JP7015057B2 - Power converter - Google Patents

Description

The present invention relates to a power conversion device.

Conventionally, a balanced two-wire antenna, a balanced two-wire line, a rectifier circuit, and a DC output unit have been formed on one main surface of the substrate, and the rectifier circuit includes a DC cutoff capacitor, a Schottky barrier diode, and a smoothing capacitor. There is a rectenna device in which the distance between the Schottky barrier diode and the smoothing capacitor is set to λg / 22.5 to λg / 14, where the wavelength of the received microwave is λg (see, for example, Patent Document 1). ).

Japanese Unexamined Patent Publication No. 2007-116515

By the way, it is difficult for the conventional rectenna device to obtain a sufficient power generation voltage when the ambient radio wave strength is weak. One of the reasons is that the impedance of the conventional rectenna device was not large enough.

Therefore, it is an object of the present invention to provide a power conversion device having a sufficiently large impedance.

The power conversion device according to the embodiment of the present invention has three or more first conductors, and each first conductor has a main body having a length corresponding to a half wavelength in free space wavelength at the frequency of received radio waves. , A first connecting portion connected to one end of the main body portion, and a second connecting portion connected to the other end of the main body portion, and three or more conductors arranged so as to be spatially adjacent to each other. It is located in a space surrounded by the first conductor and the main body of the three or more first conductors, extends from the first feeding point, and is connected to the first connection portion of the three or more first conductors. It has a first element extending from the first feeding point and a second element extending from the second feeding point constituting the balanced terminal and connected to the second connecting portion of the three or more first conductors. A second conductor constituting each first conductor and a folded dipole antenna, and a rectifying circuit connected to the first feeding point and the second feeding point are included.

It is possible to provide a power conversion device having a sufficiently large impedance.

It is a figure which shows the power conversion apparatus 300 including the folded dipole antenna 100 of embodiment. It is a figure which shows the structure of the folded dipole antenna 100 including four elements 110. It is a figure which shows the simulation result. It is a figure which shows the simulation result of the folded dipole antenna 100. It is a figure which shows the characteristic of the step ^- up ratio n2 with respect to the ratio r1 / r2 of the radius r1 of the main body 111 and the radius r2 of an element 120 in a folded dipole antenna 100. It is a figure which shows the characteristic of the step ^- up ratio n2 with respect to the radius r of the main body part 111 and the element 120 in a folded dipole antenna 100. It is a figure which shows the characteristic of the step ^- up ratio n2 with respect to the interval h in a folded dipole antenna 100. It is a figure which shows the simulation result of the folded dipole antenna 100. It is a figure which shows the dimension of each part of a dipole antenna 100. It is a figure which shows the power conversion apparatus 300M1 including the folded dipole antenna 100M1 of embodiment. It is a figure which shows the power conversion apparatus 300M2 including the folding dipole antenna 100M2 of embodiment. It is a figure which shows the structure of the folded dipole antenna 100M3. It is a figure which shows the structure of the folded dipole antenna 100M4.

Hereinafter, embodiments to which the power conversion device of the present invention is applied will be described.

<Embodiment 1>
FIG. 1 is a diagram showing a power conversion device 300 including a folded dipole antenna 100 of the embodiment.

The power conversion device 300 includes a folded dipole antenna 100 and a rectifier circuit 200. The power conversion device 300 converts the high-frequency power of the radio wave received by the folded dipole antenna 100 into DC power by the rectifier circuit 200 and outputs it.

The folded dipole antenna 100 has an inductive impedance characteristic. Therefore, the power conversion device 300 can achieve impedance matching between the rectifier circuit 200 showing the capacitive impedance and the folded dipole antenna 100 without including a filter in addition to the folded dipole antenna 100 and the rectifier circuit 200. can. The details will be described below.

The folded dipole antenna 100 has N elements 110 and one element 120. N is an integer of 3 or more. That is, the folded dipole antenna 100 includes three or more elements 110.

In FIG. 1, the folded dipole antenna 100 is manufactured by combining a copper metal rod as an example. However, the folded dipole antenna 100 may be made of a metal other than copper, or may be manufactured by patterning a metal foil on the surface of a substrate or the like.

