KR102754606B1 - WIRELESS POWER CHARGING APPARATUS FOR CHARGING IoT DEVICE - Google Patents

Abstract

The present invention relates to a wireless power transmission device for charging an IoT device, and according to an embodiment of the present invention, the wireless power transmission device for charging an IoT device includes: a transmission array antenna configured with a plurality of antennas for transmitting power to a receiver; a phase control unit for variably controlling the phase of a power signal applied to each antenna of the transmission array antenna according to a position of the receiver; a receiver detection unit for receiving a power transmission request from the receiver and estimating the position of the receiver; and a controller for controlling the phase control unit by determining the phase of the power signal applied to each antenna to form an antenna beam of the same phase at the position of the receiver through focusing beamforming in a Fresnel region according to the position of the receiver.

Description

{WIRELESS POWER CHARGING APPARATUS FOR CHARGING IoT DEVICE}

The present invention relates to a wireless power transmission device for charging an IoT device, and more specifically, to a wireless power transmission device for charging an IoT device, which estimates the location of a wireless power transmission target, selects an optimal charging area among predetermined charging areas, and transmits power, thereby reducing the complexity of power management and enabling efficient power transmission.

Recently, the importance of power management is increasing in various sensors and electronic devices for implementing technologies such as 5G mobile communications, autonomous driving, artificial intelligence, and the Internet of Things (IoT).

In particular, sensors and electronic devices that utilize wireless communication have issues such as heat generation and cost to consider when using their own power source, so it is necessary to increase the efficiency of power management for these devices through wireless power transmission.

Wireless power transmission technology is a technology that transmits power in the form of magnetic fields or electromagnetic waves using air as a medium, and can be divided into non-radiative and radiative methods.

First, the non-radiative method is a method of transmitting power using a magnetic field within a few centimeters by contact, and includes the magnetic induction method and the magnetic resonance method. This non-radiative method has the disadvantage of low freedom of movement and angle of the receiver.

Next, the radiation method is a method of transmitting power over long distances by radiating electromagnetic waves through antennas, and there is a microwave transmission method. This radiation method increases efficiency by using multiple antennas and can charge multiple devices through beamforming technology. The radiation method can improve power transmission efficiency by increasing the size and arrangement of the antennas.

To this end, the wireless power transmitter essentially includes an RF signal generator, an amplifier for amplifying the RF signal generator, and a power distribution network for distributing the RF signal to the antenna. The wireless power transmitter may further include a phase shifter for adjusting the phase of the applied signal.

However, in the past, when forming an antenna beam at a long distance, there was a limitation that the antenna beam could not be in phase with the receiver and power could not be properly transmitted because the difference in angle between the center of the receiver and the transmitter had to be overcome.

Additionally, when forming an antenna beam at a distance of several meters, the number of antennas required may be in the hundreds to thousands, and accordingly, the number of active circuits and components required may increase exponentially.

In cases where there are hundreds to thousands of RF active components, the price is very high, the power consumption and complexity are very high, and there is a possibility of component deterioration due to heat generation over time. This means that the signal strength may decrease or the phase value may change, which may increase the error in power transmission.

Therefore, it is necessary to devise a method to overcome the inefficient system of existing wireless power transmission technology and transmit power with reduced complexity over long distances.

Republic of Korea Patent Publication No. 10-1398367 (registered on May 15, 2014)

The purpose of the present invention is to provide a wireless power transmission device for charging an IoT device, which reduces the complexity of power management and enables efficient power transmission by estimating the location of a wireless power transmission target, selecting an optimal charging area among predetermined charging areas, and transmitting power.

According to one embodiment of the present invention, a wireless power transmission device for charging an IoT device may include: a transmission array antenna configured with a plurality of antennas to transmit power to a receiver; a phase control unit for variably controlling a phase of a power signal applied to each antenna of the transmission array antenna according to a position of the receiver; a receiver detection unit for receiving a power transmission request from the receiver and estimating a position of the receiver; and a controller for determining a phase of a power signal applied to each antenna to form a focusing beamforming in a Fresnel region according to the position of the receiver and controlling the phase control unit.

According to an embodiment, the apparatus may further include: a power amplifier for amplifying a power signal applied to each antenna received from the phase control unit; a power distribution unit for configuring a power distribution network that distributes the power signal applied to each antenna to the phase control unit; and an RF signal generation unit for generating a power signal provided to the power distribution unit.

