KR100902496B1 - Polarization transformation antenna and communication device including the same - Google Patents

Abstract

The present invention relates to a polarization conversion antenna using a switch, and more particularly, a polarization conversion that can generate a polarization of a desired shape by a designer by adjusting a phase of four antenna feed units each having a 90 degree phase difference using a switch. Relates to an antenna.

In addition, the present invention relates to a polarization generating method capable of generating a polarization of a desired form, such as linear polarization or circular polarization using the polarization conversion antenna.

By using the polarization conversion antenna of the present invention, it has four phase feed points of 0 degrees, 90 degrees, 180 degrees and 270 degrees, and each feed point increases clockwise or counterclockwise at 90 degree phase intervals and sequentially increases. Alternatively, it is designed to reduce and control the switch element for controlling each of the feed point can generate a polarization of the phase desired by the designer.

Polarization, phase, switch, feed

Description

Polarization transformation antenna and communication device including the same}

The present invention relates to a polarization conversion antenna using a switch, and more particularly, a polarization conversion that can generate a polarization of a desired shape by a designer by adjusting a phase of four antenna feed units each having a 90 degree phase difference using a switch. Relates to an antenna.

In addition, the present invention relates to a polarization generating method capable of generating a polarization of a desired form, such as linear polarization or circular polarization using the polarization conversion antenna.

In general, parameters representing the performance or characteristics of an antenna include radiation pattern (meaning directionality), directivity (ratio of power density and average power density in the maximum radiation direction), and gain (directivity reduced by the resistive loss of the antenna). , Polarization (shape due to the trajectory of the electric field vector during transmission), impedance (input impedance at the antenna terminal), and bandwidth (frequency range for which the main performance parameter values are available) are used.

Among these, antenna polarization is "the nature of electromagnetic waves that represent the field vector, in particular the end of the vector represented by a time function at a fixed position in space, and the change in the direction and relative magnitude of the observed state along the direction of propagation." Is defined. That is, it means the shape of a curve consisting of a trajectory drawn in time on the X-axis and the Y-axis when the radio wave propagates in the Z-axis direction.

The polarization is divided into linear polarization (vertical or horizontal) and circular polarization (right or left). In general, these antenna polarization characteristics dominate performance in communication or sensor systems.

Equation 1 is a Friis formula for calculating reception power in a general wireless transmission / reception system.

Where P _r is the receive power, G _t and G _r are the transmit and receive antenna gains respectively, λ is the wavelength of the frequency, R is the distance between the transmitting and receiving systems, e _imp is the impedance between the transmitting and receiving antennas and each system. Loss due to mismatch, e _pol means loss due to polarization mismatch between transmit and receive antennas, and P _t means transmit power.

Here, the polarization mismatch is represented by Equation 2 below, which causes a polarization loss when the polarization is not matched between the antenna of the transmitting side and the antenna of the receiving side.

In more detail, when Equation 1 is expressed in dB scale, there is no loss when the polarizations coincide, but it can be seen that the circular polarization versus linear polarization has a loss of 3 dB and the vertical and horizontal polarization theoretically have infinite loss. This means that a polarization loss is caused when the polarization between the antenna of the transmitting side and the antenna of the receiving side is not matched. A general antenna has only one of linear polarization and circular polarization, depending on the purpose. Such antennas have a problem in that the number of antennas due to polarization is increased when various polarizations are required according to a designer's purpose.

An object of the present invention is to provide a polarization conversion antenna for selectively generating horizontal polarization, vertical polarization, even circular polarization or left circular polarization in one antenna.

More specifically, the present invention has four phase feed points of 0 degrees, 90 degrees, 180 degrees and 270 degrees, and each feed point is designed to increase or decrease sequentially in a clockwise or counterclockwise direction with 90 degree phase intervals. In addition, an object of the present invention is to provide a polarization conversion antenna that generates a polarization of a desired phase by controlling a switch element that controls each of the feed points.

In addition, an object of the present invention is to provide a polarization generation method that can generate a polarization of a desired form, such as linear polarization or circular polarization using the polarization conversion antenna.

The polarization conversion antenna according to the present invention for achieving the above object, the radiation plane having four feed points formed to form a phase difference of 90 degrees, the polarization emitted through the radiation plane by controlling the four feed points A feeder circuit unit for converting, four feed points formed on the radiation surface, a feeder for electrically connecting one surface of the feeder circuit portion and a ground plane formed adjacent to the other surface of the feeder circuit portion.

Preferably, the radiation surface may be formed in a circle, triangle, square or polygon, and may adjust the position of the feed point formed on the radiation surface to satisfy the matching required when generating the polarization.

