KR102258012B1 - Band pass filter suitable for error vector magnitude - Google Patents

Abstract

The present invention relates to a band pass filter suitable for error vector magnitude (EVM). The band pass filter comprises: a housing in which first to fifth pockets each having first to fifth resonators provided therein are shielded from the outside; an input port protruding from the housing, connected to the first pocket, and receiving a signal; and an output port protruding from the housing in a direction opposite to the input port, connected to the fifth pocket, and outputting a signal. The present invention can output a value suitable for EVM while maintaining a cavity resonator method instead of a dielectric resonator method. Therefore, the present invention can significantly reduce the manufacturing cost of the band pass filter.

Description

Band pass filter suitable for EVM {BAND PASS FILTER SUITABLE FOR ERROR VECTOR MAGNITUDE}

The present invention relates to a band pass filter. More specifically, it relates to a band pass filter suitable for EVM (Error Vector Magnitude, sometimes also called receive constellation error or RCE).

In general, a filter is a device that functions to pass only a signal in a predetermined specific frequency band, and is classified into a low pass filter, a band pass filter, a high pass filter, and a band stop filter, depending on the frequency band to be filtered.

The important characteristics of the filter are insertion loss and skirt characteristics. Insertion loss refers to the power lost as the signal passes through the filter, and the skirt characteristic refers to the degree to which the passband and stopband of the filter are steep.

The above insertion loss and skirt characteristics are in a trade-off relationship with each other according to the order of the filter. The higher the order of the filter, that is, the greater the number of filters, the better the skirt characteristics but worse the insertion loss.

A method of forming a notch (attenuation pole) is mainly used to improve the skirt characteristics of the filter without increasing the order of the filter. This is a method of enhancing the skirt characteristics of the filter without increasing the order of the filter by forming a notch in a specific frequency band.

On the other hand, the band pass filter is a filter that allows only alternating current of a given upper and lower cutoff frequency to pass, and attenuating all alternating currents of other frequencies. It is made by connecting a low-pass filter and a high-pass filter in series. At this time, the cutoff frequency of the low-pass filter is always higher than that of the high-pass filter.

In addition, EVM (Error Vector Magnitude, sometimes also called receive constellation error or RCE) refers to a modulation quality measure of a signal modulated within a certain spectrum band in a wireless digital communication method.

A band pass filter suitable for EVM currently requires a Group Delay value of 35 ns max.

In order to satisfy such characteristics, a dielectric resonator (DR) may be used. However, the DR method of the dielectric resonator has a problem in that the cost is significantly increased compared to the CR method of a cavity resonator (CR).

1 is a perspective view of a conventional band pass filter made of a cavity resonator, and FIG. 2 is a graph showing output data values of FIG. 1.

Referring to FIG. 1, a band pass filter made of a conventional cavity resonator includes a first pocket 11 in which a first resonator 11a is accommodated, a second pocket 12 in which a second resonator 12a is accommodated, and a third resonator. Resonance through the sequentially opened portions to the third pocket 13 in which (13a) is accommodated, the fourth pocket 14 in which the fourth resonator (14a) is accommodated, and the fifth pocket 15 in which the fifth resonator (15a) is accommodated Can be.

Referring to FIG. 2, the group delay value at 867 MHz (the'△' point on the graph is 862 MHz, and the 4 point is a point where 5 MHz is increased from the'△' point) shows 68.797 ㎱. , There is a problem in that the value required by the band pass filter suitable for the EVM mentioned above is not satisfied.

Korean Patent Registration No. 10-1559083

The present invention is to solve the conventional problems as described above, and an object of the present invention is to provide a band pass filter suitable for EVM that can reduce the filter manufacturing cost by outputting a value suitable for the EVM while maintaining the CR method. It is to do.

