KR20110119255A - Cavity filter, and frequency band control method thereof - Google Patents

Abstract

PURPOSE: A cavity filter and a frequency band control method thereof are provided to attenuate the electric field which is generated from a resonator by inserting an TE01 mode dielectric into the resonators. CONSTITUTION: In a cavity filter and a frequency band control method thereof, a plurality of resonators(5) are included in a main housing(7). An input connector(1) is connected to one resonator through a main input coupling loop(3). An output connector(2) is connected to the other resonator through a main output coupling loop. The main cover(8) is covered in the top side of the main housing. A plurality of resonator tuning screws(9) controls the resonant frequency of each resonator. A plurality of dielectrics(20) is combined in the main cover.

Description

Cavity filter, and frequency band control method

The present invention relates to a cavity filter mounted on a base station and a repeater and a method of adjusting a frequency band thereof, and more particularly, to resonators having a relatively high magnetic field by inserting a TE 01 mode dielectric between resonators in the cavity filter. The present invention relates to a cavity filter and a method for adjusting a frequency band thereof, which reduce a frequency band by attenuating an electric field formed therebetween.

In general, the cavity filter for mobile base station and repeater is used as a high power channel filter of each transmitter, and it selects the frequency to transmit by suppressing the unwanted signal for each channel and can transmit / receive in both directions. Is also used.

At this time, since the frequency of the cavity filter is determined by the length of the cavity, the intrinsic frequency characteristics should not be changed even in a low temperature and high temperature environment. To this end, the cavity filter is provided inside the cavity filter (Dielectric Resonator) or a metal rod to have a structure that enables the resonance of the ultra-high frequency by having only the electromagnetic at the natural frequency.

In addition, the cavity filter transmits a signal to the antenna at high power at the time of transmission, and at the time of reception, a very weak signal is received by the cavity filter through the antenna, and thus a signal loss may occur when the signal passes through the cavity filter.

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

Referring to FIG. 1, the conventional cavity filter 100 is an input connector for inputting a radio frequency signal from the outside into a main housing 7, which is a rectangular metal box having a predetermined size. (1) and an output connector (2) for outputting an internally filtered frequency is attached to one side.

In addition, one or more resonators 5 having a predetermined dielectric constant are positioned at a predetermined interval inside the main housing 7, and an input connector 1 and an output connector attached to the outside of the main housing 7 are disposed. (2) is connected to a main input coupling loop (Main Input Coupling Loop) 3 and a main output coupling loop (4), respectively, which extend into the main housing 7.

In the conventional cavity filter 100 of this structure, the radio frequency signal introduced through the input connector 1 is converted into an electric field E signal through the main input coupling loop 3 to pass through the resonators 5 and have a constant frequency band. Will form.

At this time, the frequency band width is determined through the interval of the coupling wall 6 between the resonators 5, and the determined frequency signal is output to the outside through the main output coupling loop 4 and the output connector 2. do.

On the other hand, in case of mobile communication, as the carrier returns CDMA frequency, the frequency band is reduced and it is necessary to reduce the frequency bandwidth of the existing filter. The cost used for this is 70 ~ 80% of the filter manufacturing cost. Occupies.

In addition, in the conventional cavity filter 100 having the structure described above, in order to reduce the frequency band width, a method of reworking the apparatus or narrowing the wall between the resonators 5 by using the diaphragm 6 therein was used. However, this also has the disadvantage that it takes more than 60% of the manufacturing cost.

In addition, the conventional cavity filter 100 has a disadvantage in that the frequency band is not narrowly variable even though the metal post (Tuing Screw) is inserted into the diaphragm 6 to expand the electric field E to expand the frequency band. .

An object of the present invention for solving the above problems is to insert a TE01 mode dielectric between the resonators in the cavity filter to increase the magnetic field to attenuate the electric field formed between the resonators relatively to reduce the frequency band The present invention provides a filter and a method of adjusting a frequency band thereof.

