KR102156859B1 - Omni-direction antenna of village broadcasting receiver - Google Patents

Abstract

According to an embodiment of the present invention, a village broadcasting receiver includes an omni-directional antenna. The omni-directional antenna comprises: a first antenna element formed of a conductive film extending in a first direction of a printed circuit board (PCB); a second antenna element separated from the first antenna element and extending in the first direction; a third antenna element separated from the first and second antenna elements and extending in a second direction perpendicular to the first direction; a fourth antenna element separated from the first to third antenna elements and extending in the second direction; a first conductive protrusion portion protruding in a vertical direction to the PCB and electrically connecting one end of the first antenna element and one end of the second antenna element; and a second conductive protrusion portion protruding in the vertical direction to the PCB and electrically connecting one end of the third antenna element and one end of the fourth antenna element. According to the present invention, it is possible to realize a village broadcasting receiver which provides high reception sensitivity by improving the directionality of a PCB antenna at low cost.

Description

Omni-directional antenna of village broadcasting receiver {OMNI-DIRECTION ANTENNA OF VILLAGE BROADCASTING RECEIVER}

The present invention relates to a communication device, and more specifically, to an omni-directional antenna of a village broadcasting receiver.

As rural villages are aging, the importance of village broadcasting is being emphasized to provide warnings to residents of the village's major events and emergency situations. In order to efficiently provide information to residents through village broadcasting, the service quality of communication devices such as village broadcasting receivers is important.

In general, the quality of service in a communication system is greatly affected by the antenna of the transceiver. In particular, various types of reception antennas may be used in the receiver terminal according to the frequency band used. For example, a PCB antenna that receives a radio signal by an antenna pattern printed directly on the PCB board may be used in the 422 MHz band.

Since the PCB antenna of the existing village broadcasting receiver is printed in a conductive pattern on the plane of the main board, the directionality of the radio signal is greatly affected. For example, the reception sensitivity of a radio signal traveling in a direction parallel to a printed PCB board with an antenna pattern is relatively low. This directionality of the PCB antenna consequently decreases reception reliability and acts as a factor of deterioration of the quality of communication service. Therefore, there is an urgent need to improve the directionality of the PCB antenna.

An object of the present invention is to provide an omni-directional antenna for a village broadcasting receiver that provides high reception sensitivity and service quality through an omni-directional receiving antenna that is not significantly affected by the directionality of a received radio signal.

An omni-directional antenna of a village broadcasting receiver according to an embodiment of the present invention includes: a first antenna element formed of a conductive film extending in a first direction of a printed circuit board (PCB); A second antenna element separated from the first antenna element and extending in the first direction; A third antenna element separated from the first and second antenna elements and extending in a second direction perpendicular to the first direction; A fourth antenna element separated from the first to third antenna elements and extending in the second direction; A first conductive protrusion protruding in a vertical direction to the printed circuit board (PCB) and electrically connecting one end of the first antenna element and one end of the second antenna element; And a second conductive protrusion protruding in a vertical direction to the printed circuit board (PCB) and electrically connecting one end of the third antenna element and one end of the fourth antenna element.

First holes for inserting both ends of the first conductive protrusion are formed at one end of the first and second antenna elements, and both ends of the third and fourth antenna elements have both ends of the second conductive protrusion. Second holes for inserting an end are formed, and the first and second holes are formed through the printed circuit board.

According to the embodiment of the present invention as described above, the orientation of the PCB antenna can be greatly improved. Accordingly, it is possible to implement an omni-directional antenna of a wireless village broadcasting receiver capable of low-cost high-quality communication service.

1 is a block diagram showing a village broadcasting receiver including an omni-directional antenna according to an embodiment of the present invention.
2 is a plan view showing an omni-directional antenna of the present invention.
3 is a view showing a plurality of antenna elements for forming the omni-directional antenna of the present invention.
4A and 4B are views showing a conductive protrusion according to an embodiment of the present invention.
5A, 5B, and 5C are diagrams exemplarily showing antenna components of the omni-directional antenna of the present invention for each three-dimensional direction.
6A and 6B are views showing a conductive protrusion according to another embodiment of the present invention.
7A, 7B, and 7C are diagrams exemplarily showing antenna components of the omni-directional antenna of the present invention in each direction in 3D.
8 is a table showing the results of measuring the performance of the omni-directional antenna of the present invention.
9 is a block diagram showing a village broadcasting receiver according to another embodiment employing an omni-directional antenna of the present invention.