The above receiver may be an IoT device including a sensor or electronic device existing in an IoT (Internet of Things) environment.

The boundary of the above Fresnel region may satisfy the mathematical formula R ₀ ≥ 2D ² /λ (where R ₀ is the boundary of the Fresnel region, D is the antenna size dimension, and λ is the wavelength).

The above-mentioned transmitting array antenna may form an antenna group by grouping a plurality of antennas, and the phase control unit may be configured to connect each antenna group and apply a power signal to each antenna group.

The above transmitting array antenna may be a waveguide slot array antenna type.

The above slots may be formed in a direction parallel to the ground and arranged in a zigzag shape.

In addition, a wireless power transmission device for charging an IoT device according to another embodiment of the present invention may include: a transmission array antenna configured with a plurality of antennas for transmitting power to a receiver; a phase delay unit for fixing a phase of a power signal applied to each antenna of the transmission array antenna to form a phase delay circuit that forms a fixed focusing beamforming in a predetermined charging area; a receiver detection unit for receiving a power transmission request from the receiver and estimating a position of the receiver; and a controller for changing a path of the phase delay circuit through switching control to form a focusing beamforming at a position of the receiver as the receiver is located within the charging area.

According to an embodiment, the apparatus may further include: a power amplifier for amplifying a power signal applied to each antenna received from the phase delay unit; a power distribution unit for configuring a power distribution network that distributes the power signal applied to each antenna to the phase delay unit; and an RF signal generation unit for generating a power signal provided to the power distribution unit.

The above-mentioned transmitting array antenna may form an antenna group by grouping a plurality of antennas, and the phase delay unit may be connected to each antenna group to apply a power signal to each antenna group.

In addition, a wireless power transmission device for charging an IoT device according to another embodiment of the present invention may include a transmission array antenna configured with a plurality of antennas to transmit power to a receiver, wherein the antennas are arranged to form a fixed focusing beamforming at a position of the receiver, and the arrangement of each antenna is adjusted to form a focusing beamforming; a receiver detection unit configured to receive a power transmission request from the receiver and estimate the position of the receiver; and a controller configured to control the application of a power signal to each antenna when the receiver is located within a charging area formed by the transmission array antennas.

According to an embodiment, the present invention further includes: a power amplifier for amplifying a power signal applied to each antenna; a power distribution unit for configuring a power distribution network that distributes the power signal applied to each antenna; and an RF signal generation unit for generating a power signal provided to the power distribution unit; wherein the controller may control the power distribution unit to apply the power signal to each antenna.

(여기서, θ_sphere는 안테나의 구면 각도, R은 수신기까지의 거리, X는 단위 안테나의 폭, N_X는 안테나의 가로 배열 개수)를 만족하는 것일 수 있다.Each of the above antennas is arranged along the area of the sphere, using the mathematical formula

(where, θ _sphere is the spherical angle of the antenna, R is the distance to the receiver, X is the width of the unit antenna, and N _X is the number of horizontal arrays of antennas).

The present invention estimates the location of a wireless power transmission target, selects an optimal charging area among predetermined charging areas, and transmits power, thereby reducing the complexity of power management and enabling efficient power transmission.

In addition, the present invention can provide a system capable of transmitting power by overcoming a complex and inefficient system and reducing complexity.

In addition, the present invention can maintain the array gain in the Fresnel region by performing focusing beamforming to overcome the near-field performance degradation of a large antenna or antenna array.

In addition, the present invention can reduce the complexity by reducing the number of antennas to be controlled while having a high antenna gain by having one unit of antenna module controlled by RF chain per antenna rather than one per antenna.

Additionally, the present invention can reduce or eliminate the number of phase shifters by fixing the phase signals of multiple antennas.

In addition, the present invention can reduce the complexity of phase control by concentrating power in a predetermined area in the power transmission control stage.

