JP5616167B2 - Traveling wave excitation antenna - Google Patents

Description

  The present invention relates to a traveling wave excitation antenna, and more particularly to an improvement of an antenna that includes a plurality of radiating elements excited by traveling waves and transmits and receives microwaves and millimeter waves, for example, an in-vehicle antenna.

  In general, in a traveling wave excitation antenna, a large number of radiating elements are arranged at intervals corresponding to integer multiples of wavelengths to excite these radiating elements in the same phase to form a beam in the front direction. When such an antenna is used at a frequency different from the design frequency, each radiating element cannot be excited in the same phase, and a desired antenna gain cannot be obtained. For this reason, the traveling wave excitation antenna has a narrow bandwidth, and it is necessary to prepare a different antenna for each frequency to be used.

  FIG. 15 is a diagram showing an example of a conventional traveling wave excitation antenna, which shows a one-side-feed microstrip antenna (MS antenna) 201. In the MS antenna 201, the converter 3 is formed at one end of the feed line 50, and the termination element 52 is formed at the other end. The converter 3 performs power conversion between the waveguide and the planar line, and serves as a feed point for the feed line 50. Since each radiating element 51 is arranged at an interval that is an integral multiple of the guide wavelength λs of the feed line 50, each radiating element 51 is excited in the same phase by a traveling wave propagating in one direction on the feed line 50.

  In such a traveling wave excitation antenna, when a traveling wave of a design frequency is supplied, a beam is formed in the front direction perpendicular to the dielectric substrate 1 by the interaction of the radiating elements 51 excited in the same phase. . However, when a traveling wave having a frequency that deviates from the design frequency is supplied, there is a problem that the excitation phase of each radiating element 51 is deviated, a beam tilted with respect to the front direction is formed, and the antenna gain is reduced. .

  The present invention has been made in view of the above circumstances, and an object thereof is to improve the frequency characteristics of a traveling wave excitation antenna. In particular, the object is to improve the frequency characteristics of the antenna gain without significantly degrading the directivity. It is another object of the present invention to provide a broadband traveling wave excitation antenna. In particular, it is an object of the present invention to provide a traveling wave excitation antenna having a small size and a wide band.

A traveling wave excitation antenna according to a first aspect of the present invention includes a dielectric substrate having two feeding points, a linear strip line formed on the dielectric substrate and connecting the two feeding points, and the strip line. And two or more radiating elements formed on the dielectric substrate and excited in the same phase by traveling waves propagating in one direction through the strip line, and the strip line in opposite directions with respect to the feed point. A feeding means for supplying traveling waves that propagate and excite the radiating elements in phase with each other. The radiating element having the maximum element width is formed near the center of the strip line, and is formed at both ends of the strip line. The radiating element having a smaller element width is formed as it gets closer .

With such a configuration, in a traveling wave excitation antenna having two or more radiating elements excited in the same phase by a traveling wave propagating in one direction on the strip line, the strip line is reversed through two feeding points. Two traveling waves propagating in the direction can be supplied, and the radiating elements can be excited in phase with each other by these traveling waves. For this reason, the frequency characteristic of the antenna gain can be improved. In particular, the frequency characteristics can be improved without significantly degrading the directivity characteristics. Accordingly, a broadband traveling wave excitation antenna can be realized. Further, the strip line can be made shorter than that of the single-sided traveling wave excitation antenna, and a smaller traveling wave excitation antenna can be realized. That is, the frequency characteristics of the antenna gain are improved, and the strip line length is shortened without significantly degrading the directivity, so that the MS antenna can be widened and reduced in size.

In addition to the above configuration, the traveling wave excitation antenna according to the second aspect of the present invention is a waveguide in which the feeding unit branches the inputted traveling wave and supplies the branched traveling waves to the two feeding points, respectively. The feeding point is a waveguide / stripline converter. With such a configuration, if the path length after branching is changed, the difference in excitation phase due to two traveling waves in each radiating element can be adjusted. For this reason, the power feeding means can be easily manufactured.

