KR101873758B1

KR101873758B1 - 2 stages 2―arm sinuous antenna

Info

Publication number: KR101873758B1
Application number: KR1020170060127A
Authority: KR
Inventors: 윤성현
Original assignee: 경남정보대학교 산학협력단
Priority date: 2017-05-15
Filing date: 2017-05-15
Publication date: 2018-07-03

Abstract

The present invention relates to a two-stage two-arm sinuous antenna, and more specifically, to a two-stage two-arm sinuous antenna to improve reflection loss in comparison to a conventional one-stage two-arm sinuous antenna in a sinuous antenna including a frequency band of 0.8-6 GHz. A sinuous arm is divided into two areas in two stages to be designed to provide stable results in reflection loss and gain and minimize the effect of the residual current. Moreover, the two-stage two-arm sinuous antenna operates in a frequency band of 0.8-6 GHz and can provide a miniaturized design of an antenna.

Description

2 STAGES 2-ARM SINUOUS ANTENNA < RTI ID = 0.0 >

The present invention relates to a two-stage 2-arsenic antenna, and more particularly, to a sinusoidal antenna including a frequency band of 0.8 to 6 GHz, A second-stage two-arm narrow-angle antenna for making a two-stage antenna.

Characteristics such as the input impedance of the antenna, the radiation pattern, and the polarization are determined by the size and shape of the antenna, which is calculated by the wavelength unit of a given operating frequency. Even if the physical structure of the antenna is changed to a small or large size at a certain magnification, if the antenna structure is the same as the original antenna structure, all the characteristics of the antenna become frequency independent antennas.

That is, all the physical specifications of the antenna are reduced by a factor of two, and even if the operating frequency is doubled, there is no change in the characteristics of the antenna.

Also, in order to obtain continuous scaling of the antenna performance along the frequency, the structure of the antenna is characterized only by the angle. An ideal frequency-independent antenna has infinite large openings and infinite feed regions to eliminate low-frequency boundaries and high-frequency boundaries, and complete radiation must occur in one active region.

However, in the actual antenna structure, the current applied to the feed point in the center of the antenna is a part of the current in the active region, and the residual current is in the second active region, And the residual current proceeds to the end of the antenna.

Therefore, the size of the antenna must be sufficiently large so that the residual current becomes almost zero as it passes through several active regions, and the reflected wave current that returns from the terminal to the feeding point is removed.

Conventional Patent Registration No. 10-1667969 entitled " Low Input Impedance 2-Amplified Slot Sine Noise Antenna ", the residual current is not 0 due to the size of the sinusoidal antenna of the first stage 2-arm, There is a problem that it can not be removed.

In reality, infinitely large antennas are not possible, so they are cut to a size that includes the first active region of the lowest operating frequency. At this time, the input impedance and the radiation pattern performance deteriorate due to the residual current that is not copied in the active region. That is, the impedance bandwidth generates vibration in the low frequency region when the current reflected from the antenna end returns to the feeding point, and the radiation pattern is affected by the residual current reflected from the end of the arm.

Therefore, the size of the antenna operating at the lowest frequency tends to be about 100% larger than the theoretical value in order to minimize such influence.

Korean Patent Registration No. 10-1667969 entitled " 2-arm slot-sinusoidal antenna for low input impedance "

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a method and apparatus for providing a stable result in return loss and gain, To provide a short two-arm sinusoidal antenna.

The present invention also provides a two-stage two-arm sinusoidal antenna that operates in the frequency range of 0.8 to 6 GHz and is designed to provide a design for miniaturization of the antenna.

However, the objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a two-stage 2-arsenic antenna according to an embodiment of the present invention is characterized in that, in a rectangular coordinate system, The x and y coordinates of the sinusoidal curve,

,

Lt;

(R ₁ , R _p are the innermost and outermost radii constituting the sinus curves),

,

(where n is the total number of cells), α represents the rate of increase in exponentially increasing between R ₁ , the radius of the starting cell, and R _p , the radius of the last cell, and β is the angle Growth rate.