Figures 1 and 2 are drawings explaining the concept of wireless power transmission according to an embodiment of the present invention.
FIG. 3 is a drawing of a wireless power transmission device for charging an IoT device according to an embodiment of the present invention.
Figure 4 is a drawing showing various types of transmitting array antennas, and Figure 5 is a drawing explaining focusing beamforming.
Figure 6 is a drawing showing a sub-array type transmitting array antenna.
Fig. 7 is a drawing showing a slot array antenna.
Figure 8 is a drawing illustrating an outline of fixed focusing beamforming.
Figure 9 is a drawing illustrating a charging area of fixed focusing beamforming.
Fig. 10 is a diagram for a phase delay circuit.
Figure 11 is a drawing illustrating fixed focusing beamforming through antenna arrangement.
Figure 12 is a drawing showing the PoC (Proof of Concept) configuration of a wireless power transmission device.
Fig. 13 is a diagram showing the simulation results for the case where the fixed focusing beamforming of the wireless power transmission device of Fig. 12 is implemented.
Fig. 14 is a drawing showing the transmission array antenna and measurement results of Fig. 12.
Figure 15 is a drawing showing a case where the transmitting array antenna of Figure 12 is implemented in a planar form.
Fig. 16 is a drawing showing a case where the transmitting array antenna of Fig. 12 is implemented in a spherical shape.
Figure 17 is a drawing showing a PA board that implements fixed beamforming through phase delay of the RF chain of Figure 12.
Figure 18 is a drawing showing a PA board that implements fixed beamforming through antenna placement of the RF chain of Figure 12.
Fig. 19 is a drawing showing a macroscopic view of the transmitting array antenna of Fig. 18.
Figure 20 is a drawing explaining the spherical angle in the transmitting array antenna of Figure 19.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, detailed descriptions of well-known functions or configurations that may obscure the gist of the present invention in the following description and the attached drawings will be omitted. In addition, it should be noted that identical components are indicated with the same drawing reference numerals throughout the drawings as much as possible.

The terms or words used in this specification and claims described below should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of the present invention, based on the principle that the inventor can appropriately define the terms to best describe his or her invention.

Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

In the attached drawings, some components are exaggerated, omitted, or schematically depicted, and the size of each component does not entirely reflect the actual size. The present invention is not limited by the relative sizes or spacings drawn in the attached drawings.

When a part of the specification is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated. Also, when a part is said to be "connected" to another part, this includes not only the case where it is "directly connected," but also the case where it is "electrically connected" with other elements in between.

Singular expressions include plural expressions unless the context clearly indicates otherwise. It should be understood that terms such as "comprises" or "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

Also, the term "part" used in the specification means a software, hardware component such as an FPGA or an ASIC, and the "part" performs certain functions. However, the "part" is not limited to software or hardware. The "part" may be configured to be on an addressable storage medium and may be configured to execute one or more processors. Thus, by way of example, the "part" includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functionality provided in the components and "parts" may be combined into a smaller number of components and "parts" or further separated into additional components and "parts."

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are assigned similar drawing reference numerals throughout the specification.

Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings.

FIG. 1 and FIG. 2 are drawings explaining the concept of wireless power transmission according to an embodiment of the present invention, FIG. 3 is a drawing of a wireless power transmission device for charging an IoT device according to an embodiment of the present invention, FIG. 4 is a drawing showing various types of transmitting array antennas, and FIG. 5 is a drawing explaining focusing beamforming.

As illustrated in FIGS. 1 and 2, a wireless power transmission device (100) for charging an IoT device according to an embodiment of the present invention estimates the location of a wireless power transmission target, selects an optimal charging area among predetermined charging areas, and transmits power, thereby reducing the complexity of power management and enabling efficient power transmission. Here, an IoT device may comprehensively include a sensor or electronic device existing in an IoT (Internet of Thing) environment.

In the present invention, the term ‘transmitter’ corresponds to a wireless power transmission device (100), and the term ‘receiver’ corresponds to an IoT device.

Such a wireless power transmission device (100) may have the following features to reduce the complexity of power management.

First, the wireless power transmission device (100) can maintain the array gain through focusing beam forming in the Fresnel zone to overcome the performance degradation in the short range of a large antenna or antenna array. That is, the charging area becomes the Fresnel zone.

Second, the wireless power transmission device (100) can reduce complexity by reducing the number of antennas to be controlled while having a high antenna gain by having one unit of antenna module controlled by an RF chain per antenna rather than one per antenna.

