KR102190809B1 - FPCB Cable for RF - Google Patents

Abstract

The present invention relates to a FPCB cable for wireless communication. In the FPCB cable for wireless communication with a plurality of signal lines formed on a dielectric layer, ground holes are arranged between the plurality of signal lines along a transverse direction, which is an extension direction of the signal line. According to the present invention, isolation between signal lines can be maximized while securing excellent design freedom.

Description

FPCB cable for wireless communication {FPCB Cable for RF}

The present invention relates to an FPCB cable for wireless communication, and in particular, to an FPCB cable for wireless communication that maximizes isolation between high-frequency lines.

With the rapid development of communication technology, 5G service that can transmit large amounts of data at high speed in high frequency band has finally been launched.

In line with the rapid development of communication technology and the trend of light, thin, and short-sized wireless devices, the need for high-integration and high-density for the RF communication set of wireless devices to mount a larger number of components such as multiple antennas and driver chips within a limited space. As a result, FPCB cables using a flexible printed circuit board (FPCB) are used in place of the existing coaxial cables, which have poor space utilization, in RF communication sets.

The size of the FPCB cable is minimized so that it can be applied in a limited narrow space, and at the same time, according to the explosive increase in the number of antennas, it is necessary to secure as many high-frequency lines as possible to connect each antenna.

However, when a plurality of high-frequency lines are arranged in a limited space, signal distortion occurs due to signal interference between the high-frequency lines, resulting in a technical problem of deteriorating communication performance.

Accordingly, there is a need for a technology capable of securing excellent communication performance by minimizing signal interference and distortion between the lines while forming as many high-frequency lines as possible within a limited space.

Unexamined Patent Publication No. 10-2016-0011734: Flexible printed circuit cable

The present invention is proposed in order to solve the above-described problems in the related art, and an object of the present invention is required by minimizing interference between signals by maximizing isolation between high-frequency lines while ensuring sufficient design freedom within a limited size. It is to provide an FPCB cable for wireless communication that can satisfy communication performance.

As a problem solving means of the present invention for achieving the above object,

A plurality of signal lines formed in the dielectric layer and a ground hole arranged in a horizontal direction between the plurality of signal lines in an extension direction of the signal line to isolate a plurality of signal lines, the ground hole The first row and the second row consist of two rows and are repeatedly formed along the transverse direction, and the ground holes in the first row and the ground holes in the second row are alternately formed in the transverse direction, and the center of the ground hole in the first row. The FPCB cable for wireless communication corresponding to 1/2 of the diameter of the ground hole in the longitudinal direction of the center of the ground hole in the second row is disclosed.

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According to the FPCB cable for wireless communication according to the present invention,

It has the effect of satisfying the required performance characteristics by maximizing the isolation between signal lines while securing excellent design freedom by optimally utilizing the space between signal lines.

In addition, it should be noted that, in addition to the effects specifically specified as described above, unique effects that can be easily derived and expected from the characteristic configuration of the present invention may also be included in the effects of the present invention.

1 is a diagram illustrating a schematic configuration of an FPCB cable for wireless communication according to the present invention;
2 is a diagram illustrating a cross section of an FPCB cable for wireless communication according to the present invention;
3 is a diagram illustrating a ground hole arrangement structure and numerical relationship in an embodiment of the present invention;
4 is a diagram illustrating an arrangement structure of ground holes of Comparative Examples 1 to 3, respectively,
5 is a diagram illustrating an arrangement structure of ground holes of Comparative Examples 4 to 6, respectively,
6 is a diagram showing an isolation measurement result of Comparative Example 1;
7 is a diagram showing an isolation measurement result of Comparative Example 2;
8 is a diagram showing an isolation measurement result of Comparative Example 3;
9 is a diagram showing an isolation measurement result in an embodiment of the present invention;
10 is a diagram showing an isolation measurement result of Comparative Example 4;
11 is a diagram showing an isolation measurement result of Comparative Example 5;
12 is a diagram showing an isolation measurement result of Comparative Example 6;
13 is a diagram illustrating the isolation measurement results of the embodiment of the present invention and the comparative examples in a comparative graph.