In this case, the bandwidth of the sinusoidal antenna depends on the radius of the Sinusoidal curve, and the resonance frequency of the active region of the self-complementary structure in the sinusoidal structure In an approximate fashion

(? _p ,? is a radian unit).

R &_lt; ₁ > and R &_lt; _{p &}

In this case,

.

It is also preferable that? _L and? _H are the wavelengths of the lower limit and the upper limit frequency of the desired bandwidth.

In addition, since λ _H is limited in designing the feed point, it is preferable that R _p = (λ _H / 8) / (α _p + δ).

When the total radius is R ₁ = 60 mm, eight cells are designed to have a self-complementary structure (angular width of the cell is? ₁ = 90 degrees) up to a _first radius of 50 mm, and 0.5 cells (Non-magnetic complementary structure (the width of the cell is? ₁ = 720 占).

The two-stage two-arm sinusoidal antenna according to the embodiment of the present invention is designed by dividing the sinus arm into two regions in two stages to provide stable results in return loss and gain, Thereby providing an effect of minimizing the influence.

In addition, the 2-stage 2-arsenic antenna according to another embodiment of the present invention operates in the frequency range of 0.8 to 6 GHz, and it is possible to provide a miniaturized design of the antenna.

1 (a) is a view showing a first stage 1-arm, and Fig. 1 (b) is a view showing a second stage 1-arm sine.
2 is a graph showing input impedances in a first stage and a second stage.
3 is a graph showing S ₁₁ in the first and second stages.
4 is a graph showing gains in the first and second stages.
5 is a graph showing the 0.8 GHz current distribution in the first and second stages.
6 is a graph showing S ₁₁ according to R1 in a two-stage structure.
7 is a diagram illustrating a two-stage two-arm sinusoidal antenna according to an embodiment of the present invention.
FIG. 8 is a graph showing the input impedance real part according to the thickness of the substrate of the second-stage 2-arsenic antenna of FIG. 7;
9 is a graph showing the input impedance imaginary part according to the substrate thickness of the second-stage 2-arsenic antenna of Fig.
FIG. 10 is a graph showing the input impedance real part according to? _R of the second stage 2-arm sinusoidal antenna of FIG. 7,
11 is a graph showing the input impedance according to? _R of the second stage 2-arm sinusoidal antenna of FIG.
Fig. 12 (a) is a top view of a two-stage two-terminal sinusoidal antenna balun in Fig. 7, Fig. 12 (b) is a view showing a ground plane of a two-
Fig. 13 (a) is a back-to-back structure of a two-stage two-terminal sinusoidal antenna baroon in Fig. 7, and Fig. 13 (b) is a graph showing return loss and insertion loss of a baroon designed by Fig.
FIG. 14 is a view showing a state in which the baroon of FIG. 12 is connected to the second-stage two-arm sinusoidal antenna of FIG. 7;
15 is a graph showing the simulation results of the real part and the imaginary part impedance of the first-stage 2-arm sinusoidal antenna with a total radius of 60 mm and the second-stage 2-arm sinusoidal antenna with the second-
16 is a graph illustrating the reflection loss of the antenna proposed in the present invention,
17 is a graph showing an input impedance real part according to a radius of a first end of the antenna proposed in the present invention.
18 is a graph illustrating an imaginary part of input impedance according to the first radius of the antenna proposed in the present invention.
19 is a graph showing reflection loss according to the radius of one end of the antenna proposed in the present invention.
20 (a) shows an experimental setup of the antenna balun proposed in the present invention, and Fig. 20 (b) is a graph showing data of insertion loss and reflection loss of the measured balun.
FIG. 21 is a view showing a conventional 1-stage 2-arm sinusoidal antenna and a 2-stage 2-arm sinusoidal antenna proposed in the present invention.
22 (a) is an experimental set-up for measuring the input impedance of two antennas by connecting baluns having a length of 140 mm, a width of 30 mm, and a thickness of 1.6 to a sinusoidal antenna and FIG. 22 (b) Shows the real part and the imaginary part data of the input impedance of the two measured antennas.
23 is a view showing measurement of reflection loss of a conventional 1-stage 2-arm sinusoidal antenna and a 2-stage 2-arm sinusoidal antenna proposed in the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of preferred embodiments of the present invention will be given with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

A sinusoidal antenna design for a two-stage two-arm sinusoidal antenna according to an embodiment of the present invention will be described.