Thirdly, the wireless power transmission device (100) can reduce or eliminate the number of phase shifters by fixing the phase signals of multiple antennas.

Lastly, the wireless power transmission device (100) can reduce the complexity of phase control by concentrating power in a predetermined area in the power transmission control step.

As illustrated in FIG. 3, the wireless power transmission device (100) includes an RF signal generation unit (110), a power distribution unit (120), a phase control unit (130), a power amplifier unit (140), a transmission array antenna (150), a receiver detection unit (160), and a controller (170).

Specifically, the RF signal generation unit (110) can generate a power signal. For example, the power signal can be an electromagnetic wave with a constant amplitude and phase and a variety of frequency ranges.

Next, the power distribution unit (120) constitutes a power distribution network that distributes power signals to the transmitting array antennas (150), and has a single input signal and two or more output signals. The power level of the output signal is 1/N of the input power level (N is the number of outputs).

Next, the phase control unit (130) can variably control the phase of each power signal applied through the power distribution unit (120) according to the position of the receiver. At this time, the phase control unit (130) can control the phase of the power signal for each antenna group by grouping multiple antennas to reduce the possibility of performance deterioration due to heat generation from active elements.

Through this, the phase control unit (130) can implement variable focusing beamforming, while it can be replaced with a phase delay unit (180) as shown in FIG. 8 to implement fixed focusing beamforming.

Next, the power amplifier (140) amplifies the intensity of each power signal applied through the phase control unit (130).

Next, the transmitting array antenna (150) transmits power to each power signal applied through the power amplifier (140) to a receiver, i.e., an IoT device.

This transmitting array antenna (150) is composed of a plurality of antennas. Each of the plurality of antennas can be implemented as, for example, one of a waveguide antenna, a dipole antenna, a Yagi antenna, a patch antenna, a Vivaldi antenna, a wire antenna, and a slot array antenna, and can be arranged in one dimension or three dimensions. Here, a description will be given of a case where a slot array antenna is implemented for low loss, but is implemented as a waveguide antenna.

In addition, the transmitting array antenna (150) may be a planar type as in (a) of FIG. 4, a bending type as in (b) of FIG. 4, or a parabolic type as in (c) of FIG. 4, but for convenience of explanation, the case of a planar type will be described.

Next, when the receiver detection unit (160) receives a request for power transmission from an IoT device, it estimates the location of the IoT device.

At this time, the receiver detection unit (160) receives a power transmission request from the IoT device through the receiving antenna (161), confirms the location of the IoT device through the camera (162), and then estimates the location of the IoT device.

Next, the controller (170) determines the phase of the power signal applied to a plurality of antennas included in the transmission array antenna (150) based on the location of the IoT device estimated through the receiver detection unit (160) and controls the phase control unit (130).

That is, the controller (170) selects an optimal charging area to transmit power so that electromagnetic waves can be concentrated at the location of the IoT device using a number of antennas in a charging area determined according to the location of the IoT device.

At this time, if there are multiple IoT devices, the controller (170) selects a charging area according to priority and transmits power.

Referring to FIG. 5, the controller (170) forms a focusing beamforming in the Fresnel region by adjusting the phase of the signal applied to multiple antennas in beam forming of the transmission array antenna (150) in a remote area, rather than simply changing the direction of the beam. That is, the controller (170) adjusts the beam of the transmission array antenna (150) to focus on the focal point with the same phase at the position of the receiver (IoT device). At this time, since the phase of each signal at the position of the receiver becomes the same, constructive interference occurs.

In other words, the controller (170) estimates the position of the IoT device for power transmission and determines and applies the phase of the power signal to each of the multiple antennas. Then, at the position of the IoT device, each power signal is attenuated inversely proportional to the square of the distance from each antenna, but arrives with the same phase, so mutually constructive interference occurs.

Here, the Fresnel zone is a zone where the beam pattern technique in the far-field zone does not work, and is determined by the size dimension (D) of the antenna and the wavelength (λ). That is, the boundary (R ₀ ) of the Fresnel zone can be expressed as R ₀ ≥ 2D ² /λ based on Fraunhofer diffraction. For example, the Fresnel zone is within 6.62 m when the antenna length is 40 cm in the 5.8 GHz frequency band, and within 25.6 m when the antenna length is 40 cm in the 24 GHz frequency band.