Hereinafter, a preferred embodiment of the FPCB cable for wireless communication according to the present invention will be described in detail with reference to the accompanying drawings.

This embodiment is provided to more clearly describe the present invention to those with average knowledge in the art, and the shape, size, number, and spacing between elements in the accompanying drawings will be described more clearly. It may be reduced or exaggerated to emphasize, and is not limited to the items illustrated in the drawings unless specifically limited.

In addition, in describing the embodiment, if a certain component is "equipped", "formed", "installed", "combined", "fixed", "connected", "stacked" in another component It should be understood that when it is described as "is arranged" or "arranged", it may be provided, formed, installed, combined, fixed, connected, stacked, or arranged directly on the other components, but other components may exist in the middle. will be.

In addition, terms representing directions such as'before','after','left','right','transverse', and'vertical' used in this specification are shown in the drawings and may have been used to describe the observed direction. However, if the direction in which they are shown and observed is different, these terms may also change. That is, it does not indicate a specific direction, but is described with reference to FIG. 3 in order to clarify the relationship between components, and the'lateral direction' may be defined as the horizontal direction and the'longitudinal direction' It can be defined as a direction.

In addition, in describing the embodiments, in principle, the technical features of the present invention as well-known functions or well-known configurations that are already apparent to those skilled in the art, or are not related to the technical features of the present invention. If it is determined that it may be unnecessarily blurred, a detailed description thereof will be omitted.

The present invention is an FPCB cable for wireless communication that is installed in an RF communication set of a wireless device and transmits a high-frequency signal. The communication performance by minimizing signal interference by maximizing the isolation between high-frequency lines while securing sufficient design freedom within a limited area. It relates to an FPCB cable for wireless communication that improves.

1 to 3 illustrate an embodiment of the present invention for this.

First, as illustrated in FIGS. 1 to 2, the FPCB cable 100 for wireless communication according to the present invention basically includes a signal line 10 and a stacked structure in which a plurality of layers are stacked up and down. I can.

The stacked structure may include, for example, a dielectric layer 20 and a lower ground 30 and an upper ground 40 that are respectively stacked on the lower and upper sides of the dielectric layer 20.

The lower ground 30 and the upper ground 40 may be formed on both the lower and upper sides of the dielectric layer 20, but only one of them may be selectively formed.

Further, although not shown in the drawings, an insulator layer for substrate protection may be further stacked on the lower ground 30 and the upper ground 40 as necessary.

The signal line 10 is formed by patterning the dielectric layer 20, and is formed in a plurality of at least two or more. However, in the drawings, for convenience of explanation, only two signal lines 10 are formed as a pair.

The signal line 10 is a circuit pattern for transmitting an IF (Intermediate Frequency) signal for wireless communication, and when a plurality of such signal lines 10 are arranged, the coupling phenomenon of electromagnetic waves increases, and the plurality of signal lines 10 Signal distortion occurs with each other.

Accordingly, the present invention is provided between the signal line 10 and the signal line 10 along the transverse direction X, which is the extension direction of the signal line 10 for isolation between the signal lines 10. Ground holes 50 are arranged and formed.

The ground hole 50 is a hole that passes through the dielectric layer 20, the lower ground 30, and the upper ground 40 to communicate with each other, and blocks a coupling phenomenon between the plurality of signal lines 10 to form a signal line. (10) Improve liver isolation.

Referring to FIG. 3, in an arrangement structure, the ground holes 50 may be formed horizontally in two rows consisting of a first row Ar1 and a second row Ar2.

That is, the ground hole 50 is arranged along the transverse direction (X) from one side of the first row (Ar1) in the longitudinal direction (Y) and the first row (Ar1) arranged along the transverse direction (X). It may consist of the second row Ar2.

In addition, in order to maximize isolation and secure design freedom through space optimization, the ground hole 50a of the first row (Ar1) and the ground hole 50b of the second row (Ar2) are mutually transverse (X). ) Can be formed alternately.

That is, the ground hole 50a of the first row Ar1 and the ground hole 50b of the second row Ar2 may be formed in a zigzag shape along the horizontal direction X.