The sinusoidal curve is composed of n cells (n is a natural number of 1 or more) in polar coordinates as Duhamel suggests. The following equation (1) shows the pth cell (1? P? N).

Where r and φ are the radii and angles in the polar coordinates of the pth cell, and have values between -α _p ≤ φ (r) ≤α _p . ? _p is the angle width of the pth cell,? _p is the reduction ratio of the pth cell and is smaller than 1, and can be expressed by the following equation (2).

Here, R _p and R _{p + 1} are the outer radii of the pth and p + 1th cells, respectively. The polar coordinates of Equation (1) should be used in order to draw the sinusoid curve with the same reduction ratio and angular width in all cells (τ _p = τ, α _p = α) in Equation (1).

However, in the present invention, since all the simulations are performed using the CST MWS using the rectangular coordinates, the expression in Equation 1 must be converted to rectangular coordinates. In the present invention, Equation (1) can be changed as Equation (3) to Equation (4) as follows for a Sinusoidal curve in which the radius of a cell changes in an exponential function between angular widths?

In Equation (3) and Equation (4),?,?, And? Correspond to the following Equations (5) to (7).

(R ₁ , R _p are the innermost and outermost radii constituting the sinusoidal curve)

n represents the total number of cells.

That is, α represents an increase rate that exponentially increases between R ₁ , which is the radius of the starting cell, and R _p, which is the radius of the last cell, and β represents the rate of increase of angle, which increases the angle at an equal interval.

The bandwidth of the sinusoidal antenna depends on the radius of the sinusoidal curve. The resonant frequency of the active region of the self complementary structure in the sinusoidal structure can be approximated by Equation 8 below.

Where α _p and δ are in radians.

Therefore, R ₁ and R _p can be expressed by Equation (9) using Equation (7).

Here it is advantageous that λ _L, λ _H is _{R p = (λ H / 8} ) / (α p + δ) means the wavelength of the lower limit and the upper limit frequency of the desired bandwidth, since the feed point design of λ _H is limited It is known. Since the frequency band of all currently used communication services is included in the range of 0.8 to 5.8 GHz, if one antenna operating in this region is designed as a 2-arm sinusoidal antenna, if the relative dielectric constant of the substrate is 1, _{to, α p = 90 °, δ} = 45 °, the smallest radius is the radius of the R _p = 2.7441mm, the largest cell corresponding to f = _H R ₁ = 5.8GHz of the cell corresponding to _L f = 0.8GHz It is calculated as an active area of 39.7887 mm.

At this time, when R1 = 39.7887 mm corresponding to f _L = 0.8 GHz, residual current not radiated in the active region is reflected at the end of the antenna and returns to the feeding point, vibration of the input impedance occurs in the low frequency region. Resulting in deterioration of the radiation pattern and gain.

Therefore, in order to minimize such influence, the size of the radius R ₁ of the active region operating at the lowest frequency should be larger than the theoretical value. However, it can be seen that if the width? ₁ of each cell is increased in equations (8) and (9), the structure of the self-complementary type is lost, but the size of R ₁ can be reduced.

From this point of view, in the present invention, it is assumed that R ₁ is α ₁ = 90 ° Each width region, and α ₁ = 720 ° operating in a nonmagnetic complementary structure In order to reduce the size of the antenna by minimizing the influence of the current reflected from the end of the antenna by increasing the path of the residual current that is not copied in the first active region by dividing the antenna into two widths and two widths.