The element 110 has a main body portion 111 and connecting portions 112 and 113. The element 110 is an example of the first conductor. The N elements 110 are such that the central axis of the main body 111 is located on the outer peripheral surface of a virtual cylinder centered on the central axis C of the element 120, and the circumference of the adjacent main bodies 111 is opposite to each other. They are arranged so that the angles θ in the directions are equal. That is, the N elements 110 are arranged so that the main body 111 is arranged at equal intervals on the outer peripheral surface of a virtual cylinder centered on the central axis C of the element 120.

Since the N elements 110 have the same configuration as each other, one element 110 will be described here.

The main body 111 has ends 111A and 111B. The connecting portion 112 connects the end portion 111A and the end portion 122A of the element 120, and the connecting portion 113 connects the end portion 111B and the end portion 122B of the element 120.

The main body 111 extends parallel to the central axis C of the elongated cylindrical element 120 with the ends 111A and 111B at both ends. The main body 111 is arranged in parallel with the element 120.

The length L of the main body 111 is set to a length corresponding to about half a wavelength (about λ _0/2 ) of the free space wavelength λ ₀ of the radio wave received by the folded dipole antenna 100. This is because the element 110 corresponds to the total length of the folded dipole antenna 100 (the length from one end of the element 120 in the central axis direction).

Here, the length corresponding to the half wavelength (λ _0/2 ) of the free space wavelength λ ₀ of the radio wave is not strictly limited to the half wavelength (λ _0/2 ) of the free space wavelength λ ₀ of the radio wave, and is folded back. In the adjustment for functioning as the dipole antenna 100, it is meant to include the length when the wavelength is slightly shorter than the half wavelength (λ _0/2 ).

Further, the element width (cylindrical shape diameter) of the main body portion 111 of the element 110 is thicker than the element width (cylindrical shape diameter) of the element 120, and the radius of the main body portion 111 is formed to be larger than the radius of the element 120. Has been done. In the folded dipole antenna 100, the impedance is determined by the element width of the element 110 with respect to the element width of the element 120. By making the element width of the element 110 wider than the element width of the element 120, the impedance of the folded dipole antenna 100 can be increased.

When the elements 110 and 120 are made of a metal foil on the surface of the substrate, the element width with respect to the thickness of the main body 111 of the element 110 is larger than the element width with respect to the thickness of the element 120. good.

The element 120 has elements 120A and 120B. The element 120 is an example of the second conductor.

The element 120A has a feeding point 121A and an end 122A. The element 120A is an example of the first element. The feeding point 121A is an example of the first feeding point. The end portion 122A is an example of the first end portion. The element 120A is parallel to the main body 111 of the element 110. The feeding point 121A is connected to the terminal 201 of the rectifier circuit 200.

The element 120B has a feeding point 121B and an end 122B. The element 120B is an example of the second element. The feeding point 121B is an example of the second feeding point, and is arranged at a position symmetrical with the feeding point 121A with the axis perpendicular to the central axis C of the element 120 as the axis of symmetry. The end portion 122B is an example of the second end portion.

The feeding points 121A and 121B are examples of balanced terminals. Terminals 201 and 202 of the rectifier circuit 200 are connected to the feeding points 121A and 121B. The feeding points 121A and 121B and the terminals 201 and 202 of the rectifier circuit 200 may be connected by, for example, a copper foil pattern at the shortest distance. In FIG. 1, the connection portion between the feeding points 121A and 121B and the terminals 201 and 202 of the rectifier circuit 200 is shown by two broken lines.

The element 120B is parallel to the main body 111 of the element 110. The feeding point 121B is connected to the terminal 202 of the rectifier circuit 200.

The element 120B is arranged so as to be axisymmetric with the element 120A with respect to the axes of symmetry of the feeding points 121A and 121B in a plan view. The length of the element 120B is equal to the length of the element 120A. The length from the end 122A to 122B is 1/2 (λe / 2) of the electrical length λe at 1000 MHz. This length is the length including the distance between the feeding points 121A and 121B, in other words, the distance between the end portion 122A and the end portion 122B.

Since the rectifier circuit 200 has a high impedance, it is necessary to increase the impedance of the folded dipole antenna 100 in order to match the capacitive impedance of the rectifier circuit 200 with the inductive impedance of the folded dipole antenna 100.

Therefore, the element width of the element 110 is made larger than the element width of the element 120. By conjugate matching the impedance of the folded dipole antenna 100 and the impedance of the rectifier circuit 200, the rectification efficiency of the rectifier circuit 200 can be increased.