  According to the present invention, a feeding path is formed so as to connect two feeding points, and traveling waves propagating in the opposite directions to the feeding path and exciting the radiating elements in the same phase with respect to these feeding points, respectively. Supply. For this reason, the frequency characteristic of a traveling wave excitation antenna can be improved. In particular, the frequency characteristic of the antenna gain can be improved without significantly degrading the directivity. In addition, it is possible to provide a traveling wave excitation antenna that is small and has a wide bandwidth.

It is the perspective view which showed an example of the traveling wave excitation antenna by Embodiment 1 of this invention, and MS antenna 100 is shown. FIG. 2 is a developed perspective view of the MS antenna 100 of FIG. 1. It is a top view of MS antenna 100 of FIG. It is sectional drawing by the AA cutting line of FIG. 2 is a plan view showing an MS antenna 202 to be compared with the first embodiment. FIG. It is the figure which showed the analysis result of the frequency characteristic of the antenna gain by Embodiment 1 of this invention. It is the figure which showed the analysis result of the directional characteristic by Embodiment 1 of this invention. It is the figure which showed the analysis result of the reflection characteristic by Embodiment 1 of this invention. It is the figure which showed one structural example of the traveling wave excitation antenna by Embodiment 2 of this invention, and sectional drawing of MS antenna 101 is shown. It is the top view which showed the example of 1 structure of the traveling wave excitation antenna by Embodiment 3 of this invention, and MS antenna 102 is shown. 6 is a plan view showing an MS antenna 203 to be compared with Embodiment 3. FIG. It is the top view which showed the example of 1 structure of the traveling wave excitation antenna by Embodiment 4 of this invention, and MS antenna 103 is shown. It is the perspective view which showed one structural example of the traveling wave excitation antenna by Embodiment 5 of this invention, and the waveguide slot antenna 104 is shown. It is the perspective view which showed the other structural example of the traveling wave excitation antenna by Embodiment 5 of this invention, and the waveguide slot antenna 105 is shown. It is the figure which showed an example of the conventional traveling wave excitation antenna, and the MS antenna 201 of the one-side electric power feeding is shown.

Embodiment 1 FIG.
1 to 4 are diagrams showing a configuration example of a traveling wave excitation antenna according to Embodiment 1 of the present invention, in which an MS antenna 100 is shown. 1 is an external view, FIG. 2 is a developed perspective view, FIG. 3 is a plan view, and FIG. 4 is a cross-sectional view taken along the line AA in FIG. The MS antenna 100 includes a dielectric substrate 1 and a waveguide block 2.

<Dielectric substrate 1>
On the dielectric substrate 1, two converters 3a and 3b serving as feeding points are formed. An antenna pattern 5 is formed on the front surface of the dielectric substrate 1, and a ground plate 10 is provided on the back surface. The antenna pattern 5 faces the ground plate 10 with the dielectric substrate 1 interposed therebetween. The antenna pattern 5 and the ground plate 10 are formed by forming a conductive thin film such as copper on the entire surface of the dielectric substrate 1 by thermocompression bonding, sputtering, vapor deposition or the like, and then patterning the conductive thin film by photoetching. Formed by.

<Antenna pattern 5>
The antenna pattern 5 includes a feed line 50 extending so as to connect the two converters 3a and 3b, and a plurality of radiating elements 51n and 51m arranged along the feed line 50.

  The feed line 50 is a feed path in which both ends thereof are connected to the converters 3a and 3b as feed points, for example, a strip line having a linear shape with a certain width.

  The radiating elements 51n and 51m (collectively referred to as 51) are strip pieces that radiate a traveling wave propagating through the feed line 50 to free space. For example, a linear or strip shape extending in a direction intersecting the feed line 50 is used. It shall consist of Each radiating element 51 has a shape extending parallel to each other, and the planes of polarization of the radiated waves are made to coincide. In addition, the element width of each radiating element 51 increases as the distance from the feeding point increases. That is, it becomes the maximum near the center of the feed line 50 and becomes smaller as it approaches both ends. Such a radiating element 51 is disposed on both sides of the feed line 50.