1A is a view showing a first stage 1-arm and FIG. 1B is a view showing a second stage 1-arm scene. In the case of Fig. _{1a R s = 2.7441mm, R 1} = 1 will shown a cancer of Sinus Earth If 60mm, Figure 1b is R _s are the same, and R ₁ = 50mm by α ₁ = 90 ° and a 50 To 60 mm, the radius is α ₁ = 720 °, and the number of cells is 0.5.

Figure 2 shows the input impedance of the one-stage and two-stage structure, Figure 3 shows a S ₁₁ in the first-stage and two-stage structure, Figure 4 shows the gain in the single-stage and two-stage structure, Figure 5 is Shows the 0.8 GHz current distribution in the first and second stages, and FIG. 6 shows S ₁₁ according to R1 in the two-stage structure.

That is, FIG. 2 shows the input impedance real part and the imaginary part in the first and second stages of the same radius (R ₁ = 60 mm) described above. In the high frequency range, It can be seen that the influence of the reflected wave is different in the low frequency region. That is, it can be seen that the vibration of the input impedance, which is the influence of the reflected wave, is small in the two-stage structure. 3 shows S ₁₁ of the two structures, assuming that the input impedance of the 2-ary magnetic complementary structure sinusoidal antenna is 188.5? In free space.

That is, in the case of the single-stage structure, -10 dB reflection loss occurs at about 1.02 GHz, but in the two-stage structure, it occurs at about 0.89 GHz, so that the influence of the reflected wave is small in the two- FIG. 4 shows the gain of the two cases. It can be seen that, in the low frequency region, more stable results are obtained in the case of two stages rather than one stage of gain.

FIG. 5 shows the current distribution at 0.8 GHz in two structures. It can be seen that the current distribution at the end of the antenna is smaller in the two-stage structure than in the single-stage structure, and the current reflected from the feed point is small.

6 shows S ₁₁ along the starting radius R 1 of the two-stage structure among the total radius 60 mm. In FIG. 6, R ₁ = 55 is 55 mm in the first radius and 2 radii in radius from 55 mm to 60 mm. It can be seen that the larger the first radius in the figure, the -10 dB occurs at the lower frequency. From this point of view, in the present invention, it is desired to miniaturize the Sineuus antenna using a two-stage two-arm.

Next, regarding the 2-stage 2-arm sinusoidal antenna, a substrate and balun are required to manufacture a 2-stage 2-arm sinusoidal antenna. Also, the magnetic complement structure of the N-arsenic antenna satisfies the following expression (10), and the input impedance in this case is defined by the following expression (11).

That is, in order to be a 2-ary magnetic complementary structure sinusoidal antenna in a free space, δ = 45 ° because N = 2, and the angular width of the cell is α = 90 °. At this time, Z = 188.5?. However, when a dielectric substrate is used, the wavelengths according to frequencies are reduced by the effective permittivity epsilon _eff of the substrate as shown in Equation (12) below, so that the radiuses R ₁ and R _p are also reduced and the input impedance is also reduced.

7 is a view showing a two-stage two-arm narrow-angle antenna according to an embodiment of the present invention. Referring to Fig. 7, the number of arms of a first stage of a total radius of 60 mm is 8, the radius is 50 mm, the number of arms of a second stage is 0.5, the interval is 10 mm, and the angular width of the cell is 720 deg. It shows a 2-arm sinusoidal antenna.

Fig. 8 shows the input impedance real part according to the substrate thickness, Fig. 9 shows the input impedance imaginary part according to the substrate thickness, Fig. 10 shows the input impedance real part according to? _R , and Fig. 11 shows the input impedance according to? _R. Fig. 12 (a) shows the top face of the baroon, Fig. 12 (b) shows the ground plane of the baroon, Fig. 13 (a) shows the backlight structure of the baroon, and Fig. 13 (b) shows the reflection loss and insertion loss of the designed baroon.

