KR20040107892A - Radio frequency filter - Google Patents

Abstract

PURPOSE: A radio frequency filter is provided to allow for ease of manufacture and assembly and reduce manufacturing costs, by arranging a housing with an accommodation space extended in a lengthwise direction. CONSTITUTION: A radio frequency filter(700) comprises a housing(701), a fixed frame(702), a metal resonance rod(721), a window rod(725), and a front cover(704a) and a rear cover(704b). The housing has an accommodation space(711b) extended in a lengthwise direction, and both ends which are opened. The fixed frame is fixed at a bottom of the accommodation space of the housing, and extended in a lengthwise direction of the housing. The metal resonance rod is extended upward into a predetermined height from the fixed frame. The window rod is extended upward into a predetermined height from the fixed frame. The front cover and the rear cover are coupled to both ends of the accommodation space so as to close the accommodation space. The metal resonance rod and the window rod are alternately arranged in a lengthwise direction of the fixed frame.

Description

Radio Frequency Filter {RADIO FREQUENCY FILTER}

The present invention relates to a radio frequency filter, and more particularly, to a radio frequency filter which is easy to manufacture and low in production cost.

Typically, radio frequency filters are used to pass, stop, and time delay signal frequency bands. The resonance frequency of the radio frequency filter is adjusted by adjusting means such as a tuning screw, thereby adjusting the characteristics of the radio frequency filter.

Hereinafter, the conventional radio frequency filter 100 will be described with reference to FIGS. 1 to 6.

1 is a perspective view illustrating a radio frequency filter 100 provided with a disc-shaped metal resonator rod 120 according to an exemplary embodiment. As shown in FIG. 1, the radio frequency filter 100 according to an exemplary embodiment includes a housing 110, a disc-shaped metal resonator rod 120, a cover 160, and tuning screws 170 and 175. It is configured by.

The housing 110 includes an input connector 111 and an output connector 113, the inside of which is separated into a plurality of receiving spaces by the diaphragm 130, so that the disc-shaped metal resonant rods 120 each have a receiving space. Is accommodated in. The input connector 111 and the output connector 113 are provided on the same side of the housing 110, respectively, and are connected to one selected accommodation space. In addition, the diaphragm 130 has coupling windows 131, 132, 133, 134, and 135 connected in series from the accommodation space to which the input connector 111 is connected to the accommodation space to which the output connector 113 is connected. Is formed. The upper surface of the housing 110 is opened, and the upper end of the housing 110 is sealed by the cover 160 when the disc-shaped metal resonant rod 120 is accommodated in each receiving space.

The disc-shaped metal resonance rod 120 includes a metal resonance rod 121 extending from the bottom surface of the housing 110 and a disc 122 extending in the radial direction along the upper outer peripheral surface of the metal resonance rod 121. It consists of.

The radio frequency filter 100 provided with the disk 122 on the upper end of the metal resonator rod 120 assembled in the housing 110 has a characteristic of operating for a low resonance frequency.

1 to 6, the correlation between the resonance frequency and the housing 110, the disc-shaped metal resonance rod 120, the diaphragm 130, and the cover 160 will be described.

In general, the resonant frequency is the capacitive component 17 and the inductive component 19 constituting the resonant circuit, that is, the housing 110, the disc-shaped metal resonant rod 120, and the diaphragm ( 130 and the cover 160 are determined by the capacitance and inductance values formed between each other.

Meanwhile, referring to FIGS. 4 and 5, the input connector 111 and the output connector 113 are respectively connected to the disc-shaped metal resonant rods 120 by the input end coupling copper wire 115 and the output end coupling copper wire 117. Connected.

The resonant frequency of the radio frequency filter 100 configured as described above is influenced by the length, outer diameter, etc. of the disc-shaped metal resonant rod 120, and more precisely adjusted by using separate tuning screws 170 and 175. Done.

Referring to FIG. 1, the tuning screws 170 and 175 are fastened to the cover 160 in correspondence with the position of the disc-shaped metal resonant rod 120 accommodated in the housing 110, and formed in the diaphragm 130. It is also fastened to a position corresponding to the coupling window (131 to 135). The tuning screws 170 and 175 are used to adjust the resonance characteristics and coupling characteristics of the radio frequency filter 100, and after adjusting the resonance characteristics and coupling characteristics, to prevent the flow of the tuning screws 170 and 175. It is fixed by the nut 171. A fastening hole 169 for a screw 179 is formed in the cover 160, and a fastening tab 180 is formed at an upper end of the housing 110, so that the cover 160 of the housing 110 is formed. It is fixed at the top.