  The plurality of radiating elements 51n formed along one side of the feeder line 50 are arranged so as to be excited in the same phase. For example, they are arranged at intervals corresponding to the guide wavelength λs of the feed line 50, and are excited in the same phase by the traveling waves of the above-mentioned wavelength propagating in the feed line 50 in one direction. The same applies to the radiating element 51m formed along the other side of the feeder line 50.

  The radiating elements 51n and 51m formed along different sides of the feed line 50 are arranged so that their extending directions are parallel and opposite to each other and are excited in opposite phases. For example, the radiating elements 51n and 51m are arranged at an interval of λs / 2. For this reason, the radiated waves from all the radiating elements 51n and 51m are all electromagnetic waves having the same phase and the same plane of polarization in free space.

<Converters 3a and 3b>
The converter 3 a is a waveguide / planar line converter that mutually converts transmission power of the output waveguide 23 a and the feed line 50. Similarly, the converter 3b is a waveguide / planar line converter that converts the transmission power of the output waveguide 23b and the feed line 50 to each other. These converters 3 a and 3 b are constituted by a closed region 30 of the dielectric substrate 1 that closes the output openings 25 a and 25 b of the waveguide block 2, a resonance element 31, a short-circuit plate 32, and a through hole 33. The resonant element 31 and the shorting plate 32 are formed simultaneously with the antenna pattern 5 or the ground plate 10 by patterning the conductive thin film on the dielectric substrate 1.

  The short-circuit plate 32 is formed on the front surface of the dielectric substrate 1 so as to cover the closed region 30, and constitutes a short-circuit surface that terminates the output waveguides 23a and 23b communicating with the output openings 25a and 25b. The short-circuit plate 32 in the drawing is rectangular, and a strip-shaped cut 34 is formed from the long side to the inside. This cut 34 extends parallel to the short side of the closed region 30 and reaches the closed region 30. One end of the feeder line 50 is formed in the notch 34 of the short-circuit plate 32, crosses the long side of the closed region 30 and the long side of the short-circuit plate 32, and is drawn to the outside of the short-circuit plate 32.

  The ground plate 10 has an inner edge that coincides with the closed region 30, and is formed on the entire back surface of the dielectric substrate 1 except for the closed region 30. The ground plate 10 and the waveguide block 2 are made conductive by bringing the front surface of the waveguide block 2 into close contact with the ground plate 10.

  The resonant element 31 is an element formed in the closed region 30 so as not to conduct with the ground plate 10. The resonant element 31 forms a resonant region on the dielectric substrate 1 by setting the length of the output openings 25 a and 25 b in the short direction to about ½ of the wavelength in the dielectric substrate 1. The resonance element 31 is disposed so as to overlap the tip of the feed line 50 across the dielectric substrate 1 and is electromagnetically coupled to the feed line 50.

  The through hole 33 is formed by filling the through hole of the dielectric substrate 1 with a conductive material. The short-circuit plate 32 and the ground plate 10 are brought into conduction through the through-hole 33 to keep the short-circuit plate 32 at the same potential as the waveguide block 2.

<Waveguide block 2>
The waveguide block 2 forms a waveguide that connects one input opening 20 to two output openings 25a and 25b. That is, the traveling wave input to the input opening 20 is branched in the waveguide block 2, and the traveling wave after branching is transmitted to the two output openings 25a and 25b.

  In the waveguide block 2, an input waveguide 21, a branching section 22, and output waveguides 23a and 23b are formed. The input waveguide 21 is a waveguide that communicates with the input opening 20 and the branching portion 22, and the traveling wave input to the input opening 20 is transmitted to the branching portion 22 by the input waveguide 21. The branching unit 22 is a branching unit that branches a traveling wave input via the input waveguide 21 into two, and branches so as to have substantially the same power. The output waveguides 23a and 23b are waveguides that connect the branch portion 22 and the output openings 25a and 25b, and the traveling waves after branching are output to the output openings 25a and 25b by the output waveguides 23a and 23b. Is transmitted.