The rectifier circuit 200 includes terminals 201, 202, capacitors 211, 212, 213, 214, diodes 221, 222, 223, 224, and output terminals 231 and 232. The rectifier circuit 200 is, for example, a Cockcroft-Walton type rectifier circuit.

Capacitors 211 and 212 are connected in series to the terminal 201, and capacitors 213 and 214 are connected in series to the terminal 202. Further, as shown in FIG. 1, the diodes 221, 222, 223, and 224 are connected in a cross-shaped manner between the capacitors 211, 212, 213, and 214.

The rectifier circuit 200 converts the high frequency power input from the folded dipole antenna 100 into a DC voltage and outputs it from the output terminals 231 and 232. The impedance of such a rectifier circuit 200 is capacitive due to the influence of the capacitance between the terminals of the diodes 221, 222, 223, and 224.

Further, since the folded dipole antenna 100 of this embodiment has an inductive impedance characteristic, the power conversion device 300 is not provided with a filter, but a filter may be provided. In that case, the impedance of the folded dipole antenna 100 does not necessarily have to be inductive, and may be resistance or capacitive.

FIG. 2 is a diagram showing a configuration of a folded dipole antenna 100 including four elements 110. FIG. 2 shows the main body 111 and the connection 112 of the element 110, and the element 120.

Here, the length (outer dimension) between the ends 111A and 111B of the main body 111 is 150 mm, the distance between the feeding points 121A and 121B is 5 mm, and the length from the feeding point 121A to the end 122A is 72.5 mm. The simulation was performed with the length from the feeding point 121B to the end 122B set to 72.5 mm.

FIG. 3 is a diagram showing simulation results. In FIG. 3A, the radius r1 of the main body 111 and the radius r2 of the element 120 are fixed to 0.125 mm, and the distance (shortest distance) h between the surface of the main body 111 and the surface of the element 120 is 2 mm to 12 mm. The impedance R ₀ (Ω) of the folded dipole antenna 100M seen from the feeding points 121A and 121B when changed to is shown.

As shown in FIG. 3A, it was found that the impedance R ₀ (Ω) increased as the interval h narrowed. It was found that the interval h should be about 2.5 mm or less in order to make it 10 kΩ or more under this simulation condition. Since it was possible to obtain an antenna having an impedance of about 5 kΩ even with the conventional configuration, it was assumed in the embodiment that an antenna having an impedance of 10 kΩ or more was obtained.

In FIG. 3B, the main body portion is under the condition that the distance (shortest distance) h between the surface of the main body portion 111 and the surface of the element 120 is fixed to 6 mm, and the radius r2 of the element 120 is fixed to 0.125 mm. The impedance _R0 (Ω) when the ratio r1 / r2 between the radius r1 of 111 and the radius r2 of the element 120 is changed is shown.

It was found that the impedance _R0 becomes 10 kΩ or more when the ratio r1 / r2 between the radius r1 of the main body 111 and the radius r2 of the element 120 is 1.3 or more.

Here, the simulation result when the number of elements 110 is four has been described, but it was confirmed that the same tendency can be seen even if the elements 110 are different.

FIG. 4 is a diagram showing a simulation result of the folded dipole antenna 100. Under the condition that the folded dipole antenna 100 receives a radio wave of 1000 MHz, the length L of the main body 111 of the element 110 in the Y-axis direction, the radius r1 of the main body 111, the radius r2 of the element 120, and the main body 111 and the element 120. When the interval h was set to two kinds of values as shown in FIG. 4, the impedance R ₀ (Ω) and the bandwidth BW of the folded dipole antenna 100 seen from the feeding points 121A and 121B were the results as shown in FIG. Became. The bandwidth BW indicates the band of the portion where VSWR is 2 or less as a percentage with respect to 1000 MHz.

The difference between the sample of Example 1 and the sample of Example 2 is the radius r2 of the element 120, which is 0.5 mm in Example 1 and 0.125 mm in Example 2.

The impedance R ₀ of Example 1 is 12.0K (Ω) and the bandwidth BW is 2.5%, the impedance R ₀ of Example 2 is 24.1K (Ω) and the bandwidth BW is 1. It was 8.8%. As described above, it was found that the larger the radius r2 of the element 120, the smaller the impedance _R0 tends to be. Further, it was found that the larger the radius r2 of the element 120, the narrower the bandwidth BW tends to be.