In order to achieve the object of the present invention as described above, in the band pass filter suitable for the EVM according to an embodiment of the present invention, the first to fifth pockets in which the first to fifth resonators are respectively provided are shielded from the outside. A housing formed to be; An input port protruding from the housing, connected to the first pocket, and inputting a signal; And an output port protruding from the housing in a direction opposite to the input port, connected to the fifth pocket, and outputting a signal, wherein the housing includes a virtual A first pocket, a third pocket, and a fourth pocket are arranged in a first space including the input port based on a line, and a second pocket and a second pocket are included in a second space that faces the first space and includes the output port. A fifth pocket is disposed, a first partition wall provided between the second pocket and the third pocket and having a first opening opened by a predetermined height from the upper end, and provided between the third pocket and the fourth pocket, and from the upper end. A second partition wall having a second opening opened by a predetermined height, a third partition wall provided between the fourth and fifth pockets and having a third opening opened by a predetermined height from the upper end, the third pocket and the third A fourth partition wall provided between the five pockets and formed with a fourth opening that is opened by a predetermined height from the upper end, and a fifth opening formed between the second and fifth pockets and opened by a predetermined height from the upper end. A partition wall including a partition wall; And a coupling member disposed between the third pocket and the fifth pocket to couple a frequency; further comprising, the third pocket by cross-coupling the third pocket and the fifth pocket by the coupling member. The flatness of the output data value per frequency of the and fifth pockets may be refracted, and the refraction point of the output data value per frequency may be moved by coupling the second pocket and the fifth pocket.

In the band pass filter suitable for the EVM according to an embodiment of the present invention, when the frequency is changed from 862 MHz to 867 MHz, the group delay time may exceed 0 ns and be 35 ns or less.

In the band pass filter suitable for the EVM according to an embodiment of the present invention, the coupling member includes a first vertical bar having one end fixed to the bottom of the third pocket, and is first bent from the first vertical bar. A horizontal bar passing through the four openings, and a coupling bar secondly bent from the horizontal bar so that the other end is fixed to the bottom of the fifth pocket; And a resonator disposed to pass through the horizontal bar.

In the band pass filter suitable for EVM according to an embodiment of the present invention, the resonator includes: a first pillar through which the horizontal bar passes; A second pillar through which the horizontal bar passes, a diameter larger than that of the first pillar, and larger than a width of the fourth opening; And a third pillar that passes through the horizontal bar, has a diameter smaller than that of the second pillar, and corresponds to the width of the fourth opening, and includes the second pillar along the length direction of the horizontal bar around the third pillar. The pillars and the first pillars are arranged to be sequentially separated from each other, and separation may be prevented by the second pillars.

In the band pass filter suitable for the EVM according to an embodiment of the present invention, the first pocket and the second pocket are opened, the first partition wall and the third partition wall are formed to have the same height a, and the first The second partition wall and the fifth partition wall are formed to have the same height b, and the fourth partition wall may be formed to have a height of c, and a> c> b may be satisfied.

According to the band pass filter suitable for the EVM according to the present invention, it is possible to output a value suitable for the EVM while maintaining the cavity resonator method instead of the dielectric resonator method. Therefore, the present invention can significantly reduce the manufacturing cost of the band pass filter.

1 is a perspective view of a band pass filter made of a conventional cavity resonator.
2 is a graph showing the output data values of FIG. 1.
3 is a perspective view of a band pass filter suitable for an EVM according to an embodiment of the present invention.
4 is a perspective view of FIG. 3 viewed from a different angle.
5 is a plan view of FIG. 3.
FIG. 6 is a perspective view showing the cut form of FIG. 3.
7 is a perspective view of a coupling member of a band pass filter suitable for an EVM according to an embodiment of the present invention.
8 is a graph showing results of testing a band pass filter suitable for EVM according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to elements of each drawing, it should be noted that the same elements are assigned the same numerals as possible, even if they are indicated on different drawings. In addition, in describing an embodiment of the present invention, if it is determined that a detailed description of a related known configuration or function interferes with an understanding of the embodiment of the present invention, the detailed description thereof will be omitted.

In addition, in describing the constituent elements of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are for distinguishing the constituent element from other constituent elements, and the nature, order, or order of the constituent element is not limited by the term. If a component is described as being “connected”, “coupled” or “connected” to another component, that component may be directly connected or connected to that other component, but between each component another component It is to be understood that may be “connected”, “coupled” or “connected”.

Hereinafter, a band pass filter suitable for an EVM according to an embodiment of the present invention will be described with reference to the accompanying drawings.