It is to be understood that both the preceding general description and the following detailed description are exemplary, and it is to be understood that additional descriptions of the claimed invention are provided. Reference numerals are indicated in detail in the preferred embodiments of the present invention, examples of which are indicated in the reference drawings. Wherever possible, the same reference numerals are used in the description and drawings to refer to the same or similar parts.

In the following, a PCB antenna will be disclosed as an example for explaining the advantages of the present invention. However, the advantages and features of the present invention are not limited to the PCB antenna. It will be well understood that the present invention can be applied to a micro-strip type antenna or to various antenna technologies requiring improved directionality. In addition, the detailed description may be modified or changed according to viewpoints and applications without significantly departing from the scope, technical spirit, and other objects of the present invention.

1 is a block diagram showing a village broadcasting receiver including an omni-directional antenna according to an embodiment of the present invention. Referring to FIG. 1, the village broadcasting receiver 100 includes an omni-directional antenna 110, a communication unit 120, a display 130, a keypad 150, an audio processor 160, and a micro controller unit (MCU) 170 It may include.

The omni-directional antenna 110 may provide high reception sensitivity for a wireless signal received from the village broadcasting receiver 100. For example, in the case of an antenna used in a 422 MHz band wireless receiver, the antenna is formed in a pattern printed on a PCB substrate. An antenna formed on a PCB substrate is formed on a two-dimensional planar substrate. Accordingly, the antenna formed on the PCB substrate can provide an appropriate reception sensitivity for electromagnetic waves propagating in a direction perpendicular to the substrate. However, when it propagates in a direction parallel to the substrate plane and the polarization direction is perpendicular to the substrate, the reception sensitivity of the signal rapidly decreases.

The omni-directional antenna 110 of the present invention includes an antenna element formed in a pattern on a PCB substrate and a conductive protrusion protruding in a vertical direction on the PCB substrate. That is, a conductive protrusion capable of receiving an electromagnetic wave polarized in a vertical direction on the PCB substrate is included. The conductive protrusion may be formed of bypass conductive lines electrically connecting the two electrically separated antenna elements by protruding in a vertical direction to the PCB base. The configuration and characteristics of the conductive protrusion will be described in detail in the drawings to be described later.

The communication unit 120 processes a radio signal transmitted or received through the omni-directional antenna 110. In the reception mode, the communication unit 120 may amplify and filter a signal received from the omni-directional antenna 110 of the present invention. In addition, the communication unit 120 may provide a demodulator or a modem function for demodulating the filtered received signal.

The display 130 may display an image or text under the control of the MCU 170. For example, the display 130 may be display devices such as Liquid Crystal Display (LCD) or Organic Light Emitting Diodes (OLDE).

The battery 140 supplies power for driving the village broadcasting receiver 100. The battery 140 may charge power through a wired or wireless charging method. The battery 140 may further include a charging circuit for charging or a Power Management IC (PMIC) for stabilizing output power. The battery 140 is disclosed as an example of a power source for supplying power to the village broadcasting receiver 100, but it will be well understood that it may be replaced with various power circuits.

The keypad 150 is an input device for a user to input information into the village broadcasting receiver 100. Through the keypad 150, the user can input control information or data for the village broadcasting receiver 100. It will be well understood that the keypad 150 may be various input means such as a touch pad from a simple keyboard form.

As one of the output devices, the audio processor 160 processes audio information and provides it to the amplifier 162. For example, the audio processor 160 may perform decoding on audio data provided from the MCU 170 and provide it to the amplifier 162. Then, the amplifier 162 amplifies the decoded audio information and transmits it to the speaker 164. Voice or sound in an audio format may be output through the speaker 164.

The MCU 170 may control all components of the village broadcasting receiver 100. That is, the MCU 170 may be driven by an operating system (OS) for providing a specific function of the village broadcasting receiver 100. For example, the MCU 170 may include interfaces for controlling a micro processing unit (MPU) in which an OS is driven, a storage device in which an OS is stored, a RAM, and peripheral devices. A specialized function of the village broadcasting receiver 100 may be provided through the MCU 170.

