KR101062224B1 - Micro Wireless High Frequency Filter - Google Patents

Abstract

Wireless high frequency filter according to the present invention includes a plate-shaped housing having a plurality of fixed resonator rods; Input and output connectors provided at both ends in the longitudinal direction of the housing and connected to the resonance rods, respectively; And a plate-shaped upper and lower cover mounted to the housing, wherein at least one of the upper and lower covers has a notch pattern for electromagnetically connecting the resonance bars.

High frequency, filter, resonance rod, tuning, insertion loss,

Description

Ultra-compact wireless high frequency filter {MICROMINIATURE RF HIGH FREQUENCY FILTER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wireless high frequency filters, and more particularly, to the structure of ultra-small wireless high frequency filters.

The ultra-small filter used in the frequency band of several GHz to several tens of GHz generally uses a suspended substrate in order to reduce the size of the filter. That is, a pattern is printed on a thin printed circuit board (PCB) to implement a resonator, and the PCB is inserted into a housing as a suspended substrate to construct a filter.

1 is a plan view of a filter having a PCB type resonator according to the prior art, and FIG. 2 is a perspective view of a PCB type resonator provided in the filter of FIG. 1. 1 and 2, a filter according to the prior art includes a PCB 10 provided as a suspended substrate, an outer housing 20 configured to insert and fix the PCB 10, and input and output terminals 30, 35). In particular, the PCB 10 has a predetermined resonance pattern 13 printed on the dielectric substrate 11 in consideration of the frequency band passed by the filter, and has a screw hole for coupling with the external housing 20. 15).

The filter according to the prior art is constructed by coupling the PCB 10 to the outer housing 20 and mounting the cover (not shown). Therefore, the electrical characteristics of the filter may be changed according to an error occurring in the coupling process. In order to solve this problem when the electrical characteristics of the filter are changed, tuning of the filter is performed by artificially removing or adding a part of the resonance pattern 13 printed on the PCB 10, which increases the defective rate of the manufacturing process. There is a problem that the fine tuning is impossible. In addition, in order to artificially tune the filter, it is necessary to repeat the process of releasing and coupling the PCB 10 coupled to the outer housing 20, this coupling and release of the cover causes an additional error of the filter characteristics It can be a cause, and it takes a lot of time and money to tune.

On the other hand, in the design of a small high frequency filter, frequency selectivity is considered as an important design element along with the size and weight of the filter. In general, in order to improve frequency selectivity, many methods of increasing the number of filter resonators are used. However, increasing the number of resonators improves frequency selectivity but increases losses and increases mechanical size and weight, making them unsuitable for ultra-compact filters and causing more assembly and tuning time.

Accordingly, an object of the present invention is to provide a wireless high-frequency filter that can facilitate the process when manufacturing the filter to reduce the process time and cost, and can increase the frequency selectivity without increasing the number of filter resonators.

In order to achieve the above object, the wireless high frequency filter according to the present invention comprises a plate-shaped housing having a plurality of fixed resonant rods; Input and output connectors provided at both ends in the longitudinal direction of the housing and connected to the resonance rods, respectively; And a plate-shaped upper and lower cover mounted to the housing, wherein at least one of the upper and lower covers has a notch pattern for electromagnetically connecting the resonance bars.

As described above, the wireless high frequency filter according to the present invention can reduce the number of resonance rods provided therein, and can reduce the size and weight of the filter.

In addition, it is possible to easily insert the nutch inside and reduce the time spent in the manufacture of the filter.

In addition, it is possible to stably maintain the product characteristics of the high frequency filter in which the nutch is inserted.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Specific details appear in the following description, which is provided to help a more general understanding of the present invention, and it is common knowledge in the art that such specific matters may be changed or modified within the scope of the present invention. It is self-evident to those who have.

Figure 3 is an exploded perspective view of a wireless high frequency filter according to an embodiment of the present invention, showing the overall structure of the filter, Figure 4 is a plan view of a housing provided in the filter according to an embodiment of the present invention, The structure is shown in detail.

3 and 4, a wireless high frequency filter according to an embodiment of the present invention includes a housing 100, input and output terminals 101 and 103 connected to the housing 100, and an upper portion of the housing 100. And upper and lower covers 310 and 350 covering the lower portion.

The housing 100 may be a metal plate 110 made of a material such as iron (Fe), brass (Bs), aluminum (Al), or the like.