FIG. 5 is a diagram showing the characteristics of the step ^- up ratio n2 with respect to the ratio r1 / r2 of the diameter r1 of the main body 111 and the diameter r2 of the element 120 in the folded dipole antenna 100. Here, the length L of the main body 111 is 150 mm, and the interval h is 2 mm. Further, the radio wave received by the folded dipole antenna 100 is set to 1000 MHz.

Here, the step-up ratio n ² represents the ratio (increase) of the impedance R ₀ of the folded dipole antenna 100 to the impedance of a general dipole antenna. Here, it is assumed that the impedance R ₀ becomes 10 kΩ when the step-up ratio n ² is 137.

When the ratio r1 / r2 of the diameter r1 and the diameter r2 of the element 120 was shaken, it was found that the step-up ratio n ² was 137 or more when the ratio r1 / r2 was 1 or more, as shown in FIG. rice field. Further, it was found that the ratio r1 / r2 increased up to 4, but showed a decreasing tendency when the ratio was higher than that.

Although the simulation result when the received radio wave is 1000 MHz has been described here, it was confirmed that the same tendency is shown even if the frequency of the radio wave is different.

FIG. 6 is a diagram showing the characteristics of the step-up ratio n ² with respect to the radius r of the main body portion 111 and the element 120 in the folded dipole antenna 100. Here, the radius r1 of the main body 111 and the radius r2 of the element 120 are equal, and both are shown as the radius r. Here, the length L of the main body 111 is 150 mm, and the interval h is 6 mm. The radio wave received by the folded dipole antenna 100 was set to 1000 MHz.

When the radius r was swayed, as shown in FIG. 6, the characteristic that the step-up ratio n ² increased as the radius r increased was obtained. That is, it was found that the impedance _R0 of the folded dipole antenna 100 increases as the radius r increases.

It was found that the radius r should be 0.33 mm or more because the step-up ratio n ² should be 137 or more in order for the impedance R ₀ to be 10 kΩ or more. 0.33 mm is 1/90 of the electric length λe at 1000 MHz.

Although the simulation result when the received radio wave is 1000 MHz has been described here, it was confirmed that the same tendency is shown even if the frequency of the radio wave is different.

Therefore, when the radius r is expressed by an equation with the frequency of the radio wave received by the folded dipole antenna 100 as F (MHz), (0.33 (mm) × F (MHz)) / 1000 (MHz) <r (mm). It becomes. From the above, it was found that the radius r should be (0.33 × F) / 1000 <r.

FIG. 7 is a diagram showing the characteristics of the step-up ratio n ² with respect to the interval h in the folded dipole antenna 100. Here, the length L of the main body 111 is 150 mm, and the radii r1 and r2 are both 0.125 mm. The radio wave received by the folded dipole antenna 100 was set to 1000 MHz.

The distance h is the distance (shortest distance) between the element 120 and the main body 111 of the element 110 in the folded dipole antenna 100.

When the interval h was swung from 1 mm to 12 mm, the step-up ratio n ² was 137 or more and less than 300 in the range of the interval h from 1 mm to 2.5 mm. Therefore, it was found that the interval h is preferably in the range of 1 mm to 2.5 mm.

At 1000 MHz, 1 mm corresponds to 1/30 of the electric length λe, and 2.5 mm corresponds to 1/12 of the electric length λe. Therefore, it was found that the interval h may be λe / 30 ≦ h ≦ λe / 12.

Although the simulation result when the received radio wave is 1000 MHz has been described here, it was confirmed that the same tendency is shown even if the frequency of the radio wave is different. Therefore, even if the frequency is other than 1000 MHz, the interval h may be λe / 30 ≦ h ≦ λe / 12.

FIG. 8 is a diagram showing a simulation result of the folded dipole antenna 100. Under the condition that the folded dipole antenna 100 receives a radio wave of 1000 MHz, the length L of the main body 111 of the element 110 in the Y-axis direction, the radius r1 of the main body 111, the radius r2 of the element 120, and the main body 111 and the element 120. When the interval h was set to a value as shown in Example 3 of FIG. 8, the impedance R ₀ (Ω) of the folded dipole antenna 100 seen from the feeding points 121A and 121B was 32.0 kΩ, and the bandwidth BW was 0.5%. Met.