14 shows a sinusoidal antenna to which a designed baroon is connected;

Fig. 15 shows the real part and the imaginary part of the sinusoidal antenna, Fig. 16 shows the return loss of the proposed antenna, Fig. 17 shows the input impedance real part according to the first radius, Fig. 18 shows the input impedance imaginary part according to the first radius, 19 is a diagram showing reflection loss according to the first radius.

8 and 9 show the real part and the imaginary part of the input impedance of the 2-stage 2-arsenic antenna according to the thickness of the FR4 substrate. As the thickness of the substrate is thicker, the oscillation width is small at low frequencies, It can be seen that the width is large.

10 and 11 show that the substrate has a height of 1 mm and an input impedance according to the relative dielectric constant. The larger the relative dielectric constant is, the larger the vibration is, but the smaller the vibration width is at the lower frequency.

From this point of view, in order to downsize the 2-arm sinusoidal antenna, the present invention uses a 2-stage 2-arm sinusoid and uses a FR4 having a thickness of 0.4 mm and a relative dielectric constant of 4.4 as an antenna substrate. In addition, balun is required for supplying power with a coaxial cable of 50 ?, but in the present invention, balun having a tapered structure as shown in Fig. 12 is used. That is, the impedance of the port 1 was 50?, The impedance of the port 2 was 110 ?, the length 140 mm, the width 30 mm, and the thickness 1.4 mm.

13 (a) shows a baroon having a back-to-back structure for simulating reflection loss and insertion loss. FIG. 13 (b) shows the loss tangent of FR4 at 0.025, As a result of the simulation, the insertion loss was about -1.87 dB at 0.8 GHz, about -6.7 dB at 6 GHz, and a return loss of about -20 dB or less in the entire frequency range.

Next, FIG. 14 shows a state in which the balloon of FIG. 12 is connected to the two-stage two-arm sinusoidal antenna of FIG. 7, and FIG. 15 shows a state in which the first- The second stage 2-arm shows the simulation results of the real part and the imaginary part impedance of the 2-stage 2-arm sinusoidal antenna with the interval of 50mm to 60mm. It oscillates between a minimum of 30Ω and a maximum of 75Ω and the imaginary part vibrates between -17Ω and 25Ω but the real part of the first two-arm vibrates between a minimum of 25Ω and a maximum of 92Ω and the imaginary part oscillates between 38Ω and -27Ω Could know. Therefore, it is considered that the input impedance of the 2-stage 2-arm sinusoidal antenna approaches 50 Ω on average, so that it is well matched to 50 Ω coaxial cable in the entire frequency range of interest.

16 shows the return loss of the two sinusoidal antennas mentioned above. The reflection loss of less than -10 dB occurred at about 0.8 GHz for the two-stage two-arm, but about 0.95 GHz for the first- It can be seen that the antenna radius must be larger than 60 mm in order for the reflection loss of -10 dB to occur at 0.8 GHz. FIGS. 17, 18 and 19 show the real part, imaginary part and reflection loss of the impedance when the total radius is fixed to 60 mm and the radius of the first step is increased to 50, 52, 54 and 56 mm. It can be seen that the frequency at which the vibration occurs moves toward the low frequency and the frequency at which the reflection loss of less than -10 dB occurs also moves toward the low frequency. That is, when the radius of the first stage is 50 mm, a reflection loss of -10 dB occurs at about 0.8 GHz, while a reflection loss of -10 dB occurs at about 0.7 GHz in the case of 56 mm. Which means that the overall radius of the antenna can be further reduced.

This is because the residual current, which is not copied at the first active region radius of 0.8 GHz, which is the smallest frequency of the region of interest, which is the radius of the first active region, becomes smaller as the radius of the first stage becomes smaller, This is because the current that flows is small. Therefore, theoretically, miniaturized sinusoidal antennas can be made by maximizing the radius of the first stage and maximizing the rotation angle width of the second stage sinusoidal arm for the same total radius.

However, in such a case, there is a difficulty in designing and manufacturing because the distance between the arm and the arm is very narrow because there are two stages of sinusoidal arms in a narrow space.

