Planar antenna and its manufacturing method

Abstract

To enable the use of multiple radiating conductors to provide multi-band antennas with resonant frequencies that are widely separated.SOLUTION: The present disclosure is a planar antenna having a rectangular conductor 11 on one side of an insulating substrate 31 that is fed from a first feeding section 12 and whose fundamental mode resonates at a first frequency, and an annular conductor 21 that is fed from a second feeding section 22 different from the first feeding section and whose fundamental mode resonates at a second frequency lower than the fundamental mode of the rectangular conductor 11.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a planar antenna and a method for manufacturing the same. [Background technology]

[0002] There is a demand for a multi-band antenna with widely separated bands. When a conventional rectangular or circular radiation conductor is used, multiple higher modes occur at a second frequency that is distant from the fundamental mode frequency (see, for example, Patent Documents 1 and 2). As a result, the multiple higher modes interfere with the antenna for the second frequency, causing degradation of the radiation pattern and reflection characteristics at the second frequency. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4227089 [Patent Document 2] Japanese Patent Application Publication No. 01-243704 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a multi-band antenna with widely separated resonant frequencies using a plurality of radiation conductors. [Means for solving the problem]

[0005] The planar antenna of the present disclosure has a structure including: a rectangular conductor fed from a first feeding section and resonating in a fundamental mode at a first frequency; an annular conductor fed from a second feeding section different from the first feeding section, the annular conductor having a fundamental mode resonating at a second frequency lower than the fundamental mode of the rectangular conductor; Equipped with.

[0006] The method for manufacturing a planar antenna according to the present disclosure includes: A method for manufacturing a planar antenna having resonant frequencies in multiple frequency bands, comprising: a rectangular conductor whose fundamental mode resonance frequency corresponds to a frequency band on the high frequency side, and an annular conductor whose fundamental mode resonance frequency corresponds to a frequency band on the low frequency side, mounted on one surface of an insulating substrate; The rectangular conductor and the annular conductor are each provided with a power supply portion.

[0007] In the present disclosure, the fundamental mode at the first frequency is TM 10 mode, and the fundamental mode at the second frequency is TM 11 It may be a mode. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a multi-band antenna with resonant frequencies widely separated by the use of a plurality of radiation conductors. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an example of the configuration of a planar antenna. [Figure 2] 1 shows a perspective view of a planar antenna. [Figure 3] An example of the A-A' cross section is shown. [Figure 4] 1 is an example of the configuration of a planar antenna. [Figure 5] 1 shows a perspective view of a planar antenna. [Figure 6] An example of the B-B' cross section is shown. [Figure 7] 1 is an example of the configuration of a planar antenna. [Figure 8] 1 is an example of the configuration of a planar antenna. [Figure 9] An example of the current direction and electric field distribution in a rectangular conductor, where (a) shows the fundamental mode TM10, (b) shows the second higher-order mode TM02, (c) shows the third higher-order mode TM21, (d) shows the fourth higher-order mode TM30, and (e) shows the fifth higher-order mode TM23. [Figure 10]2 shows an example of the resonant frequency of a rectangular conductor. [Figure 11] 1 shows an example of the current direction and electric field distribution in a ring conductor, where (a) shows the fundamental mode TM11, (b) shows the second higher-order mode TM21, and (c) shows the third higher-order mode TM31. [Figure 12] 2 shows an example of the resonant frequency of the annular conductor. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present disclosure can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings indicate the same components.

[0011] 1 and 2 show an example of the configuration of a planar antenna according to the present disclosure. The planar antenna according to this embodiment is a multiband antenna having resonant frequencies in multiple frequency bands, and includes a rectangular conductor 11 and an annular conductor 21 that function as radiation conductors on the upper surface of an insulating substrate 31. The inner and outer edges of the annular conductor 21 have shapes similar to the outer shape of the rectangular conductor 11.

[0012] 3 shows an example of the cross-sectional configuration taken along line A-A' in FIG. 1. Power feeding units 12 and 22 are arranged on the upper surface of insulating substrate 31, and ground conductor 33 is arranged on the back surface of insulating substrate 31. Power feeding unit 12 is connected to a coaxial connector (not shown) connected to the back surface of insulating substrate 31 by via conductor 14. Power feeding unit 22 is connected to a coaxial connector (not shown) connected to the back surface of insulating substrate 31 by via conductor 24. This makes it possible for the planar antenna of the present disclosure to independently control the power supply to rectangular conductor 11 and annular conductor 21 in a single-layer planar antenna.

[0013] 4 and 5 show configuration examples of a planar antenna according to the present disclosure. FIG. 6 shows a cross-sectional configuration example taken along line B-B' in FIG. 4. In the example shown in FIGS. 4 and 5, insulating substrates 31 and 32 have a multilayer structure, and power feeders 12 and 22 are disposed between the insulating substrates 31 and 32. Power feeder 12 is connected to a coaxial connector (not shown) connected to the rear surface of insulating substrate 32 by a via conductor 14. Power feeder 22 is connected to a coaxial connector (not shown) connected to the rear surface of insulating substrate 32 by a via conductor 24. This allows the planar antenna according to the present disclosure to independently control the power supply to rectangular conductor 11 and annular conductor 21 in a multilayer planar antenna.