The village broadcasting receiver 100 described above can provide high reception sensitivity even in a shaded area according to a surrounding environment or condition through the omni-directional antenna 110 of the present invention. That is, the omni-directional antenna 110 of the present invention includes an antenna element formed in a pattern on a PCB substrate and a conductive protrusion formed in a direction perpendicular to the PCB base. An antenna element is provided for any radio signal traveling in a direction perpendicular to the PCB substrate by the antenna element. In addition, an antenna component may be provided for a wireless signal traveling in a horizontal direction and polarized in a vertical direction on the PCB substrate by the conductive protrusion. That is, through the omni-directional antenna 110 of the present invention, it is possible to improve the directionality that affects the reception of the village broadcasting receiver 100.

2 is a plan view showing an omni-directional antenna of the present invention. Referring to FIG. 2, the omnidirectional antenna 110 is a conductive protrusion connecting the antenna elements 111, 113, 115, 117, 119 and the antenna elements printed on the surface of the PCB substrate 100a in a vertical direction. They may include 112, 114, 116, 118. Here, it is assumed that the plane of the PCB substrate 100a is the XY plane, and the vertical direction of the PCB board is the Z direction to express the Cartesian coordinates.

In general, the PCB antenna may be configured in a pattern in the form of a dipole antenna. That is, the PCB antenna only needs to be formed in a pattern having a half-wavelength (λ/2) length of the received radio signal. In this case, the PCB antenna provides reception sensitivity for a vertically polarized or horizontally polarized radio signal passing through the PCB plane in a vertical direction or in a direction inclined at a predetermined angle. However, it is difficult to detect a wireless signal traveling in a direction parallel to the PCB plane (for example, in the X or Y direction) with the PCB antenna. Therefore, the reception sensitivity for a radio signal parallel to the PCB plane is relatively low.

The omni-directional antenna 110 of the present invention includes conductive protrusions 112, 114, 116, and 118 for detecting a radio signal traveling in a direction parallel to the PCB substrate 110a. The conductive protrusion 112 connects the printed antenna elements 111 and 113 in an electrically separated form on the PCB substrate 100a. In other words, the conductive protrusion 112 may be formed of a semicircular or'c' shaped copper line or conductive line protruding from the top of the PCB substrate 100a. The conductive protrusion 114 connects the printed antenna elements 113 and 115 in an electrically separated form on the PCB substrate 100a. Contrary to the conductive protrusion 112, the conductive protrusion 114 may be a semicircular or'U' shaped copper line or a conductive line protruding below the PCB substrate 100a. Accordingly, although the conductive protrusions 112 and 114 proceed in a direction parallel to the PCB substrate 100a, a radio signal having a component traveling along the Y-axis can be detected.

The conductive protrusion 116 connects the printed antenna elements 115 and 117 in an electrically separated form on the PCB substrate 100a. In other words, the conductive protrusion 116 may be formed of a semicircular or'C' shaped copper line or conductive line protruding from the top of the PCB substrate 100a. The conductive protrusion 118 connects the printed antenna elements 117 and 119 in an electrically separated form on the PCB substrate 100a. Contrary to the conductive protrusion 116, the conductive protrusion 118 may be a semicircular or'U' shaped copper line or a conductive line protruding below the PCB substrate 100a. The conductive protrusions 112 and 114 proceed in a direction parallel to the PCB substrate 100a, but an electromagnetic wave in which a component traveling along the X-axis is present can be detected.

Exemplary shapes of the conductive protrusions 112, 114, 116, and 118 will be described in detail through drawings to be described below showing a cross section by a cutting line A-A' or a cutting line B-B'.

3 is a view showing a plurality of antenna elements for forming the omni-directional antenna of the present invention. Referring to FIG. 3, antenna elements 111, 113, 115, 117, and 119 may be printed in patterns separated from each other on a PCB substrate 100a.

Each of the antenna elements 111 and 113 may be printed in a conductive pattern extending in the X-axis direction on the PCB substrate 100a. The end portions of the antenna element 111 and the antenna element 113 are electrically separated. This part is shown in a more enlarged shape at the top. The antenna element 111 and the antenna element 113 each include holes 111a and 113a for inserting the conductive protrusion 112. The holes 111a and 113a penetrate to the antenna elements 111 and 113 and the PCB substrate 100a. When the conductive protrusions 112 connected to the holes 111a and 113a are inserted in the Z-direction, the antenna elements 111 and 113 are electrically connected.

