JP5971304B2 - Horn antenna - Google Patents

Description

  The present invention relates to a horn antenna used for an immunity test.

  In recent years, for example, with the advancement of vehicle control, the number of electronic devices installed in vehicles has been increasing. These electronic devices are required to have electromagnetic incoherence and tolerance, so-called EMC (Electro-Magnetic Compatibility). Among EMCs, there is an immunity test in which an electromagnetic immunity, that is, an electromagnetic susceptibility that does not hinder its operation by electromagnetic waves generated from other electronic devices in the vicinity is tested in a laboratory.

  As one of the immunity tests, an electronic device is placed in an electric field intentionally generated by a horn antenna to test the electromagnetic resistance of the electronic device. The strength of the electric field in this test (hereinafter simply referred to as the electric field) is defined as a standard. Recently, the standard value of this electric field has been changed in consideration of radio wave interference caused by aircraft radar. For example, in the United States, the standard value of the electric field has been raised to 600 V / m from the conventional 200 V / m.

  Along with the increase in the standard value, a horn antenna used for immunity tests is required to generate a larger electric field. In order to increase the strength of the electric field, a higher output amplifier may be used, but this requires a large cost.

  In order to solve this, Patent Document 1 proposes a radiation antenna including an electromagnetic horn and a waveguide plate that guides an electromagnetic wave radiated from the electromagnetic horn to an electronic device. In particular, it is said that the loss of electromagnetic waves can be reduced more satisfactorily by configuring the waveguide plate to be made of a waveguide.

JP 2006-308546 A

  Patent Document 1 describes that an electromagnetic horn and a waveguide are provided separately, and the strength of an electric field that can be applied to an electronic device varies depending on the distance between them, and this distance is mentioned.

  As a waveguide, this document describes a result of verification of a waveguide having a certain rectangular cross-sectional shape in the radiation direction of electromagnetic waves. As another example, the waveguide is described as being widened or contracted in the radiation direction of the electromagnetic wave while being separated from the electromagnetic horn.

  However, if the electromagnetic horn and the waveguide are provided separately, the positions of the two must be accurately adjusted along the radiation direction of the electromagnetic wave. For this purpose, a slide rail or the like for sliding the waveguide must be provided. Furthermore, in order to increase the strength of the electric field, the electromagnetic horn and the waveguide must be separated from each other by a predetermined distance, which increases the overall size. For this reason, there is a problem that the cost is increased with respect to carrying into the test room.

  The present invention has been made in view of the above problems, and an object of the present invention is to obtain a better output without increasing the size of a horn antenna that can be used with a low-cost amplifier.

  The invention disclosed herein employs the following technical means to achieve the above object. Note that the reference numerals in parentheses described in the claims and in this section indicate a corresponding relationship with specific means described in the embodiments described later as one aspect, and limit the technical scope of the invention. Not what you want.

In order to achieve the above object, the present invention is used for an immunity test of an electronic device (300), and the frequency is 1.2 GHz to 1.4 GHz, or 2.7 GHz to 3.1 GHz toward the electronic device. A horn antenna that radiates the following electromagnetic waves, having a cylindrical shape with both ends opened in the radiation direction of the electromagnetic waves, and a first small opening (11) that is an opening at one end and an opening at the other end A first large opening (12), and the inner wall surface (13) is constant in each direction of the magnetic field vector and the electric field vector of the electromagnetic wave from the first small opening toward the first large opening. A first taper portion (10) widened at a rate, a cylindrical shape having both ends opened in the direction of electromagnetic wave radiation, a second small opening (21) which is an opening at one end, and an opening at the other end A second large opening (22), and an inner wall surface ( 3) includes a second taper portion (20) widened at a constant rate in the respective directions of the magnetic field vector and the electric field vector of the electromagnetic wave from the second small opening portion toward the second large opening portion, The cross section perpendicular to the radial direction of the taper portion and the second taper portion is formed into a rectangle by a side parallel to the magnetic field vector of the electromagnetic wave and a side parallel to the electric field vector, and the first taper portion and the second taper portion are The first large opening and the second small opening are integrally formed such that the inclination of the inner wall surface of the second tapered portion with respect to the radial direction is inclined with respect to the radial direction of the inner wall surface of the first tapered portion. It is characterized by being more lenient.