The tuning screws 170 and 175 are fastened to a screw hole (not shown) formed in the cover 160 and used to adjust the resonance frequency, inductance or capacitance. That is, the radio frequency filter 100 is tuned by tightening or releasing the tuning screws 170 and 175 to obtain desired resonance characteristics and coupling characteristics. When the tuning of the radio frequency filter 100 is completed, the tuning screw 170, 175 flows so that the tuning screw using a nut 171 or the like to prevent the resonance frequency, resonance characteristics and coupling characteristics from changing. Fixes 170 and 175 on the cover 160.

On the other hand, the tuning screw 170, 175 is fixed to a position corresponding to the disk-shaped metal resonator rod 120, the first tuning screw 170 used to adjust the resonance characteristics, and the coupling window (131 to 135) The second tuning screw 175 is fixed to a position corresponding to and used to adjust the coupling characteristics. The second tuning screw 175 may also be referred to as a coupling screw. The first and second tuning screws 170 and 175 may have different roles depending on their positions.

Hereinafter, the operation of the radio frequency filter 100 will be described with reference to FIGS. 1 and 6.

First, the input end coupling copper line 115 and the output end coupling copper line 117 provide inductive couplings 52 and 58, and the housing 110, the disc-shaped metal resonant rod 120, and the cover 160. Parallel LC resonant circuits (10, 11, 12, 13, 14, 15) are configured, and the respective resonant circuits (10 to 15) are adjacent to each of the disk-shaped metal resonant rods 120 adjacent to each other. Between the disk-shaped metal resonator rod 120 and the housing 110, the coupling window (131 to 135) by the mutual relationship of each of the capacitive (17) or inductive (19) coupling is provided.

When a radio frequency signal (radio frequency signal) is applied to the input connector 111, an electric field energy is formed as a current flows through the input end coupling copper wire (115). The electromagnetic field energy is transmitted to the parallel LC resonant circuit 10 including the housing 110, the disc-shaped metal resonator rod 120, and the cover 160. Electromagnetic energy delivered to the parallel LC resonant circuit 10 is transmitted to the next parallel LC resonant circuit 11 adjacent only to the frequency energy corresponding to the resonant frequency F ₀ of the parallel LC resonant circuit 10, and other frequencies. Energy is grounded (G). An inductive coupling 53 is provided between the parallel LC resonant circuit 10 and the next parallel LC resonant circuit 11 adjacent to transmit frequency energy corresponding to the resonant frequency. As described above, the radio frequency filter 100 is configured in series with alternating parallel LC resonant circuits 10 to 15 and inductive or capacitive coupling between the input connector 111 and the output connector 113. .

Therefore, the frequency signal applied to the input connector 111, only the signal corresponding to the resonant frequency of the parallel LC resonant circuit (10 to 15) is output through the output connector 113.

However, the conventional radio frequency filter has a plurality of diaphragms in the housing, so that the housing has to be manufactured through a high-precision casting process such as die casting, or has to be manufactured by processing using milling or the like. This causes a problem that the manufacturing cost of the radio frequency filter is increased. That is, a casting process such as die casting is disadvantageous for small quantity production due to high mold making cost, and a method such as milling process is advantageous for small quantity production but disadvantageous for mass production. Moreover, since the metal resonant rods must be fixed to the respective accommodation spaces, the assembly process becomes cumbersome.

In order to solve the above problems, an object of the present invention is to provide a radio frequency filter which is easy to manufacture and low manufacturing cost.

Another object of the present invention is to provide a radio frequency filter that is easy to assemble.

In order to achieve the above object, the present invention provides a radio frequency filter,

A housing having a receiving space extending in the longitudinal direction, the both ends of which are configured as open ends;

A fixed frame fixed to a bottom surface of the accommodation space of the housing and extending in the longitudinal direction of the housing;

At least one metal resonator rod extending upwardly from the fixed frame to a predetermined height;

At least one window rod extending upwardly from the fixed frame to a predetermined height, respectively;

A tuning screw fastened to an upper surface of the housing and having an end thereof facing an upper end of the metal resonance rod in the receiving space; And

It is coupled to both ends of the accommodation space, and provided with a front cover and a rear cover to seal the accommodation space,

The metal resonance rod and the window rod disclose a radio frequency filter arranged alternately along the longitudinal direction of the fixed frame.