Cavity filter according to the present invention for achieving the above object, a plurality of resonators in the main housing, an input connector connected to one of the plurality of resonators through a main input coupling loop and the other of the plurality of resonators A cavity filter having an output connector connected through a main output coupling loop to a resonator, the cavity filter comprising: a main cover covered and fastened to an upper portion of the main housing; A plurality of resonator tuning screws coupled at regular intervals on the main cover at positions corresponding to the plurality of resonators to adjust resonant frequencies of each of the plurality of resonators; And a plurality of dielectrics coupled on the main cover at regular intervals between the plurality of resonator tuning screws.

Here, the plurality of dielectrics are electromagnetic TE 01 mode dielectrics of electric field components having low resonances below a predetermined standard.

In addition, one of the plurality of dielectrics is fastened to the connecting bolt after the screw for fixing the dielectric resonator is inserted into the dielectric resonator for coupling tuning.

In addition, when an arbitrary frequency signal is input to the input connector, the arbitrary frequency signal is transferred from the input connector to the one resonator via the main input coupling loop, and the main input coupling loop is in a traveling direction. An electric field (E) is formed and a magnetic field (M) is formed around the main input coupling loop, and the magnetic field (M) formed around the main input coupling loop is connected to the main input coupling loop. Excited by one resonator and the dielectric closest to each other (M'1), the magnetic field M1 is formed in the circumferential direction while the electric field E1 is formed in the circumferential direction, and the one resonator is formed. The magnetic field M1 is excited by other resonators and other dielectrics in the periphery to form magnetic fields M2 and M'2, respectively. To the magnetic field (Mn) is formed in the magnetic field (M'n) of the plurality of dielectrics respectively, spaced around each resonator is formed here in accordance with the.

The magnetic fields M1 to Mn formed in the plurality of resonators are output to the outside through the main output coupling loop connected to the output connector, and the magnetic fields M'1 to M'n formed by the dielectrics, respectively. As a result of the increase in the overall magnetic field, the electric fields E1 to En formed between the resonators are attenuated relatively to adjust the frequency band.

On the other hand, the frequency band adjustment method of the cavity filter according to the present invention for achieving the above object, a main housing having a plurality of resonators, input connectors connected to the main input coupling loop and output connectors connected to the main output coupling loop A plurality of resonator tuning screws are coupled to a position corresponding to the plurality of resonators to adjust the resonant frequencies of the plurality of resonators, the plurality of resonator tuning screws being coupled between the plurality of resonator tuning screws. A frequency band adjusting method of a cavity filter including a main cover having a dielectric coupled thereto, the method comprising: (a) inputting an arbitrary frequency signal to the input connector; (b) the frequency signal is delivered to one resonator via the main input coupling loop; (c) forming an electric field and a magnetic field in the one resonator; (d) magnetic fields formed in the one resonator are excited by other resonators and dielectrics to form magnetic fields in the other resonators and dielectrics; And (e) the magnetic field formed by the resonator is output to the output connector, the overall magnetic field is increased by the magnetic field formed by the dielectric, and the electric field formed by the resonator and the other resonators is attenuated so that the frequency band is adjusted. Steps.

According to the present invention, due to the mechanical constraints of the existing cavity filter, it is difficult to reduce the used frequency bandwidth, but by using the TE01 mode of the dielectric resonator (DR), it is possible to reduce the frequency bandwidth without modifying the mechanism, This reduces the cost of rebuilding existing instruments.

In addition, it can be recycled by reducing the cost of manufacturing the cavity filter to 15% or less, and was previously adjustable from 1MHz to 2MHz for the frequency band, but can be adjusted from 10MHz to 12MHz according to the present invention.

1 is a perspective view showing the structure of a conventional cavity filter.
2 is a block diagram showing the configuration of a cavity filter according to an embodiment of the present invention.
3 is an exploded perspective view of a dielectric according to an embodiment of the present invention.
4 is a flowchart illustrating a frequency band adjusting method of a cavity filter according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing the configuration of a cavity filter according to an embodiment of the present invention.