The housing 100 is provided with an opening 105 in a longitudinal direction appropriately designed according to the filtering frequency, and is provided with first and second frames 107 and 109 separated from the opening 105. The first and second frames 107 and 109 are provided with a plurality of resonant rods 110 protruding in opposite directions. The plurality of resonator rods 110 are provided to form a predetermined pattern in consideration of attenuation characteristics and insertion loss of the filter. For example, the plurality of resonator rods 110 may be integrally connected to different frames 107 and 109, that is, the first frame 107 and the second frame 109, and may be sequentially arranged to cross each other. For example, the first frame 107 is provided with first, third, fifth, and seventh resonator rods 110a, 110c, 110e, and 110g integrally connected to the first frame 107, and the second frame ( 109 is provided with second, fourth and sixth resonant rods 110b, 110d, and 110f, and the first to seventh resonant rods 110a to 110g are provided with a first frame 107 and a second frame ( 109) arranged in a cross shape with each other. In addition, the protruding lengths of the plurality of resonator rods 110 may be set in consideration of the filtering frequency, and the number of the resonator rods 110 may be set in consideration of attenuation characteristics and insertion loss. The thickness of the 110 may be formed relatively smaller than the thickness of the first and second frames 107 and 109. The housing 100 preferably cuts the opening 105 and the resonant rod 110 simultaneously by cutting a portion of the metal plate integrally formed.

In addition, it is preferable that a plurality of screw holes 150 are formed in the housing 100 at positions facing the ends of the resonator rods 110. For example, a first screw hole 150a penetrating the housing 100 is provided in the second frame 109 facing the end of the first resonator rod 110a formed in the first frame 107. The second screw hole 150b penetrating the housing 100 may be provided in the first frame 107 facing the end of the second resonance rod 110b formed in the second frame 109. have.

The plurality of screw holes 150 are fastened to each of the tuning adjustment screws 210 used to tune the radio frequency filter. That is, the first tuning adjustment screw 210a may be fastened to the first screw hole 150a, and the second tuning adjustment screw 210b may be fastened to the second screw hole 150b, respectively.

Furthermore, in order to prevent the movement of the tuning adjustment screw 210 by an external force not intended by the user, it is supported on the housing 100 and maintains a fixed state of each of the plurality of tuning adjustment screws 210. It is preferable to further provide a plurality of fixing nuts 230 to be made. The fixing nut 230 is to maintain a fixed state of each tuning adjustment screw 210, at least one fixing nut 230 may be fastened to each tuning adjustment screw 210. For example, the first fixing nut 230a may be fastened to the first tuning adjustment screw 210a, and the second fixing nut 230b may be fastened to the second tuning adjustment screw 210b.

In one embodiment of the present invention, the first resonator rod (110a), the second resonator rod (110b), the first screw hole (150a), the second screw hole (150b), the first tuning adjustment screw (210a), the first Although only the structure and coupling of the two tuning adjustment screw 210b, the first fixing nut 230a, and the second fixing nut 230b are illustrated, the structure and the coupling are a plurality of resonant rods 110 and a screw hole 150, respectively. ), The tuning adjustment screw 210, the fixing nut 230 can be applied to all of course.

The tuning adjustment screw 210 is provided to adjust the gap with the plurality of resonator rods 110 provided with a fixed length in a position facing each other. For example, as the tuning adjustment screw 210 is rotated in the clockwise direction, the tuning adjustment screw 210 moves in a direction in which the opposite resonance rod 110 is fixed, and a gap with the resonance rod 110. It is provided to gradually decrease. The value of the capacitance between the resonator rod 110 and the tuning adjustment screw 210 and the value of inductivity due to the change in the length of the tuning adjustment screw 210 entering the opening 105 are It can be determined experimentally, and in this case, it is possible to adjust the wireless high frequency filter to a desired frequency band by using the tuning adjustment screw 210.

The upper cover 310 may be formed of a plate-shaped member that closes the upper portion of the opening 105 provided in the housing 100, and the lower cover 350 closes the lower portion of the opening 105. It may be made of a plate-shaped member.

The upper and lower covers 310 and 350 are implemented to be coupled to the upper and lower portions of the housing 100, respectively. Preferably, the upper and lower covers 310 and 350 may be coupled through the fastening members 371 and 373. That is, the upper and lower covers 310 are provided with a plurality of screw holes 311 and 351 through which the plurality of fixing male screws 371 may pass. In addition, the fixing holes 170 through which the plurality of fixing male screws 371 may pass through the first and second frames 107 and 109 of the housing 100 at positions corresponding to the plurality of screw holes 311 and 351, respectively. This is further formed. Accordingly, the plurality of fixing male screws 371 are respectively provided in the plurality of upper screw holes 311 provided in the upper cover 310, the fixing holes 170 provided in the housing 100, and the lower cover 350. It passes through the plurality of lower screw holes 315 provided, a part of which protrudes through the lower screw holes 315. The plurality of fixing female screws 373 are respectively fastened to the plurality of fixing male screws 371 protruding from each other to couple and fix the upper cover 310, the housing 100, and the lower cover 350. . For example, the first fixing male screw 371a passes through the first upper screw hole 311a, the first fixing hole 170a, and the first lower screw hole 315a to the first fixing female screw 373a. By being fastened, the upper cover 310, the housing 100, and the lower cover 350 are coupled and fixed.