The radius r1 of the main body 111 and the radius r2 of the element 120 are thicker than those of Examples 1 and 2 shown in FIG. 4, but mainly by making the radius r1 of the main body 111 thicker, the coupling between the element 110 and the element 120 increases. It is considered that the impedance _R0 is larger than that of Examples 1 and 2 shown in FIG.

When the folded dipole antenna 100 is configured to receive radio waves of 920 MHz and 2.45 GHz, the dimensions of each part are as shown in FIG.

The length L between the ends 111MA and 111MB of the main body 111M-1 to 111M-4 is 163 mm at 920 MHz, 61 mm at 2.45 GHz, and the distance wf between the feeding points 121A and 121B is 5.4 mm at 920 MHz. The radius r1 of the main bodies 111M-1 to 111M-4 is 0.135 mm at 920 MHz, 0.05 mm at 2.45 GHz, and the distance h between the main bodies 111M-1, 111M-2 and the element 120 is 2 mm at 45 GHz. It was 6.5 mm at 920 MHz and 2.44 mm at 2.45 GHz. The distance between the main body portions 111M-1 and 111M-4 and the distance between the main body portions 111M-2 and 111M-3 are both 2h.

As described above, according to the embodiment, the folded dipole antenna having a very large impedance seen from the feeding points 121A and 121B by including three (three) or more elements 110 arranged around the element 120. 100 was obtained. This is because the coupling with the element 120 is increased by increasing the number of the elements 110.

Therefore, according to the embodiment, it is possible to provide the power conversion device 300 having a sufficiently large impedance.

In the above description, the form in which the angles θ in the circumferential direction of the main body portions 111 of the elements 110 of the folded dipole antenna 100 are the same has been described, but the intervals are not necessarily equal. However, from the viewpoint of increasing the coupling between the three or more elements 110 and the element 120, in the three or more elements 110, the main body 111 is not arranged (two-dimensionally) on the same plane. It is preferable that they are arranged three-dimensionally.

Further, in the above, the mode in which the connecting portions 112 and 113 of the element 110 are connected to the main body portion 111 at an angle of 90 degrees and connected to the element 120 at an angle of 90 degrees has been described. However, the connecting portions 112 and 113 may be configured to be connected to the main body portion 111 or the element 120 at an angle other than 90 degrees.

Further, the connecting portions 112 and 113 may be curved instead of linear. Further, the main body portion 111 is not limited to a linear shape, and may have a shape such that the end portions 111A and 111B sides are curved, for example.

Further, the connection portions 112 and 113 may be connected to the main body portion 111 at positions offset to the center of the end portions 111A and 111B of the main body portion 111. Similarly, the connecting portions 112 and 113 may be connected to the element 120 at a position offset toward the center of the end portions 122A and 122B of the element 120.

Further, when there are N elements 110 as shown in FIG. 1, the connection portions 112 and 113 of one element 110 are connected to the end portions 122A and 122B of the element 120, and the remaining N-1 elements 110 are connected. Connection portions 112 and 113 may be connected to the end portions 122A and 122B of the element 120 via the connection portions 112 and 113 of one element 110.

Further, although the embodiment in which the number N of the elements 110 is 3 or more has been described above, the upper limit of the number N of the elements may be 10. This is because if there are 10 elements 110, a sufficiently high bond with the elements 110 can be obtained, and if the number of elements 110 is limited to 10, it is easier to manufacture. Further, the radiation efficiency when the number of elements 110 is 10 is about 80% of the radiation efficiency when the number of elements 110 is 3, which is a practical lower limit when practicality is taken into consideration. This is because the radiation efficiency is further reduced.

The folded dipole antenna 100 may be deformed as shown in FIGS. 10 to 13 below.

FIG. 10 is a diagram showing a power conversion device 300M1 including the folded dipole antenna 100M1 of the embodiment. FIG. 10A shows an exploded view, and FIG. 10B shows an assembled state. In the following, it will be described using the XYZ coordinate system.

The power converter 300M1 includes a folded dipole antenna 100M1 and a rectifier circuit 200. The folded dipole antenna 100M1 is mounted on the substrates 130A and 130B, and is different from the folded dipole antenna 100 in FIG. 1 in that it is composed of a metal foil formed on the surfaces of the substrates 130A and 130B.

