present invention, a tunable filter capable of changing the center frequency is proposed. In the related art, a screw is fixed by a nut in order to vary the center frequency. However, there is a problem in that insertion of the nut is not sufficient and insertion loss is increased due to the lack thereof.

In order to solve the above problem, an intermediate lid 507 is added in Fig. 5, the intermediate lid 507 is precisely machined to match the diameter of the linear motor tuning screw, and the shape is circular, And the function of the intermediate lid 507 is the same as the function of the tuning screw 508 connected to the driving unit 509. The driving unit 509 is a driving unit, It serves as an intermediate cover for interference fit to eliminate play.

The structure of the present invention includes a housing having one or more cavities formed in a metal material of arbitrary shape and a predetermined window formed between the cavities and the cavities; A resonator received in the at least one cavity; A cover capable of covering the housing in which at least one arbitrary-shaped through-hole is formed; A tuning screw capable of passing through the through hole of the cover; A driving device connected to the tuning screw to transfer the tuning screw; And a frequency variable filter having a control unit capable of controlling the driving unit is formed to solve the problem.

According to the present invention, the contact length of the tuning screw is adjusted by the driving unit and the protruding portion is provided to improve the contact state, thereby adjusting the center frequency of the frequency variable filter and reducing the insertion loss.

1 is a view showing the structure of a conventional filter;
2 is a cross-sectional view of one cavity in a conventional filter;
3 is an exploded perspective view of a frequency tunable filter in which a tuning screw 308 is inserted according to an embodiment of the present invention.
4 is a cross-sectional view of one cavity in the filter shown in Fig. 3; Fig.
5 is an exploded perspective view of a frequency tunable filter in which an intermediate plate 507 according to an embodiment of the present invention is inserted.
6 is a cross-sectional view of one cavity in the filter shown in Fig. 5; Fig.
7 is an exploded perspective view of a variable frequency filter in which a projection-shaped protrusion 711 is inserted according to an embodiment of the present invention.
8 is a cross-sectional view of one of the cavities in the filter shown in Fig. 7; Fig.
9 is an exploded perspective view of a variable frequency filter having protrusions 907 having conductivity and elasticity in the form of protrusions between an intermediate lid 901 and a drive unit 909 according to an embodiment of the present invention.
Figure 10 shows a cross-sectional view of one cavity in the filter shown in Figure 9;

Hereinafter, preferred embodiments of the tunable filter will be described in detail by adjusting the length of the tuning screw by the control of the driving unit according to the present invention with reference to the accompanying drawings.

Example 1

3 is an exploded perspective view of a tunable filter having a structure for adjusting a length of a tuning screw by controlling a driving unit according to an embodiment of the present invention.

3, the tunable filter for adjusting the length of the tuning screw 307 by the driving unit according to an embodiment of the present invention includes a housing 300, a driving unit 308 for varying the length of the tuning screw 307 ); And an intermediate cover 301 connected between the tuning screw 307 and the body 300.

The coupling between the tuning screw 307 and the intermediate cover 301 is an interference fit so that the tuning screw 307 and the intermediate cover 301 are spaced apart from each other in order to reduce the clearance between the tuning screw 307 and the intermediate cover 301. [ The bonding site of the liver requires precision machining.

FIG. 4 is a sectional view of FIG. 3. It is necessary to precisely process the tuning screw 307 and the intermediate cover 301 to minimize the clearance 400 between the tuning screw 307 and the intermediate cover 301 .

Example 2

5 is a view for explaining another embodiment of the present invention. The intermediate plate 507 and the tuning screw 508 are disposed between the driving portion 509 and the intermediate cover 501 so as to substantially cover the intermediate plate 507, And the tuning screw 508 are brought into contact with each other to vary the resonance frequency and reduce the insertion loss.

Fig. 6 is a sectional view of Fig. 5, in which the intermediate plate 507 is additionally provided to minimize the clearance 601 between the intermediate plate 507 and the driving unit shaft 510 of the driving unit 509. Fig.

Example 3

7 is a view for explaining another embodiment of the present invention. The intermediate plate 707 and the tuning screw 708 are disposed between the driving unit 709 and the intermediate cover 701, A protruding portion 711 having protruding conductivity and buffering properties is additionally provided between the intermediate plate 710 and the intermediate plate 707. [ Thus, the contact between the driving shaft 710 of the driving unit 709 and the intermediate lid 701 is facilitated by the elastic action, thereby reducing the insertion loss. The protruding portion 711 is made of a material such as copper, silver, gold, or the like, which is excellent in conductivity.

7 is a cross-sectional view of FIG. 7 showing an intermediate plate 707 and a tuning screw 708 between a driving unit 709 and an intermediate lid 701 and a driving shaft 710 and an intermediate plate 707 of a driving unit 709, It is possible to increase the contact force between the driving shaft 710 and the intermediate lid 701 by providing a protruding portion 711 having a protruding shape and elasticity between the driving shaft 710 and the intermediate lid 701.