1 is a perspective view showing a radio frequency filter according to a conventional embodiment,

FIG. 2 is a partially cutaway perspective view illustrating a configuration of the radio frequency filter illustrated in FIG. 1;

3 is a side cross-sectional view showing a cut part in the configuration of the radio frequency filter shown in FIG.

4 is a perspective view showing the inside of the input terminal of the radio frequency filter by cutting along the line B shown in FIG.

5 is a perspective view showing the inside of the output terminal of the radio frequency filter by cutting along the line C shown in FIG.

6 is an equivalent circuit diagram for explaining the operation of the radio frequency filter shown in FIG.

7 is an exploded perspective view showing a radio frequency filter according to an embodiment of the present invention;

<Description of Major Symbols in Drawing>

700: radio frequency filter 701: housing

702: fixed frame 721: metal resonant rod

725: window rod 704a: front cover

704b: back cover

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

FIG. 7 is an exploded perspective view illustrating a radio frequency filter 700 according to a preferred embodiment of the present invention, and shows a portion of the housing cut away.

As shown in FIG. 7, the radio frequency filter 700 according to an exemplary embodiment of the present invention includes a fixed frame in which the housing 701, the metal resonant rod 721, and the window rod 725 extend in parallel in one direction. 702, front cover 704a, and rear cover 704b.

The housing 701 has accommodation spaces 711a and 711b extending along the longitudinal direction, and both ends of the accommodation spaces 711a and 711b are configured as open ends. The accommodation spaces 711a and 711b are divided into two spaces by the diaphragm 713a extending in the longitudinal direction of the housing 701. One end of the diaphragm 713a is in contact with one end of the housing 701, and the other end of the diaphragm 713a is spaced apart from the other end of the housing 701 by a predetermined width. Therefore, between the other end of the housing 701 and the other end of the diaphragm 713a, the accommodation spaces 711a and 711b divided into two are communicated with each other through a predetermined amount of space. Meanwhile, a coupling screw 703b may be fastened to a space between the diaphragm 713a and the other end of the housing 701. The coupling screw 703b may be used to adjust the coupling characteristics between the two divided receiving spaces 711a and 711b. The coupling screw 703b may be fastened to the bottom of the accommodation spaces 711a and 711b from an upper end of the housing 701.

The housing 701 is generally made of metal, but may be made of synthetic resin according to a product. However, when made of synthetic resin, the coating material of the metal material may be coated on the surface according to the characteristics of the radio frequency filter 700.

The housing 701 configured as described above is composed of the receiving spaces 711a and 711b and the diaphragm 713a extending in the longitudinal direction, so that manufacture using extrusion is possible. The extrusion process has the advantage of low cost compared to the precision casting process such as die casting or the machining process such as milling, regardless of the amount of production. By extrusion, the first housing is manufactured in a kind of frame shape, and finally, after cutting to a length that meets the specifications of the product to be produced, fastening holes, screw holes, etc. are formed. In this case, the housing 701 may be divided into two or more spaces, depending on the product, and may be configured as a single space without being divided by the diaphragm 713a. .

The fixing frame 702 extends in the longitudinal direction of the housing 701 and is fixed to bottom surfaces of the housing 701 accommodation spaces 711a and 711b. The fixing frame 702 shown in FIG. 7 is fastened to the bottom surfaces of the accommodation spaces 711a and 711b by a fastening means such as a screw, but according to an embodiment, the fixing frame 702 may be connected to the bottom surfaces of the accommodation spaces 711a and 711b. A slot having a predetermined shape extending in the longitudinal direction may be formed, and a rail having a shape corresponding to the slot may be formed and inserted at a lower end of the fixing frame 702. Further, according to an embodiment, the fixing frame 702 may be inserted. Slots may be formed on the lower surface of the), and rails may be formed on the lower surfaces of the accommodation spaces 711a and 711b.