Referring to FIG. 2, the cavity filter 200 according to the present invention includes an input connected through a main input coupling loop 3 to a plurality of resonators 5 of FIG. 1 and one of the plurality of resonators. On the top of the main housing 7 in a main housing 7 with an output connector 2 connected via a main output coupling loop 2 to a connector 1 and the other of the plurality of resonators; A main cover 8 to be fastened; A plurality of resonator tuning screws 9 coupled at regular intervals on the main cover 8 at positions corresponding to the plurality of resonators to adjust resonant frequencies of each of the plurality of resonators; And a plurality of dielectric units 20 coupled on the main cover 8 at regular intervals between the plurality of resonator tuning screws 9.

Here, the plurality of dielectrics 20 are electromagnetic wave TE (Transverse Electric Waves) 01 mode dielectrics of electric field components having low resonances below a predetermined reference.

Also, each of the plurality of dielectrics has a coupling DR fix type PC screw 10 coupled to a coupling tuing type dielectric resornator 11 as shown in FIG. 3. After being inserted into the fastening bolt (13). 3 is an exploded perspective view of a dielectric according to an embodiment of the present invention.

Meanwhile, a plurality of resonator tuning screws 9 and a plurality of dielectrics 20 inserted into the main cover 8 are fastened to a tuning screw support nut 12 for fixing to the main cover 8. Are combined.

4 is a flowchart illustrating a frequency band adjusting method of a cavity filter according to an exemplary embodiment of the present invention.

Referring to FIG. 4, when the arbitrary frequency signal is input to the input connector 1 (S410), the cavity filter 200 according to the present invention receives a random frequency signal from the input connector 1 to the main input coupling loop ( It is transmitted to one resonator 5 via 3) (S420).

At this time, the main input coupling loop 3, also called a coupling probe, forms an electric field E in the advancing direction and a magnetic field M around the main input coupling loop 3. S430).

The magnetic field M formed around the main input coupling loop 3 is excited to one resonator 5 and the closest dielectric 20 connected to the main input coupling loop 3. Accordingly, the magnetic field M1 is formed in the outer circumferential direction while the electric field E1 is formed in the circumferential direction in one resonator 5, and the magnetic field M'1 is also formed in the dielectric 20 that is closest (S440). .

In this way, the magnetic field M1 formed in one resonator 5 is excited by the other resonators 5 and other dielectrics 20 in the periphery to form magnetic fields M2 and M'2, respectively. As the magnetic field Mn is formed to the last resonator for each resonator, the magnetic field M'n is excited and formed in each of the plurality of dielectrics spaced around each resonator (S450).

Therefore, the magnetic fields M1 to Mn formed in the plurality of resonators are output to the outside through the main output coupling loop 4 connected to the output connector 2, and the magnetic fields M'1 to M'n formed by the dielectrics, respectively. As the overall magnetic field is increased by), the electric fields E1 to En formed between the resonators 5 are attenuated so that the frequency band is adjusted (S460).

Here, adjusting the tuning screw 9 of the main cover 8 fastened to each resonator 5 changes the distance between the upper surface of the resonator 5 and the tuning screw 9. Therefore, the resonance Q value of the resonator 5 causes the high frequency frequency having the initially set resonance frequency fo to couple to another resonator 5 spaced apart by the distance change. The output of the changed frequency is then achieved by the tuning screw 9 by continuous coupling as described above.

At this time, when the resonance Q value of each of the resonators 5 changes, the resonant frequencies fo of the resonators 5 appear different from each other. Therefore, by adjusting the tuning screws 9 respectively formed in the resonator 5, it is possible to pass only the frequency of the desired band among the high frequency signals input to the input connector 1.

Further, in the cavity filter 200 according to the present invention, the distance between the main input coupling loop 3 and the resonator 5, the distance between the resonator 5 and the main output coupling loop 4, the resonator 5 and The spacing between the other resonators 5 and the spacing between the resonators 5 and the dielectric 20 determine the coupling density of the magnetic field M, and may be said to influence the performance and characteristics of the filter. Therefore, the spacing between components should be designed considering the performance and characteristics of the filter.

As described above, according to the present invention, the electromagnetic field formed between the resonators is attenuated by inserting an electromagnetic wave TE01 mode dielectric of an electric field component having a low resonance below a predetermined standard between the resonators in the cavity filter to increase the magnetic field. Cavity filters for base stations and repeaters that can reduce the frequency band can be realized.