In addition, the power supply circuit unit, an input formed on a port for inputting and outputting an electrical signal, four connection points having a phase difference of 90 degrees formed in a portion connecting the power supply unit, and a path electrically connecting the port and the four connection points. It may include a pair of SPDT switches having one path and two output paths, and a pair of SPST switches having one input path and two output paths interposed between the SPDT switch and the connection point.

In addition, if the port is two ports or a single port, the same function as the two ports may be implemented by forming an SPDT switch at an input terminal and sequentially applying an input signal through the SPDT switch.

More preferably, the power supply circuit unit may suppress the open stub effect that may occur in the power supply unit by forming the SPDT and the SPST switch in close proximity to the power supply unit.

In addition, a first SPDT switch is formed on a path connecting between a connection point having a 0 degree and a 270 degree phase, and a second SPDT switch is formed on a path connecting a connection point having a 90 degree and a 180 degree phase. 2 A first SPST switch is formed on the path connecting the connection point having the 90 degree phase from the SPDT switch, and a second SPST switch is formed on the path connecting the connection point having the 180 degree phase from the first SPDT switch. Can be.

On the other hand, by inserting a dielectric between the radiating surface and the feeder circuit portion can reduce the height of the feeder.

In addition, the present invention can provide a communication device including the polarization conversion antenna described above.

On the other hand, the polarization generation method using a polarization conversion antenna according to the present invention controls the first and second SPDT switch and the first and second SPST switch of the polarization conversion antenna to connect two connection points of the four connection points formed in the power supply circuit portion Selecting, and generating a corresponding polarization through two feed points on the radial surface electrically connected through the two selected connection points and the feed part.

Preferably, the linear linear polarization radiated from the radiation plane is such that the first SPST switch is turned off and the second SPST switch is turned on when an input signal is applied to a first port. The SPDT switch short-circuits the connection point having a phase of 180 degrees, opening the connection point having a 270 degree phase, the second SPDT switch is turned off and at feed points of 0 and 180 degree phases formed on the radiating surface. It may be generated in a step in which radiation is made.

In addition, in the horizontal linear polarization radiated from the radiation surface, when an input signal is applied to a second port, the first SPST switch is turned on and the second SPST switch is turned off. Is turned off, the second SPDT switch short-circuits the connection point having a phase of 270 degrees, opens the connection point having a 180 degree phase, and emits at a feed point of 90 and 270 degree phases formed on the radiation surface Can be generated in a step made.

In addition, the even-circular polarization radiated from the radiation surface, when the signal is applied to the first port, the first and second SPST switch is turned off, the first SPDT switch short-circuit the connection point of 270 degree phase Opening a 180 degree phase connection point, turning off the second SPDT switch, and radiating an even circular polarization at feed points of 0 degree and 270 degree phases formed on the radiation surface. have.

In addition, the left-circular polarized wave emitted from the radiation surface, when the signal is applied to the second port, the first and second SPST switch is turned off, the first SPDT switch is turned off, the second SPDT The switch may be generated by shorting the connection point of 180 degree phase, opening the connection point of 270 degree phase, and radiating left-circular polarization polarization at feed points of 90 degree and 180 degree phases formed on the radiation surface. have.

As described above, the present invention can generate horizontal polarization, vertical polarization, even circular polarization or left circular polarization from one antenna using a polarization conversion antenna.

More specifically, the present invention has four phase feed points of 0 degrees, 90 degrees, 180 degrees, and 270 degrees using a polarization conversion antenna, and each feed point has a 90 degree phase interval in a clockwise or counterclockwise direction. Designed to increase or decrease sequentially, the switch element controlling each of the feed points may be controlled to generate a polarization of a desired phase by the designer.

Hereinafter, with reference to the accompanying drawings, it will be described the most preferred embodiment of the polarization conversion antenna according to the present invention.

1 is a diagram illustrating a polarization conversion antenna according to an embodiment of the present invention.

Referring to FIG. 1, a radiation surface 100 having four feed points formed to have a phase difference of 90 degrees, a feed circuit unit 200 controlling the four feed points, and 4 formed on the radiation surface 100. And a power supply unit 300 electrically connecting one power supply point and one surface of the power supply circuit unit 200, and a ground plane 400 formed adjacent to the other surface of the power supply circuit unit 200.

The polarization conversion antenna may be configured to convert the polarization of the antenna according to the purpose by configuring the feed circuit unit 200 electrically connected to the radiation surface 100 having four feed points.

Meanwhile, a height of the power feeding part 300 may be lowered by inserting a dielectric between the radiating surface 100 and the power feeding circuit part 200 to extend an electrical length.

Figure 2 is a view showing in more detail the radiation surface according to an embodiment of the present invention.