The metal resonance rod 721 extends in one direction from the fixed frame 702, and a screw hole 723 is formed at an upper end thereof. The number of the metal resonance rods 721 may be configured differently according to the specifications required for the radio frequency filter 700. The disk 705 is fastened to the upper end of the metal resonance rod 721. Therefore, one surface of the disk 705 is provided with a screw rod 751 corresponding to the screw hole 723 formed on the top of the metal resonance rod 721. In addition, the other surface of the disk 705 is formed with a tuning hole 753 recessed to a predetermined depth. The disk 705 is preferably spaced apart from the upper surface of the receiving space (711a, 711b) by a predetermined width.

The window rod 725 extends in a direction parallel to the metal resonance rod 721 from the fixed frame 702, and a screw hole 727 is formed at an upper end thereof. The height from the lower end of the fixed frame 702 to the upper end of the window rod 725 corresponds to the heights of the accommodation spaces 711a and 711b. Meanwhile, depending on the product, the height of the window rod 725 may be lower than the height of the accommodation spaces 711a and 711b, and the screw hole 727 may not be formed.

The metal resonator rods 721 and the window rods 725 are alternately arranged along the longitudinal direction of the fixed frame 702.

The metal resonator rods 721 and the window rods 725 are formed integrally with the fixed frame 702, and may be manufactured by machining, mold, extrusion, or the like. After fabricating a frame having a space, the fixed frame 702, the metal resonator rod 721 and the window rod 725 are simultaneously formed by cutting to an appropriate width.

When the fixing frame 702 is located at the bottom of the accommodation spaces 711a and 711b, a screw is engaged from the bottom of the housing 702 to allow the fixing frame 702 to the bottom of the accommodation spaces 711a and 711b. It is fixed at. In addition, a screw 739 fastened from an upper surface of the housing 701 may be provided and coupled to an upper end of the window rod 725.

On the other hand, the tuning screw 703a is coupled to the upper surface of the housing 701 at a position corresponding to the tuning hole 753 of the disk 705. The tuning screw 703a adjusts the resonance characteristic of the radio frequency filter 700 according to its fastening depth. The tuning screw 703a faces the tuning hole 753 in the accommodation spaces 711a and 711b, and an end thereof may be located in the tuning hole 753 in some cases.

The front cover 704a seals one end of the housing 701. The front cover 704a has a pair of coupling copper wires 745. The coupling wire 745 electrically connects an input or output connector (not shown) and a metal resonator rod 702 adjacent thereto. The front cover 704a is fastened to one end of the housing 701 by fastening means such as a screw. The rear cover 704b is fastened to the other end of the housing 701 to seal the receiving space.

On the other hand, the pair of coupling copper wire 745 is all installed on the front cover 704a, the position may vary depending on the configuration of the radio frequency filter 700. For example, when three metal resonant rods 702 are arranged in one row, the accommodation spaces 711a and 711b of the housing 701 may be configured as a single space, wherein the coupling copper wire 745 is The front cover 704a and the rear cover 704b are respectively installed. Design changes to the radio frequency filter 700 as described above will be readily understood by those skilled in the art.

In the radio frequency filter 700 according to the preferred embodiment of the present invention illustrated in FIG. 7, an equivalent circuit is configured as the radio frequency filter 100 illustrated in FIG. 1. Hereinafter, the operation of the radio frequency filter 700 configured as described above will be described with reference to FIG. 6.

The coupling copper wire 745 in the radio frequency filter 700 provides inductive coupling 52, 58. The parallel LC resonant circuits 10 to 15 are formed by the metal resonant rods 721 and the housing 701, and the parallel LC resonant circuits 10 to 15 are resonant such as resonance frequencies by the tuning screw 703a. The characteristics are adjusted. Each of the resonant circuits 10 to 15 is provided with an inductive or capacitive coupling 53 to 57 by various configurations. For example, inductive or capacitive coupling between the adjacent metal resonance rods 721, inductive or capacitive coupling between the metal resonance rods 721 and the housing 701, and the window rod 725. Inductive or capacitive coupling between the metal resonant rods 721 or the housing 701 adjacent thereto. Coupling characteristics such as the inductive or capacitive coupling 53 to 57 may vary depending on the shape, size, and the like of the window rod 725, which will be appreciated by those skilled in the art to match the characteristics of the radio frequency filter 700. ) You can adjust the size.