  That is, in the MS antenna 100, the traveling wave input from the input opening 20 is branched in the waveguide block 2, and the branched traveling wave is transmitted to the converters 3a and 3b. For this reason, the traveling waves after branching are respectively supplied to both ends of the feed line 50 and propagate on the feed line 50 in opposite directions.

<Excitation phase by each traveling wave>
Two traveling waves propagating in the opposite direction through the feeder line 50 are configured to have the same phase in an arbitrary radiation element 51. The phase difference between the two traveling waves can be controlled by adjusting the path length from the branching section 22 to the target radiating element 51 via the converters 3a and 3b.

  For example, when the length La of the output waveguide 23a is the same as the length Lb of the output waveguide 23b, traveling waves having the same phase are input to the converters 3a and 3b (see FIG. 4). . In the converters 3a and 3b, since the feed line 50 is drawn in the reverse direction with respect to the resonant element 31, when the traveling waves having the same phase are input from the waveguides 23a and 23b, the traveling waves having the opposite phase are generated. Each is output to the feeder line 50. For this reason, when the distance L1 from the transducer 3a to the nearest radiating element 51m is the same as the distance L2 from the transducer 3b to the nearest radiating element 51n, these radiating elements 51n and 51m are excited in opposite phases. Thus, electromagnetic waves having the same plane of polarization can be emitted (see FIG. 3).

  That is, when the relationship of La = Lb and L1 = L2 is established, the traveling wave propagating in the reverse direction on the feeder line 50 through the converters 3a and 3b causes the arbitrary radiation element 51 to have the same phase. Can be excited. For this reason, a gain can be improved compared with the conventional microstrip line 201 which has a feeding point only on one side of the feeding line 50. Therefore, the frequency band can be expanded without decreasing the antenna gain by using a smaller number of the radiating elements 51 and the shorter feed line 50.

  Needless to say, La = Lb and L1 = L2 are not the only conditions for a traveling wave propagating in the reverse direction on the feed line 50 to excite an arbitrary radiation element 51 in the same phase. For example, La and Lb may have a difference that is an integral multiple of the guide wavelength λg of the output waveguides 23a and 23b, and L1 and L2 may be a difference that is an integral multiple of the guide wavelength λs of the feed line 50. You may have. Further, the phase difference due to the path difference between La and Lb may be offset by the phase difference due to the path difference between L1 and L2.

<Comparative example>
FIG. 5 is a plan view showing the MS antenna 202 to be compared with the present embodiment. The MS antenna 202 includes two converters 3a and 3b and two single-sided feeding antenna patterns 5a and 5b.

  The antenna pattern 5a includes a feed line 50a having one end connected to the converter 3a and the other end connected to a termination element 52a, and a plurality of radiating elements 51 arranged along the feed line 50a. Similarly, the antenna pattern 5b includes a feed line 50b having one end connected to the converter 3b and the other end connected to the termination element 52b, and a plurality of radiating elements 51 arranged along the feed line 50b. Composed.

  The feed lines 50a and 50b are arranged on the same straight line so that the termination elements 52a and 52b are on the inside and the converters 3a and 3b are on the outside. The radiation elements 51 of the antenna patterns 5a and 5b have a plane of polarization. Arranged to emit matching electromagnetic waves. That is, the antenna patterns 5a and 5b are arranged in series and form one antenna pattern as a whole.

  Compared with MS antenna 100 according to the first embodiment, this MS antenna 202 is common in that converters 3a and 3b as two feeding points are arranged at both ends of a series of feeding lines 50a and 50b. However, the feed lines 50a and 50b are separated at the center and the termination elements 52a and 52b are provided.