In addition, the distance d1 in the longitudinal direction (Y) between the center (c1) of the ground hole 50a of the first column (Ar1) and the center (c2) of the ground hole 50b of the second column (Ar2) is a ground hole ( 50) It may be formed to correspond to 1/2 of the diameter, that is, the radius of the ground hole 50.

That is, the center (c1) of the ground hole 50a of the first column (Ar1) and the center (c2) of the ground hole 50b of the second column (Ar2) are 1 of the diameter of the ground hole 50 in the longitudinal direction (Y). They are separated from each other by /2.

In other words, the longitudinal (Y) linear distance (d2) from one end of the ground hole 50a in the first row Ar1 to the other end of the ground hole 50b in the second row Ar2 is the diameter of the ground hole 50 It is formed to be 3/2.

Hereinafter, the result of measuring the isolation between the signal lines 10 in comparison with the FPCB cable according to the embodiment of the present invention having the above configuration and various comparative examples will be described.

In the embodiment and comparative examples of the present invention, the lengthwise (Y) linear distance (d3) between the pair of signal lines 10 is 0.8 mm, and the diameter of the ground hole 50 is 0.2 mm. Formed as.

<Example>

First, in the FPCB cable according to the embodiment of the present invention, as illustrated in FIG. 3, the ground hole 50 is formed in two rows horizontally between a pair of signal lines 10, but the first row Ar1 The ground hole 50a and the ground hole 50b of the second row (Ar2) are crossed in the horizontal direction (X), and the center of the ground hole 50a of the first row (Ar1) (c1) and the second row (A2) The distance d1 in the longitudinal direction (Y) between the center (c2) of the ground hole (50b) of the ground hole (50b) was formed to be 0.1 mm, which is 1/2 of the diameter of the ground hole (50).

Therefore, in the FPCB cable of the present invention, the lengthwise (Y) straight line distance (d2) occupied by the ground hole 50 is 0.3 mm, and the ratio value (d2/d3) with the linear distance (d3) between the signal lines 10 Is 0.37.

<Comparative Example 1>

Comparative Example 1 is an FPCB cable in which no ground hole is formed between a pair of signal lines 10, as illustrated in FIG. 4A.

<Comparative Example 2>

Comparative Example 2 is an FPCB cable in which ground holes 50 are arranged in one row between a pair of signal lines 10, as illustrated in FIG. 4B.

Therefore, in the FPCB cable of Comparative Example 2, the lengthwise (Y) straight line distance (d2) occupied by the ground hole 50 is 0.2 mm, and the ratio value (d2/d3) to the straight line distance (d3) between the signal lines 10 ) Is 0.25.

<Comparative Example 3>

In Comparative Example 3, as illustrated in (c) of FIG. 4, ground holes 50 are formed in two rows between a pair of signal lines 10, but the ground holes 50a of the first column Ar1 And the ground hole 50b of the second row (Ar2) and the ground hole 50b of the second row (A2) and the center of the ground hole 50a of the first row (Ar1) (c1) and the ground hole (50b) of the second row (A2) alternately in the horizontal direction (X). ) The center (c2) was formed so that the distance d1 in the longitudinal direction (Y) between the center (c2) was 0.05 mm, which is 1/4 of the diameter of the ground hole 50.

Therefore, in the FPCB cable of Comparative Example 3, the vertical direction (Y) linear distance (d2) occupied by the ground hole 50 is 0.25 mm, and the ratio value (d2/) to the linear distance (d3) between the signal lines 10 d3) is 0.31.

<Comparative Example 4>

In Comparative Example 4, as illustrated in (d) of FIG. 5, a ground hole 50 is formed in two rows between a pair of signal lines 10, but the ground hole 50a of the first column Ar1 And the ground hole 50b of the second row (Ar2) and the ground hole 50b of the second row (A2) and the center of the ground hole 50a of the first row (Ar1) (c1) and the ground hole (50b) of the second row (A2) alternately in the horizontal direction (X). ) The center (c2) was formed so that the distance d1 in the longitudinal direction (Y) was 0.15 mm, which is 3/4 of the diameter of the ground hole 50.

Therefore, in the FPCB cable of Comparative Example 4, the vertical direction (Y) linear distance (d2) occupied by the ground hole 50 is 0.35 mm, and the ratio value (d2/) to the linear distance (d3) between the signal lines 10 d3) is 0.44.