  According to the electromagnetic field simulation by the inventor, the horn antenna has such a configuration, and as a second tapered portion (corresponding to the waveguide in Patent Document 1), a better electric field than the conventional configuration is obtained. The strength of can be realized. That is, in a simple configuration in which the first taper portion and the second taper portion are integrally formed, better output can be realized.

It is an arrangement plan in an immunity test of a horn antenna concerning a 1st embodiment. It is a perspective view which shows schematic structure of a horn antenna. It is a side view in alignment with xz plane of a horn antenna. It is a top view in alignment with xy plane of a horn antenna. It is a figure which shows the correlation between the shape parameter k and the dimension of a horn antenna. It is a figure which shows the intensity | strength of the electric field with respect to the shape parameter k. It is a figure which shows the correlation between the shape parameter k which concerns on 2nd Embodiment, and the dimension of a horn antenna. It is a figure which shows the intensity | strength of the electric field with respect to the shape parameter k.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same reference numerals are given to the same or equivalent parts. For the direction, an x direction, a y direction orthogonal to the x direction, and a z direction orthogonal to the xy plane defined by the x direction and the y direction are defined.

(First embodiment)
Initially, with reference to FIG. 1, the structure for implementing the immunity test using the horn antenna which concerns on this embodiment is demonstrated.

  The horn antenna according to this embodiment is an antenna used for an immunity test. In the immunity test, an evaluation is performed in a state where an electric field defined by a standard is applied to an electronic device.

  As shown in FIG. 1, the horn antenna 100 is disposed in a dark room 200 in which electromagnetic waves in the frequency bands of 1.2 GHz to 1.4 GHz and 2.7 GHz to 3.1 GHz are prevented from entering. In the dark room 200, a horn antenna 100 and an electronic device 300 are arranged.

  The horn antenna 100 includes a generation unit 400 that is a source of electromagnetic waves, and a horn unit 500 that efficiently guides the electromagnetic waves generated by the generation unit 400 to the electronic device 300. The horn part 500 includes a first taper part 10 and a second taper part 20. The horn antenna 100 is fixed to the antenna mount 600 and is installed so that the radiation direction of electromagnetic waves is parallel to the installation surface 600 a of the horn antenna 100. Hereinafter, the radiation direction of the electromagnetic wave is defined as the x direction, and the installation surface 600a is a surface along the xy plane. Further, the horn antenna 100 according to the present embodiment has a shape that is plane-symmetric with respect to a predetermined plane parallel to the xy plane, and further has a shape that is plane-symmetric with respect to a predetermined plane parallel to the xz plane. . Hereinafter, a straight line where these surfaces intersect with each other is defined as a radial axis A. That is, the horn antenna 100 has a two-fold symmetrical shape about the radiation axis A in the yz plane. The detailed configuration of the horn antenna 100, particularly the horn unit 500, will be described in detail later.

  The dark room 200 is prevented from entering electromagnetic waves in frequency bands of 1.2 GHz to 1.4 GHz and 2.7 GHz to 3.1 GHz. Further, a radio wave absorber (not shown) is formed on the inner wall surface 200a of the dark room 200 so that the electromagnetic waves radiated from the horn antenna 100 are not reflected by the wall surface 200a. As a result, the reflected wave does not affect the electronic device 300.