  FIG. 6 is a diagram showing the analysis result of the frequency characteristics of the antenna gain according to the first embodiment of the present invention, and shows the frequency on the horizontal axis and the relative gain on the design frequency of 76.5 GHz on the vertical axis. In the figure, G1 represents the frequency characteristics of the MS antenna 100 according to the present embodiment, G2 represents the MS antenna 202 of the comparative example, and G3 represents the frequency characteristic of the MS antenna 201 of the conventional example.

  According to this analysis result, the maximum value of the gain decrease in the range of ± 1.5 GHz of the design frequency is 1.4 dB in the frequency characteristic G2 of the comparative example and 1.7 dB in the frequency characteristic G3 of the conventional example. The frequency characteristic G1 of the first embodiment is 0.5 dB. Therefore, according to this embodiment, it can be seen that the frequency characteristics of the antenna gain are greatly improved.

  Here, the frequency characteristic G2 of the comparative example is better than the conventional frequency characteristic G3, and is close to the frequency characteristic G1 of the first embodiment particularly on the low frequency side. The reason why such a result was obtained is that, in the MS antenna 202 of the comparative example, the feed lines 50a and 50b are separated, and the maximum distance between the radiating elements 51 arranged along the same feed line is the MS of the conventional example. This is considered to be because the phase difference generated between the radiating elements 51 is small due to the frequency shift, which is shorter than the antenna 201.

  In the MS antenna 202 of the comparative example, the feed lines 50a and 50b are separated and connected to the termination elements 52a and 52b. Since the power reaching the termination elements 52a and 52b is lost, the MS antenna 202 of the comparative example can obtain only a small gain as compared with the MS antenna 100 according to the first embodiment in which the feed lines 50a and 50b are connected.

  FIG. 7 is a diagram showing the analysis result of the directivity characteristics according to the first embodiment of the present invention, in which the angle with respect to the front direction is shown on the horizontal axis and the relative gain with respect to the front direction is shown on the vertical axis. D1 in the figure is the directivity characteristic of the MS antenna 100 according to the present embodiment, and D2 is the directivity characteristic of the MS antenna 202 of the comparative example.

  According to the analysis result, in the directivity characteristic D1 of the first embodiment, the level of the first side lobe is reduced by 0.6 dB compared to the directivity characteristic D2 of the comparative example, and the directivity characteristics are improved as compared with the comparative example. You can see that The reason why such a result was obtained is thought to be that the feed lines 50a and 50b of the MS antenna 202 of the comparative example are separated at the center. That is, in the MS antenna 202 of the comparative example, a blank area where the radiating element 51 is not arranged is generated at the center of the element array in which the radiating elements 51 are aligned, and the excitation distribution is broken. As a result, in the MS antenna 202 of the comparative example, the side lobe level is considered to be higher than that of the MS antenna 101 of the first embodiment.

  FIG. 8 is a diagram showing the analysis result of the reflection characteristic according to the first embodiment of the present invention, and shows the value obtained as the scattering parameter S11 with the frequency on the horizontal axis and the reflection amount on the vertical axis. In the figure, R1 is the reflection characteristic of the MS antenna 100 according to the present embodiment, and R2 is the reflection characteristic of the MS antenna 202 of the comparative example. According to this analysis result, it can be seen that the first embodiment can obtain substantially the same reflection characteristics as in the comparative example.

  In the MS antenna 100 according to the present embodiment, the antenna pattern 5 formed on the dielectric substrate 1 includes a feed line 50 connecting the converters 3a and 3b as feed points and a plurality of feed lines 50 formed along the feed line 50. The radiating element 51 is configured. These radiating elements 51 are arranged so as to be excited in the same phase by a traveling wave propagating in one direction through the feeder line 50. The traveling waves supplied from the converters 3a and 3b and propagating in the reverse direction through the feed line 50 excite the arbitrary radiating elements 51 in the same phase.

  With such a configuration, the frequency characteristics of the antenna gain can be improved as compared with the MS antenna 201 that is fed on one side. In addition, the side lobe level can be suppressed and the directivity can be improved without degrading the reflection characteristics even when compared with the double-sided power supply MS antenna 202 from which the feed line 50 is separated.