Hereinafter, fabrication and measurement of baroon and sinusoidal antennas for a two-stage two-arm sinusoidal antenna according to an embodiment of the present invention will be described.

Table 1 shows the antenna and baroon parameters for the simulation of the 2-stage 2-arsenic antenna proposed in the present invention, and a prototype was manufactured using these parameters.

Parameter value Parameter value Operating frequency band 0.8 to 6 GHz 1st stage α _p 90 ° Number of 1st stage arm 2 1st stage δ 45 ° Number of 1st Stage Cells 8 1st stage τ _p 0.71 Number of 2nd stage arm 2 2nd stage α _p 90 ° Number of 2nd stage cell 1/2 2nd stage δ 720 [deg.] Antenna radius 60mm Antenna substrate and thickness FR4
0.4mm 1st stage radii 50mm Baron substrate and thickness FR4
1.6mm 2nd stage interval 10mm

In order to measure the characteristics of the designed balun, the back-to-back balun shown in Fig. 13 (a) was fabricated on the FR4 substrate and measured using a RHODE & SCHWARZ ZNB8 network analyzer as shown in Fig. 20 (a). Fig. 20 (b) shows the measured insertion loss and return loss data. The insertion loss was about -1.0 dB at 0.8 GHz and about -5.8 dB at 6 GHz, which is better than the simulation result. However, the reflection loss partially incurred reflection loss of about -20 dB or more.

In order to compare the superiority of the proposed antenna according to the present invention, FIG. 21 shows a conventional 1-stage 2-arm sinusoidal antenna and a 2-stage 2-arm sinusoidal antenna proposed in the present invention. The total radius was 60 mm, but the 2-stage 2-arm sinusoidal antenna was fabricated with 60 mm in the first stage, 50 mm in the first stage, 10 mm in the second stage, and 720 degrees in the angle α of the second stage cell.

22 (a) is an experimental set-up for measuring the input impedance of two antennas by connecting baluns having a length of 140 mm, a width of 30 mm, and a thickness of 1.6 to a sinusoidal antenna and FIG. 22 (b) Shows the real part and imaginary part of the input impedance of the two measured antennas. In Fig. 22 (b), the impedance of the reference line is 50 OMEGA, the y-axis scale is set to 10 OMEGA per square, Trc1 is the first stage 2-arm input impedance real part (blue), Trc2 is the 2- (Red) of the input impedance. In other words, except for the low frequency region near 0.8 GHz, the 2-stage 2-arm sinusoidal antenna oscillates between the maximum of about 70 Ω and the minimum of 35 Ω in the entire frequency range, and the first- It was found that it oscillates between at least 35 Ω. In the imaginary part measurement of Fig. 22 (c), the case of one stage oscillated between -25 Ω and 25 Ω at the maximum, and the case of the two stages oscillated between a maximum of 20 Ω and a minimum of -20 Ω. Moreover, it can be seen that it is less than 10? In the vicinity of 0.8 GHz, but vibrates up to 50? In the case of the first stage. Therefore, it is considered that the 2-stage 2-arm sinusoidal antenna is well matched to 50 Ω on average.

FIG. 23 shows the measured return loss of the fabricated two antennas. The simulation results in FIG. 16 show that the reflection loss of -10 dB or less occurs at 0.95 GHz for the first stage and 0.8 GHz for the second stage. The measurement result is 0.878 GHz for the first stage, and -10 dB or less for the second stage And the measured values were similar to those of the simulation results.