  The generation unit 400 generates an electromagnetic wave that irradiates the electronic device 300. In the generator 400, a probe 420 for generating an electromagnetic wave is disposed inside a waveguide housing 410 that is open at one end. The probe 420 is connected to an oscillator, an amplifier, and a circulator (not shown). The oscillator can sweep the frequency of the electromagnetic wave to be generated, and the electromagnetic wave having a desired frequency can be generated from the probe 420. In addition, the input power input to the generation unit 400 is variable, and in this embodiment, for example, 200 watts of power is input. When power is supplied to the oscillator, the signal generated by the oscillator is amplified by the amplifier. The amplified signal is supplied to the probe 420 via the circulator. Then, an electromagnetic wave having a predetermined frequency is radiated from the probe 420. The electromagnetic waves in this embodiment are linearly polarized waves such that the electric field vector is oriented in the z direction and the magnetic field vector is oriented in the y direction.

  The electronic device 300 is a device such as an electronic control device. The electronic device 300 is placed on the test table 700. As shown in FIG. 1, the electronic device 300 is placed on the radiation axis A of electromagnetic waves, and the distance between the center of the electronic device 300 and the horn antenna 100 is 1 meter. The tester confirms the behavior of the electronic device 300 in a state where the electronic device 300 is irradiated with electromagnetic waves, and evaluates the electromagnetic resistance.

  Next, the horn antenna 100 according to the present embodiment, in particular, the horn unit 500 will be described in detail with reference to FIGS.

  As shown in FIG. 1, the horn antenna 100 includes a generation unit 400 and a horn unit 500. The horn part 500 is made of aluminum having a constant thickness, and includes a first taper part 10 and a second taper part 20 as shown in FIG. In addition, the generation unit 400 is connected to the horn unit 500. The waveguide housing 410 in the generating unit 400 is made of aluminum and is formed integrally with the horn unit 500. The shape of the horn part 500 shown in FIGS. 2 to 4 shows the shape of a space part through which electromagnetic waves pass, and the outer shape of the horn part 500 for forming this space part is not limited.

  The first taper portion 10 has a cylindrical shape with both ends opened, and the openings at both ends are parallel to the yz plane. The first tapered portion 10 has a truncated pyramid shape with openings at both ends as upper and lower bases, respectively. Of the openings at both ends, the side with the smaller opening area is referred to as the first small opening 11, and the side with the larger opening area is referred to as the first large opening 12. Since the first taper portion 10 has a truncated pyramid shape, the first small opening portion 11 and the first large opening portion 12 are rectangular. And the 1st small opening part 11 and the 1st large opening part 12 consist of the edge | side which comprises a rectangle along the y direction, and the edge | side which follows az direction. In other words, the cross section perpendicular to the radiation direction in the first taper portion 10 is formed in a rectangular shape by a side parallel to the magnetic field vector H of the electromagnetic wave and a side parallel to the electric field vector E. The first small opening 11 is connected to the opening of the waveguide housing 410 of the generating unit 400, and the electromagnetic wave radiated from the generating unit 400 is input to the first small opening 11.

  In the first small opening 11, the length of the side in the y direction (direction along the magnetic field vector) is defined as Ai, and the length of the side in the z direction (direction along the electric field vector) is defined as Bi. In the first large opening 12, the length of the side in the y direction is defined as Am, and the length of the side in the z direction is defined as Bm. Further, the inter-surface distance between the first small opening 11 and the first large opening 12 is defined as L1.

  The second taper portion 20 has a cylindrical shape with both ends opened, and the openings at both ends are parallel to the yz plane. The second taper portion 20 has a truncated pyramid shape with openings at both ends as upper and lower bases, respectively. Of the openings at both ends, the side with the smaller opening area is referred to as the second small opening 21, and the side with the larger opening area is referred to as the second large opening 22. Since the second taper portion 20 has a truncated pyramid shape, the second small opening portion 21 and the second large opening portion 22 are rectangular. And the 2nd small opening part 21 and the 2nd large opening part 22 consist of the side which follows the y direction, and the side which follows az direction, which comprises a rectangle. In other words, the cross section perpendicular to the radiation direction in the second taper portion 20 is formed in a rectangular shape by a side parallel to the magnetic field vector H of the electromagnetic wave and a side parallel to the electric field vector E.