Referring to FIG. 2, the polarization conversion antenna has four feed points having phases of 0 degrees 110, 90 degrees 111, 180 degrees 112, and 270 degrees 113, and any of four feed points Select two feed points to generate linear or circular polarization.

The radiating surface 100 may be implemented in various shapes such as triangles, squares, or polygons, not circular, as shown in FIG. .

3 is a diagram illustrating in detail a power supply circuit unit according to an embodiment of the present invention.

Referring to FIG. 3, the power supply unit 300 receives signals input through the first port 210 and the second port 211, the first port 210, and the second port 211 through which electrical signals are input and output. 0 degrees 220, 90 degrees 221, 180 degrees 222, and 270 degrees () formed at a point electrically connected to the feeder for transmission to the feed point formed on the radiation surface 100 through). Four connection points having a phase of 223, and two single-pole-double-through (SPDT) switches formed on a path electrically connecting the first and second ports 210 and 211 and the four connection points. And two Single-Pole-Single-Through (SPST) switches. In more detail, a first SPDT switch 230 is provided on a path connecting a connection point having a phase of 0 degrees 220 and 270 degrees 223. Is formed, and a second SPDT switch 231 is formed on a path connecting the connection points having a phase of 90 degrees 221 and 180 degrees 222. All. By this configuration, the phase of the connection points can be adjusted according to the line length. Phases of 0 degrees and 90 degrees can be implemented according to the principle of the divider, and phases of 270 and 180 degrees can be implemented through the SPDT switches 230 and 231 and the divider. The distributor may be the same as the principle of the Wilkinson distributor, it is also possible to implement the phase by having a separate phase shifter in addition to this method.

In addition, a first SPST switch 240 is formed on a path connecting the connection point of the phase of 270 degrees 223 from the second SPDT switch 231, and 180 degrees 222 from the first SPDT switch 230. The second SPST switch 241 is formed on a path connecting the connection points of the phases.

Meanwhile, a pin type connector may be used as the feeder 300 of the polarization conversion antenna shown in FIG.

In the polarization conversion method of the polarization conversion antenna, two connection points are selected from four connection points through control of the first and second SPDT switches 230 and 231, and the two connection points are connected through the power supply unit 300. Generate the desired polarization through the feed point. This will be described in more detail below with reference to FIGS. 4 to 7.

On the other hand, for the convenience of the designer, the antenna input may use two ports as in the proposed structure, but in the case of using a single port, an SPDT switch is formed at the input terminal, and the input signal is sequentially applied through the SPDT switch. Can be implemented in the same way as

The feed circuit unit 200 is configured to close the SPDT and SPST switch as close as possible to the feed unit 300 to suppress the open-stub effect that the SPDT and SPST switch may occur in the feed unit 300. Can be. On the other hand, even if a device such as a coupler other than the Wilkinson divider can be used to operate the same.

4 is a diagram illustrating an example of linear polarization generation in a vertical direction through a polarization conversion antenna according to an embodiment of the present invention.

Referring to FIG. 4, the principle of generating linear polarization in a vertical direction at a given radiation plane is as follows. First, when an input signal is applied to the first port 210, the first SPST switch 240 is turned off, and the second SPST switch 241 is turned on to conduct current. . On the other hand, the first SPDT switch 230 is short-circuited with a connection point having a phase of 180 degrees 222 and is opened with a connection point having a phase of 270 degrees 223. In addition, the second SPDT switch 231 is turned off so that current is conducted only to a connection point having a phase of 0 degrees 220 and a connection point having a phase of 180 degrees 222 and a connection point having a phase of 0 degrees 220. Radiation occurs at feed points in the 0 degree 110 and 180 degree 112 phases that are shorted to the junction having a 180 degree 222 phase.

In more detail, the connection point of the 0 degree 220 phase and the connection point of the 180 degree 222 phase are formed to have a phase difference of 180 degrees by adjusting the length of a shorted transmission line, which generates a linear polarization in a vertical direction. .

5 is a diagram illustrating an example of linear polarization generation in the horizontal direction through a polarization conversion antenna according to an embodiment of the present invention.

Referring to FIG. 5, when a horizontal polarization is applied to the second port 211, the first SPST switch 240 is turned on and the second SPST switch 241 is turned off. On the other hand, the first SPDT switch 230 is turned off, the second SPDT switch 231 is short-circuited with a connection point having a phase of 270 degrees 223, and is opened with a connection point having a phase of 180 degrees 222. Here, the connection point of the 90 degrees 221 phase and the connection point of the 270 degrees 223 phase are formed to have a phase difference of 180 degrees by adjusting the length of the shorted transmission line, which generates linear polarization in the horizontal direction.