Like the antenna elements 111 and 113, the antenna elements 113 and 115 also have holes formed at the end portions. A conductive protrusion 114 inserted in the Z-direction into the antenna elements 113 and 115 may be fitted into the holes. Like the antenna elements 113 and 115, the antenna elements 115 and 117 also have holes formed at the end portions. A conductive protrusion 116 inserted in the Z-direction into the antenna elements 115 and 117 may be fitted into the holes. Holes are also formed at the ends of the antenna elements 117 and 119. A conductive protrusion 118 inserted in the Z-direction into the antenna elements 117 and 119 may be inserted into these holes.

Looking at the cross section corresponding to the cut line A-A', immediately after the antenna elements 111, 113, 115 are formed, there is almost no antenna component in the Z-direction. However, the antenna component in the Z-direction may be provided through the conductive protrusions 112 and 114 inserted thereafter.

Looking at the cross section corresponding to the cut line B-B', immediately after the antenna elements 115, 117, and 119 are formed, there is almost no antenna component in the Z-direction. However, the antenna component in the Z-direction may be provided through the conductive protrusions 116 and 118 inserted thereafter.

When a plurality of antenna elements (111, 113, 115, 117, 119) are connected by conductive protrusions (112, 114, 116, 118), the omni-directional antenna 110 with respect to the XY-plane is the half wavelength of the radio signal An antenna component of length (λ/2) may be provided. In addition, the conductive protrusions 112, 114, 116, and 118 may provide an antenna component in the Z-direction having an effective length, although shorter than the half wavelength (λ/2) of the radio signal. Accordingly, antenna components may be provided for each three-dimensional direction by the omni-directional antenna 110 of the present invention.

4A and 4B are views showing a conductive protrusion according to an embodiment of the present invention.

Referring to FIG. 4A, the shape and insertion direction of the conductive protrusions 112a and 114a according to an embodiment of the present invention in a cross section corresponding to the cut line A-A' are briefly shown. The conductive protrusions 112a and 114a may be implemented through a copper wire in a'C' shape or various conductors. When formed of a copper wire, a copper wire-shaped conductive protrusion 112a is inserted from the top to the bottom side in the Z-direction. In addition, the conductive protrusion 114a may be inserted from the lower side in the Z-direction toward the upper side. In addition, the conductive protrusions 112a and 114a and the antenna elements 111, 113 and 115 may be fixed through soldering. The material of the conductive protrusions 112a and 114a is not limited to copper wire. The conductive protrusions 112a and 114a may be manufactured in the form of various conductor lines or components and mounted on a PCB substrate. An antenna component (2D length) for a radio signal traveling in the Y-direction perpendicular to the XZ-plane can be secured by the conductive protrusions 112a, 114a and the antenna elements 111, 113, 115.

Referring to FIG. 4B, the shape and insertion direction of the conductive protrusions 116a and 118a according to an embodiment of the present invention in a cross section corresponding to the cutting line B-B' are briefly shown. Like the conductive protrusions 112a and 114a, the conductive protrusions 116a and 118a may be implemented through a'C'-shaped copper wire or various conductors. The conductive protrusion 116a is inserted from top to bottom in the Z-direction. In addition, the conductive protrusion 118a may be inserted from the lower side to the upper side in the Z-direction. In addition, the conductive protrusions 116a and 118a and the antenna elements 115, 117 and 119 may be fixed through soldering. The conductive protrusions 116a and 118a are also not limited to copper wire, and may be made of various conductors and mounted on a PCB substrate. An antenna component (2D length) for a radio signal traveling in the X-direction perpendicular to the YZ-plane can be secured by the conductive protrusions 116a, 118a and the antenna elements 115, 117, 119.

5A, 5B, and 5C are diagrams exemplarily showing antenna components of the omni-directional antenna of the present invention for each three-dimensional direction.

5A, the Z-direction component of the omni-directional antenna 110 of the present invention is schematically illustrated. It is assumed that the electric field E of the received radio signal has a polarization characteristic in the X-direction and proceeds in the Z-direction (ie, a direction perpendicular to the PCB substrate). Then, the omni-directional antenna 110 of the present invention may provide an antenna component having a length of half a wavelength (λ/2) that provides optimal sensitivity to the XY-plane.