  In the horn part 500, the first large opening 12 in the first taper part 10 and the second small opening 21 in the second taper part 20 are integrally formed. Therefore, the first large opening 12 and the second small opening 21 have the same dimensions. That is, in the second small opening 21, the length of the side in the y direction is Am, and the length of the side in the z direction is Bm. In the second large opening 22, the length of the side in the y direction is defined as Ao, and the length of the side in the z direction is defined as Bo. Further, the inter-surface distance between the first small opening portion 11 and the second large opening portion 22, that is, the total length of the horn portion 500 is defined as L.

  Further, as shown in FIG. 3, an angle formed by the inner wall surface 13 of the first taper portion 10 and the radial direction in the cross section perpendicular to the y-axis of the horn portion 500 is defined as θ1v. In addition, an angle formed by the inner wall surface 23 of the second taper portion 20 and the radial direction is defined as θ2v. On the other hand, as shown in FIG. 4, in the cross section orthogonal to the z-axis of the horn part 500, the angle formed by the inner wall surface 13 of the first taper part 10 and the radial direction is defined as θ1h. In addition, an angle formed by the inner wall surface 23 of the second taper portion 20 and the radial direction is defined as θ2h. In the horn portion 500, the inclination of the inner wall surface 23 in the second taper portion 20 with respect to the radial direction is made gentler than the inclination of the first taper portion 10 with respect to the radial direction of the inner wall surface 13. In other words, θ1v> θ2v and θ1h> θ2h.

  As described above, the horn antenna 100 is a two-stage tapered horn antenna provided with the first tapered portion 10 and the second tapered portion 20 as the horn portion 500. The electromagnetic wave generated by the generator 400 is input from the first small opening 11 and output from the second large opening 22. When the immunity test is performed, the distance from the second large opening 22 to the electronic device 300 is 1 meter.

  The specific dimensions of the horn unit 500 in this embodiment are Ai≈180 mm, Bi≈90 mm, Am≈670 mm, Bm≈383 mm, Ao≈785 mm, Bo≈668 mm, L≈1200 mm, and L1≈175 mm. In this case, θ1v≈39.9 degrees, θ2v≈7.9 degrees, θ1h≈54.5 degrees, and θ2h≈3.2 degrees.

  Next, the effect of the horn antenna 100 according to the present embodiment will be described.

  The inventor scrutinized the relationship between the dimensions of the horn unit 500 and the electric field strength at the position where the electronic device 300 is disposed by computer simulation. The electric field shown here is the minimum value of the electric field at a distance of 1 meter from the second large opening 22 when the frequency of the input electromagnetic wave is 1.2 GHz to 1.4 GHz. The simulator designates 1 watt as the input power.

  Although there are a plurality of parameters for uniquely determining the shape of the horn unit 500, the inventor has defined the shape parameter k as follows.

  The shape parameter in the conventional one-stage tapered horn antenna mode is k = 0. Specifically, k = 0 when Ai = 180 mm, Bi = 90 mm, Am = 251 mm, Bm = 153 mm, Ao = 670 mm, Bo = 525 mm, L = 1200 mm, and L1 = 175 mm. When k = 0, θ1v = θ2v≈10.27 degrees and θ1h = θ2h≈11.54 degrees.

  In addition, the shape parameter in the above-described embodiment of the horn unit 500 is k = 1. Then, when k changes linearly from 0 to 1, k is determined so that each parameter Ai, Bi, Am, Bm, Ao, Bo, L, and L1 changes linearly. Specifically, as shown in FIG. 5, k is linear from 0 to 1 under the condition that L is constant at 1200 mm, L1 is constant at 175 mm, Ai is constant at 180 mm, and Bi is constant at 90 mm. As it increases, Am increases linearly from 251 mm to 670 mm, Bm increases linearly from 153 mm to 383 mm, Ao increases linearly from 670 mm to 785 mm, and Bo increases to 525 mm. From 680 mm to 668 mm.