FIG. 6 is a diagram illustrating an example of generating a good circularly polarized wave through a polarization conversion antenna according to an embodiment of the present invention, and FIG. 7 is a diagram illustrating an example of generating a left circularly polarized wave.

In general, circular polarization can be generated by using two orthogonal modes of feed point. In general, assume that the axial ratio is 3dB or less and VSWR 1.5 or less. In the antenna using multiple feeds, circular polarization in the opposite direction may occur due to reflected waves. Therefore, it is designed to cancel the reflected signal by using 90 degrees of phase between feeds.

Referring to FIG. 6, when a signal is applied to the first port 210, the first and second SPST switches 240 and 241 are turned off, and the first SPDT switch 230 is 270 degrees 223. It is short-circuited with the connection point of a phase, and is open with the connection point of 180 degree | times (222) phase. In addition, the second SPDT switch 231 is turned off so that current is conducted only at the connection point of the zero degree phase 220 and the connection point of the 270 degree 223 phase, so that the second SPDT switch 231 is 270 from the connection point of the zero degree 220 phase. Right / handed circular polarization is generated which rotates to the junction of phase 223.

Referring to FIG. 7, when a signal is applied to the second port 211, the first and second SPST switches 240 and 241 are turned off, and the first SPDT switch 230 is turned off. In addition, the second SPDT switch 231 is short-circuited with a connection point of 180 degrees 222 phase and is opened from a connection point of 270 degrees 223 phase. Finally, current is conducted only at the connection point of the 90-degree phase 221 and the connection point of the 180-degree 222 phase, and rotates from the connection point of the 90-degree phase 221 to the connection point of the 180-degree phase 222. / Handed) circularly polarized wave occurs.

The polarization conversion antenna and the polarization generation method using the same according to the present invention have been described above. Such a technical configuration of the present invention will be understood by those skilled in the art that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention.

Therefore, the above-described embodiments are to be understood in all respects as illustrative and not restrictive, and the scope of the present invention is indicated by the following claims rather than the foregoing detailed description. All changes or modifications derived from the meaning and scope and equivalent concept thereof should be construed as being included in the scope of the present invention.

1 is a diagram illustrating a polarization conversion antenna according to an embodiment of the present invention.

Figure 2 shows a more detailed view of the radiation surface according to an embodiment of the present invention.

3 is a more detailed view of a power supply circuit unit according to an embodiment of the present invention.

4 is a diagram illustrating an example of linear polarization generation in a vertical direction through a polarization conversion antenna according to an embodiment of the present invention.

5 is a diagram illustrating an example of linear polarization generation in a horizontal direction through a polarization conversion antenna according to an embodiment of the present invention.

6 is a diagram illustrating an example of generating a circular good polarized wave through a polarization conversion antenna according to an embodiment of the present invention.

7 is a diagram showing an example of left-circular polarization generation through a polarization conversion antenna according to an embodiment of the present invention.

Claims (6)

A radiation surface having four feed points formed so that each feed signal having four phases of 0 degrees, 90 degrees, 180 degrees, and 270 degrees is supplied to have a phase difference of 90 degrees between adjacent feed points; And A feed circuit unit for controlling the four feed points to convert the polarization emitted through the radiation surface; The power supply circuit unit, A port through which an electrical signal is input / output; Four connection points formed at portions connected to each of the feed points and supplied with a feed signal having the same phase as a feed signal supplied to each feed contact; An SPDT switch having one input path and two output paths formed on a path electrically connecting the port and two of the four connection points; And And a SPST switch interposed between the SPDT switch and one of the connection points and having one input path and one output path. delete The method of claim 1, The port includes a port for receiving an input signal sequentially through the SPDT switch connected to the port to implement the same function as the two ports receiving the input signal. The method of claim 1, The antenna includes the pair of ports, the SPDT switch, and the SPST switch, respectively; A first SPDT switch is formed on a path connecting the first port, which is one of the pair of ports, with a connection point receiving a feed signal having a 270 degree phase and a connection point receiving a feed signal having a 180 degree phase, On the path connecting the second port which is the other one of the pair of ports except the first port and the connection point receiving the feed signal having the 180 degree phase and the connection point receiving the feed signal having the 270 degree phase A second SPDT switch is formed, A first SPST switch is formed on a path connecting the connection point to which the feed signal having the 270 degree phase is supplied from the second SPDT switch; And a second SPST switch formed on a path connecting a connection point to which the feed signal having the 180 degree phase is supplied from the first SPDT switch. The method of claim 1, A polarization conversion antenna having a dielectric inserted between the radiating surface and the power supply circuit portion. A communication device comprising the polarization converting antenna of claim 1.

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