의 관계를 갖는다. 여기서, r_n은 각 안테나에서 수신기(IoT 디바이스) 까지의 거리이고, λ는 파장 길이이다.The phase (β _n ) of the power signal applied to each antenna is

has the relationship, where r _n is the distance from each antenna to the receiver (IoT device), and λ is the wavelength.

The receiver reception power (P _r ) can be expressed as the following mathematical expression 1 according to the Friis formula, which expresses the transmission and reception power relationship of a wireless link through free space.

Here, P _t is the total transmit power, N _t is the number of transmit antennas, G _t is the transmit antenna gain, G _r is the receive antenna gain, and k is the free-space path loss factor. Directivity is expressed in spherical coordinates (θ, φ) with respect to how G _t and G _r are distributed in any given direction in three dimensions. Here, θ is the elevation or angle above a specified reference plane (e.g., the ground), and φ is the azimuth, which is the angle between the projection of a particular directional reference plane and a particular reference direction (e.g., north or east) in that plane.

As seen above, in the Fresnel region, the efficiency is higher than that of general beamforming due to the characteristics of focusing beamforming, and an area where power signals are concentrated is formed.

That is, the controller (170) can improve the efficiency of power transmission by making the antenna beam have the same phase at the position of the receiver through focusing beamforming in the Fresnel region.

To this end, the phase of the power signal applied to each antenna can be adaptively adjusted according to the position of the receiver using a phase adjustment unit (130) for each antenna. That is, the phase adjustment unit (130) implements variable focusing beamforming.

This is because if the number of active components, such as phase control units (130), increases, there is a possibility that performance degradation due to the active components may occur. Therefore, it is desirable to adaptively control the phase of the power signal applied to each antenna according to the position of the receiver by grouping some antennas and using the phase control unit (130) for each antenna group. This will be described with reference to FIGS. 6 and 7 described below.

In addition, the phase of the power signal applied to each antenna can be adaptively adjusted and determined according to the position of the receiver by the phase adjustment unit (130), but as another embodiment, instead of the phase adjustment unit (130), a phase delay unit (180) can be used to fix the phase according to the position of the receiver determined in advance for each antenna. This will be described with reference to FIGS. 8 to 10 described below.

And, the phase of the power signal applied to each antenna can be determined by physically adjusting the antenna arrangement as another embodiment so that constructive interference occurs at the location of the receiver. This will be described with reference to FIG. 11 below.

First, with reference to FIGS. 6 and 7, we will examine a case in which variable focusing beamforming is implemented through an antenna group in determining the phase of a power signal applied to each antenna.

Fig. 6 is a drawing showing a sub-array type transmitting array antenna, and Fig. 7 is a drawing showing a slot array antenna.

Referring to FIGS. 6 and 7, the transmitting array antenna (150) groups a plurality of antennas, and RF chains (i.e., one phase control unit (130) and one power amplifier unit (140)) are connected to each antenna group to control the phase of the power signal for each antenna group. That is, one RF chain is connected to one antenna group.

The number of each antenna group is determined within a limit that does not cause more than 30% loss in power transmission efficiency. In Fig. 6, each antenna group includes 16 array slot antennas.

The slot array antenna of Fig. 7 can be implemented as a hexahedral waveguide antenna having a side length of 5λ (1λ = 12.5mm). That is, the transmitting array antenna (150) is a waveguide slot array antenna type. The slots are formed in a direction parallel to the ground and arranged in a zigzag shape.

In this way, the transmitting array antenna (150) forms an antenna group, and the RF chain is connected to each antenna group to adjust the phase of the power signal, thereby reducing the number of active circuits or active elements, thereby reducing power consumption and complexity.

Next, in determining the phase of the power signal applied to each antenna in FIGS. 8 to 10, we will examine a case where fixed focusing beamforming is implemented through a phase delay unit (180). In this case, fixed focusing beamforming can also be implemented through the antenna groups of FIGS. 6 and 7 described above. That is, one RF chain can be connected to one antenna or one antenna group.

FIG. 8 is a drawing explaining an outline of fixed-type focusing beamforming, FIG. 9 is a drawing explaining a charging area of fixed-type focusing beamforming, and FIG. 10 is a drawing for a phase delay circuit.