  In addition, the shape parameter in the aspect of the horn antenna having the waveguide, which is the conventional technique described in Patent Document 1, is k = 2. Specifically, k = 2 when Ai = 180 mm, Bi = 90 mm, Am = 670 mm, Bm = 533 mm, Ao = 670 mm, Bo = 533 mm, L = 1200 mm, and L1 = 414 mm. In k = 2, θ2v = 0 degrees and θ2h = 0 degrees. That is, a portion corresponding to the second tapered portion 20 in the present embodiment does not have a taper.

  When k changes linearly from 1 to 2, k is determined so that each parameter Ai, Bi, Am, Bm, Ao, Bo, L, and L1 changes linearly. Specifically, as shown in FIG. 5, k is linear from 1 to 2 under the condition that L is constant at 1200 mm, Ai is constant at 180 mm, Am is constant at 670 mm, and Bi is constant at 90 mm. L1 increases linearly from 175 mm to 414 mm, Bm increases linearly from 383 mm to 533 mm, Ao decreases linearly from 785 mm to 670 mm, and Bo increases to 668 mm. From 533 mm to 533 mm.

  When the electric field at a distance of 1 meter from the second large opening 22 is calculated by the simulator with respect to the shape parameter k defined as described above, the result is as shown in FIG.

  In the prior art k = 0, the electric field is E≈33.6 V / m, and in k = 2, E≈38.3 V / m. According to FIG. 6, the second taper portion 20 is configured to have a taper that is gentler than the first taper portion 10 while having a taper (θ2v ≠ 0 degree and θ2h ≠ 0 degree). It can be seen that an electric field larger than 38.3 V / m in the conventional configuration can be realized. That is, in a simple configuration in which the first taper portion and the second taper portion are integrally formed, it is possible to achieve a better output than the conventional mode.

More specifically, as shown in FIG. 6, when testing using electromagnetic waves having a frequency of 1.2 GHz to 1.4 GHz, the shape parameter k satisfies 0.75 ≦ k ≦ 1.85. If the shape of the horn antenna 100 is determined, an electric field larger than 38.3 V / m can be realized with certainty. In particular, as described in the present embodiment, if the shape of the horn antenna 100 is determined so that k = 1, the electric field is E≈48.1 V / m, and the maximum is in the range of 0 ≦ k ≦ 2. It becomes. The horn antenna 100 having a shape corresponding to k = 1 can obtain an electric field 48.1 / 33.6≈1.43 times that of a general one-step tapered horn antenna (k = 0). . In other words, the power required to obtain the same electric field can be suppressed to 1 / (1.43) ² ≈0.49 times.

(Second Embodiment)
In the first embodiment, the horn antenna 100 whose main frequency of the input electromagnetic wave is 1.2 GHz to 1.4 GHz has been described. On the other hand, in this embodiment, the case where the main frequency of the input electromagnetic wave is 2.7 GHz to 3.1 GHz is illustrated. The configuration of each element excluding the specific dimensions of the horn unit 500 and the relationship in magnitude (θ1v> θ2v and θ1h> θ2h) are the same as those in the first embodiment, and thus the description thereof is omitted. .

  The specific dimensions of the horn unit 500 in this embodiment are Ai≈90 mm, Bi≈45 mm, Am≈388 mm, Bm≈276 mm, Ao≈552 mm, Bo≈457 mm, L≈1200 mm, and L1≈204 mm. In this case, θ1v≈29.5 degrees, θ2v≈5.2 degrees, θ1h≈36.1 degrees, and θ2h≈4.7 degrees.

  The inventor scrutinized the relationship between the dimensions of the horn unit 500 and the intensity of the electric field at the position where the electronic device 300 is arranged by computer simulation, as in the first embodiment. The electric field shown here is the minimum value of the electric field at a distance of 1 meter from the second large opening 22 when the frequency of the electromagnetic wave is 2.7 GHz to 3.1 GHz. The simulator designates 1 watt as the input power.