Although in the exemplary embodiment of the present invention, the upper and lower covers 310 and 350 are illustrated to be fixed to the housing 100 through the fastening members 371 and 373, the present invention is not limited thereto. It is sufficient that the upper and lower covers 310 and 350 can be fixed in close contact with the upper and lower portions of the housing 100.

On the other hand, in the design of a small high frequency filter, in order to improve the frequency selectivity, increasing the number of resonators increases the frequency selectivity but increases the loss. However, since the mechanical size and weight are increased, they are not suitable for the micro filter and cause problems that require longer assembly and tuning time. In order to solve this problem, a method of inserting a notch into a filter is attempted, but it is not easy to assemble copper wire and copper plate in a narrow internal space of a micro filter, and an assembly error is large due to unstable assembly. There is a problem that can not be maintained stably.

In consideration of the above points, the wireless high frequency filter according to an embodiment of the present invention is configured to maintain stable product characteristics while maintaining assembly stability. Specifically, in order to maintain assembly stability, a notch pattern 390 is formed on at least one of the upper cover 310 and the lower cover 350.

In addition, the nugget pattern 390 may be formed in a shape for implementing a nugget filter while forming an at least one coupling coupling between non-neighboring resonator rods. For example, a wireless high frequency filter in accordance with one embodiment of the present invention includes a notch filter that forms an cross coupling past two or more resonant rods. Specifically, the nutch pattern 390 is the second resonator rod (110b) and the fifth resonator rod (110e) to facilitate the cross coupling, the second resonator rod (110b) and the fifth resonator rod (110e) Position corresponding to the may be provided in a "c" shape formed relatively long. Accordingly, the wireless high frequency filter of the present invention, like the equivalent circuit shown in FIG. 5, may form a notch filter by the natch pattern 390 between the second resonance rod 110b and the fifth resonance rod 110e. Can be.

Although, in one embodiment of the present invention, one notch pattern for implementing a notch filter is illustrated, the present invention does not limit the number of the notch patterns, and the notch pattern is at least not neighboring resonant rods. It is sufficient if it is possible to form the cross coupling between the livers. For example, the wireless high frequency filter according to the embodiment of the present invention may be provided with two or more notch patterns in order to obtain the characteristics of the notch filter.

Furthermore, the wireless high frequency filter according to an embodiment of the present invention implements a knot pattern having a desired size and location by using an etching technique in order to stably maintain product characteristics. In particular, when the high frequency filter is very small, if the nutch is used as a cover by implementing the nutch on the PCB, it is possible to obtain more stable characteristics than the nipple insertion by the conventional method. In addition, by assembling only a cover on which a nugget pattern is formed, without the step of assembling the nugget into a small high frequency filter, it is possible to easily insert the nugget into the high frequency filter and reduce the time required for the manufacture of the filter. In addition, by inserting by inserting the form of a nugget, there is an advantage that can be reduced in size and weight than conventional filters. Accordingly, the nutch pattern 390 is preferably formed by an etching technique, and more preferably, the at least one cover is made of a printed circuit board (PCB) on which the nutch pattern 390 is formed by an etching technique.

On the other hand, the upper and lower covers 310 and 350 are implemented to be coupled to the upper and lower portions of the housing 100, respectively. Preferably, the upper and lower covers 310 and 350 may be coupled through the fastening members 371 and 373. That is, the upper and lower covers 310 are provided with a plurality of screw holes 311 and 351 through which the plurality of fixing male screws 371 may pass. In addition, the fixing holes 170 through which the plurality of fixing male screws 371 may pass through the first and second frames 107 and 109 of the housing 100 at positions corresponding to the plurality of screw holes 311 and 351, respectively. This is further formed. Accordingly, the plurality of fixing male screws 371 are respectively provided in the plurality of upper screw holes 311 provided in the upper cover 310, the fixing holes 170 provided in the housing 100, and the lower cover 350. It passes through the plurality of lower screw holes 315 provided, a part of which protrudes through the lower screw holes 315. The plurality of fixing female screws 373 are respectively fastened to the plurality of fixing male screws 371 protruding from each other to couple and fix the upper cover 310, the housing 100, and the lower cover 350. . For example, the first fixing male screw 371a passes through the first upper screw hole 311a, the first fixing hole 170a, and the first lower screw hole 315a to the first fixing female screw 373a. By being fastened, the upper cover 310, the housing 100, and the lower cover 350 are coupled and fixed.