Referring to FIGS. 8 to 10, the phase of the power signal applied to each antenna can be determined by using a phase delay unit (180) that is fixed according to a predetermined charging area, replacing the phase adjustment unit (130) that can be adaptively adjusted according to the position of the receiver.

That is, fixed focusing beamforming can reduce performance degradation caused by the active component by using a passive component, a phase delay unit (180), instead of an active component, a phase control unit (130).

The phase control unit (130) can continuously perform phase control by varying the charging area according to the position of the receiver when implementing variable focusing beamforming, whereas the phase delay unit (180) performs phase control only when the receiver is located within a predetermined charging area when implementing fixed focusing beamforming.

In Fig. 8, the controller (170) transmits a phase control signal for N phase controls to the phase control unit (130) in order to cover N charging regions in the case of variable focusing beamforming, but transmits a phase control signal for phase control to the phase delay unit (180) only when the receiver is located in four charging regions in order to cover four charging regions in the case of fixed focusing beamforming.

In this way, the phase delay unit (180) forms an antenna beam to concentrate power transmission to a predetermined charging area when the receiver is located in the predetermined charging area.

The charging area of Fig. 9 can be designed to have a constant length and width, and the predetermined charging area can be set by pre-adjusting the phase of the signals applied to each antenna. It is preferable that these charging areas do not have overlapping areas with adjacent areas.

To this end, the phase delay unit (180) configures a phase delay circuit according to a predetermined charging area, and then forms an antenna beam to the corresponding charging area where the receiver is located through switching.

Referring to Fig. 10, the phase delay circuit can configure the remaining phase delay paths that can provide phase delay in addition to the reference path (Ref.). The paths in the phase delay circuit are formed through a combination of one or more phase delay units (180) included in the RF chain.

At this time, the controller (170) can change the phase delay path through switching control of a switching element (e.g., SPDT, SP4T, etc.). Here, the number of phase delay paths can be 2 to 4.

The phase delay unit (180) fixes the phase of the power signal applied to each antenna of the transmission array antenna (150) to form a phase delay circuit that forms a fixed focusing beamforming in a predetermined charging area.

And, the controller (170) changes the path of the phase delay circuit through switching control to form an antenna beam of the same phase at the position of the receiver as the receiver is located within the charging area.

Next, we will examine the case where fixed focusing beamforming is implemented through physical antenna arrangement in determining the phase of the power signal applied to each antenna in Fig. 11.

Figure 11 is a diagram illustrating fixed focusing beamforming through antenna arrangement.

In the case of implementing fixed focusing beamforming through the phase delay unit (180) of the above-described FIGS. 8 to 10, it may be the case that each antenna is arranged in a planar shape, but fixed focusing beamforming through antenna arrangement physically changes the position of each antenna to make the distance from the desired power transmission position the same. That is, each antenna of the transmitting array antenna (150) changes its position spatially.

In this case, the phase control unit (130) or the phase delay unit (180) may not be used. That is, the RF chain includes only the power amplification unit (140), and a power signal of the same phase is applied from the power distribution unit (120). Through this, the signal radiated from each antenna undergoes constructive interference at the power transmission location through the same path delay due to the physical change in the arrangement of each antenna.

The transmitting array antenna (150) forms a fixed focusing beamforming by adjusting the arrangement of each antenna to form an antenna beam of the same phase at the location of the receiver.

The controller (170) controls the application of a power signal to each antenna as the receiver is positioned within the charging area formed by the transmitting array antenna (150).

The power amplifier (140) amplifies the power signal applied to each antenna, the power distribution unit (120) configures a power distribution network that distributes the power signal applied to each antenna, and the RF signal generation unit (110) generates a power signal provided to the power distribution unit (120). At this time, the controller (170) controls the power distribution unit (120) to apply the power signal to each antenna.

FIG. 12 is a diagram showing a PoC (Proof of Concept) configuration of a wireless power transmission device, FIG. 13 is a diagram showing simulation results for a case where fixed focusing beamforming of the wireless power transmission device of FIG. 12 is implemented, FIG. 14 is a diagram showing a transmission array antenna and measurement results of FIG. 12, FIG. 15 is a diagram showing a case where the transmission array antenna of FIG. 12 is implemented in a planar shape, and FIG. 16 is a diagram showing a case where the transmission array antenna of FIG. 12 is implemented in a spherical shape.