  The shape parameter in the conventional one-stage tapered horn antenna mode is k = 0. Specifically, k = 0 when Ai = 90 mm, Bi = 45 mm, Am = 157 mm, Bm = 96 mm, Ao = 487 mm, Bo = 344 mm, L = 1200 mm, and L1 = 204 mm. When k = 0, θ1v = θ2v≈7.1 degrees and θ1h = θ2h≈9.4 degrees.

  In addition, the shape parameter in the above-described embodiment of the horn unit 500 is k = 1. Then, when k changes linearly from 0 to 1, k is determined so that each parameter Ai, Bi, Am, Bm, Ao, Bo, L, and L1 changes linearly. Specifically, as shown in FIG. 7, k is linear from 0 to 1 under the condition that L is constant at 1200 mm, L1 is constant at 204 mm, Ai is constant at 90 mm, and Bi is constant at 45 mm. As it increases, Am increases linearly from 157 mm to 388 mm, Bm increases linearly from 96 mm to 276 mm, Ao increases linearly from 487 mm to 552 mm, and Bo increases to 344 mm. From 457 mm to 457 mm.

  In addition, the shape parameter in the aspect of the horn antenna having the waveguide, which is the conventional technique described in Patent Document 1, is k = 2. Specifically, k = 2 when Ai = 90 mm, Bi = 45 mm, Am = 464 mm, Bm = 324 mm, Ao = 464 mm, Bo = 324 mm, L = 1200 mm, and L1 = 547 mm. In k = 2, θ2v = 0 degrees and θ2h = 0 degrees. That is, a portion corresponding to the second tapered portion 20 in the present embodiment does not have a taper.

  When k changes linearly from 1 to 2, k is determined so that each parameter Ai, Bi, Am, Bm, Ao, Bo, L, and L1 changes linearly. Specifically, as shown in FIG. 7, k increases linearly from 1 to 2 under the condition that L is constant at 1200 mm, Ai is constant at 90 mm, and Bi is constant at 45 mm. L1 increases linearly from 204 mm to 547 mm, Am increases linearly from 388 mm to 464 mm, Bm increases linearly from 276 mm to 324 mm, and Ao decreases linearly from 552 mm to 464 mm. Bo is decreased linearly from 457 mm to 324 mm.

  When the electric field at a distance of 1 meter from the second large opening 22 is calculated by the simulator with respect to the shape parameter k defined as described above, the result is as shown in FIG.

  In the prior art k = 0, the electric field is E≈49.3 V / m, and in k = 2, E≈57.0 V / m. According to FIG. 8, the second taper portion 20 has a taper (θ2v ≠ 0 degree and θ2h ≠ 0 degree) but a gentler taper than the first taper portion 10 while having a taper. It can be seen that an electric field larger than the electric field of 57.0 V / m in the conventional configuration can be realized. That is, in a simple configuration in which the first taper portion and the second taper portion are integrally formed, it is possible to achieve a better output than the conventional mode.

More specifically, as shown in FIG. 8, when testing using an electromagnetic wave having a frequency of 2.7 GHz to 3.1 GHz, the shape parameter k satisfies 0.70 ≦ k ≦ 1.90. If the shape of the horn antenna 100 is determined, an electric field larger than 57.0 V / m can be realized with certainty. In particular, as described in the present embodiment, if the shape of the horn antenna 100 is determined so that k = 1, the electric field is E≈72.3 V / m, and the maximum is in the range of 0 ≦ k ≦ 2. It becomes. The horn antenna 100 having a shape corresponding to k = 1 can obtain an electric field 72.3 / 49.3≈1.47 times that of a general one-step tapered horn antenna (k = 0). . In other words, the power required to obtain the same electric field can be suppressed to 1 / (1.47) ² ≈0.47 times.

(Other embodiments)
The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the simulation in the above-described embodiment, the shape parameter k is calculated discretely in units of 0.05, but the change of the shape parameter k is continuous. Therefore, if the frequency of the electromagnetic wave is 1.2 GHz to 1.4 GHz, the shape of the horn unit 500 can be determined so as to satisfy 0.75 ≦ k ≦ 1.85 without being limited to the dimensions shown in FIG. Thus, an electric field larger than 38.3 V / m can be realized with certainty.