In conclusion, the present invention proposes a two-stage 2-arm sinusoidal antenna that operates in the frequency range of 0.8 to 6 GHz, thereby suggesting the possibility of downsizing the antenna. That is, in the conventional method, 2-arm sinusoidal arm is made by applying the same angular width to n cells in antenna radius R. [ In this case, the active region having the lowest operating frequency corresponds to the radius of the antenna. In this active region, no complete radiation occurs, residual current is generated, and the residual current is reflected from the terminal end of the antenna to the feeding point, Lt; / RTI > To solve this problem, the size of the antenna becomes very large because the conventional method is about twice as large as the theoretical antenna radius. However, in the present invention by dividing the radius of the antenna in two stages the first stage is the condition of the existing self-complementary so as to satisfy, additional second stage is very large as a two-stage 0.5 of the width of each cell and the cell 720 ⁰ 2-cancer A sinusoidal antenna is presented. In this case, the residual current flowing in the active region is long, so that it reaches the end of the antenna, and the residual current reflected back to the feeding point becomes smaller, so that the vibration of the input impedance becomes smaller. That is, a 1-stage 2-arm sinusoidal antenna with an antenna radius of 60 mm was fabricated and measured, and stable input impedance vibrations occurred from about 0.878 GHz. Therefore, in order to obtain a stable input impedance from 0.8 GHz, the antenna radius should be larger. However, in the present invention, the two-stage two-arm sinusoidal antenna manufactured by rotating one half of the total radius of 60 mm to 50 mm and the two-step interval to 10 mm and rotating 0.5 cells therebetween at about 720 ° is about 0.8 GHz It is possible to reduce the radius of the sinusoidal antenna by generating a stable input impedance vibration.

As described above, preferred embodiments of the present invention have been disclosed in the present specification and drawings, and although specific terms have been used, they have been used only in a general sense to easily describe the technical contents of the present invention and to facilitate understanding of the invention , And are not intended to limit the scope of the present invention. It is to be understood by those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

Claims

The sinusoidal curve forming the sinusoidal antenna is composed of n cells (n is a natural number of 1 or more) in the polar coordinates,
The polar coordinates for generating a cell are expressed as in Equation (1)
[Equation 1]

Lt;
Here, r,

Is the radius and angle at the polar coordinates of the pth cell,

(r) is at least -α _p ,

(r), and has a value of _p less than ≤α, α _p is the width of each of the p th cell (angle width), τ _p is the reduction ratio of the p th cell,
(Τ _p = τ, α _p = α) in all the cells in Equation (1), the polar coordinates are converted into rectangular coordinates, and the width of each cell is -α or more + α or less The x and y coordinates of the sinusoidal curve in which the radius of the cell varies as an exponential function are as shown in Equations (2) and (3)
&Quot; (2) "

&Quot; (3) "

Lt;
here,

,

(α will increase, β of from the radius of the starting cell R ₁ increase between the radius of R _p of the last cell exponentially with the angle rate, R ₁ to increase the angle to the even spacing is the constituting Sinus Earth curve the inner radius, R _p is the radius of the outermost layer constituting the earth Sinus curves, n is the total number of cells), and
The bandwidth of the sinusoidal antenna depends on the radius of the sinusoidal curve,
The resonance frequency of the active region of the self-complementary structure in the sinusoidal structure is approximately

(Where? _P is the rate of increase in the Pth cell in radians,? Is the cell width of the Sinus curves, and? Is the wavelength of the frequency of the bandwidth)
R ₁ , the radius of the starting cell, and R _p , the radius of the last cell,

In this case,

It is expressed as
(where _L is the wavelength of the lower limit frequency of the desired bandwidth and [lambda] _H is the wavelength of the upper limit frequency of the desired bandwidth)
The area of the sinusoidal antenna that operates in the self-complementary structure is designed such that the cell width is set to α ₁ = 90 °. In the region that operates with the non-self-complementary structure, the cell width is set to α ₁ = 720 °, And the second antenna is formed by dividing the antenna into two.

delete

The method according to claim 1,
When the total radius R of the sinusoidal antenna is 60 mm, eight cells are formed in the first stage with a self-complementary structure in which the angular width of the cell is α ₁ = 90 ° at a total radius (R) of the sinusoidal antenna of 50 mm or less , And the second stage forms 0.5 cells with a non-magnetic complementary structure in which the angular width of the cell is? ₁ = 720 ° at a total radius (R) of more than 50 mm and 60 mm or less of the sinusoidal antenna. Earth antenna.