  Also, the MS antenna 100 according to the present embodiment includes the waveguide block 2 having the branching section 22, branches the traveling wave input, and propagates the branched traveling wave to the converters 3a and 3b. . Therefore, by adjusting the path length of the converters 3a and 3b from the branching unit 22 or the path length from the converters 3a and 3b to the radiating element 51, each traveling wave passing through the converters 3a and 3b is radiated. The element 51 can be excited in the same phase.

Embodiment 2. FIG.
FIG. 9 is a cross-sectional view showing a configuration example of a traveling wave excitation antenna according to Embodiment 2 of the present invention, and shows a cross section of the MS antenna 101 as another example of the AA cut plane of FIG. ing. This MS antenna 101 is different from the MS antenna 100 of FIGS. 1 to 4 in that the waveguide block 2 does not have a branching portion 22.

  In this waveguide block, two input openings 20a and 20b are formed, a waveguide 21a communicating the input opening 20a with the output opening 25a, and an input opening 20b communicating with the output opening 25b. And a waveguide 21b.

  The MS antenna 101 can be used in the same manner as the MS antenna 100 of the first embodiment by inputting traveling waves that excite the radiating element 51 in the same phase to the input openings 20a and 20b. The traveling waves input to the input openings 20a and 20b may be one traveling wave branched from the outside, or two traveling waves generated independently.

Embodiment 3 FIG.
FIG. 10 is a plan view showing a configuration example of a traveling wave excitation antenna according to Embodiment 3 of the present invention, in which an MS antenna 102 is shown. In this MS antenna 102, antenna patterns 5c and 5d with one side feeding are added on both sides of the antenna pattern 5 of the MS antenna 100 shown in FIG.

  The one-sided feeding antenna pattern 5c includes a feeding line 50c having one end connected to the converter 3a and the other end connected to a termination element 52c, and a plurality of radiating elements 51 arranged along the feeding line 50c. Is done. Similarly, an antenna pattern 5d that is fed on one side includes a feed line 50d having one end connected to the converter 3b and the other end connected to a termination element 52d, and a plurality of radiating elements arranged along the feed line 50d. 51.

  The feed lines 50 and 50c are extended in the reverse direction from the same converter 3a. Similarly, the feed lines 50 and 50d are also extended in the reverse direction from the same converter 3b. Further, these feed lines 50, 50c, 50d are arranged on the same straight line, and the respective radiating elements 51 are arranged so as to emit electromagnetic waves having the same plane of polarization. That is, the antenna patterns 5, 5c and 5d are arranged in series and form one antenna pattern as a whole.

  FIG. 11 is a plan view showing the MS antenna 203 to be compared with the present embodiment. In the MS antenna 203, antenna patterns 5c and 5d with one side feeding are further added outside the antenna patterns 5a and 5b with one side feeding of the MS antenna 202 shown in FIG.

  If the MS antennas 102 and 203 are compared, the antenna patterns between the converters 3a and 3b are different. Due to this difference, the MS antenna 102 has improved antenna gain frequency characteristics and improved directivity characteristics compared to the MS antenna 203.

Embodiment 4 FIG.
FIG. 12 is a plan view showing a configuration example of a traveling wave excitation antenna according to the fourth embodiment of the present invention, in which an MS antenna 103 is shown. In this MS antenna 103, three end-fed antenna patterns 5 and two one-sided fed antenna patterns 5c and 5d are formed on a dielectric substrate 1 having four converters 3a to 3d. 5, 5c and 5d form one antenna pattern as a whole.

  In this MS antenna 103, the dielectric substrate 1 has four feeding points, antenna patterns 5 with both-end feeding are respectively disposed between adjacent feeding points, and antenna patterns extending outwardly at both feeding points. 5c and 5d are formed, respectively.

  Similarly, when the dielectric substrate 1 has three or more feeding points, the antenna patterns 5 that are fed at both ends are arranged between adjacent feeding points, and the antenna patterns 5c and 5d that extend outward are formed at the feeding points at both ends. If so, an MS antenna having good antenna gain frequency characteristics and good directivity characteristics can be configured according to the number of feed points.