The substrates 130A and 130B are substrates with low dielectric loss such as, for example, a Teflon (registered trademark) substrate or a PPE (Polyphenylene Ether) substrate. Further, the substrates 130A and 130B are not limited to the Teflon substrate or the PPE substrate, and may be, for example, a FR-4 (Flame Retardant type 4) standard wiring board, a substrate of another type, or a flexible substrate.

The substrate 130A is parallel to the XY plane and has a thickness in the Z-axis direction. The substrate 130A has a notch 131A provided at the center of the width of the end on the negative side of the Y-axis in the X-axis direction and a notch provided at the center of the width of the end on the positive side of the Y-axis in the X-axis direction. It has a portion 132A.

The substrate 130B is parallel to the YZ plane and has a thickness in the X-axis direction. The substrate 130B has a slit 131B penetrating in the X-axis direction at the center of the width in the Z-axis direction from the negative Y-axis side to the positive Y-axis side. The length of the slit 131B in the Y-axis direction corresponds to the length between the cutout portions 131A and 132A of the substrate 130A. Further, the width of the slit 131B in the Z-axis direction corresponds to the thickness of the substrate 130A in the Z-axis direction. The thickness of the substrates 130A and 130B is, for example, 0.5 mm.

The folded dipole antenna 100M1 has four elements 110 and one element 120. The same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. When distinguishing the four elements 110, they are referred to as 110-1 to 110-4.

The elements 110-1, 110-3 and the element 120 are provided on the surface of the substrate 130A on the positive direction side of the Z axis. The elements 110-1, 110-3 and the element 120 are manufactured, for example, by patterning a copper foil provided on the surface of the substrate 130A.

The elements 110-1 and 110-3 and the element 120 connect the connection portions 112 of the elements 110-1 and 110-3 to each other, and the center of the width in the X-axis direction of the rectangular annular pattern connecting the connection portions 113 to each other. Is made by patterning to connect the ends 122A and 122B of the element 120.

The end portion 122A of the element 120 is connected to the connection point (the portion located near the notch 132A) between the connection portions 112 of the rectangular annular elements 110-1 and 110-3, and the elements 110-1 and 110 are connected. The end portion 122B of the element 120 is connected to the connection points (the portion located near the notch portion 131A) of the connection portion 113 of -3.

The elements 110-2 and 110-4 are provided on the surface of the substrate 130B on the positive direction side of the X-axis. The elements 110-2 and 110-4 are patterned in a rectangular ring shape in which the connection portions 112 of the elements 110-2 and 110-4 are connected to each other and the connection portions 113 are connected to each other.

The line width w1 of the element 110 indicates the element width, and the line width w1 corresponds to twice the radius r1 of the main body portion 111 of the element 110 shown in FIGS. 1 and 2. Similarly, the line width w2 of the element 120 indicates the element width, and the line width w2 corresponds to twice the radius r2 of the element 120 shown in FIGS. 1 and 2.
The thickness of the elements 110-1 to 110-4 is 18 μm as an example.

The sizes of the substrates 130A and 130B in a plan view are equal to each other, and the size in which the rectangular annular pattern of the elements 110-1 and 110-3 and the rectangular annular pattern of the elements 110-2 and 110-4 can be arranged, respectively. It should be.

In this way, the substrate 130A provided with the elements 110-1, 110-3 and the element 120 is inserted into the slit 131B of the substrate 130B, and the notch 131A of the substrate 130A is on the Y-axis negative direction side of the slit 131B of the substrate 130B. If the cutout portion 132A is inserted into the slit 131B in a state of being engaged with the end portion of the above, the substrates 130A and 130B can be assembled as shown in FIG. 10B.

In addition, in order to secure an electrical connection between the end portion 122A of the element 120 and the connection point between the connection portions 112 of the elements 110-2 and 110-4, this portion may be joined by soldering. Similarly, in order to secure an electrical connection between the end portion 122B of the element 120 and the connection point between the connection portions 113 of the elements 110-2 and 110-4, this portion may be joined by soldering.

In the folded dipole antenna 100, as shown in FIG. 6, in order for the impedance R ₀ to be 10 kΩ or more, the step-up ratio n ² may be 137 or more, so the radius r may be 0.33 mm or more. , 0.33 mm corresponds to 1/90 of the electric length λe at 1000 MHz. By the way, the electric length λe is the wavelength of the electromagnetic wave transmitted in the transmission medium such as the elements 110 and 120 provided on the substrates 130A and 130B, and the shortening rate differs depending on the relative permittivity of the substrates 130A and 130B and the like. By this shortening rate, 1/90 of λe of the electric length λe is shortened. Therefore, the folded dipole antenna 100M1 of the present embodiment can be miniaturized.