Referring to Fig. 12, the PoC configuration of the wireless power transmission device consists of an RF source, an 8-way divider delay line, a transmitting RF chain, and a transmitting array antenna (96×96). The receiver uses a receiving array rectenna (24×24).

Figure 13 shows the results of measuring the reception power level when the position of the receiver is changed according to the distance when the wireless power transmission device of Figure 12 attempts to transmit power to receivers in the 5 m and 10 m areas.

(a) shows the reception power level for adaptive beamforming (Friis equation), (b) shows the reception power level for fixed beamforming in a 10m area (10m fixed beamforming), and (c) shows the reception power level for fixed beamforming in a 5m area (5m fixed beamforming).

Based on a point 3dB away from 5m, it covers a radius of about 4m. Through this, by specifying an area of 5m and 10m, it is possible to cover an area of about 14m in front and behind.

Referring to FIGS. 12 and 14, the unit antennas of the transmitting array antennas are waveguide slot antennas and are grouped into a 12×12 array.

The unit antenna made of aluminum is designed to operate in a 24 GHz frequency band, and the antenna reflection coefficient (S11) is -16.4 dBi and the antenna gain is 27.7 dBi as shown in the measurement results of Fig. 14. Accordingly, Fig. 15 shows a planar transmitting array antenna, and Fig. 16 shows a spherical transmitting array antenna.

FIG. 17 is a drawing showing a PA board that implements fixed beamforming through phase delay of the RF chain of FIG. 12, FIG. 18 is a drawing showing a PA board that implements fixed beamforming through antenna arrangement of the RF chain of FIG. 12, FIG. 19 is a drawing showing a macroscopic view of the transmitting array antenna of FIG. 18, and FIG. 20 is a drawing explaining a spherical angle in the transmitting array antenna of FIG. 19.

Referring to Fig. 17, a PA board implementing an RF chain for a planar-shaped transmitting array antenna pre-configures phase values capable of concentrating power at 5 m and 10 m and reconfigures them through a PIN diode switch. In addition, it is equipped with a driver amplifier that amplifies power.

Figure 18 shows a case where fixed beamforming based on 10 m is configured through antenna placement.

Referring to Fig. 18, the PA board implementing the RF chain for the spherical-shaped transmitting array antenna consists of a driver amplifier that amplifies power without a separate phase delay circuit.

Figure 19 shows a spherical transmitting array antenna, and the antennas are arranged along the area of the sphere to form a phase delay of the antenna targeting 10 m.

Referring to FIG. 20, assuming that the width and length of the antenna or antenna group (150) used are the same and the number of horizontal and vertical arrays is the same, the spherical angle (θ _sphere ) of the antenna is determined as in the following mathematical expression 2.

Here, R represents the distance to the receiver, X represents the width of the unit antenna, and N _X represents the number of horizontally arranged antennas.

The method according to some embodiments may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., alone or in combination. The program instructions recorded on the medium may be those specially designed and configured for the present invention or may be those known to and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CDROMs and DVDs, magneto-optical media such as floptical disks, and hardware devices specially configured to store and execute program instructions such as ROMs, RAMs, flash memories, etc. Examples of the program instructions include not only machine language codes generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

Although the above description has focused on the novel features of the present invention as applied to various embodiments, it will be understood by those skilled in the art that various deletions, substitutions, and changes in the form and details of the devices and methods described above may be made without departing from the scope of the present invention. Accordingly, the scope of the present invention is defined by the appended claims rather than by the above description. All changes which come within the scope of equivalency of the claims are intended to be embraced therein.