When a radio frequency signal is applied to the coupling copper wire 745 on one side of the radio frequency filter 700, electromagnetic energy is formed while current flows. The electromagnetic field energy is transferred to the parallel LC resonant circuit 10 configured by the metal resonant rod 721 and the housing 701. Of the electromagnetic energy transmitted to the resonant circuit 10, the frequency energy corresponding to the resonant frequency of the resonant circuit 10 is transmitted to the next parallel LC resonant circuit 11, and the other frequency energy is grounded (G). Is induced. Between the parallel LC resonant circuit 10 and the next parallel LC resonant circuit 11 adjacent to the parallel LC resonant circuit 10 formed by a structural relationship between the metal resonant rod 721 and the housing 701, the window rod 725, or the like. Frequency energy is transferred through capacitive coupling 53. That is, the frequency energy filtered by the parallel LC resonant circuit 10 is adjacent to the next parallel LC resonant circuit 11 through the inductive or capacitive coupling 53 between the resonant circuit 10 and the resonant circuit 11. Will be delivered to.

Through the above process, the frequency energy corresponding to the resonant frequency of the resonant circuits 10 to 15 is transmitted to the resonant circuit 15 connected to the coupling copper line on the other side. The frequency energy transferred to the resonant circuit 15 connected to the coupling copper wire 745 on the other side generates a current by the inductive coupling 58 of the coupling copper wire 745, and thus, the resonance circuit 10 to. Only a signal corresponding to the resonance frequency of 15) is output through the coupling copper wire.

In the foregoing detailed description of the present invention, specific embodiments have been described. However, it will be apparent to those skilled in the art that various modifications can be made without departing from the scope of the present invention.

As described above, the radio frequency filter according to the present invention has a housing in which a receiving space extending in the longitudinal direction is formed, thereby making it easy to manufacture and having a low manufacturing cost. That is, in the related art, in order to manufacture a housing having a large number of diaphragms formed therein, a radio frequency filter uses a high-precision die casting process or a milling process to increase the individual unit cost of a product due to a high mold manufacturing cost or a machining process. Although there was a problem, the present invention is to manufacture the housing through the extrusion process, to ensure the precision of the product and at the same time lower the individual unit cost to reduce the manufacturing cost of the radio frequency filter. Moreover, the housing manufactured by the extrusion process is manufactured in the form of the first long frame, and can be cut and used at an appropriate length according to the specifications required for the product, thereby actively coping with the specifications of the product. Furthermore, by forming the metal resonant rods and the window rods integrally in one fixed frame, it is easy to install the metal resonant rods and the window rods in the housing. In addition, in the related art, the distance error between the window and the metal resonant rod that may occur in the process of fastening each metal resonant rod to the housing affects the resonance characteristics such as the resonant frequency of the radio frequency filter, but according to the present invention. The filter has an advantage in that the resonance characteristics of the radio frequency filter are stabilized because the distance between the metal resonance rod and the window rod or the metal resonance rod and the metal resonance rod is fixed by manufacturing the metal resonance rod and the window rod in one piece.

Claims (7)

In the radio frequency filter, A housing having a receiving space extending in the longitudinal direction, the both ends of which are configured as open ends; A fixed frame fixed to a bottom surface of the accommodation space of the housing and extending in the longitudinal direction of the housing; At least one metal resonator rod extending upwardly from the fixed frame to a predetermined height; At least one window rod extending upwardly from the fixed frame to a predetermined height, respectively; And It is coupled to both ends of the accommodation space, and provided with a front cover and a rear cover to seal the accommodation space, The metal resonance rod and the window rod are alternately arranged along the longitudinal direction of the fixed frame. According to claim 1, A fastening hole extending downward from an upper surface of the metal resonance rod; And The radio frequency filter, characterized in that it further comprises a disk provided on one surface of the screw rod is fastened to the fastening hole. According to claim 1, And said receiving space is divided into two or more spaces by a longitudinally extending diaphragm. The method of claim 3, wherein The fixed frame is fixed to each of the receiving space divided into the two spaces, the radio frequency filter. The method of claim 3, wherein The diaphragm extends to a position spaced apart from the other end of the housing by a predetermined length so that the receiving space divided into two communicates with each other, and is fastened from an upper surface of the housing to be located in a space between the ends of the diaphragm from the other end of the housing. A radio frequency filter, characterized in that the coupling screw is further provided. According to claim 1, The housing is a radio frequency filter, characterized in that made of a metallic material. According to claim 1, It is fastened to the upper surface of the housing, the end of the radio frequency filter, characterized in that further comprising a tuning screw facing the upper end of the metal resonator rod in the receiving space.