Although in the exemplary embodiment of the present invention, the upper and lower covers 310 and 350 are illustrated to be fixed to the housing 100 through the fastening members 371 and 373, the present invention is not limited thereto. It is sufficient that the upper and lower covers 310 and 350 can be fixed in close contact with the upper and lower portions of the housing 100.

6 is a graph illustrating electrical characteristics of the high frequency filter according to the comparative example, and FIG. 7 is a graph illustrating electrical characteristics of the high frequency filter according to the embodiment of the present invention.

The high frequency filter according to the comparative example exemplifies that it is an eleven stage filter having eleven resonant bars, and the high frequency filter according to the embodiment of the present invention is based on the configuration of the high frequency filter according to the embodiment of the present invention. Two resonator rods, and the lower cover has a nutch pattern coupling the second and fifth ends.

6 and 7, when looking at the electrical characteristics of the high frequency filter according to the comparative example and the embodiment, it can be seen that the attenuation of the DC ~ 1400MHz and more than 2600 frequencies are almost similar. It can be seen that a replaceable effect of four resonators can be obtained with one notch. In addition, since the insertion loss of the high frequency filter according to the comparative example is 1.02 [dB] and the insertion loss of the high frequency filter according to the embodiment is 0.58 [dB], the high frequency filter according to the embodiment is relatively higher than the high frequency filter according to the comparative example. The insertion loss is less and efficient.

As described above, according to the above-described wireless high frequency filter of the present invention, a wireless high frequency filter having excellent insertion loss can be easily implemented by using a housing in which the resonant rod is integrally provided. In addition, the at least one cover may be provided with a nutch pattern to reduce the number of resonant rods and to maintain frequency attenuation and to reduce insertion loss.

Meanwhile, in the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. For example, the number of resonant rods, the number of screw holes, and the number of fixing holes disclosed in the above description may be variously changed. In addition, in the above description, the plate-shaped housing and tuning adjusting screw may be made of a material such as iron (Fe), brass (Bs), aluminum (Al), but the present invention is not limited thereto, and the wireless high frequency filter Sufficient material is enough to provide the required conductivity. In addition, although the illustrated notch pattern is provided on the lower cover, it is sufficient that the cover includes the notch pattern, and the position and shape of the notch pattern may be variously changed by those skilled in the art. Of course.

In addition, there may be various embodiments of the present invention, and therefore, the scope of the present invention should be determined by the claims and the equivalents of the claims.

1 is a plan view of a filter having a PCB type resonator according to the prior art,

2 is a perspective view of a PCB type resonator provided in a filter according to the prior art,

3 is an exploded perspective view of a wireless high frequency filter according to an embodiment of the present invention;

4 is a plan view of a housing provided in a filter according to an embodiment of the present invention;

5 is an equivalent circuit diagram of a wireless high frequency filter according to an embodiment of the present invention;

6 is a graph showing electrical characteristics of a high frequency filter according to a comparative example of the present invention;

7 is a graph showing electrical characteristics of a high frequency filter according to an embodiment of the present invention.

Claims (8)

In the wireless high frequency filter, A plate-shaped housing having first and second frames arranged in parallel in the longitudinal direction and having an opening in the longitudinal direction therein; A plurality of first resonator rods formed on one side of the first frame in the opening; A plurality of second resonator rods formed on one side of the second frame in the opening; Input and output connectors provided at both ends in the longitudinal direction of the housing and connected to the resonance rods, respectively; On the one side of the first and second frame, a screw hole is formed in a position facing the first and second resonator rod, respectively, a plurality of fastening to the screw hole, respectively, the degree of protrusion to the opening is adjusted Tuning adjustment screw; And A plate-shaped upper and lower cover mounted to close at least the opening of the housing, The first resonator rods are alternately arranged one by one with the respective second resonator rods, and at least one of the upper and lower covers has a notch pattern for electromagnetically connecting the resonant rods. Wireless high frequency filter. The method of claim 1, The nutch pattern is a wireless high frequency filter, characterized in that one side forms a coupling with the selected one of the plurality of resonator rods, the other side forms a coupling with one other resonator rod. delete The wireless high frequency filter according to claim 1 or 2, wherein at least one of the upper and lower covers is a printed circuit board (PCB) on which the notch pattern is formed by an etching technique. The wireless high frequency filter of claim 1, wherein the housing forms an opening by removing a portion of the metal substrate, and the opening and the resonance rod are formed in the formed opening. The wireless high frequency filter of claim 5, wherein an opening is formed by removing a portion of the metal substrate through a wire cutting method. The wireless high frequency filter according to claim 1, wherein each of the first resonance rod and the second resonance rod is arranged on the same horizontal plane. The wireless high frequency filter according to claim 1, wherein the protruding lengths of the first resonance rod and the second resonance rod are larger than 1/2 of the width of the opening.

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