[0014] As shown in Figures 1 to 6, the present disclosure may be either a single-layer double-sided board or a multi-layer board, and the power supply sections 12 and 22 may take any form that can supply power independently to the rectangular conductor 11 and the annular conductor 21.

[0015] 7 and 8 show configuration examples of a planar antenna according to the present disclosure. The planar antenna of this embodiment has the configurations of FIGS. 1 and 4, but with cutouts 13 and 23 on the outer edges of the rectangular conductor 11 and the annular conductor 21. The figures show an example in which the cutouts 13 and 23 are arranged at diagonal positions, respectively. This makes it possible to obtain radiation characteristics of circularly polarized waves. Note that in the configurations of FIGS. 1 and 4, where the rectangular conductor 11 and the annular conductor 21 do not have the cutouts 13 and 23, it is possible to obtain radiation characteristics of linearly polarized waves. The configuration of FIG. 8 will now be described.

[0016] 9 and 10 show examples of the electric field distribution and the resonant frequency of the rectangular conductor 11, respectively. The arrows in FIG. 9 indicate the direction of current flow. FIG. 10 shows an example of the resonant frequency of the rectangular conductor. As shown in FIG. 9(a), the rectangular conductor 11 has a fundamental wave, TM 10 The TM mode is excited, and the current distribution is uniform in the Y direction. In the rectangular conductor 11, as shown in Figs. 9(b), 9(c), 9(e), and 10, the TM mode is excited as a higher-order wave. mnThere are as many combinations of m as there are of m = 0, 1, 2, ..., n = 0, 1, 2, ..., and they occur more frequently as the frequency increases. For this reason, it cannot be used in conjunction with an antenna that resonates at frequency f12, which is far away in frequency band.

[0017] 11 and 12 show examples of the electric field distribution and resonant frequency of the annular conductor 21, respectively. The arrows in FIG. 11 indicate the direction of current flow. FIG. 12 shows an example of the resonant frequency of the annular conductor 21. As shown in FIGS. 11(b), 11(c), and 12, in the ring-shaped annular conductor 21, current flows along the element shape, and the fundamental wave is TM 11 The higher order mode is the TM m1 Only combinations of (m=0, 2, 3, 4, ...) are considered, which are fewer than the rectangular conductor 11. Also, on the high frequency side of the frequency f21, a second higher order mode TM 21 and the third higher mode TM 31 appears, but the third higher mode TM 31 There is a frequency band at frequency f22 on the higher frequency side where no higher order modes appear.

[0018] Therefore, the method for manufacturing a planar antenna according to the present disclosure matches the frequency f11 of the fundamental mode of the rectangular conductor 11 with the frequency f22. More specifically, the method for manufacturing a multiband antenna according to the present disclosure mounts, on one surface of an insulating substrate 31, a rectangular conductor 11 whose resonance frequency f11 of the fundamental mode matches a frequency band on the high frequency side, and an annular conductor 21 whose resonance frequency f21 of the fundamental mode matches a frequency band on the low frequency side, and provides power feeding portions 12 and 22 to the rectangular conductor 11 and the annular conductor 21, respectively.

[0019] As a result, the present disclosure provides that the rectangular conductor 11 and the annular conductor 21 have different fundamental mode frequencies at which they resonate, and the fundamental mode frequency of the annular conductor 21 is f21 is the fundamental mode frequency of the rectangular conductor 11. f11and the frequency f11 of the fundamental mode of the rectangular conductor 11 matches the frequency f22. Therefore, the present disclosure realizes a composite antenna with resonant frequencies f21 and f22 that are widely separated, and can provide a multi-band antenna with resonant frequencies that are widely separated.

[0020] In the present disclosure, the frequencies f21 and f22 are not limited as long as the rectangular conductor 11 oscillates in a higher frequency band and the annular conductor 21 oscillates in a lower frequency band. Although the present embodiment shows an example in which there is one annular conductor 21, the number of annular conductors 21 may be any number equal to or greater than one. [Industrial Applicability]

[0021] The present disclosure can be applied to the information and communications industry. [Explanation of symbols]

[0022] 11: Rectangular conductor 12, 22: Power supply unit 13, 23: Notch 14, 24: Via conductor 21: Ring conductor 31, 32: insulating substrate

Claims

1. On one side of the insulating substrate, a rectangular conductor fed from a first feeding section and resonating in a fundamental mode at a first frequency; an annular conductor fed from a second feeding section different from the first feeding section, the annular conductor having a fundamental mode resonating at a second frequency lower than the fundamental mode of the rectangular conductor; Equipped with the fundamental mode at the second frequency is a TM 11 mode; Multi-band planar antenna.

2. The first frequency is higher than a second higher mode of the annular conductor.

2. The planar antenna according to claim 1.

3. A method for manufacturing a multi-band planar antenna having resonant frequencies in multiple frequency bands, comprising: a rectangular conductor whose fundamental mode resonant frequency corresponds to a high-frequency frequency band, and an annular conductor whose fundamental mode TM 11 mode resonant frequency corresponds to a low-frequency frequency band, are mounted on one surface of an insulating substrate; a power supply portion is provided on each of the rectangular conductor and the annular conductor; Method for manufacturing a planar antenna.

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