5B, the Y-direction component of the omni-directional antenna 110 of the present invention is schematically illustrated. It is assumed that the electric field (E) of the received radio signal has a polarization characteristic in the X-direction and proceeds in the Y-direction (ie, the horizontal direction to the PCB substrate). Then, the omni-directional antenna 110 of the present invention can provide an antenna component having a length of 2D through the conductive protrusions 112a and 114a for radio waves traveling in the Y-direction in the XZ-plane.

5C, the X-direction component of the omni-directional antenna 110 of the present invention is schematically illustrated. It is assumed that the electric field (E) of the received radio signal has a polarization characteristic in the X-direction and proceeds in the Y-direction (ie, the horizontal direction to the PCB substrate). Then, the omni-directional antenna 110 of the present invention can provide a 2D-length Z-direction antenna component by conductive protrusions 116a and 118a for radio waves traveling in the Z-direction in the YZ-plane.

According to the antenna components described above, the antenna components are provided in the omnidirectional direction regardless of the propagation direction or polarization characteristic of the radio signal received by the omnidirectional antenna 110 of the present invention. Accordingly, the receiver including the omni-directional antenna 110 of the present invention can provide high reception sensitivity even in various reception conditions or environments.

6A and 6B are views showing a conductive protrusion according to another embodiment of the present invention.

Referring to FIG. 6A, the shape and insertion direction of the conductive protrusions 112b and 114b according to an embodiment of the present invention in a cross section corresponding to the cut line A-A' are briefly shown. The conductive protrusions 112b and 114b may be implemented through a semicircular or'U'-shaped copper wire having a radius R or various conductors. When formed of a copper wire, a copper wire-shaped conductive protrusion 112b is inserted from the top to the bottom side in the Z-direction. In addition, the conductive protrusion 114b may be inserted from the lower side in the Z-direction toward the upper side. In addition, the conductive protrusions 112b and 114b and the antenna elements 111, 113 and 115 may be fixed through soldering. The material of the conductive protrusions 112b and 114b is not limited to the copper wire. The conductive protrusions 112b and 114b may be manufactured in the form of various conductor lines or components and mounted on the PCB substrate. An antenna component (2R length) for a radio signal traveling in the Y-direction can be secured by the conductive protrusions 112b and 114b and the antenna elements 111, 113 and 115.

Referring to FIG. 6B, the shape and insertion direction of the conductive protrusions 116b and 118b according to an embodiment of the present invention in a cross section corresponding to the cut line B-B' are briefly shown. Like the conductive protrusions 112b and 114b, the conductive protrusions 116b and 118b may be implemented through semicircular or'U'-shaped copper wires or various conductors. The conductive protrusion 116b is inserted from top to bottom in the Z-direction. In addition, the conductive protrusion 118b may be inserted from the lower side in the Z-direction toward the upper side. In addition, the conductive protrusions 116b and 118b and the antenna elements 115, 117 and 119 may be fixed through soldering. The conductive protrusions 116b and 118b are also not limited to copper wires, and may be made of various conductors and mounted on the PCB substrate 100a. An antenna component (2R length) for a radio signal traveling in the X-direction perpendicular to the YZ-plane may be secured by the conductive protrusions 116b and 118b and the antenna elements 115, 117, and 119.

7A, 7B, and 7C are diagrams exemplarily showing antenna components of the omni-directional antenna of the present invention for each three-dimensional direction.

Referring to Figure 7a, the Z-direction component of the omni-directional antenna 110 of the present invention is schematically shown. It is assumed that the electric field E of the received radio signal has a polarization characteristic in the X-direction and proceeds in the Z-direction (ie, a direction perpendicular to the PCB substrate). Then, the omni-directional antenna 110 of the present invention may provide an antenna component having a length of half a wavelength (λ/2) that provides optimal sensitivity to the XY-plane.

Referring to FIG. 7B, the Y-direction component of the omni-directional antenna 110 of the present invention is schematically illustrated. It is assumed that the electric field (E) of the received radio signal has a polarization characteristic in the X-direction and proceeds in the Y-direction (ie, the horizontal direction to the PCB substrate). Then, the omni-directional antenna 110 of the present invention may provide an antenna component having a length of 2R by the conductive protrusions 112b and 114b for radio waves traveling in the Y-direction in the XZ-plane.