3 is a perspective view of a band pass filter suitable for an EVM according to an embodiment of the present invention, FIG. 4 is a perspective view of FIG. 3 viewed from a different angle, FIG. 5 is a plan view of FIG. 3, and FIG. 6 is a cut-out of FIG. Fig. 7 is a perspective view of a coupling member of a band pass filter suitable for an EVM according to an embodiment of the present invention, and Fig. 8 is a band pass filter suitable for an EVM according to an embodiment of the present invention. This is a graph of the test results.

3 to 7, a band pass filter suitable for an EVM according to an embodiment of the present invention may include a housing 100, an input port 200, and an output port 300.

The housing 100 may be a rectangular parallelepiped, and a space may be provided therein. First to fifth pockets 110, 120, 130, 140, and 150 may be prepared as the space. First to fifth pockets 110, 120, 130, 140, and 150 may be provided with first to fifth resonators 111, 121, 131, 141, and 151, respectively. In the drawings, the first to fifth resonators 111, 121, 131, 141, 151 are shown in a cylindrical shape, but the first to fifth resonators 111, 121, 131, 141, 151 are various according to the manufacturer's selection. It can be provided in a shape. At this time, it is preferable that the first to fifth pockets 110, 120, 130, 140, 150 are shielded from the outside.

An input port 200 may be provided on one surface of the housing 100, and an output port 300 may be provided on the other surface. In the drawing, the input port 200 and the output port 300 are shown to protrude from the housing 100 in opposite directions, but this is an option of the manufacturer, and the position where the input port 200 and the output port 300 are arranged. Or, its shape can be changed in a wide variety.

The input port 200 is connected to the first pocket 110 and may resonate by inputting an electrical signal.

The output port 300 is connected to the fifth pocket 150 and an electrical signal may be output through resonance.

The first to fifth pockets 110, 120, 130, 140, 150 provided in the housing 100 look at the protruding directions of the input port 200 and the output port 300 in the longitudinal direction, It can be divided based on the formed virtual center line. In this case, for convenience, the space including the input port 200 is referred to as a first space (unsigned), and the space including the output port 300 is referred to as a second space (unsigned).

An input port 200, a first pocket 110, a third pocket 130, and a fourth pocket 140 may be disposed in the first space. The second space may face the first space, and an output port 300, a second pocket 120, and a fifth pocket 150 may be disposed in the second space.

A partition wall 160 may be provided between the pockets 110, 120, 130, 140, and 150. The partition wall 160 may include first to fifth partition walls 161, 162, 163, 164, 165.

The first partition wall 161 may be provided between the second pocket 120 and the third pocket 130 to separate the second pocket 120 and the third pocket 130. The first partition wall 161 has a first opening 161a, and the first opening 161a may be opened from an upper end, that is, a ceiling of the housing 100 to a predetermined height.

The second partition wall 162 may be provided between the third pocket 130 and the fourth pocket 140 to separate the third pocket 130 and the fourth pocket 140. The second partition wall 162 has a second opening 162a, and the second opening 162a may be opened from an upper end, that is, a ceiling of the housing 100 to a predetermined height.

The third partition wall 163 may be provided between the fourth pocket 140 and the fifth pocket 150 to separate the fourth pocket 140 and the fifth pocket 150. The third partition wall 163 has a third opening 163a formed therein, and the third opening 163a may be opened from an upper end, that is, a ceiling of the housing 100 to a predetermined height.

The fourth partition wall 164 may be provided between the third pocket 130 and the fifth pocket 150 to separate the third pocket 130 and the fifth pocket 150. The fourth partition wall 164 has a fourth opening 164a, and the fourth opening 164a may be opened from an upper end, that is, a ceiling of the housing 100 to a predetermined height. A coupling member 170 to be described later may be provided in the fourth opening 164a of the fourth partition wall 164. By coupling the third pocket 130 and the fifth pocket 150 by the fourth partition wall 164 and the fourth opening 164a, the refraction point of the output data value per frequency on the graph of FIG. 8 is determined by the user or the manufacturer. You can move it according to your intentions. Referring to FIG. 8, a refraction point is formed at 5 MHz, but the refraction point can be formed at 6 MHz or 7 MHz instead of 5 MHz.

The fifth partition wall 165 may be provided between the second pocket 120 and the fifth pocket 150 to separate the second pocket 120 and the fifth pocket 150. The fifth partition wall 165 has a fifth opening 165a, and the fifth opening 165a may be opened from an upper end, that is, a ceiling of the housing 100 to a predetermined height. The fifth partition wall 165 and the fifth opening 165a allow the flatness to be refracted according to the intention of the user or the manufacturer on the graph of FIG. 8. Referring to FIG. 8, it can be seen that the refraction is performed at 5 MHz.