110 ; RF signal generation unit 120 ; Power distribution unit
130 ; Phase control section 140 ; Power amplifier section
150 ; Transmitting array antenna 160 ; Receiver detector
170 ; Controller 180 ; Phase delay unit

Claims (16)

A transmitting array antenna composed of a plurality of antennas for transmitting power to a receiver;
A phase control unit for variably controlling the phase of a power signal applied to each antenna of the transmitting array antenna according to the position of the receiver;
A receiver detection unit for estimating the location of the receiver by receiving a power transmission request from the receiver; and
A controller for controlling the phase control unit by determining the phase of a power signal applied to each antenna to form a focused beamforming in a Fresnel region according to the position of the receiver;
The above transmitting array antenna,
Grouping multiple antennas to form an antenna group,
The above phase control unit,
Connect each antenna group and apply a power signal to each antenna group.
The above-mentioned transmitting array antenna is a wireless power transmission device for charging an IoT device, which is a waveguide slot array antenna type.
In paragraph 1,
A power amplifier for amplifying the power signal applied to each antenna received from the phase control unit;
A power distribution unit for forming a power distribution network that distributes power signals applied to each antenna to the phase control unit;
An RF signal generation unit for generating a power signal provided to the above power distribution unit;
A wireless power transmission device for charging an IoT device further comprising:
In paragraph 1,
The above receiver is a wireless power transmission device for charging an IoT device, which is an IoT device including a sensor or electronic device existing in an IoT (Internet of Things) environment.
In paragraph 1,
A wireless power transmission device for charging an IoT device, wherein the boundary of the Fresnel region satisfies the mathematical formula R ₀ ≥ 2D ² /λ (where R ₀ is the boundary of the Fresnel region, D is the antenna size dimension, and λ is the wavelength).
In paragraph 1,
The above phase control unit,
A wireless power transmission device for charging an IoT device, which connects each antenna group and applies a power signal to each antenna group.
delete In paragraph 1,
The above slots are formed in a direction parallel to the ground but arranged in a zigzag shape, and are a wireless power transmission device for charging IoT devices.
A transmitting array antenna composed of a plurality of antennas for transmitting power to a receiver;
A phase delay unit for fixing the phase of a power signal applied to each antenna of the transmitting array antenna to form a phase delay circuit that forms a fixed focusing beamforming in a predetermined charging area;
A receiver detection unit for estimating the location of the receiver by receiving a power transmission request from the receiver; and
A controller for changing the path of the phase delay circuit through switching control to form a focused beamforming at the position of the receiver as the receiver is positioned within the charging area;
The above transmitting array antenna,
Grouping multiple antennas to form an antenna group,
The above-mentioned transmitting array antenna is a wireless power transmission device for charging an IoT device, which is a waveguide slot array antenna type.
In Article 8,
A power amplifier for amplifying the power signal applied to each antenna received from the phase delay unit;
A power distribution unit for forming a power distribution network that distributes power signals applied to each antenna to the phase delay unit;
An RF signal generation unit for generating a power signal provided to the above power distribution unit;
A wireless power transmission device for charging an IoT device further comprising:
In Article 8,
The above receiver is a wireless power transmission device for charging an IoT device, which is an IoT device including a sensor or electronic device existing in an IoT (Internet of Things) environment.
In Article 8,
The above phase delay unit,
A wireless power transmission device for charging an IoT device, which connects each antenna group and applies a power signal to each antenna group.
delete In Article 8,
The above slots are formed in a direction parallel to the ground but arranged in a zigzag shape, and are a wireless power transmission device for charging IoT devices.
A transmitting array antenna composed of a plurality of antennas for transmitting power to a receiver, wherein the arrangement of each antenna is adjusted to form a fixed focusing beamforming at the location of the receiver;
A receiver detection unit for estimating the location of the receiver by receiving a power transmission request from the receiver; and
A controller for controlling the application of a power signal to each antenna as the receiver is positioned within a charging area formed by the transmitting array antennas;
The above transmitting array antenna,
Grouping multiple antennas to form an antenna group,
The above-mentioned transmitting array antenna is a wireless power transmission device for charging an IoT device, which is a waveguide slot array antenna type.
In Article 14,
A power amplifier for amplifying the power signal applied to each of the above antennas;
A power distribution unit for forming a power distribution network that distributes power signals applied to each of the above antennas;
Further comprising an RF signal generating unit for generating a power signal provided to the above power distribution unit;
The above controller is a wireless power transmission device for charging an IoT device, which controls the power distribution unit to apply a power signal to each antenna.
In Article 15,
Each of the above antennas is arranged along the area of the sphere,
Mathematical formula

(Wherein, θ _sphere is the spherical angle of the antenna, R is the distance to the receiver, X is the width of the unit antenna, and N _X is the number of horizontal arrays of antennas) An IoT device, a wireless power transmission device for charging an IoT device.