As those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features, the embodiments described above are intended to be illustrative in all respects and should not be considered as limiting. Should be. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

The present invention can be applied to a cavity filter used for a mobile communication repeater or a base station.

In addition, a resonator for generating a resonant frequency and a tuning screw for adjusting the resonant frequency may be applied to a cavity filter requiring adjustment of the frequency band.

In addition, the present invention can be applied to a cavity filter that can adjust the frequency band used by reducing the manufacturing cost without modifying the mechanism.

100: conventional cavity filter 200: cavity filter of the present invention
1: input connector 2: output connector
3: Main input coupling loop 4: Main output coupling loop
5: resonator 6: bulkhead
7: main housing 8: main cover
9: resonator tuning screw 10: DR fixing PC screw
11 DR for coupling tuning 12 Tuning screw support nut
13: connecting bolt 20: dielectric

Claims (6)

The main housing includes a plurality of resonators, an input connector connected through a main input coupling loop to one of the plurality of resonators, and an output connector connected through a main output coupling loop to another resonator of the plurality of resonators. Cavity filter,
A main cover covered and fastened to an upper portion of the main housing;
A plurality of resonator tuning screws coupled at regular intervals on the main cover at positions corresponding to the plurality of resonators to adjust resonant frequencies of each of the plurality of resonators; And
A plurality of dielectrics coupled on the main cover at regular intervals between the plurality of resonator tuning screws;
Cavity filter comprising a.
The method of claim 1,
And the plurality of dielectrics are electromagnetic wave transverse electric waves (TE) 01 mode dielectrics having electric field components having low resonances below a predetermined standard.
The method of claim 1,
Each of the plurality of dielectrics is a cavity filter, characterized in that the screw for fixing the dielectric resonator is inserted into the coupling tuning dielectric resonator (Coupling Tuing type Dielectric Resornator) and then fastened with a connecting bolt.
The method of claim 1,
When an arbitrary frequency signal is input to the input connector, the arbitrary frequency signal is transferred from the input connector to the one resonator via the main input coupling loop, and the main input coupling loop is an electric field in a traveling direction. (E) is formed and a magnetic field (M) is formed around the main input coupling loop, and the magnetic field (M) formed around the main input coupling loop is the one connected to the main input coupling loop. Coupling to the resonator and the closest dielectric (M'1), the magnetic field (M1) is formed in the circumferential direction while the electric field (E1) is formed in the one resonator in the circumferential direction, The formed magnetic field M1 is excited for each of the plurality of resonators in such a manner as to be excited with other resonators and other dielectrics around to form magnetic fields M2 and M'2, respectively. As the magnetic field Mn is formed up to the membrane resonator, magnetic fields M'1 to M'n are also formed in each of the plurality of dielectrics spaced around each resonator, and magnetic fields M1 to M1 formed in the plurality of resonators. Mn) is output to the outside through the main output coupling loop connected to the output connector.
The method of claim 4, wherein
As the overall magnetic field is increased by the magnetic fields M'1 to M'n formed by each of the dielectrics, the electric fields E1 to En formed between the resonators are attenuated so that the frequency band is controlled. Cavity Filter.
A main housing having a plurality of resonators, an input connector connected to a main input coupling loop, and an output connector connected to a main output coupling loop, and covered and fastened on top of the main housing to adjust the resonant frequencies of the plurality of resonators In order to adjust the frequency band of the cavity filter including a plurality of resonator tuning screw coupled to the position corresponding to the plurality of resonator and a plurality of dielectrics coupled between the plurality of resonator tuning screw,
(a) inputting an arbitrary frequency signal to the input connector;
(b) the frequency signal is delivered to one resonator via the main input coupling loop;
(c) forming an electric field and a magnetic field in the one resonator;
(d) magnetic fields formed in the one resonator are excited by other resonators and dielectrics to form magnetic fields in the other resonators and dielectrics; And
(e) adjusting the frequency band by outputting the magnetic field formed by the resonator to the output connector, increasing the overall magnetic field by the magnetic field formed by the dielectric, and attenuating the electric field formed by the resonator and the other resonators; ;
Frequency band adjustment method of the cavity filter comprising a.

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