For reference, it is preferable that the first pocket 110 and the second pocket 120 be opened without a partition wall.

In addition, the first partition wall 161 and the third partition wall 163 may be formed to have the same height a. The second partition wall 162 and the fifth partition wall 165 may be formed to have the same height b. The fourth partition wall 164 may be formed to have a height of c. At this time, the height of the partition wall 160 is preferably a> c> b.

In the drawing, it appears that a partition wall (not shown) is provided between the first pocket 110 and the third pocket 130, but no opening is formed between the first pocket 110 and the third pocket 130, thus blocking resonance. Therefore, in the present specification, a description of the partition wall (not shown) between the first pocket 110 and the third pocket 130 will be omitted.

The coupling member 170 may be disposed between the third pocket 130 and the fifth pocket 150 and may couple frequencies.

By cross-coupling the third pocket 130 and the fifth pocket 150 by the coupling member 170, the flatness of the output data value per frequency may be refracted.

The coupling member 170 may include a coupling bar 171 and a resonator 172.

The coupling bar 171 may include first and second vertical bars 171a and 171c and a horizontal bar 171b, and may be formed in a “C” shape.

One end of the first vertical bar 171a is fixed to the bottom of the third pocket 130 and is disposed perpendicular to the bottom, and the other end may be first bent by 90° in the horizontal direction.

One end of the horizontal bar 171b may extend from the first vertical bar 171a, and the other end may be secondly bent by 90° in a direction perpendicular to the floor. The horizontal bar 171b may pass through the fourth opening 164a.

The second vertical bar 171c may have one end extending from the other end of the horizontal bar 171b, and the other end may be fixed to the bottom of the fifth pocket 150 and disposed perpendicular to the floor.

The resonator 172 may pass through the horizontal bar 171b and may be disposed to pass through the fourth opening 164a.

The resonator 172 may include first to third pillars 172a, 172b, and 172c. The resonator 172 installed on the horizontal bar 171b includes a first pillar 172a, a second pillar 172b, a third pillar 172c, and a second pillar 172b along the longitudinal direction of the horizontal bar 171b. ), may be arranged in the order of the first pillar 172a.

The horizontal bar 171b may pass through the first to third pillars 172a, 172b, and 172c.

The second pillar 172b may have a larger diameter than the first pillar 172a. The second pillar 172b may be formed larger than the width of the fourth opening 164a.

The third pillar 172c may have a smaller diameter than the second pillar 172b and may correspond to the width of the fourth opening 164a.

That is, the resonator 172 may be symmetrical around the third pillar 172c. In other words, the second pillar 172b and the first pillar 172a may be arranged to be sequentially separated from the third pillar 172c along the longitudinal direction of the horizontal bar 171b.

In addition, the third pillar 172c may be disposed to span the fourth opening 164a, that is, the upper end of the fourth partition wall 164. In this case, it means that the outer diameter of the third pillar 172c is equal to or smaller than the width of the fourth opening 164a.

In addition, the resonator 172 is not separated from the fourth opening 164a due to the size of the second pillar 172b.

As mentioned above, frequencies may be coupled between neighboring pockets through the openings 161a, 162a, 163a, 164a, and 165a. As the number of pockets increases, the filtering of the frequency becomes sharper and the pass or block characteristics are improved. However, insertion loss or group delay may deteriorate and the size of the filter may increase.

The band pass filter suitable for the EVM according to an embodiment of the present invention may be sequentially resonated from the first resonator 111 to the fifth resonator 115 through the open portion.

However, the flatness of the output value may be refracted by the fourth opening 164a and the coupling member 170 located in the fourth partition wall 164 between the third pocket 130 and the fifth pocket 150.

In addition, the refraction point may be moved by the fifth opening 165a located in the fifth partition wall 165 between the second pocket 120 and the fifth pocket 150.