<Comparative Example 5>

In Comparative Example 5, as illustrated in (e) of FIG. 5, ground holes 50 were simply arranged horizontally in two rows without gaps between a pair of signal lines 10.

Therefore, in the FPCB cable of Comparative Example 5, the lengthwise (Y) straight line distance (d2) occupied by the ground hole 50 is 0.4 mm, and the ratio value (d2/d3) to the straight line distance (d3) between the signal lines 10 ) Is 0.5.

<Comparative Example 6>

In Comparative Example 6, as illustrated in FIG. 5(f), ground holes 50 were simply arranged horizontally in three rows without gaps between a pair of signal lines 10.

Therefore, in the FPCB cable of Comparative Example 6, the vertical direction (Y) linear distance (d2) occupied by the ground hole 50 is 0.6 mm, and the ratio value (d2/d3) to the linear distance (d3) between the signal lines 10 ) Is 0.75.

<Measurement result>

For the embodiment of the present invention and Comparative Examples 1 to 6 having the above ground hole arrangement structure, the insertion loss (S12) between signal lines was measured, respectively. As the dB value of the insertion loss between signal lines becomes negative, it means that the isolation between signal lines becomes better.

6 to 12 show the isolation measurement results of each of the examples and comparative examples of the present invention.

In addition, each measurement result is summarized in Table 1 below, and a comparative graph of the measurement result is shown in FIG. 13.

d2
d2 / d3
Isolation Max.

Comparative Example 1

0
0
-29 dB
Comparative Example 2

0.2 mm
0.25
-34 dB
Comparative Example 3

0.25 mm
0.31
-38 dB
This example

0.3 mm
0.37
-49 dB
Comparative Example 4

0.35 mm
0.44
-48 dB
Comparative Example 5

0.4 mm
0.5
-49 dB
Comparative Example 6

0.6 mm
0.75
-50 dB

Referring to Tables 1 and 13, the FPCB cable of this embodiment has significantly improved excellent isolation characteristics compared to the FPCB cables of Comparative Examples 1 to 3, and compared with the FPCB cables of Comparative Examples 4 to 6 As a result, it can be confirmed that it has the same isolation characteristics, which are hardly different.

At the same time, the FPCB cable of the present embodiment is in the ratio (d2/23) of the longitudinal linear distance (d2) occupied by the ground hole (50) and the longitudinal (Y) linear distance (d3) between the signal lines (10). , It can be seen that it has a minimum value compared to the FPCB cables of Comparative Examples 4 to 6.

Therefore, when the above isolation characteristics and the comparison measurement results of d2 and d2/d3 values are summarized, the FPCB cable of the present embodiment maximizes the isolation between signal lines to satisfy the required performance characteristics, while at the same time, ground between signal lines. It can be seen that the area and space occupied by the hall are minimized, so that excellent space utilization and design freedom can be secured.

Preferred embodiments of the present invention have been described in detail above, but the technical scope of the present invention is not limited to the contents described in the above-described embodiments and drawings, and is modified or modified by a person having ordinary skill in the art. It will be said that the changed equivalent configuration does not depart from the scope of the technical idea of the present invention.

References to the main parts of the accompanying drawings will be described as follows.
10: signal line
20: dielectric layer
30: lower ground
40: upper ground
50: ground hole

Claims (4)

A plurality of signal lines 10 formed on the dielectric layer 20;
A ground hole 50 arranged between the plurality of signal lines 10 along the transverse direction X, which is an extension direction of the signal line 10, to isolate the plurality of signal lines 10 from each other; Including,
The ground hole 50 is formed in a horizontal direction consisting of a first row (Ar1) and a second row (Ar2), and is repeatedly formed along the transverse direction (X),
The ground holes 50a of the first row Ar1 and the ground holes 50b of the second row Ar2 are formed to be alternately formed in the transverse direction X, and the ground holes of the first row Ar1 ( 50a) The distance (d1) in the longitudinal direction (Y) between the center (c1) and the ground hole (50b) center (c2) of the second row (Ar2) corresponds to 1/2 of the diameter of the ground holes (50a, 50b). FPCB cable for wireless communication, characterized in that. delete delete delete

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