Referring to Figure 7c, the X-direction component of the omni-directional antenna 110 of the present invention is schematically shown. It is assumed that the electric field (E) of the received radio signal has a polarization characteristic in the X-direction and proceeds in the Y-direction (ie, the horizontal direction to the PCB substrate). Then, the omni-directional antenna 110 of the present invention can provide a Z-direction antenna component having a length of 2R by the conductive protrusions 116b and 118b for radio waves traveling in the Z-direction in the YZ-plane.

According to the antenna components described above, the antenna components are provided in the omnidirectional direction regardless of the propagation direction or polarization characteristic of the radio signal received by the omnidirectional antenna 110 of the present invention. Accordingly, the receiver including the omni-directional antenna 110 of the present invention can provide high reception sensitivity even in various reception conditions or environments.

Here, although the shape of the conductive protrusions has been exemplarily disclosed in a'C' shape or a'U' shape, it will be understood that the present invention is not limited thereto. The shape of the conductive protrusion may be changed into various shapes according to a capacity or inductance optimized for impedance matching of the omni-directional antenna 110.

8 is a table showing the results of measuring the performance according to the distance of the omnidirectional antenna of the present invention. Referring to FIG. 8, antenna 1 and antenna 4 are a case in which the omni-directional antenna 110 of the present invention is applied, and antenna 2 and antenna 3 show reception sensitivity in a receiver to which a general PCB antenna is applied. Based on the transmission power 1W, the reception sensitivity according to the distance was tested for each distance. Since it is not a fixed test condition or a communication environment, the omni-directional antennas (antenna 1, antenna 4) of the present invention are not predominant in all conditions. However, it is shown that the omni-directional antenna (antenna 1, antenna 4) of the present invention provides a much higher reception sensitivity compared to the general PCB antenna (antenna 2, antenna 3) at most test distances.

9 is a block diagram showing a village broadcasting receiver according to another embodiment employing an omni-directional antenna of the present invention. Referring to FIG. 9, the village broadcast receiver 200 may further include a level meter 280 and a sensor 290 compared to the village broadcast receiver 100 of FIG. 1. Here, the omni-directional antenna 210, the communication unit 220, the display 230, the keypad 250, the audio processor 260, and the MCU 270 may be provided substantially the same as those of FIG. 1.

The level meter 280 may monitor the reception sensitivity of the omni-directional antenna 210 and provide it to the MCU 270. The reception sensitivity monitored by the level meter 280 may be displayed on the display 230.

The sensor 290 may sense information on various environments inside or outside the village broadcasting receiver 200 and provide it to the MCU 270. For example, the sensor 290 may include at least one of a temperature sensor, a humidity sensor, a proximity sensor, an acceleration sensor, an atmospheric pressure sensor, and a magnetic sensor.

As described above, embodiments have been disclosed in the drawings and specifications. Although specific terms have been used herein, these are only used for the purpose of describing the present invention, and are not used to limit the meaning or the scope of the present invention described in the claims. Therefore, those of ordinary skill in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

Claims (2)

In the omni-directional antenna of the village broadcasting receiver,
A first antenna element formed of a conductive film extending in a first direction of the printed circuit board;
A second antenna element separated from the first antenna element and extending in the first direction;
A third antenna element separated from the first and second antenna elements and extending in a second direction perpendicular to the first direction;
A fourth antenna element separated from the first to third antenna elements and extending in the second direction;
A first conductive protrusion protruding in a vertical direction of at least one of an upper or lower side of the printed circuit board, and electrically connecting one end of the first antenna element and one end of the second antenna element; And
A second conductive protrusion protruding from the printed circuit board in at least one of an upper or lower side in a vertical direction, and electrically connecting one end of the third antenna element and one end of the fourth antenna element,
First holes for inserting both ends of the first conductive protrusion are formed at one end of the first and second antenna elements,
At one end of the third and fourth antenna elements, second holes for inserting both ends of the second conductive protrusion are formed,
Since the first holes are formed through the printed circuit board, both ends of the first conductive protrusion are inserted into either the upper or lower side of the printed circuit board to electrically connect the first and second antenna elements. and,
Since the second holes are formed through the printed circuit board, both ends of the second conductive protrusion are inserted into either the upper or lower side of the printed circuit board to electrically connect the third and fourth antenna elements. Omnidirectional antenna. delete

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