Referring to FIG. 8, looking at a portion of a circle or an ellipse displayed on a graph, it can be seen that in an embodiment of the present invention, the flatness of the output value is refracted compared to the conventional value shown in FIG. 2. In addition, the Group Delay value at this time at 867 MHz (the'△' point on the graph is 862 MHz, and the 4 point is the point where 5 MHz is increased from the'△' point) is 31.089 ㎱, as shown in FIG. It can be seen that the group delay is much shorter than that of the conventional result of 68.797 ㎱ and satisfies the reference value of 35 ㎱ max required by EVM (Error Vector Magnitude).

What has been described above is only an embodiment for implementing a band pass filter suitable for the EVM according to the present invention, and the present invention is not limited to the above embodiment, and departs from the gist of the present invention claimed in the following claims. Without it, anyone of ordinary skill in the technical field to which the present invention pertains will have the technical spirit of the present invention to the extent that it can be implemented by making various changes.

100: housing 110: first pocket
111: first resonator 120: second pocket
121: second resonator 130: third pocket
131: provided novelty 140: fourth pocket
141: fourth resonator 150: fifth pocket
151: fifth resonator 160: bulkhead
161: first partition wall 161a: first opening
162: second bulkhead 162a: second opening
163: third bulkhead 163a: third opening
164: fourth bulkhead 164a: fourth opening
165: fifth bulkhead 165a: fifth opening
170: coupling member 171: coupling bar
171a: first vertical bar 171b: horizontal bar
171c: second vertical bar 172: resonator
172a: first pillar 172b: second pillar
172c: 3rd pillar 200: input port
300: output port

Claims (5)

A housing formed such that first to fifth pockets each provided with first to fifth resonators therein are shielded from the outside;
An input port protruding from the housing, connected to the first pocket, and inputting a signal; And
An output port protruding from the housing in a direction opposite to the input port, connected to the fifth pocket, and outputting a signal;
Including,
The housing,
A first pocket, a third pocket, and a fourth pocket are arranged in a first space including the input port based on a virtual line dividing the input port and the output port along the length direction, and the output port is included. A second pocket and a fifth pocket are arranged in a second space facing the first space,
A first partition wall provided between the second and third pockets and having a first opening opened from an upper end by a predetermined height, and a first partition provided between the third and fourth pockets and opened by a predetermined height from the upper end. A second partition having two openings, a third partition provided between the fourth and fifth pockets and having a third opening formed at a predetermined height from the upper end, and provided between the third and fifth pockets and at the upper end A partition wall including a fourth partition wall having a fourth opening that is opened by a predetermined height from, and a fifth partition wall provided between the second and fifth pockets and having a fifth opening that is opened by a predetermined height from an upper end; And
A coupling member disposed between the third and fifth pockets to couple frequencies;
Including more,
The third pocket and the fifth pocket are cross-coupled by the coupling member to refract the flatness of the output data value per frequency of the third and fifth pockets, and the second and fifth pockets are coupled. Bandpass filter suitable for EVM that moves the refraction point of the output data value per frequency by ringing.
The method of claim 1,
Bandpass filter suitable for EVM where the group delay time exceeds 0ns and is less than 35ns when the frequency is changed from 862MHz to 867MHz.
The method of claim 1,
The coupling member,
A first vertical bar having one end fixed to the bottom of the third pocket, a horizontal bar that is first bent from the first vertical bar and passes through a fourth opening, and a second end is bent from the horizontal bar so that the other end is the fifth pocket. A coupling bar fixed to the bottom of the door; And
A resonator disposed to pass through the horizontal bar;
Bandpass filter suitable for EVM including a.
The method of claim 3,
The resonator,
A first pillar through which the horizontal bar passes;
A second pillar through which the horizontal bar passes, a diameter larger than that of the first pillar, and larger than a width of the fourth opening; And
A third pillar through which the horizontal bar passes, a diameter smaller than that of the second pillar, and corresponding to a width of the fourth opening;
Including,
A band pass filter suitable for EVM in which the second pillar and the first pillar are arranged to be sequentially separated from each other along the longitudinal direction of the horizontal bar with the third pillar as the center, and separation is prevented by the second pillar.
The method of claim 1,
An opening between the first pocket and the second pocket,
The first partition wall and the third partition wall are formed to have the same height a,
The second partition wall and the fifth partition wall are formed to have the same height b,
The fourth partition wall is formed to a height of c,
A band pass filter suitable for EVM that satisfies a>c> b.

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