Example 4

9 is a view for explaining another embodiment of the present invention. A tuning screw 908 and a protrusion-shaped protrusion 907 having a protruding shape and having conductivity and elasticity are provided between a driving portion 909 and an intermediate lid 901 It is a configuration. Thus, the contact between the driving shaft 910 of the driving unit 909 and the intermediate lid 901 is facilitated by the spring action, thereby reducing insertion loss. The projecting portion 907 is made of a material such as copper, silver, gold, etc., which is excellent in conductivity, and is in the form of a projection having elasticity.

The housings (100, 300, 500, 700, and 900) protect the components such as the resonator inside the filter and shield the electromagnetic wave. The housings 100, 300, 500, 700, and 900 may be formed of aluminum and formed with a base. Typically, RF equipment, such as filters and waveguides, use silver with high 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 a plating method may be used.

The cover 101 is coupled to the housing at the top of the housing, and can be coupled to the housing by bolting, for example. The cover 101 is also made of a metal material. The cover 101 covers the filter portion provided with the cavity and the resonator, but the cover 308 is not covered with the cover.

A plurality of partitions are formed in the filter, which define the cavity in which the resonators are received together with the housing of the filter. The number of cavities and resonators is related to the degree of the filter. The higher the degree of the filter, the higher the skirt characteristic, but the trade-off relation is that the insertion loss is worse. The degree of the filter is set by the required insertion loss and skirt characteristic do. Various types of resonators such as a disk resonator and a cylindrical resonator may be used.

The input connector 102 is a connector to which a RF signal is input and the output connector 103 is a connector to which a filtered RF signal is output. Coupling windows are formed in some of the barrier ribs corresponding to the traveling direction of the RF signal. The RF signal, which is resonated by the cavity and the resonator, travels through the coupling window to the next cavity.

When the tuning element is made of a metal material, the position of the tuning element is varied to change the cross-sectional area between the resonator and the tuning element, thereby changing the capacitance, thereby tuning the filter bandpass characteristic. When the tuning element is made of a dielectric material, the tuning element is tuned by varying the dielectric constant affecting the capacitance while varying the position of the tuning element. A tuning bolt for tuning can be inserted into the filter inside the cover, and the function of the inserted tuning bolt is the same as that of the conventional filter. The shape of the tuning element may be variously selected such as an original plate.

100,300,500,700,900 Housing
101,301,501,701,901 Cover
102, 302, 502,
103,303,503,703,903 Output
104,304,504,704,904 Resonators
105,305,505,705,905 Cavity
106,307,508,708,908 Tuning Screw
107,306,506,706,906 Windows
309,
309,510,710,910 Drive shaft
400,600 shorts
507,707 intermediate plate
711,

Claims (8)

One or more cavities 105, 305, 505, 705, and 905 are formed which are open on one side and are provided for accommodating the resonators 104, 304, 504, 704, and 904 therein, , Housing (100, 300, 500, 700, 900) forming windows (107, 306, 506, 706, 906)
A cover (101, 301, 501, 701, 901) which hermetically seals with the open face of the housing (100, 300, 500, 700, 900) and forms at least one through hole;
Tuning screws (106, 307, 508, 708, 908) having an outer diameter coinciding with an inner diameter of the through holes of the lids (101, 301, 501, 701, 901) and capable of passing through the through holes;
Driving parts (308, 509, 709, 909) for drawing the tuning screws (106, 307, 508, 708, 908) into the inside and vertically feeding the tuning screws;
A control unit for controlling the driving units 308, 509, 709, and 909 is provided,
A metal ring of a tube shape is inserted between the through holes of the lids 101, 301, 501, 701 and 901 and the clearances of the tuning screws 106, 307, 508, 708 and 908, 701 and 901 and the tuning screws 106, 307, 508, 708 and 908,
The driving units 308, 509, 709, and 909 are linear motors,
(100) according to claim 1, further comprising a cover (101, 301, 501, 701, 901) having a circular hole through which the thread of the linear motor can pass, And inserted into the holes of the intermediate plates 507 and 707 arranged between the lids 101, 301, 501, 701 and 901,
The intermediate plates 507 and 707 and tuning screws 106, 307, 508, 708 and 908 are disposed between the driving units 308, 509, 709 and 909 and the lids 101, 301, 501, 701 and 901, Between the drive shaft 309, 510, 710, and 910 of the drive units 308, 509, 709, and 909 and the intermediate plates 507 and 707, protruding portions 711 and 907, The contact between the drive shafts 309, 510, 710 and 910 of the drive units 308, 509, 709 and 909 and the lid 101, 301, 501, 701 and 901 is brought into contact with each other Frequency filter. delete delete delete Claim 1
In order to minimize the clearance between the tuning screws 106, 307, 508, 708 and 908 and the lids 101, 301, 501, 701 and 901, the tuning screws 106, 307, 508, (101, 301, 501, 701, 901) are made to coincide with each other. delete Claim 1
The protruding portions 711 and 907 are made of a material such as copper, silver, gold or the like having excellent conductivity, Claim 1
Tuning screws 106, 307, 508, 708, and 908 are provided between the driving portions 308, 509, 709, and 909 and the lids 101, 301, 501, (711, 907).

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