  If the frequency of the electromagnetic wave is 2.7 GHz to 3.1 GHz, the shape of the horn unit 500 can be determined to satisfy 0.70 ≦ k ≦ 1.90 without being limited to the dimensions shown in FIG. Thus, an electric field larger than 57.0 V / m can be realized with certainty.

  Moreover, each dimension shown in the above-mentioned embodiment shows the shape of the part through which the electromagnetic wave passes, and the part other than the part through which the electromagnetic wave passes, such as the outer shape, is not limited. For example, a rectangular parallelepiped aluminum is hollowed out so that the inner shape has the dimensions in the above-described embodiment, so that the first small opening 11 and the second large opening 22 are exposed on two opposing faces of the rectangular parallelepiped. The horn unit 500 may be formed.

  In the above-described embodiment, an example in which aluminum is used for the waveguide housing 410 and the horn unit 500 of the generation unit 400 has been described, but the embodiment is not limited to aluminum. The material constituting them may be a conductor. However, it is preferable to use aluminum in order to reduce the weight of the horn antenna 100 itself.

  In the above-described embodiment, the mode in which the direction of the electric field vector is directed in the z direction has been described. However, the generation unit 400 and the horn unit 500 can rotate around the radiation axis A, and the direction of the polarization plane can be changed. It is. Specifically, as in the present embodiment, it is possible to change the vertical polarization in which the electric field vector is directed in the z direction, the horizontal polarization in which the electric field vector is directed in the y direction, or other directions. .

DESCRIPTION OF SYMBOLS 10 ... 1st taper part, 11 ... 1st small opening part, 12 ... 1st large opening part 20 ... 2nd taper part, 21 ... 2nd small opening part, 22 ... Second large opening 100 ... horn antenna

Claims (2)