FIG. 11 is a diagram showing a power conversion device 300M2 including the folded dipole antenna 100M2 of the embodiment. FIG. 11A shows an exploded view, and FIG. 11B shows an assembled state. In the following, it will be described using the XYZ coordinate system.

The folded dipole antenna 100M2 has a configuration in which the substrate 130B is removed from the folded dipole antenna 100M1 shown in FIG. In this case, the elements 110-2 and 110-4 may be made of a rigid metal member such as a wire. Further, the elements 110-2 and 110-4 may be, for example, a metal foil or the like formed on the inner surface of a housing (not shown).

Further, the configuration may be such that the folded dipole antenna 100M3 shown in FIG. The folded dipole antenna 100M3 has a rectifier circuit 200 provided at the center of one of four surfaces having the same shape among the six surfaces of the rectangular parallelepiped housing 130M, and has four sides that form boundaries of the four surfaces having the same shape. Has a configuration in which the columnar main body portions 111M-1 to 111M4 of the element 110M are arranged. The four main body portions 111M-1 to 111M4 are connected by the four connecting portions 112M and 113M corresponding to the connecting portions 112 and 113 in FIG.

Of the main body portions 111M-1 to 111M4, the main body portions 111M-1 and 111M-2 have a configuration closer to the element 120 than the main body portions 111M-3 and 111M-4.

Further, as in the dipole antenna 100M4 shown in FIG. 13A, the three elements 110M, the element 120, and the flexible substrate 150 may be provided and rolled into a columnar shape as shown in FIG. 13B.

Although the power conversion device according to the exemplary embodiment of the present invention has been described above, the present invention is not limited to the specifically disclosed embodiments and does not deviate from the scope of claims. , Various modifications and changes are possible.

100, 100M1, 100M2, 100M3, 100M4 Folded dipole antenna 110, 110M, 120, 120A, 120B Element 111, 111M-1 to 111M4 Main body 112, 113 Connection 121A, 121B Power supply point 122A, 122B End 200 Rectifier circuit 300 Power converter

Claims (10)

Three or more first conductors, each of which is connected to a main body having a length corresponding to a half wavelength in the free space wavelength at the frequency of the received radio wave, and one end of the main body. Three or more first conductors having one connecting portion and a second connecting portion connected to the other end of the main body portion and arranged so as to be spatially adjacent to each other.
With a first element located in a space surrounded by the main body portion of the three or more first conductors, extending from the first feeding point, and connected to the first connection portion of the three or more first conductors. The first conductor has a second element extending from the first feeding point and the second feeding point constituting the balanced terminal and connected to the second connecting portion of the three or more first conductors. And the second conductor that constitutes the folded dipole antenna,
A power conversion device including the first feeding point and a rectifying circuit connected to the second feeding point. The power conversion device according to claim 1, wherein the impedance of the second conductor and the three or more first conductors seen from the rectifier circuit is 10 kΩ or more. The power conversion device according to claim 1 or 2, wherein the first conductor is 10 or less. 1. The power conversion device described in the section. The width r of the first conductor and the second conductor is (0.33 × F) / 1000 <r, where F (MHz) is the frequency of the received radio wave, whichever is one of claims 1 to 4. The power conversion device described in the section. Any one of claims 1 to 5, wherein the distance h between the main bodies of the three or more first conductors is λe / 30 <h <λe / 12, where λe is the electrical length at the frequency of the received radio wave. The power conversion device according to paragraph 1. The first element and the second element of the second conductor extend linearly.
In each first conductor, the first connecting portion extends in a direction of a predetermined angle with respect to the extending direction of the second conductor, and the main body portion extends along the second conductor. The power conversion device according to any one of claims 1 to 6, wherein the second connecting portion extends at the predetermined angle with respect to the extending direction of the second conductor. The power conversion device according to claim 7, wherein the main body of the first conductor is parallel to the second conductor. The power conversion device according to claim 7 or 8, wherein the predetermined angle is 90 degrees. Claims 7 to 9 indicate that the three or more first conductors are arranged at equal angles on the same circumference with the second conductor as a center when viewed from the extending direction of the main body of the first conductor. The power conversion device according to any one of the above.

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