Embodiment 5. FIG.
FIG. 13 is a perspective view showing a configuration example of a traveling wave excitation antenna according to Embodiment 5 of the present invention, in which a waveguide slot antenna 104 (hereinafter referred to as a WG antenna) is shown. In the WG antenna 104, a plurality of slots 27 are formed in the waveguide 26. The slot 27 is a radiating element that emits electromagnetic waves having the same plane of polarization, and is arranged to be excited in the same phase. For example, the waveguides 26 are arranged at intervals corresponding to the in-tube wavelength λg, and are excited in the same phase by the traveling waves having the above-described wavelength propagating in the waveguide 26 in one direction. The slots 27 are arranged so that the extending directions are parallel to each other, and the radiated waves from all the slots 26 become electromagnetic waves having the same phase and the same plane of polarization in free space.

  The traveling wave input to the input opening 20 is transmitted to the branching section 22 by the input waveguide 21. The branching unit 22 is a branching unit that branches a traveling wave input via the input waveguide 21 into two, and branches so as to have substantially the same power. The output waveguides 23a and 23b are waveguides that connect the branch portion 22 and both ends of the waveguide 26, and the traveling waves after branching are transmitted to the waveguide 26 by the output waveguides 23a and 23b. Is done. That is, the waveguide 26 is a feed line connecting the feed points 24a and 24b, and the traveling wave supplied through the feed points 24a and 24b propagates in the waveguide 26 in the reverse direction. If these traveling waves are configured to excite an arbitrary slot 27 in the same phase, a WG antenna with good antenna gain frequency characteristics and good directivity characteristics can be realized.

  FIG. 14 is a perspective view showing another configuration example of a traveling wave excitation antenna according to Embodiment 5 of the present invention, in which a waveguide slot antenna 105 is shown. The WG antenna 105 is obtained by extending the waveguide 26 of the WG antenna 104 in FIG. 13 to the outside of the feeding points 24a and 24b. That is, the waveguide 26 is configured by connecting a feed line that feeds both ends connecting the feed points 24a and 24b and a feed line that feeds one side and extends outward from the feed points 24a and 24b. Therefore, as in the case of the third embodiment, compared with the waveguide slot antenna in which the center of the waveguide 26 is separated, the frequency characteristic of the antenna gain is improved and the directivity is also improved.

DESCRIPTION OF SYMBOLS 1 Dielectric board | substrate 2 Waveguide block 3, 3a-3d Converter 5, 5a-5d Antenna pattern 10 Grounding board 20,20a, 20b Input opening part 21,21a, 21b Input waveguide 22 Branch part 23a, 23b Output Waveguides 24a and 24b Feed points 25a and 25b Output opening 26 Waveguide 27 Slot 30 Closed region 31 Resonant element 32 Short-circuit plate 33 Through hole 50, 50a to 50d Feed lines 51, 51n, 51m Radiating elements 52, 52a to , 52d Termination element 100 to 103 MS antenna 104, 105 WG antenna λg In-tube wavelength of waveguide λs In-tube wavelength of strip line

Claims (2)

A dielectric substrate having two feed points;
A linear strip line formed on the dielectric substrate and connecting the two feeding points;
Two or more radiating elements formed on the dielectric substrate along the strip line and excited in the same phase by traveling waves propagating in the strip line in one direction;
A feeding means for propagating the stripline in opposite directions to the feeding point and supplying traveling waves for exciting the radiating elements in the same phase ;
A traveling wave excitation antenna, wherein the radiating element having the maximum element width is formed near the center of the strip line, and the radiating element having a smaller element width is formed closer to both ends of the strip line . The power feeding means is composed of a waveguide for branching an input traveling wave and supplying the branched traveling waves to the two feeding points, respectively.
2. The traveling wave excitation antenna according to claim 1 , wherein the feeding point comprises a waveguide / stripline converter.

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