A horn antenna that is used for an immunity test of an electronic device (300) and emits an electromagnetic wave having a frequency of 1.2 GHz to 1.4 GHz, or 2.7 GHz to 3.1 GHz toward the electronic device. ,
A cylindrical shape having both ends opened in the radiation direction of the electromagnetic wave, a first small opening (11) that is an opening at one end, and a first large opening (12) that is an opening at the other end, A first taper portion having an inner wall surface (13) widened from the first small opening portion toward the first large opening portion at a constant rate in each direction of the magnetic field vector and the electric field vector of the electromagnetic wave. (10) and
A cylindrical shape having both ends opened in the radiation direction of the electromagnetic wave, a second small opening (21) that is an opening at one end, and a second large opening (22) that is an opening at the other end, And the inner wall surface (23) is widened at a constant rate in the directions of the magnetic field vector and the electric field vector of the electromagnetic wave from the second small opening toward the second large opening. (20)
A cross section perpendicular to the radiation direction in the first taper portion and the second taper portion is formed into a rectangle by a side parallel to the magnetic field vector of the electromagnetic wave and a side parallel to the electric field vector,
The first tapered portion and the second tapered portion are integrally formed so that the first large opening and the second small opening coincide with each other,
The inclination of the inner wall surface of the second tapered portion with respect to the radial direction is made gentler than the inclination of the inner wall surface of the first tapered portion with respect to the radial direction ,
The length of the side along the magnetic field vector of the first small opening is Ai, the length of the side along the electric field vector is Bi,
The length of the side along the magnetic field vector of the first large opening is Am, the length of the side along the electric field vector is Bm,
The length of the side along the magnetic field vector of the second large opening is Ao, the length of the side along the electric field vector is Bo,
When the inter-surface distance between the first small opening and the first large opening is L1, and the inter-surface distance between the first small opening and the second large opening is L,
L is constant at 1200 mm,
L1 is constant at 175 mm,
Ai is constant at 180 mm,
Bi is constant at 90 mm,
Ao increases linearly from 670 mm to 785 mm,
Bo increases linearly from 525mm to 668mm,
Am increases linearly from 251 mm to 670 mm,
Define a change in shape where Bm increases linearly from 153 mm to 383 mm as a linear change from 0 to 1,
L is constant at 1200 mm,
L1 increases linearly from 175 mm to 414 mm,
Ai is constant at 180 mm,
Bi is constant at 90 mm,
Ao decreases linearly from 785 mm to 670 mm,
Bo decreases linearly from 668 mm to 533 mm,
Am constant at 670 mm,
A shape parameter k that defines a change in shape in which Bm increases linearly from 383 mm to 533 mm as a linear change from 1 to 2,
When the electromagnetic wave having a frequency of 1.2 GHz or more and 1.4 Gz or less is input to the first small opening in the first taper portion, 0.75 ≦ k ≦ 1.85 is satisfied. The horn antenna, wherein the first taper portion and the second taper portion are formed. A horn antenna that is used for an immunity test of an electronic device (300) and emits an electromagnetic wave having a frequency of 1.2 GHz to 1.4 GHz, or 2.7 GHz to 3.1 GHz toward the electronic device. ,
A cylindrical shape having both ends opened in the radiation direction of the electromagnetic wave, a first small opening (11) that is an opening at one end, and a first large opening (12) that is an opening at the other end, A first taper portion having an inner wall surface (13) widened from the first small opening portion toward the first large opening portion at a constant rate in each direction of the magnetic field vector and the electric field vector of the electromagnetic wave. (10) and
A cylindrical shape having both ends opened in the radiation direction of the electromagnetic wave, a second small opening (21) that is an opening at one end, and a second large opening (22) that is an opening at the other end, And the inner wall surface (23) is widened at a constant rate in the directions of the magnetic field vector and the electric field vector of the electromagnetic wave from the second small opening toward the second large opening. (20)
A cross section perpendicular to the radiation direction in the first taper portion and the second taper portion is formed into a rectangle by a side parallel to the magnetic field vector of the electromagnetic wave and a side parallel to the electric field vector,
The first tapered portion and the second tapered portion are integrally formed so that the first large opening and the second small opening coincide with each other,
The inclination of the inner wall surface of the second tapered portion with respect to the radial direction is made gentler than the inclination of the inner wall surface of the first tapered portion with respect to the radial direction ,
The length of the side along the magnetic field vector of the first small opening is Ai, the length of the side along the electric field vector is Bi,
The length of the side along the magnetic field vector of the first large opening is Am, the length of the side along the electric field vector is Bm,
The length of the side along the magnetic field vector of the second large opening is Ao, the length of the side along the electric field vector is Bo,
When the inter-surface distance between the first small opening and the first large opening is L1, and the inter-surface distance between the first small opening and the second large opening is L,
L is constant at 1200 mm,
L1 is constant at 204 mm,
Ai is constant at 90 mm,
Bi is constant at 45 mm,
Ao increases linearly from 487 mm to 552 mm,
Bo increases linearly from 344 mm to 457 mm,
Am increases linearly from 157 mm to 388 mm,
Define a change in shape where Bm increases linearly from 96 mm to 276 mm as a linear change from 0 to 1,
L is constant at 1200 mm,
L1 increases linearly from 204 mm to 547 mm,
Ai is constant at 90 mm,
Bi is constant at 45 mm,
Ao decreases linearly from 552mm to 464mm,
Bo decreases linearly from 457 mm to 324 mm,
Am increases linearly from 388 mm to 464 mm,
A shape parameter k that defines a change in shape in which Bm increases linearly from 276 mm to 324 mm as a linear change from 1 to 2,
When the electromagnetic wave having a frequency of 2.7 GHz to 3.1 Gz is input to the first small opening in the first taper portion, 0.70 ≦ k ≦ 1.90 is satisfied. The horn antenna, wherein the first taper portion and the second taper portion are formed.

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